The strongest correlate of opinion on climate change is partisan affiliation. Two-thirds of Republicans (67%) say either that the Earth is getting warmer mostly because of natural changes in the atmosphere (43%) or that there is no solid evidence the Earth is getting warmer (24%). By contrast, most Democrats (64%) say the Earth is getting warmer mostly because of human activity. … The divide is even larger when party and ideology are both taken into consideration. Just 21% of conservative Republicans say the Earth is warming due to human activity, compared with nearly three-quarters (74%) of liberal Democrats. — Pew Research Center

In other words, most of the general public appears to believe that the existence of abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. (formerly known as anthropogenic ‘Human-caused’ global warming) is a question of politics rather than science. They’re not looking at evidence published in peer-reviewed science journals before adopting a position. Instead, they seem to decide that their political party’s position on climate change is “X,” so they believe “X.” Finally, this explains why some people who watch a documentary that exaggerates the science end up imitating that smug politician’s You have to realize that I view ‘politician’ as a VERY dirty word in order to get the full effect of this sentence. alarmism. I run into hordes of them on campus, and I always rebuff their attempts to guilt me out of driving by saying “Why worry about the Earth when we’ve got 7 planets R.I.P. Pluto, 1930-2006 to spare?!”

Keep in mind that I’m only saying the existence of abrupt climate change is a purely scientific question. I realize that our response to climate change is a legitimate political question. But let’s set that question aside to contemplate the existence of abrupt climate change. Instead of lining up behind politicians, let’s take the road less traveled by examining some evidence given to us by modern science.

To begin with, it’s indisputable that the Earth’s climate has varied wildly in the past. Vostok ice core data confirm that for nearly half a million years, the climate has changed cyclically. In all that time, the maximum CO₂ concentration never went above 300 ppm parts per million . It’s hit higher levels 15 million years ago, but usually Heinrich and Dansgaard-Oeschger events (among other examples of natural abrupt climate change) show that the natural climate is only fairly stable in the long run. These events show that the climate can quickly move from one stable “attractor” to another. I should stress, however, that results like Meehl 2004 show that today’s changes aren’t natural. in gradual ways. Plus, the Earth was essentially a different planet back then, with a different biosphere basking under the light of a very slightly The Sun was only barely fainter tens of millions of years ago, but high CO2 concentrations hundreds of millions of years ago or more were partially compensated for by the lower solar luminosity. Also, the continents shift on these timescales which affects the climate too. dimmer Sun so comparisons across that much time are tricky at best.

Natural variations are evident in the data, of course. The most prominent cycles over geological time are governed by (among other effects) Milankovitch cycles which are caused by periodic variations in the Earth’s orbit.

Bizarrely, the CO₂ concentration is at 380 ppm parts per million today. That’s ~26% higher than it’s been in the last half million years. Notice that the current CO₂ concentration is off the scale of the Vostok data graph. If this is due to natural variability alone, it’s quite a coincidence that it’s happening right after we started burning enough oil to fuel ~800 million cars, and burning coal by the ton to supply ~50% of our electricity.

Furthermore, it seems like the CO₂ at Vostok typically increased centuries after the temperature started to increase. (Ice core data are difficult to analyze in this manner, though.) At least, that’s the way it used to work. Right now, the CO₂ concentration is at an unprecedented level but the temperature is barely above normal. Again, this implies that we’re not experiencing natural climate variability because what’s happening today doesn’t match the behavior of the ancient climate.

According to physics that was firmly established decades before I was born, CO₂ warms the planet by absorbing infrared radiation from the ground better than it absorbs visible radiation from the Sun. So this rapidly increasing CO₂ should cause a rapid temperature increase:

The above graphs are quite busy, so here’s an overview of each one:

1. The top graph shows temperatures over the last 300 years, as recorded by instruments. Notice that several independent instruments are telling us that the temperature has increased dramatically in recent decades.
2. The middle graph shows temperatures over the last 1000 years as reconstructed from various proxies such as ice cores, tree rings, boreholes, glacier retreat, etc. The different curves are based on different data and algorithms, and were derived by scientists from all over the world. Note that all of them show an abrupt temperature increase in the last few decades. More details can be found in pages 465-474 of chapter 6 here, especially Table 6.1 on page 469.
3. The bottom graph shows a “most likely” temperature reconstruction over the last 1000 years. This estimate uses all the previous curves, weighted according to their statistical uncertainties. The shading represents the combined uncertainty; darker areas are more confidently known.

Perhaps this is a coincidence? All the evidence up to this point just shows that CO₂ and temperatures have both risen in an apparently artificial manner in the last few decades. But Meehl 2004 tested whether or not recent temperature observations could be explained by natural variations alone:

The black curve represents observations. The blue curve represents the result of a computer simulation that accounts for natural variations like volcanic eruptions and changes in the brightness of the Sun. The shaded blue area represents the uncertainty of that simulation. The red curve includes all the natural variations in the blue curve, but adds human emissions like CO₂, sulfates and aerosols. Notice that after ~1970 the observed temperatures aren’t consistent with natural variations, but they are within the error bars of the prediction made by accounting for human emissions.

The Earth is so massive and ancient that we tend to instinctively believe ‘Don’t treat C02 as a pollutant’ in the Christian Science Monitor by Mark W. Hendrickson on June 23, 2009 wrongly says “And how do you propose to regulate Earth’s temperature when as much as three-quarters of the variability is due to variations in solar activity, with the remaining one-quarter due to changes in Earth’s orbit, axis, and albedo (reflectivity)? This truly is ‘mission impossible.’ Mankind can no more regulate Earth’s temperature than it can the tides. … 1. Human activity accounts for less than 4 percent of global CO2 emissions. 2. CO2 itself accounts for only 10 or 20 percent of the greenhouse effect. This discloses the capricious nature of the EPA’s decision to classify CO2 as a pollutant, for if CO2 is a pollutant because it is a greenhouse gas, then the most common greenhouse gas of all – water vapor, which accounts for more than three-quarters of the atmosphere’s greenhouse effect – should be regulated, too. The EPA isn’t going after water vapor, of course, because then everyone would realize how absurd climate-control regulation really is.” that humans aren’t powerful enough to affect the climate on this scale. For example, those awe-inspiring volcanic eruptions simply must dwarf anything we do, right? Surprisingly, humans emit ~100x more CO₂ than volcanoes.

Even still, the Earth is a stable system, right? Won’t our changes to the atmosphere just provoke a natural response that cancels them out, preventing us from significantly altering the climate? Well… maybe. The natural climate certainly did appear fairly Heinrich and Dansgaard-Oeschger events (among other examples of natural abrupt climate change) show that the natural climate is only fairly stable in the long run. These events show that the climate can quickly move from one stable “attractor” to another. I should stress, however, that results like Meehl 2004 show that today’s changes aren’t natural. stable in our absence. However, a number of positive feedback effects present the disturbing possibility that the climate is only metastable:

• Melting snow/ice uncovers dark ocean water in the Arctic and dark dirt in the Antarctic. In each case, the albedo of the snow is higher, which means more heat is absorbed after the ice starts to melt, which speeds up the remaining melting…
• Warmer oceans will evaporate more water vapor into the atmosphere, which is a more effective greenhouse gas than CO₂.
• Warmer deep ocean temperatures may destabilize methane hydrate deposits, releasing another more potent greenhouse gas.
• Melting permafrost releases CO₂ and methane.
• Melting glaciers help to lubricate the slide of the glacier into the ocean, speeding up the loss of glaciers once the process starts.
• Higher temperatures increase the risk of forest fires, which release the CO₂ stored in the wood.
• The dust caused by vegetation loss due to shifting precipitation patterns, fires and even other pollutants darkens snow, causing it to melt earlier.

There are also negative feedback effects, such as the fact that trees grow faster in higher CO₂ and thus store more CO₂ in their wood. [Update Thanks to Dr. Geoffrey A. Landis for his additions and corrections to this section and the faint young Sun caveat, as well as the abcnews link in the 'ice age in the 1970s' section. by Dr. Landis: Also, the Stefan-Boltzmann equation says that hotter objects radiate more, and higher temperatures = more evaporation = more clouds = higher albedo.] But I worry that the abrupt spike in CO₂ levels might cause positive feedback effects to dominate– at least temporarily. In other words, it seems likely that a little bit of warming will lead to more warming.

Bottom line: As far as I can tell there’s a mountain of scientific evidence showing that abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. is a matter of serious concern.

On a completely different note, as an ordinary American I think we should do something about this matter. We’re still the most technologically advanced nation in the world, with one of the largest, best educated workforces in history. Our economy is very capitalistic, which makes us highly adaptable compared to more socialist countries that are mired in bureaucracy. If any country can solve this problem, it’s us.

The legislation currently in the Senate needs to be passed. This bill has already been weakened in the House and it’s only the first step, but it’s the least we can do to convince the world that the United States is ready to lead once again.

I’ve been discussing abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. on the internet for several years, mostly at Slashdot under the pseudonym khayman80. The interesting bits of these conversations have been copied here, but please note that my statements have been edited Each comment is linked back to the original location in the Slashdot archives so you can compare the current version to the original. Those links look like: [Dumb Scientist] or [Jane Q. Public] and expanded since I first wrote them. Here’s an index with links to each conversation:

1. People wonder why “climate change” replaced “global warming.”

2. rrvau asks if scientists predicted an ice age in the 1970s.

3. People inquire about the scale and impact of human CO₂ emissions.

4. An Onerous Coward asks about nuclear and solar power.

5. Stormcrow309 asks about potential flaws in the Vostok ice core analysis.

6. m4cph1sto doubts that temperatures are increasing.

7. Jane Q. Public asks if sunspot activity causes global warming, among many other topics:

   1. The importance of peer review.
   2. “Cosmic rays are responsible for global warming.”
   3. “Water vapor is a stronger greenhouse gas than CO₂.”
   4. The accuracy of the “hockeystick” graph.
   5. What does the IPCC say about hurricanes?
   6. “CO₂ increases after temperature, so it doesn’t warm the planet.”
   7. “CO₂ is already saturated, so adding more CO₂ isn’t going to warm the planet any more.”
   8. “It’s not that simple.”
   9. We agree that the media over-hypes disaster scenarios.
   10. The Salem Hypothesis and the application of a modified version to this debate.
   11. “The troposphere isn’t warming enough, which disproves global warming.”
   12. Jane says her comments have been taken out of context and deliberately portrayed in a negative light. So please compare her statements to the originals at Slashdot, which can be accessed through links that look like [Jane Q. Public]
   13. “The stratosphere isn’t cooling, so greenhouse warming models are fundamentally flawed.” Now including bonus troposphere content.

8. Kyle asks about the political and economic implications of climate change. Also, he asks if temperatures are only appearing to increase due to urban expansion.

9. Jim P.E. asks if the President is receiving sound advice.

10. Bopeth asks about our population growth, and economic issues associated with climate change.

11. Anonymous says that my “comments exhibit the most profound and disturbing kind of scientific elitism,” along with:

    1. “How do you wager on whether climate change is anthropogenic or not?”
    2. I criticize peer review.
    3. “What I want to see next is the contrary case from a well-versed expert who has reached conclusions that conflict with yours.”
    4. Why shouldn’t we look to politicians for scientific answers?
    5. “What, exactly, would you like to see from the general public in terms of reasoning about this subject?”
    6. Marbs asks “What opinion do you currently hold that contradicts the mainstream scientific community?”
    7. Why do high tides happen on opposite sides of the Earth at the same time?
    8. “… we can’t do ‘parallel earth’ experiments to test various parameters … and nobody has a track record of ‘getting it right’ long term because there hasn’t been a long term yet.”
    9. Marbs asks about the graph on Steven Fielding’s website and the “due diligence report.”

12. gkai asks about clouds, the Earth’s albedo and model validations.

People wonder why “climate change” replaced “global warming.”

[Dumb Scientist]

When did “Global Warming” become politically incorrect and “Climate Change” became politically correct? [dwiget001]

When they realized they might be wrong. [girlintraining]

I’ve noticed that shift in wording too. I think it was intended to address some misconceptions the general public has regarding “abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. ” (the officially accepted title).

Most people don’t seem to understand the difference between “local weather” and “global climate.” Local weather is a phenomenon that changes very quickly– sometimes in a matter of minutes. For example, “will it rain tomorrow in Denver?” Local weather is very hard to predict because that requires solving vector-valued numerical models of the motion … and many other properties like pressure, temperature, phase changes, wind speed, humidity, ground water, electric charge, pollution density, tidal forcing, turbulence caused by ground structures, albedo of ground structures, the exact position of the Sun in the sky at each moment, etc. of the atmosphere on a very high-resolution grid. The global climate Hereafter referred to simply as ‘climate.’ ignores these fast variations by averaging the weather over a long period of time (years, at least) and a large area (the entire globe in this case.) Ironically, the climate is actually easier to predict because it just requires Obviously this is a ridiculous oversimplification, but the point is that weather modeling (emphasizing conservation of momentum) brings modern supercomputers to their knees, whereas climate models (emphasizing conservation of energy) aren’t nearly as demanding. Weather models can be described as “initial value” problems which lose “skill” as time goes on, whereas climate models are “boundary value” problems that don’t suffer from the same forecasting limitations. summing energy input and subtracting energy output.

A good analogy is that it’s easy to predict the pressure in a tire based on the amount of air you put in it, but nearly impossible to predict the exact path of all the air molecules bouncing around inside the tire. Predicting the climate is like predicting the tire’s pressure, while predicting tomorrow’s local weather is more like predicting the path of a single air molecule. Our inability to model weather says very little about our ability to model the climate, and local weather will always vary randomly. Scientists want to emphasize the word “climate” to stress that cold temperatures on [random day] in [Random Town] don’t disprove abrupt climate change.

Update: NOAA has a much better analogy: One way to distinguish between weather and climate is that the climate of your hometown will determine how many sweaters you have in your closet. The weather will determine whether you should be wearing a sweater right now.

Also, the term “global warming” is oversimplified. A more accurate description is that our addition of greenhouse gases has reduced the rate at which thermal energy leaves the planet. As a result, the average energy in the atmosphere and ocean is increasing, which allows this system to “explore more of its phase space.” More energy means more chances of extreme weather– even weather that involves colder temperatures! (Again, note that weather is local and temporary.)

The word “abrupt” was added to emphasize that what we’re experiencing is too fast to be a natural process. The ice core from Vostok shows that CO₂ hasn’t risen above 300 ppm parts per million in the last half million years. It has varied in the past, but usually Heinrich and Dansgaard-Oeschger events (among other examples of natural abrupt climate change) show that the natural climate is only fairly stable in the long run. These events show that the climate can quickly move from one stable “attractor” to another. I should stress, however, that results like Meehl 2004 show that today’s changes aren’t natural. over a timespan measured in millennia. Atmospheric CO₂ is at 380 ppm parts per million now, and this dramatic rise occurred in the span of several decades. As a result, temperatures are rising faster each decade. Changes this rapid haven’t occurred in the hundreds of thousands of years over which we have records. Keep in mind that scientists are primarily concerned about the unprecedented rate of the current changes in our climate.

rrvau asks if scientists predicted an ice age in the 1970s.

[Dumb Scientist]

Paraphrased: “Didn’t scientists predict an ice age in the 1970s?” [rrvau]

In a word: no. That myth can be traced back to sensationalist articles in media like Newsweek. Genuinely peer-reviewed scientific articles were far more responsible, which is one reason why I highly recommend learning science from them rather than the general media.

… I still think that it is the ultimate arrogance that humans think they can alter the planets evolution. Think of continental drift and the accompanying earthquakes, volcanic activity etc. and you’ll understand how insignificant humans are. [rrvau]

Continental drift and earthquakes are completely irrelevant to the climate on the kind of timescale we care about. As for volcanic activity, eruptions only put about a hundredth of the CO₂ into the atmosphere that humans do. Massive eruptions in the geologically distant past (such as the Siberian traps which are a suspected cause of the Permian extinction) have likely put more CO₂ into the atmosphere, but none of the eruptions in the last 500,000 years pushed the CO₂ level above 300 ppm parts per million .

People inquire about the scale and impact of human CO₂ emissions.

[Dumb Scientist]

Global warming is a consequence of climate change. Global cooling is a consequence of climate change. [smoker2]

I think the term global dimming more accurately describes a separate problem that is sometimes referred to as global cooling. Aerosols decrease the size of cloud droplets, thus increasing the albedo of the clouds. This reflects more sunlight back into space. Its effects have been seen in long term trends of sunlight brightness, and in long term evaporation rate measurements. Surprisingly, evaporation depends on the rate at which photons hit the water’s surface more than Roderick, et. al. 2007– that’s the link in this sentence– also shows that wind speed is a strong factor. typical changes in temperature or humidity, so it serves as an independent check of the phenomenon.

Update: Consider this table of radiative forcings. Forcings that warm the planet are colored red, while forcings that cool the planet are blue. Each forcing has an error bar associated with it, and a “Level of Scientific Understanding” (LOSU) on the right hand side.

Global dimming isn’t a threat anymore because regulations were effective at curbing emissions of these aerosols. Plus, aerosols don’t stay in the atmosphere for very long, so once we stopped spewing them into the atmosphere the problem went away. CO₂, however, stays in the atmosphere for ~100 years, so our children and grandchildren will have to deal with it. Unfortunately, aerosols used to counter the effects of greenhouse gases like CO₂. (No, we can’t just start emitting aerosols again and hope they cancel each other out!)

… I am not a denier, but I am not about to be told we must halt climate change. This is a phenomenon that is as old as the earth, and to think we can just stop it when we want to is ludicrous. If you want to limit our impact on that change, fair enough. But don’t tell me it has to stop, because you make yourselves look like idiots. The climate has changed in cycles … if you take those same records which are used to promote the current scare tactics, you would see that after it (CO₂) goes up, it goes down – way way down. It is cyclic. So even if we completely stop producing CO₂ now, the cycle will continue. … So go ahead and do your worst. The only way to stop climate change is to kill the planet.

I think we’re talking about different things. You’re talking about natural variability, and I’m talking about human-caused climate change. Scientists are aware that both phenomena exist, and we can see that our CO₂ emissions have recently pushed the climate beyond the range of natural variations.

[Dumb Scientist]

The fact is, automobiles account for (at most) 2 percent of CO₂ emissions. … We need to convert our major power generation systems to something more reasonable like wind, solar, tidal, geothermal, and (yes) NUCLEAR. [Someone]

Huh? All the data I’ve seen places the “transportation sector” near the top of the list. Here’s a quote: “The transportation sector is the second largest source of CO₂ emissions in the U.S. Almost all of the energy consumed in the transportation sector is petroleum based, including gasoline, diesel and jet fuel. Automobiles and light-duty trucks account for almost two-thirds of emissions from the transportation sector and emissions have steadily grown since 1990.”

That said, I do agree that nuclear power is our best course of action.

An Onerous Coward asks about nuclear and solar power.

[An Onerous Coward]
While I’d replace all coal with nuclear in a heartbeat given the chance, I don’t think nuclear power is viable. To me, it seems too expensive, too politically infeasible, too centralized, and too prone to terrorism. Concentrating solar looks very viable at the moment, and I think geothermal could become a major player before 2020 with the right incentives.

But I think energy efficiency is the untapped gold mine. I’ve seen quotes for nuclear running about $6000-$11000 per installed kW of capacity. By my rough calculations, for $3500 you could buy enough CFL bulbs up front* to eliminate the need for that kW of capacity for 30 years.** Even better, CFLs eliminate that demand precisely when the energy is needed. Any generation-based solution has to predict demand and compensate.

* If you assume that the cost of bulbs will go down over time, or that you could invest the money for the bulbs you don’t need immediately, or that another high-efficiency lighting technology will beat CFLs in the future, the strategy works even better.

** $3/bulb, bulbs last an average of 5 years, running for 3 hours a day on average, 17w CFL vs. 60w incandescent.

[Dumb Scientist]
Nuclear power is expensive, but it’s the only option available right now that we know works on an industrial scale. Update: My dad just told me about an interesting proposal for small, self-contained, tamper-proof nuclear generators which wouldn’t be as centralized or expensive as our sadly obsolete nuclear plants.

Concentrated solar is certainly the most promising renewable, but it requires massive battery banks, or expensive water pumping schemes to provide a base load at night. That said, I like it a lot more than photovoltaics. Geothermal only works in certain places, and corrosion makes them very expensive to maintain. In either case, we’d need a superconducting power grid to avoid losses from moving energy from the deserts (solar) or hotspots (geothermal). All these goals are noble, but we need power now to replace coal and oil.

Incidentally, tide power and osmotic power are also good long term goals.

And you’re right- efficiency is absolutely necessary. But the newer technology has to be better in every way, otherwise people won’t switch. My mom doesn’t use CFLs because she can’t stand the quality of the light (yes, some are better than others, but still no cigar) and the fact that they don’t reach full brightness immediately. I have them nearly everywhere, but my reading light is still an incandescent because the CFLs that can be dimmed are expensive and don’t look as nice.

[Dumb Scientist]

My understanding of CSP was that, to increase its baseload ability, you just made it bigger (especially the molten salt tank). I don’t remember the source, but I remember someone was quoted as saying that you can store energy as heat 20x cheaper than you could store it in a battery. As the reservoir gets bigger, it loses heat more slowly. Build it big enough, and you can keep it warm all night, even as you’re drawing power from it. [An Onerous Coward]

Yeah, you might be right about that. I think I remember seeing similar studies, and probably spoke too soon. I’ve yet to be convinced that this is a sure bet, but I’m delighted that Obama is putting more research money into these areas.

You also have the option of burning something to keep the fluid warm, for cloudy days or to provide more baseload.

The only thing we can afford to burn in the long run is hydrogen, which requires energy to produce.

Update: No, actually that’s wrong. You were right about concentrated solar allowing for a burner backup. Biofuels won’t cause any net CO₂ increase because their combustion only releases the CO₂ they’ve recently absorbed to grow. I’m not a big fan of generation 1 biofuels, because they tend to provide an incentive for farmers to grow crops that humans can’t eat. But generation 2 biofuels use the discarded husks of human-edible plants and might be industrially feasible some day. Genetically engineered bacteria also look like they could produce biofuels given enough time. Also, artificial leaves look promising; they might eventually split water into hydrogen and oxygen far more cleanly than any method available now.

I’m not sure there’d be a point to building that kind of backup into the concentrated solar plant, though. The ability to use the molten salt loop with an oil burner might not be worth the added design complexity, materials and labor. Wouldn’t that be exactly like Well, except for the fact that the soot from this burning would likely fall onto the mirrors. building an ordinary oil-powered backup generator, which we already have in abundance? One potential benefit is that we could decommission the old generators and recycle their parts, but that’s probably more trouble than it’s worth right now.

Transmission losses, while not negligible, seem manageable. I’ve seen figures of about 2-3% to move electricity 600mi using HVDC. I mean, it’s on Wikipedia, so it must be right.

Yes, HVDC looks promising, but some population centers are farther away than that from a good spot for solar or geothermic (not all northern countries are as fortunate as Iceland). In the long run this isn’t a serious problem because we’ll eventually build a superconducting grid, but until then it’s a nuisance.

The big problem I see with the “we need power now” argument is that we could probably install several gigawatts of CSP and wind before we could even get the nuclear reactor through the permitting process.

If it works, that’s great. The problem is that no country has ever successfully powered their civilization in that manner, so it’s a bit of a gamble. France gets 80% of their power from nuclear, so we know it works. I’m also inclined to say that the delay in getting new nuclear plants online is more of a problem with lenders being extremely cautious about nuclear energy because of public disapproval, so the permitting process is much more ridiculous than it should be. Nuclear power isn’t nearly as dangerous as it’s commonly made out to be, and we need enrichment for medical isotopes anyway so terrorism will always be a problem.

I think concentrated solar is great, and might be our best bet in the long run. I just don’t want these unproven technologies to be our only bet. It’d be nice to see our civilization put no more than, say, 30% of our power generation into one particular technology so that the loss of any one mode of power generation isn’t catastrophic.

Update: I’m going to write a separate article about nuclear power whenever school gets less crazy, but for now I’ll quote another couple of paragraphs from the same recent survey:

… About half (51%) of Americans favor building more nuclear power plants to generate electricity, while 42% oppose this. … More college graduates (59%) favor building nuclear power plants than do those with a high school education or less (46%). … Seven-in-ten scientists favor building more nuclear power plants to generate electricity, while 27% are opposed. Among scientists, majorities in every specialty favor building more nuclear power plants, but support is particularly widespread among physicists and astronomers (88% favor). … — Pew Research Center

In other words, statistically speaking, the more someone knows about physics, the more they favor nuclear power. I’m just sayin…

Stormcrow309 asks about potential flaws in the Vostok ice core analysis.

[Dumb Scientist]

… What are the problems with the Vostok data? … [Stormcrow309]

Diffusion of isotopes over time leads to large horizontal error bars (i.e. it’s uncertain when particular temperature/CO₂ measurements occurred, especially relative to each other). Accumulation rate uncertainty makes these horizontal uncertainties larger at deeper depths (older ages). But vertical uncertainty is smaller (i.e. the absolute maximum of CO₂ is less uncertain). Furthermore, the correlation of those values to the global paleoclimate is still a matter of debate, but ice cores from other locations and other independent proxies yield similar reconstructions.

[Stormcrow309]
… Petit et al. (1999) takes no effort to describe the methodologies used in handling ice cores, which raises questions on the process used. The line “Ice cores give access to palaeoclimate series that includes local temperature and precipitation rate, moisture source conditions, wind strength and aerosol fluxes of marine, volcanic, terrestrial, cosmogenic and anthropogenic origin” is not attributed, which leads it reading as opinion or possible plagerism (Petit et al., 1999, p. 429). Since it is the bases of the work’s analysis, it would make sense to give that sentence more concrete foothold in established theory. There is no discussion on this approach’s appropriateness or flaws. There is a good discussion on the research team’s reason for limiting the data set but not the impact of that limitation. There is no review of further research questions. It reads as a set of scientists too worried about analysis and not with synthesis. The work is biased to its approach and thusly flawed in its presentation.

[Dumb Scientist]

… Petit et al. (1999) takes no effort to describe the methodologies used in handling ice cores, which raises questions on the process used. [Stormcrow309]

That’s because they didn’t handle the ice core at all. They simply applied a newer computational algorithm to the data collected from the ice core by other scientists years before they published. In fact, the second to last sentence in the paper says “We thank C. Genthon and J. Jouzel for performing the CO₂ spectral analysis…” Their papers are, of course, listed at the end with all the other references.

Just in case you don’t have free access to Nature articles, I’ve found a source (see section II) that provides a rough overview of the way the ice core was handled. It was sliced into 1.5m sections, put into a clean stainless steel tube in Grenoble, France and melted so that various types of spectroscopic and chemical analysis could be performed. Update: Eric Steig points out that handling methods were studied decades ago, so they’re careful to keep the temperature of the ice cores below -10°C.

But it needs to be stressed that a deep understanding of this process is only available from the original peer-reviewed articles. I only linked that website for the benefit of people who don’t have free access to journals through their universities.

The line “Ice cores give access to palaeoclimate series that includes local temperature and precipitation rate, moisture source conditions, wind strength and aerosol fluxes of marine, volcanic, terrestrial, cosmogenic and anthropogenic origin” is not attributed, which leads it reading as opinion or possible plagerism (Petit et al., 1999, p. 429). Since it is the bases of the work’s analysis, it would make sense to give that sentence more concrete foothold in established theory.

It might be a good idea to read at least the next few sentences before making accusations of plagiarism. When you do, notice that the sentence you quoted is the “topic sentence” of the paragraph. Other sentences in that paragraph serve to expand on individual points in the topic sentence, and they’re all referenced. In fact, there are no less than 14 references you can read (they’re all listed at the end of the article) to catch up on the science contained in that sentence.

There is no discussion on this approach’s appropriateness or flaws.

Really? How about…

1. Page 431, paragraph 2, sentence 4. “This approach underestimated deltaTs by a factor of ~2 in Greenland (ref 22) and, possibly, by up to 50% in Antarctica (ref 23).”
2. Page 431, paragraph 3. The entire paragraph is devoted to understanding shortcomings in the deuterium-temperature connection.
3. Page 431, paragraph 4, sentence 3. “… the Vostok record may differ from coastal (ref 28) sites in E. Antarctica and perhaps from West Antarctica as well.”
4. Page 434, paragraph 6, sentence 4: “However, considering the large gas-age/ice-age uncertainty (1000 years, or even more if we consider the accumulation-rate uncertainty), we feel that it is premature to infer the sign of the phase relationship between CO₂ and temperature at the start of the terminations.”

There is a good discussion on the research team’s reason for limiting the data set but not the impact of that limitation.

Limiting the data set in what sense? If you’re referring to the fact that they stopped drilling to avoid contaminating Lake Vostok, the impact of that limitation is that the time series stops roughly 500,000 years ago rather than extending slightly farther back in time. If you’re talking about some other data set limitation, you’ll need to be a little more specific so I know precisely what you mean.

There is no review of further research questions.

Really? how about…

1. Page 433, paragraph 4, sentence 3: “We suggest that there also may be some link between the Vostok dust record and deep ocean circulation through the extension of sea ice in the South Atlantic Ocean, itself thought to be coeval with a reduced deep ocean circulation34.”
2. Page 435, paragraph 1, sentence 1: “We speculate that the same is true for terminations II, III and IV.”
3. Page 435, paragraph 1, sentence 6: “We speculate that variability in phasing from one termination to the next reflects differences in insolation curves (ref 41) or patterns of abyssal circulation during glacial maximum.”

[Dumb Scientist]

Are you talking about: J R Petit, J Jouzel, D Raynaud, N I Barkov, et al. (1999). Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature, 399(6735), 429-436. Retrieved April 7, 2009, from ProQuest Medical Library database. (Document ID: 42351682)? Because the phrase is not in there. The paper reads like the researchers were involved in the drilling. [Stormcrow309]

Yeah, that’s the paper I originally linked, but you’re right– the phrase isn’t there. I was at work (with access to the journals) when I wrote that, and had 4-5 of the older Vostok papers open at once. That particular phrase is probably in one of those papers, but I don’t have journal access at home (and my cache is empty) so I can’t verify that right now. The phrase you’re looking for in the paper I did link is below the references, in the Acknowledgements section: “We thank the drillers from the St. Petersburg Mining Institute; the Russian, French and US participants for field work and ice sampling…”

Sorry about the confusion; I was juggling too many papers to keep them all straight on my desktop. But you can also verify that J. Jouzel is referenced many times, with reference 6 being published in 1987 (several years after the section from 950-2083m was extracted in 1982-83), and 12,13 published in 1993 and 1996. C. Genthon is reference 14, published in 1987.

I must humbly disagree that the paper “read like the researchers were involved in the drilling.” They’ve certainly tried to describe the drilling process in a brief manner for the benefit of the reader, but acknowledged the hard work of their fellow scientists, thanked them for their contributions, and provided citations to their original work in extracting and sampling the ice core. It all seems perfectly civilized.

They limited the ice core due to volcanic activity without discussing the impact. None of my editors would allow me to get away with that.

That limitation has exactly the same impact as stopping the drilling above Lake Vostok. It merely truncates the time series, preventing the reconstruction of data earlier than 423,000 years ago. You’re probably thinking about studies which fail to sample the population in a uniform or unbiased manner, and thus alter the resulting statistics because they’re using a skewed sample. This is a serious problem in many sociological studies, but it’s not a relevant concern here. An ice core taken from a shallower hole (like the 3310m core in the paper) has precisely one impact: it provides data back to 423,000 years before the present instead of even further back in time.

Update: The Vostok ice core data have now been confirmed by the EPICA ice core data. Not only does it agree with the Vostok data, EPICA extends the time series back to 650,000 years before the present.

In addition, the flaws I listed have been addressed, and the historical maximum was defended– this is the reference he mentions. Also, here’s a good list of Vostok references and the actual data.

m4cph1sto doubts that temperatures are increasing.

[Dumb Scientist]

I’m a scientist too, and I judge theories based on merit, not popular opinion. [m4cph1sto]

(Ed. note: In a much later post, he elaborates on a similar claim by explaining that he’s an engineer. See the Salem Hypothesis, or my discussion of its application to this debate.)

As a rule, scientific theories are not accepted by the scientific community until they have done two things: (1) explained known observations in a more simple or fundamental way than alternative theories, and (2) made a prediction about something that is currently unknown and that other theories don’t predict, which is then confirmed by observation.

Global Warming theory has met neither of those requirements. The main statement of Global Warming is something like this: “small changes in the amount of CO₂ in the atmosphere cause large changes in global temperature”. Despite this theory, there is absolutely no evidence that a change in CO₂ has ever caused the temperature to change, over the entire billions-years history of the planet. So GW theory doesn’t explain past observations.

Abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. is the direct result of an unprecedented excavation of fossil fuels, and the combustion of said fuels which releases CO₂ into the atmosphere that’s been trapped for millions of years. It’s not supposed to explain past observations.

It doesn’t explain current observations either: CO₂ concentration has steadily increased over the past 100 years, while temperatures have gone up, then down, then up again, then down again (as they are currently). There is no dramatic warming trend as predicted by GW theory.

I’ve never met a scientist who made a claim like the one you’re attributing to me. Most scientists recognize that long term trends are only discernable in the data after accounting for annual variations, multi-year variations, etc. Once those fluctuations are removed by a 5 year averaging procedure, a disturbing upward trend is apparent.

Finally, GW has not made any unique predictions that have later been confirmed as true. It predicted more and bigger hurricanes; that hasn’t happened. It predicted significant temperature increases; that hasn’t happened. In fact, the theory seems totally based on computer models that have failed to make a single correct prediction about the climate ever since I first started following the issue, in 1998.

To summarize, GW theory does not meet the standards of scientific acceptance, not by a long shot.

First, the temperature is increasing. Second, the IPCC’s Fourth Assessment Report made a very limited claim regarding hurricanes: “It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity.”

Third, Meehl 2004 showed convincing proof that natural forcing can’t account for recent global temperature trends, but including anthropogenic forcing provides a good match for the data.

[Dumb Scientist]

Look at the data again. There is most assuredly a dramatic warming trend, despite the slight decrease in global mean temperature over the past few years. Run a regression on the data, it’s quite clear. [Red Flayer]

You mean this data? … Or this one? [m4cph1sto]

Interestingly, I posted another reply to your parent comment that also included those links. Except, I linked to the main page. I was referring to the figures above the one you directly linked to. Figures A2 and A show the Global Annual Mean Surface Air Temperature Change, measured using two different data sets. Uncertainty is indicated by the green bars. Notice the trend in both figures.

Instead, look at the temperature trends I linked to above, based only on direct measurements made in the United States since 1880, or “mean global temperature” using modern measurement techniques (since 1996). These datasets are, IMO, the only ones we can believe with any confidence. Is there a dramatic warming trend? The answer is as likely no as yes, or a resounding “we don’t know”.

The graph you’re talking about from 1880 onwards is from this paper, where they specifically state that the warming in the U.S. is known to be smaller than the rest of the world. The reasons for this are not (to my knowledge) completely understood. But the rest of the world have had temperature sensors too, we’ve had satellites up for decades, and we can use proxies to confirm that global temperatures are increasing at an unprecedented rate. Update: More recent studies confirm that the U.S. temperature increase matches those in the rest of the world.

In my opinion, any evidence based on “global temperature” that includes data from more than just recent years should be viewed with scepticism, because our worldwide measurement and calculation techniques have changed dramatically, which likely skews the results in one direction or another. NASA presents data on mean global temperature extending from today back to 1880 as a single line graph with no error bars, which is ridiculous.

Figure A is based on this article, which describes adjusting for inhomogeneities in station records and station history adjustments. Sensibly integrating differing data sets is an irritating task, and it’s an ongoing process. But it doesn’t seem to be a problem climate scientists are ignoring– the techniques for dealing with non-uniform noise characteristics and biases in different data sets are well known.

Furthermore, we don’t just have to rely on mechanical recording devices. Tree rings, coral growth rates, borehole measurements and ice core proxies can be used to independently verify the temperature record. They agree to within the limits of experimental and algorithmic uncertainty.

My point is that arriving at a “mean global temperature” is a very difficult calculation to make.

I wholeheartedly agree. I think scientists should be careful to state the estimated uncertainty in all their statements, and abrupt climate change is no exception. It’s just that the error bars are now small enough to rule out the hypotheses “climate change isn’t happening” and “climate change is largely natural.”

Update: After further thought, I think m4cph1sto was referring to a recent argument circulating around “skeptic” sites claiming that the average temperature has been decreasing since 1998. I’ll let Rei handle this one:

FYI: 1998 was one of the strongest El Nino events in modern history. El Nino raises the atmosphere’s temperature by slowing the upwelling of deep, cold water in the eastern pacific. La Nina cools it by just the opposite. It doesn’t change the long-term picture, of course; the rate at which water cycles in the ocean has no bearing on how much total heat input there is into the system; ocean waters aren’t magically decoupled from the rest of our atmosphere. It’s just a source of white noise on top of the blatantly obvious signal. [Rei]

Another Update: This subject came up again here.

Jane Q. Public asks if sunspot activity causes global warming, among many other topics.

[Jane Q. Public]
…one theory is that lack of sunspots causes Earth to warm up. (There is a very strong negative correlation between sunspot activity and temperature on Earth.)

Maybe now we’ll find out who’s right.

[DarkHelmet]

No it doesn’t [youtube.com].

[Jane Q. Public]
I was wrong about the correlation being negative, but I was not wrong about the correlation. But one thing pointed out in your video, that solar activity has not corresponded to temperature in just the last few years, is totally meaningless. Long-term trends are the only ones that matter. And as for long-term predictions, nothing comes close to beating the analysis of sunspots. The science is good. Very good.

I’ll see your YouTube video, and raise you one:
video [youtube.com]
video [youtube.com]

And a whole bunch of articles:
article [typepad.com]
article [wordpress.com]
article [bbc.co.uk]
article [examiner.com]
article [mlive.com]
article [wordpress.com]

[Repossessed]
Do you have any citable sources? Those are blog postings and new sites (which is even worse than a blog).

[Jane Q. Public]
Sources were referenced in both the videos and the articles. I would think that a few minutes with Google should lead you to them.

[Repossessed]
Wikipedia is not a citable source, nor does it have the details necessary for me to do a peer review.

None of your links have any actual data to them, they do not have citations which include the data. They do not include the equations used to come to the conclusions either. Without those, there is no way to determine if the theory has merit.

[Jane Q. Public]
I see. So a presentation by a University professor about his research project is not self-citing?

Are you completely inept at Google? You can’t find his name or the research he was demonstrating?

Look, bud. This is not a peer-reviewed journal itself. If you can’t find the data from the information given (I did), then just blow it off and say you don’t believe it. I don’t care one way or another. But I am not going to spend a half hour looking it up again just for you.

[Repossessed]
I have no interest in believing thing or not believing them, I have an interest in knowing if they are true.

[Jane Q. Public]
Look, guy. I literally just spent 10 seconds on Google and found plenty of information about David Archibald, including a new paper he published just this month.

Do you own damned homework, and stop demanding to be spoon-fed by others. I won’t respond to you again.

[Repossessed]
And yet you are incapable of providing me with that information.

[Jane Q. Public]
NO, just unwilling, you lazy ass. When I was young (NOT that damned long ago), finding information like this meant spending a day at the library finding out what books contained the information, then arranging for inter-library loans, and waiting a week to a month or even longer for the books to even get there.

I am not Al Gore, to pretend that I “invented the internet”. But I have spent a good part of my life helping to build the infrastructure that brings this information to your fingertips. And if you are too goddamned lazy to lift those fingertips to even bother to look something the fuck up, when you so easily can, then I am NOT going to help you!

Is there anything unclear about that???

[Dumb Scientist]
You’re suggesting that other people should embark on a wild goose chase to try to find respectable references behind the pseudoscientific sites that you clearly believe are more rigorous than Nature and Science? Curiously, you haven’t even responded to the reasonable and insightful comments by Geoffrey Landis in this very page. I guess it really is true that “You can’t reason someone out of a position that she didn’t reason herself into in the first place.”

Incidentally, I know this won’t sway you, but I study the climate in my day job and all your posts prove is that you’ve never taken graduate-level classes in this area. Every serious climatologist that I’ve met at the conferences agrees with the mountain of evidence showing that sunspots aren’t strongly correlated with climate. Again, see Geoffrey’s posts.

(Ed note: At this point, Jane responds to Geoffrey with a truly epic post that I later responded to.)

[Jane Q. Public]
No, I was suggesting that ONE particular person was being a lazy ass, and trying to put demands on me as a result. As I have mentioned, one of his questions could have easily been answered had he bothered to spend literally 10 seconds on Google.

Further, I had in fact answered one of Geoffrey’s posts, and I have just answered another one, at length, with a reply that indirectly references about 150 or more peer-reviewed scientific papers. That will have to be good enough, because I am tired of catering to lazy asses who believe what they are told on the 11 o’clock news, and who can’t be bothered to do any real research or even lookups on their own.

[Dumb Scientist]
Or maybe scientists aren’t the brainwashed idiots you clearly think we are? We’re aware that the Sun exists, and that it impacts the climate. But the overwhelming evidence is that sunspots have a negligible impact on the climate.

People are asking you for serious, peer-reviewed references not because scientists are idiots who “believe what they are told on the 11 o’clock news, and who can’t be bothered to do any real research or even lookups on their own” but because we’ve spent our lives studying these issues and what you’re saying contradicts all the evidence we’ve seen.

Further, I had in fact answered one of Geoffrey’s posts, and I have just answered another one, at length, with a reply that indirectly references about 150 or more peer-reviewed scientific papers. [Jane Q. Public]

Here’s proof that the Moon doesn’t cause the tides, that the Earth is less than 10,000 years old, and that the Earth doesn’t move. The website has more than 150 peer-reviewed references, I’m sure!

Not convinced? Why not? Do you see any difference between the post you wrote in response to Geoffrey Landis and the fixedearth.com website? Because I don’t. That’s why we’re asking you to provide us with a direct link to an actual peer-reviewed article supporting your claim that sunspots are responsible for global warming. It’s all too common for pseudoscientists to quote legitimate articles to support their outlandish claims, and then ignore the scientists’ complaints.

[Dumb Scientist]

Apparently you think *I* am an idiot. Try reading the goddamned thread. … If you really don’t want to be perceived as a “brainwashed idiot”, maybe you could bother to figure out what the argument is about before you put in your irrelevant 2 cents. … As for the rest, you are one of those lazy asses I mentioned. … But you are too damned lazy to look any of them up? … And yes, that to me means “brainwashed idiot”. … get off your lazy ass and LOOK IT UP YOURSELF!!! … since you insist on being spoon-fed … There are many more, very easily found, but I am not going to do your homework for you. Now go away. You disgust me. [Jane Q. Public]

There’s really no need to be so uncivilized. I’m just saying that all your posts on this subject clearly imply that scientists are either so stupid that they overlook trivially obvious “problems” with their own research, or that they’re willing members in a global conspiracy. Based on your (mistaken) assumption that I haven’t read this thread, I don’t have to guess which of these alternatives you’ve chosen in my case. Pity. I bet conspirators get jetpacks!

And I most certainly do not think you’re an idiot. At worst, I think you’re making mistakes while talking about a highly advanced subject that lies far outside of your own professional experience. Everyone does that. It’d be a different story if I were saying that you were pathetically wrong about your own life’s work… the subject that you’ve studied since childhood with the passionate intensity of a monk. I’d never insult you like that; at most I’d simply ask polite questions to try to understand your subject of expertise better.

First, the Petition Project is a legitimate collection of scientists.

I asked for peer-reviewed references, not a list of people with PhDs. There’s a difference. A list of PhDs is an appeal to authority. A peer-reviewed article is evidence of a very specific claim, along with equations and links to data that I could use to verify the claim. It’s given weight by the confrontational nature of the review process in addition to the fact that everyone involved has a PhD in that specific field. Like other people who take your position, you appear to think that science is democratic– that scientific decisions are made by comparing the number of people on each side. It’s not. It’s about evidence.

So, since you insist on being spoon-fed, here is one: Solar Cycles and Predicted Climate Response, which appeared in Energy & Environment (an appropriately peer-reviwed journal) in 2006. You asked for one, you got it.

My apologies. I wasn’t nearly specific enough in my original request. Scientific journals are rather specialized, and we’re discussing a very specialized hard science topic. It wouldn’t be appropriate to reference an article from a social science journal (which is what Energy & Environment is). The reason is that the referees need to be experts in their field in order to properly vet the paper. Journals I’d suggest reading are Science, Nature, Journal of Geophysical Research, Geophysical Research Letters, Physical Review, Physical Review Letters, Journal of Atmospheric and Solar-Terrestrial Physics, Journal of Climate, Environmental Research Letters, Climatic Change, Eos, etc.

I’m sorry for not making that caveat more explicit, but I figured it was an assumption that all scientists would make…

But I’ll make it up to you. Here’s an article by Friis-Christensen and K. Lassen, published in Science in 1991. This would have been a legitimate example of a peer-reviewed journal article supporting your claim.

Of course, it’s incorrect. You can find out how– if you’re interested– by following its citations in google scholar to the present. For nonscientists, read the summary here. The moral of this story is that data smoothing is difficult to do in an objective manner, which is something all computational scientists screw up on occasion. Please don’t mistake this comment as criticism of Friis-Christensen or K. Lassen– I’ve certainly made far bigger mistakes in my own research. The ability to admit a mistake and move on is the mark of a true scientist.

[Dumb Scientist]

Like other people who take your position, you appear to think that science is democratic… [Dumb Scientist]

THAT is complete bullshit. That is the exactly the point that I made in a preceding post… and you claim to have read this thread??? Go back and read it again. You are in error. [Jane Q. Public]

When asked for a peer-reviewed article, you presented a list of scientists. It doesn’t really matter what you’ve written in any other post– this kind of category error gives the appearance that you think science is democratic because that’s the only scenario in which this wouldn’t be a category error.

… Note that peer review is a necessary but not sufficient condition for establishing a valid scientific claim. Not all peer-reviewed papers are accurate, as I’ve shown. But if you want respect from scientists, you have to first rise above this reliance on pseudo-scientific websites that display approximately the same level of rigor and oversight as this site.

And perhaps that particular article WAS wrong. But I have cited — and pointed you to — much more recent research that contradicts that. [Jane Q. Public]

More recent != This is C++ for “is not equal to.” more credible. If they were both articles in Science, yes, all other things being equal, the more recent article would have more weight (unless it was so new that other scientists hadn’t yet had time to respond to it.) In fact, that article you’re leaning on quotes Friis-Christensen and K. Lassen (1991) several times, without seeming to understand that the reason their conclusions aren’t valid has little to do with the data they used; the real problem is the way they smoothed the data. My other post quotes legitimate, peer-reviewed articles showing this warming is due mainly to anthropogenic CO₂.

Journals I’d suggest reading are Science, Nature, Journal of Geophysical Research, Geophysical Research Letters, Physical Review… [Dumb Scientist]

Aha. Exactly those journals that have been experiencing famous failures of the peer-review system in recent years? Of course. Sir, that was only one paper out of a great many. I repeat: why do you want me to do your homework for you? You refuse to look these things up for yourself… [Jane Q. Public]

… I can’t help but point out that you’ve casually dismissed every top-tier hard-science journal, in favor of a social science journal. With all due respect, Science, Nature and all the other journals I mentioned are where science actually happens. The claim that sunspot cycle length correlates well with Earth’s average temperature was made in the mainstream journals in 1991. But it was quickly shown to be a spurious connection based on data smoothing parameters. The fact that Energy & Environment didn’t catch this when the argument was made again 15 years later just shows that they’re not experts in the field. As I’ve said, there’s no shame in that. I’m not an expert in all subjects in the universe, so I don’t fault their lack of highly specialized knowledge in this particular subject any more than my lack of knowledge about synchronized swimming is a black mark on my career as a climate scientist. I’m sure their journal is excellent at analyzing the social science issues associated with energy use, and those issues are important too.

[Jane Q. Public]
As I stated before, I only found that paper after you asked me to find one, and I was not particularly careful in choosing it; you had asked for a peer-reviewed paper, and I just grabbed the first one that was visible. And indeed, some of its claims do appear to be refuted, particularly in a paper by P. Damon, published in Eos in 2004. However, though you apparently knew this (as, I could guess, did Mr. Landis), neither of you bothered to cite any kind of actual data in an attempt to refute the one paper I provided, per your request.

After you mentioned the data smoothing issue, it took me about 2 minutes to find Damon’s paper. If I had been aware of it in advance, I would of course not have offered that paper. But if you really wanted to make a point — and practice what you preach — you should have cited your sources. Instead, you left me to look it up… which makes you are guilty of exactly the same faux pas of which you accuse me. In point of fact, Damon’s paper itself states, “The graphs [from Friis-Christensen and Lassen] are still widely referred to in the literature,and their misleading character has not yet been generally recognized.” Without citing sources, then, how did you expect me to know? …

[Dumb Scientist]
Thanks for the link. You’re right, it is a good paper. I’m sorry that I missed it.

(Ed note: This post was written in response to Jane’s huge post which she wrote in response to Geoffrey Landis.)

[Dumb Scientist]
Mon Dieu! Quantity != This is C++ for “is not equal to.” quality. You’d get a lot more respect if you’d simply link to one or two legitimate, peer-reviewed articles instead of dozens of pseudoscientific websites. I don’t have time to relieve you of all your misconceptions, but here are the most glaring errors:

If you had done your homework (or even watched the YouTube videos I posted above), … On the contrary, if you had watched those YouTube videos I linked to… [Jane Q. Public]

We’re scientists, not preteens looking for cat videos. Link to peer-reviewed articles or expect to be ignored.

Anthropogenic CO₂ is the cause of a small, but measurable, increase in average global temperature. This temperature increase is a detectable deviation away from the statistical variations due to natural causes, and is now quite well understood. [Geoffrey Landis]

That is the most ridiculous thing I have heard to date. It is NOT known, precisely because it has been impossible to statistically separate it from other influencing factors. (Including sunspots!) While many scientists believe that it probably has some effect, nobody has yet managed to measure it with any real statistical significance. Where did you get this idea, anyway? Do you have any sources that purport to have this measurement? The fact is that such a beast does not exist! [Jane Q. Public]

Geoffrey’s statement is most certainly not ridiculous. I suggest looking at the IPCC 4th report. Download chapter 3, open the PDF to page 15 (which is labeled 249) and look at figure 3.6. These data show a global temperature increase of 0.65 °C plus or minus 0.2 °C over the period from 1901 to 2005. The report notes that this rate is higher than at any other point since the 11th century. Meehl 2004 shows that this warming can’t be explained by natural forcings alone, but including anthropogenic CO₂ emissions matches the observations very well. And, yes, those “natural forcings” include variations in solar output, which can be measured by satellites so there’s no need to search for weak correlations in sunspot data.

Furthermore, as I’ve repeatedly argued, Vostok shows that the current CO₂ level is higher than it’s been in half a million years. If you don’t think that CO₂ can warm the planet, I suggest you remember your sophomore-level physics classes and examine the spectrum of the Sun. Then open a textbook and examine the absorption spectrum of CO₂. Notice that the peak of the Sun’s radiation goes through? Now open your thermodynamics textbook and calculate the blackbody radiation of a planet at 286K. Notice that the CO₂ absorbs more of this radiation.

That’s why scientists say that CO₂ is warming the planet. It’s not exactly cutting-edge science.

Most of the science that is used to support the greenhouse warming model come from the IPCC Assessment reports, and much of that “science” has been shown to be flawed, not to mention that the reports themselves are heavily politicized, and their conclusions do not match the actual science that they reference. [Jane Q. Public]

That’s exactly backwards. The IPCC reports are simply compilations of pre-existing, peer-reviewed science. I’ve read their reports and talked with scientists whose work is referenced in the IPCC reports. No scientist I’ve met (in public or private) thinks your conspiracy theory is valid. In fact, I’ve personally confirmed the mass loss in Greenland’s glaciers with my own research. I’ve seen climate change happening with my own data and my own personal algorithms. Does that mean I’m part of the conspiracy too?

Below I link to a letter from Chris Landsea, who is the one who actually did the research on whether hurricanes and typhoons would increase in number or severity due to global warming. His conclusion was that they would not. BUT… the IPCC didn’t let that stop them.

Yes, science is sometimes contentious (which seems to contradict your opinion that scientists are either brainwashed into accepting global warming, or engaged in a massive conspiracy.) Also, the IPCC’s Fourth Assessment Report made a very limited claim regarding hurricanes: “It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity.”

The giant red “hockey stick” graph from Al Gore’s movie? (The researches who published that paper have publicly admitted that it was based on faulty procedures and have officially withdrawn it.)

I’m not sure what you’re referring to here, but I see no reason to doubt the overall accuracy of that graph.

[Dumb Scientist]

Therefore, the statement in AR4 that “It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity.” is likely an exaggeration, not supported by the actual research. [Jane Q. Public]

According to the IPCC guidance note on uncertainty, that’s basically the weakest statement they could make without being utterly silent. (See table 4.) Months ago, I said that hurricane intensity couldn’t be linked to climate change, and I later corrected another poster who was under the impression that the available data contained a clear correlation between hurricanes and climate change.

If the IPCC report had used any other qualifier from table 4, you might have a more convincing point. Furthermore, another paper in Science says “Results show that the increasing trend in number of category 4 and 5 hurricanes for the period 1970-2004 is directly linked to the trend in SST [sea surface temperature].” Dr. Landsea is a legitimate scientist, but he’s not the only one studying hurricanes, and I fail to see how his claims automatically rule out those of other scientists– especially when they’re making such a weak claim given the observed trends.

And, yes, those “natural forcings” include variations in solar output, which can be measured by satellites at L1 so there’s no need to search for weak correlations in sunspot data. [Dumb Scientist]

Please be specific. “Solar output” can mean many things. [Jane Q. Public]

I was quoting Meehl 2004 in that sentence, which itself quotes Meehl 2003 to show that variations in solar luminosity affect the climate. Of course, Meehl 2004 shows that this effect isn’t responsible for the warming in the latter half of the century, which is shown to be due to anthropogenic CO₂ emissions.

And by the way, I would like to point out a mistake you have made more than once: there is in fact a clear and valid correlation between sunspot cycles and Earth surface temperature, from the distant past up to at least the mid-20th century. [Jane Q. Public]

Further, while it was implied by Mr. Landis, neither of you bothered to acknowledge that there is in fact a strong correlation, at least up to the mid-20th century. Instead, you gave me the impression that you were disputing any correlation at all, which I knew to be incorrect. [Jane Q. Public]

First of all, Dr. Landis and I were careful to hedge our claims. Here are all the statements I’ve made (unless I’ve missed one?) regarding the correlation between sunspot cycle length and the climate:

• Every serious climatologist that I’ve met at the conferences agrees with the mountain of evidence that show sunspots aren’t strongly correlated with climate. [emphasis added]
• … the overwhelming evidence is that sunspots have a negligible impact on climate. [emphasis added]
• The claim that sunspot cycle length correlates well with Earth’s average temperature was made in the mainstream journals in 1991. [emphasis added]
• … so there’s no need to search for weak correlations in sunspot data. [emphasis added]

Which of these statements gave you the impression that I was “disputing any correlation at all”?

Based on your response to Abcd1234 (who carefully said that the correlation hasn’t been true for the last 50 years), I’d assumed you were talking about the last 50 years. In fact, that’s why I stopped lurking. Did I misunderstand your post?

Secondly, you’ve been emphatically denying that the correlation you’re proposing is between luminosity and climate. But that’s precisely what Meehl 2003,2004 and most other peer-reviewed papers show. A correlation between luminosity variations and Earth’s climate isn’t in dispute. What those papers emphatically don’t show is that variations in luminosity are responsible for recent warming, or that variations in sunspot cycle length have a significant effect on the climate.

Update: A good reference regarding solar variability is section 2.7.1 on pages 188-193 of chapter 2 in the 4th IPCC report.

Previously, you cited luminosity data when I had clearly stated that the correlation was with period length, not luminosity.

That’s because other correlations have been disproven by later research, as you now seem to agree. I was just trying to steer you back towards the only correlation that’s well-established in the peer-reviewed literature.

Another problem with your claim is that some kind of mechanism other than variations in luminosity would be needed to support your hypothesis. For example, in this post you claim “The sunspot activity tends to blow away the solar winds, allowing more radiation to get through to Earth’s surface.”

This is indeed a claim made in a real journal. But it’s far more controversial than you’re implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover. Furthermore, there’s no long term trend in Svensmark’s data, which would be necessary to explain the long term warming trend that’s been observed. For more information, see chapter 7.10 of this textbook.

Furthermore, as I’ve repeatedly argued, Vostok shows that the current CO₂ level is higher than it’s been in half a million years. [Dumb Scientist]

Once again: correlation alone does not imply causation. You have to show cause, not just correlation. Otherwise you have demonstrated nothing. [Jane Q. Public]

Strong correlation plus a demonstrated causal mechanism does imply causation, though. Many nonscientists seem to get stuck on the fact that the causal mechanism between CO₂ and temperature works both ways. In the paleoclimate record, temperature swings induced by (among other things) Milankovitch cycles are amplified by CO₂. An astonishing number of “skeptics” appear to think the ~800 year phase lag between CO₂ and temperature proves that CO₂ can’t drive temperatures. This sort of bizarre statement seldom (if ever) shows up in peer-reviewed journals, though, because it’s simply not true.

The real point of these ice core analyses is that the natural climate experiences a temperature rise centuries before CO₂ rises. That’s not happening now, because the CO₂ in the air isn’t part of a natural feedback cycle. Instead, we dug it out of the ground in unprecedented amounts and pumped it straight into the atmosphere. Thus we’re not looking at natural climate change, it’s anthropogenic abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. .

Also, the natural climate exhibits feedback effects wherein higher temperatures release CO₂ from natural reservoirs such as the ocean and permafrost. This feedback CO₂ is completely different from the anthropogenic CO₂ that’s already pushed the concentration 26% above its natural peak, which means that the climate is likely to get even warmer due to natural feedback effects when that natural CO₂ is released.

In short, the phase lag has persisted for at least 650,000 years, but it isn’t happening today because we’re not experiencing natural climate change any more.

Then open a textbook and examine the absorption spectrum of CO₂. [Dumb Scientist]

I suggest that YOU look at the absorption spectrum of a cloud. See how they compare… it is not as simple as all that. [Jane Q. Public]

I first encountered the absorption spectrum of water in my first thermodynamics class, ~10 years ago when I was a sophomore physics undergrad. My professor, Dr. Glenn Agnolet, was an especially good lecturer, and pointed out that it’s not a coincidence that humans consider 400nm-700nm to be “visible light.” That’s because there’s a very narrow range of low absorption surrounding those values. It’s also not a coincidence that bees and small birds can see UV while we can’t, because our large watery eyes filter it out, but a smaller eye filters less UV so they evolved receptors for it.

Amusingly, this spectrum even has military significance in that the only frequency ranges useful for talking to submerged submarines have wavelengths longer than a kilometer. Not only does the transmitter have to be kilometers across and placed on a site with very low ground conductivity so it’s located in Wisconsin, the low frequency also results in very slow data transfer rates. That’s why subs receive messages in shorthand even to this day. Water’s absorption spectrum has fascinated me ever since.

But presumably you were implying that the existence of a stronger greenhouse gas like H₂O (which in our atmosphere accounts for roughly 3x the warming of CO₂) means that CO₂ is irrelevant. However, the lifetime of CO₂ in the atmosphere is much longer than water vapor, because oceans cover 71% of the Earth’s surface and therefore H₂O reaches equilibrium in a matter of days. In other words, if we pumped gigatons of water vapor into the atmosphere, it would be back in the oceans within a few weeks. On the other hand, CO₂ stays in the atmosphere for many decades, which is why it’s so dangerous. Water vapor concentration is also low in the stratosphere, so CO₂ is more important there.

I am not citing some “conspiracy theory”, though I will admit that it may seem that way. [Jane Q. Public]

Yes, it definitely does. Ironically, the very next statements in your post tend to reinforce my earlier conclusion.

Most of the science that is used to support the greenhouse warming model come from the IPCC Assessment reports, and much of that “science” has been shown to be flawed, not to mention that the reports themselves are heavily politicized, and their conclusions do not match the actual science that they reference. [Jane Q. Public]

No scientist I’ve met (in public or private) thinks your conspiracy theory is valid. In fact, I’ve personally confirmed the mass loss in Greenland’s glaciers with my own research. I’ve seen climate change happening with my own data and my own personal algorithms. Does that mean I’m part of the conspiracy too? [Dumb Scientist]

But aside from that, your “own research”, even if it does indeed show mass loss in Greenland’s glaciers, does not make your point at all… unless it demonstrates that the mass loss was caused by raised CO₂ levels. Remember: nobody here is disputing that the globe is warming! The debate is about the cause! [Jane Q. Public]

Note that I wasn’t attempting to use my research to support any particular cause of climate change. That statement was aimed squarely at your conspiracy theory. You might be able to convince nonscientists that there’s a massive conspiracy (intentional or not) among scientists, and any reference I produce to show that ~84% of scientists oppose your position would probably just solidify your belief in an evil conspiracy. My anecdote was only intended to show you that I’ve personally verified glacier melt through its effect on time-variable gravity above the glaciers in Greenland and Alaska. Because of this first-hand experience, I’m very skeptical that there’s any large-scale incompetence or data manipulation in the scientific community.

I’m also a little confused. You say “nobody here is disputing that the globe is warming!” but at the end of the very same post you present the Wegman Report in an attempt to discredit Figure 5(b) here which shows that the Earth is warming. Doesn’t that mean you are “disputing that the globe is warming”?

Obviously, this is not a peer-reviewed paper… but it IS a clear damning statement by one of the official reviewers, and I don’t see how you can ignore that. Nor is he the only one. Now, please don’t chide me about that last one… it is not a peer-reviewed paper either but it IS an official statement by the U.S. Senate Committee on Environment and Public Works, and cites over 400 renowned scientists around the world who disagree with the IPCC conclusions. … Now, remember… that was yet another official reviewer of the IPCC reports.

First of all, I’m allergic to politicians so I’m only going to comment on the genuinely peer-reviewed articles you’ve referenced. Secondly, your focus on reviewers seems to assume that I’m worshipping my fellow scientists as high priests. I’m not. I respect peer review precisely because it’s very confrontational, even downright nasty at times. I respect the process of peer review, not necessarily the people involved. Because 16% of scientists disagree with abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. (which seems to confirm my personal assessment based on what I saw at the Fall 2008 AGU conference), I’m not surprised that some people with PhDs (even people holding respectable positions) voice those views in public. If those reviewers ever publish their research in a respectable peer-reviewed journal, I’ll read their articles. This is because I have a limited lifespan– if I were immortal I’d have time to read every last skeptic argument in existence. But I’ve only got a precious few decades of life left, so I don’t waste my time on “science” that hasn’t satisfied the minimum acceptable standard for evidence: peer review.

I’m not sure what you’re referring to here, but I see no reason to doubt the overall accuracy of that graph. [Dumb Scientist]

I am referring here to the particular graph that appeared in Gore’s movie, nothing else. [Jane Q. Public]

I’ve never seen the movie. This is partially because of my fetish for learning science from physics classes at accredited universities, textbooks and peer-reviewed articles rather than YouTube videos and documentaries. But it’s mainly because the thought of that smug, pompous politician accepting a Nobel prize for exaggerating the science makes me want to gouge my eyes out with a rusty spoon just to get the image out of my head.

So I’m going to assume that by “hockey stick,” you were referring to Figure 5(b) here.

McIntyre and McKitrick, in about 5 reviewed papers in 2003 and 2005 … thoroughly debunked the statistical methods used to produce this graph. … Further, a review committee, consisting of Edward J. Wegman (Center for Computational Statistics, George Mason University), David W. Scott (Noah Harding Professor of Statistics, Rice University), and Yasmin H. Said (The Johns Hopkins University) recently reviewed and confirmed these findings.

The Wegman report wasn’t peer-reviewed, but it did contain genuinely useful criticisms of Mann’s methodology. However, followup journal articles such as Rutherford 2005 used completely different analysis methods and arrived at the same result. Also, Wahl and Ammann 2007 independently confirmed that conclusion. If you’d like, you can download their code here to confirm for yourself that the PCA centering issues raised by MM03 and MM05 don’t noticeably impact the results. I’m not disputing that better inter-disciplinary communication leads to better science. I’m just disputing the claim that these errors had any significant impact on the graph itself.

Furthermore, even if Mann et. al. really did make some kind of fatal error in their calculations, that has practically no impact on the current scientific understanding of “recent” temperature reconstructions. Here’s a compilation of time series produced by a dozen independent studies, using different algorithms, different statistical methods and different data. They vary significantly, but the abrupt temperature increase appears in all of them.

[Dumb Scientist]

My apologies, but this is the last comment I can write. I’m struggling under the weight of academic deadlines, and I don’t want to fail out of school because of my Slashdot addiction…

Meehl does not actually show that CO₂ causes warming, he relies on the research of others to do so. In fact, while this may be a slight exaggeration, about all Meehl did here was to integrate the work of a number of other authors. [Jane Q. Public]

At least you’re aware of the exaggeration, if not the magnitude or (more importantly) the fact that this criticism could be applied to any research that expands on previous results… which includes nearly every paper in the history of science.

(Ed. note: Slashdot adds notes like [iop.org] to all links, which I’ve restored here to demonstrate how the original posts looked.)

This is indeed a claim [ameyamhatre.com] made in a real journal. But it’s far more controversial than you’re implying. The maximum impact of this mechanism has been estimated [iop.org] to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover. [Dumb Scientist]

“This is indeed a claim made in a real journal. But it’s far more controversial than you’re implying. The maximum impact of this mechanism has been estimated to be responsible for no more than 23% of the 11-year cyclical variation of cloud cover.”

Estimated by whom? I have already shown you at least one peer-reviewed paper (although you objected to the journal’s lack of reputation for “hard science”) in which the estimation was far over what you state here. (Which, I admit, appears to be validly refuted for a specific period of time.) But if you are going to make an argument, as you seem to be doing here, then refute my source with one of your own, otherwise you are wasting my time. [Jane Q. Public]

That estimate was by T. Sloan and A.W. Wolfendale in the article I originally linked… that’s the link which was originally followed by “[iop.org]” before you quoted it. Also, the paper you previously found contains similar criticisms of Svensmark 1998 on its second page.

Update: Other relevant papers include Kristjansson 2002 and Laut 2003, followed by Svensmark’s response and Laut’s rebuttal. More recently, Erlykin et al suggest that the apparent correlation is due to direct solar activity, while Pierce and Adams state: “In our simulations, changes in CCN [cloud condensation nuclei concentrations] from changes in cosmic rays during a solar cycle are two orders of magnitude too small to account for the observed changes in cloud properties; consequently, we conclude that the hypothesized effect is too small to play a significant role in current climate change.”

But there are a lot of complex interactions going on here, including the fact that reflection by CO₂ tends to be logarithmic… requiring a doubling of CO₂ concentration to equal an incremental increase in reflection. … Books could be written about it and probably will be. [Jane Q. Public]

Yes, of course. The fact that CO₂ absorption depends logarithmically on concentration has been known since 1900 when Angstrom and Koch Ångström, Knut (1900). ‘Über die Bedeutung des Wasserdampfes und der Kohlensaüres bei der Absorption der Erdatmosphäre.’ Annalen der Physik 4(3): 720-32. published online 308(12): 720-32 (2006) [doi: 10.1002/andp.19003081208] first measured it in a tube filled with CO₂. The absorption dropped by less than 1% when Koch lowered the pressure by 33%, which convinced an entire generation of climatologists that CO₂ wasn’t dangerous because it was already “saturated.” In other words, they believed that adding more CO₂ wouldn’t warm the planet because it was already absorbing almost all it could.

But this research is 109 years old. Books have already been written about it. As early as 1931, Hulburt Hulburt, E.O. (1931). ‘The Temperature of the Lower Atmosphere of the Earth.’ Physical Review 38: 1876-90. used the brand-new theory of quantum mechanics to study absorption in more detail. He concluded that doubling the CO₂ concentration would warm the Earth by 4°C. This is still the conventional method of expressing “climate sensitivity” with respect to CO₂. (Although it’s important to note that this convention ignores slow feedback effects which may sum to produce a temporary(?) net positive feedback effect, given the unnaturally abrupt nature of the forcing.) His prediction is still within the error bars of modern estimates which assign a maximum likelihood value of 2.9°C, with a 95% confidence that it’s less than 4.9°C but greater than 1.7°C. Sadly, his breakthrough wasn’t recognized at the time.

In the 1950s, the Cold War prompted U.S. scientists to study the atmosphere for military purposes. They mounted spectrometers on planes and sent them high into the atmosphere, where the absorption spectrum changed Kaplan, Lewis D. (1952). ‘On the Pressure Dependence of Radiative Heat Transfer in the Atmosphere.’ J. Meteorology 9: 1-12. . At standard pressure, CO₂ absorbs radiation in broad “peaks” in frequency space because of pressure broadening but the lower pressure at altitude narrows these peaks. Thus, CO₂ acts as a less effective greenhouse gas at higher altitudes.

Subsequent studies confirmed and expanded on these results. The short version is that the atmosphere needs to be modeled as a series of layers, where the pressure in each layer causes CO₂ to absorb differing amounts of radiation at different wavelengths. Each layer insulates all the layers below it, and the outer layer of the atmosphere isn’t saturated until it reaches a higher concentration than would be required to saturate at standard pressure. Furthermore, water vapor concentration falls off rapidly with altitude while CO₂ concentration doesn’t, so water vapor doesn’t play a role in the outer layer of the atmosphere.

If you’re wondering why these references aren’t linked, it’s because this debate is ancient and certainly not news to any climatologist who’s less than 50 years behind the cutting edge. Many of these articles’ abstracts aren’t even available online, so you’ll have to search your local university library to find them. You may find this overview (complete with references) helpful in your search, but nonscientists may prefer this less technical version.

Of course, it’s possible that you weren’t “trying to make any earth-shattering observations there,” and were just waxing eloquent about the beauty of science. If that’s true then I apologize for wasting your time, and we agree that science is really frakking cool. This response would then be aimed solely at pseudoscientists like Joanne Nova who claim that “CO₂ is already absorbing almost all it can!”

So, I was not trying to make any earth-shattering observations there, just: it’s not so simple.

Virtually no subject in modern physics is simple enough to be described completely in a single Slashdot post, a single textbook, a single semester, or even a single college degree. For example, high school students learn that gravity is described by F=m*g, where “g” is a constant 9.8 m/s². This is oversimplified because “g” decreases with altitude. Undergrads learn that gravity is described by F=G*m₁*m₂/r². This is oversimplified because it can’t account for the precession of Mercury’s orbit or the orbital decay of binary pulsars due to energy loss from gravitational waves. Graduate students learn that gravity is one of several physical manifestations of the curvature of spacetime due to the stress-energy tensor. This is also an oversimplification because it can’t be quantized and produces unphysical predictions at black hole singularities.

In this sense, abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. is no different from general relativity. It’s a hideously complicated subject that requires at least a graduate education in physics to struggle through the many layers of simplification in order to reach the frontiers of knowledge. When talking with the public, physicists need to make simplifications, or the explanations would take years. Be wary of assuming that these simplifications are anything but pedagogical tools.

We already know of the penchant that the media has for sensationalism. Have you not heard the news reports that “sea levels are expected to rise as much as 10 meters in our lifetime”?? I have. Yet even the IPCC says nothing of the sort. … Which made it prime fodder for Mr. Gore’s movie. Which caught the attention of the public. Which caused alarmism out of proportion to the actual problem.

I completely agree with every statement you’ve made here. My advisor is a world-renowned expert [*] in geophysics And a really nice guy! :) Hi! I’m working, I promise! who recently said “I don’t think climate change is going to kill anyone.” (Provided we take decisive action I agree, but worry that the effects will act as a catalyst to worsen existing political conflicts.) That’s why I’ve insisted on restricting this conversation to peer-reviewed papers. The mainstream media is biased towards sensationalism, and the internet is a tarpit of misinformation.

[*] I’m sorry that I can’t provide more details with which to judge this claim, but my career is just starting so I don’t want to commit professional suicide by making my views on, say, gay marriage or gun rights Pro-2nd amendment article coming soon, to be linked in permanent version of this article. available to potential employers. I’ll say this, though: I suspect that the last woman I dated (a fellow geophysicist) was with me at least partly because I promised to introduce her to him. This suspicion is based on her reaction when she found out who my advisor was, which wasn’t unusual Sadly, I only mean that the initial jaw-drop isn’t unusual… at all.

If you had been paying attention, you might have understood that the Wegman, et al. report was “peer review”

Articles published in scientific journals are peer-reviewed. Again, peer review isn’t about worshipping scientists, so it’s not just about the qualifications of the reviewer. It’s about a process. Scientific articles are subjected to a process called peer review, which means the author gets viciously attacked by people who (sometimes) think he’s an moronic asshole. This process is the bedrock of modern science because it results in articles that are better for it after surviving the inferno. But the nasty emails sent by the reviewers to the author haven’t been through peer review themselves. And that’s basically what the Wegman report is, except they “reviewed” it among themselves. It makes some good points, but draws a completely exaggerated conclusion which hopefully wouldn’t have made it through a proper peer review.

… even if Mann et. al. really did make some kind of fatal error in their calculations, that has practically no impact on the current scientific understanding of “recent” temperature reconstructions. [Dumb Scientist]

Possibly. But it means you have to find other research to make your point. [Jane Q. Public]

Each time series in the graph I previously linked is referenced in chapter 6 here. Turn to page 469 and examine Table 6.1 (later, if you get bored, consider checking out column 2 of page 466 which reviews the claims of MM03 and MM05.) Every time series is referenced well enough to be found on google scholar– for example here’s one of them. As you’ve seen from the graph, they all support the abrupt temperature increase in Mann’s graph. (I freely admit that all these authors could be drooling morons, sheeple incapable of independent thought, or evil conspirators… any of these scenarios or a linear combination of them would completely discredit my position.)

You might be able to convince nonscientists that there’s a massive conspiracy (intentional or not) [emphasis added] among scientists, and ironically any reference I produce to show that ~84% of scientists oppose your position would probably just solidify your belief in an evil conspiracy. [Dumb Scientist]

… they essentially all complain about the same problem: the fact that those involved in the IPCC reporting and review process who disagreed with a preconceived conclusion were blatantly ignored. … IPCC reports are politicized and unreliable. … the IPCC has had a chronic problem with bias and failure of peer review. … Well, not exactly. It’s because until that point, I was not aware that other possible correlations were ever even taken seriously. … That is almost correct, if you are looking at it in a sort of sideways-logic kind of way. … If these statements, by the both of you, do not imply that there is no correlation, I will eat my hat. But of course some of the very literature you rely on contradicts that. … I could not possibly accept the results of this survey as anything but an exercise in data manipulation — intentional or otherwise. … I cannot accept those reported results as anything. As reported, they are meaningless. The word “valid” is not on the horizon. … Oh, come on. Are you being deliberately obtuse? Or did you just not bother to read the papers? … The fact is that the Mann, et al. graph was out of proportion, and tended to exaggerate the appearance of the recent warming. Which you would know, if you actually read the papers. But I suspect that you were just baiting me. … so far you have not managed to validly refute even one point I have made. … it was more like destroying his methodology, not just criticizing it. … What a COSMIC coincidence. The same three people who did the original paper! And they reached a similar conclusion??? How outrageously surprising! Seriously, how can you be surprised? And the fact that they used a different methodology does not impress me in the least. Wegner, et al. strongly implied that while those people might otherwise be competent researchers, they do not know their statistical asses from a hole in the ground … Further, a textbook is anything but a peer-reviewed paper. Would you like me to do a brief review of how many of my high-school and university textbooks contained errors that seem laughable now? Get real. By the time half of them get to publication, they have significant errors. … If you will not accept Energy and Environment as a source because it may not be “sufficiently hard-science” for your taste, then I am sure as hell not going to accept your textbook. [emphasis added] … This was not apparent to me at first, but as it turns out, Meehl’s climate model has relied upon the data generated in the 1998 Mann study. So, at least until some adjustments are made, I have no choice but to consider the Meehl model to have also been successfully refuted. … When a climate model relies upon past temperature variations that are shown to be inaccurate, to say that the whole model becomes questionable is an understatement. … (Ed. note: here I’m referring to your statements in general.) That sounds like a “conspiracy theory” to you? [Jane Q. Public]

In a word: yes. I’ve encountered the same attitude here and in my discussions with creationists and people who dispute the Big Bang. In each case, they insist that peer review is broken. Sometimes they merely say this is because of widespread incompetence or “groupthink,” but it’s also common to see them accuse scientists of active conspiracy. They perform “research” by browsing pseudoscience websites rather than pursuing a graduate education in the field they’re obviously interested in. With all due respect to the parties involved, I think they’re making errors that could be avoided by opening graduate-level textbooks (which have little in common with high school or lower-level undergraduate texts) and solving the problems inside.

Curiously, they’re often computer scientists or engineers. I suspect this is because natural sciences like physics, chemistry and biology appear similar to computer science and engineering. We all use math (in fact, electrical engineers use way more math than biologists) and the first year of college classes are quite similar. Our fields are highly complex and probably equally mysterious to the general public, so we become used to being “the person with the answers.”

However, engineers and computer scientists are, fundamentally, “builders.” Engineers figure out how to use materials like metals and plastic to build amazing technological marvels that enrich our lives. Computer scientists build shining edifices out of pure logic which have bound the human race together and (IMHO) will play a central role in giving our descendants “technology indistinguishable from magic.” In each case, notice that the emphasis lies on creating something that didn’t exist before. They develop preconceptions of the form their algorithm or building will take, then beat raw materials into a shape that conforms to their original vision.

Scientists, on the other hand, are more like detectives. They observe the natural world and try as hard as they possibly can to avoid letting their preconceptions contaminate the results of their experiments. Scientists are supposed to avoid creating something that didn’t exist before!

This isn’t to say engineers don’t have to think critically; for example, they have to recognize why the Tacoma Narrows bridge was badly designed and foresee similar mistakes. But they’re working within known natural laws, and it seems to me that the challenge of deducing those laws without prejudice is completely different. I’m starting to think that computer scientists and engineers are prone to assuming that their skills transfer to the natural sciences better than they actually do, which could explain why rational thought occasionally mutates into rationalizing.

Please don’t misunderstand me: I’m not insulting computer scientists or engineers; I’m definitely not saying a significant percentage of them are pseudoscientists. I spent several years as an aerospace engineering major, my dad is a mechanical engineer, and many of my family and friends are in these fields. My physics degrees certainly don’t mean I can design a skyscraper or write a new programming language. I’m just speculating as to why some of them tend to be over-represented in the ranks of pseudoscientists.

[Dumb Scientist]

… The proponents of “man-made global warming” have seized upon the CO₂-based warming model as their poster child. Unfortunately for them in the long run, that model has some serious problems. For example, in order for the CO₂-based warming model to work, the upper atmosphere must be warming in proportion to the surface. However, it simply is not. Weather balloon and satellite data just do not find the upper-atmosphere warming that would have to be there if the CO₂ warming model were true. You can look that up for yourself. Use actual data, dude, not what you find on the 10:00 news. But enough of the basic background. … [Jane Q. Public, Oct 24, 2007]

… the CO₂-based warming theory REQUIRES the upper atmosphere to be warming at a rate proportional to the low-altitude temperature… and it simply has not been. Actual satellite and weather balloon temperature data do not support the CO₂ warming theory at all. … ALL greenhouse gas “global warming” theories require the upper atmosphere to warm proportionally to the surface temperature. That is directly involved in the whole mechanism that is supposed to be CAUSING the warming from such gases! Whether CO₂ were the “sole” greenhouse gas involved is irrelevant! They all require that the upper atmosphere be warming to a degree that it just has not been. Actual satellite and weather balloon temperature data DIRECTLY CONTRADICT the greenhouse warming theories. And if something that MUST be happening in order for those theories to be true is not happening (and it isn’t), then those theories are fundamentally flawed. [Jane Q. Public, June 22, 2008]

… Once again: the greenhouse gas models, specifically, require that the upper atmosphere be warming to a degree that has SIMPLY NOT BEEN HAPPENING according to the actual temperature data. If you disbelieve that, then try googling NOAA along with a few choice key words and do your own homework for a change. [Jane Q. Public, June 25, 2008]

… And contrary to popular belief, the troposphere has not been warming to the degree it would have to, were the greenhouse models of warming correct. But they are not. They have some very serious flaws. …[Jane Q. Public, July 9, 2009]

I presume you’ve been referring to an algebra error in assimilations of satellite temperature measurements of the troposphere.

1. This error was corrected in 2005.
2. The troposphere is actually the lowest portion of the Earth’s atmosphere. The upper atmosphere is divided into the stratosphere and the mesosphere.
3. Greenhouse warming models predict cooling and contraction of the stratosphere.

Kyle asks about the political and economic implications of climate change.

[Kyle]
Interesting. For the record, what’s your view on all this climate change stuff? Personally, regardless of how the data is broken down, I think it’s crazy to build US legislation to tax all of our energy production based on the notion we can control the earth’s climate.

[Dumb Scientist]

(Ed. note: I’ve removed many points from my emails to Kyle because they’ve already appeared above.)

The scientific case is quite clear: humans have dug up gigatons of CO₂ and pumped it into the atmosphere. This has raised our average temperatures and will continue to do so unless we stop it.

Of course, science doesn’t imply any particular political response. But fighting climate change is almost exactly the same thing as “energy independence” which we desperately need anyway, if only to stop throwing money at so many corrupt governments for their oil. The only difference is that we need to stop burning coal, which is something we have in abundance here in the U.S. All I can say is that this might be bad in the short term, but absolutely necessary in the long term. It’s not clear to me that these taxes would slow the economy down over the medium to long term. The U.S. is still the world’s leader in science and technology, so we’re most likely to be the ones to invent and sell the new cleaner energy tech which would actually make Americans richer in the end…

To replace coal, I liked McCain’s plan to build 45 new nuclear power stations. (Oh, how I wish Obama would listen to him on that particular subject!) Not the crazy new fusion plants (which don’t exist yet and may never exist), just better versions of the fission nuclear plants we already know work because they supply 80% of France’s electricity.

[Dumb Scientist]

I have no problem with using technology to develop cleaner energy sources. I do find fault in the idea of punitive tax policy that punishes consumers for being good capitalists – buying the energy that is the most efficient to produce. [Kyle]

But that’s the way regulation has worked for decades. For example, companies can’t simply dump toxic chemicals into the water (even though that’s cheaper than responsible disposal) because they’d get fined by the EPA. That’s basically the only reason our rivers aren’t even more polluted than they already are. Without a clear disincentive to pollute, companies will choose the most “efficient” means of creating their product, regardless of how much pollution they create in the process.

The only difference here is that the effects of CO₂ pollution are more subtle than, say, dumping acid into a river. But it’s even more dangerous in the long run because CO₂ causes a global problem rather than a local one.

The thing that kills me about the proposed plan is the idea of creating carbon credits, essentially fake money to be bought and sold, and forcing US energy companies to pay new taxes on all the carbon they produce.

Actually, cap and trade strikes me as a very capitalist way of addressing the problem. This is just the latest example of regulation to compensate for what economists call a “negative externality.”

Negative externalities represent rare failures of capitalism; they’re situations in which economic transactions can hurt people who aren’t directly involved. Again, the best example is that of a chemical plant dumping waste into a river. The people downstream will be affected regardless of whether they buy that company’s products. That’s why regulation exists: to protect people from situations where it’s cheaper to ruin the environment than to act responsibly.

This new kind of regulation will have the effect of making dirty technology expensive which will then prompt companies to invest in cleaner technologies for the most capitalist reason imaginable: to make a profit. I hope that the environmentalists will eventually relent and let us build nuclear power plants, because they’re the cleanest form of energy we have that can power our civilization. But I seriously doubt they’re rational enough to see that their fears of radiation are due more to Hollywood than actual physics…

America has always had an advantage in the global economy by having the best infrastructure and cheap energy. I can’t believe that any other countries are going to levy similar requirements on their businesses.

That’s a very serious problem indeed. If other countries don’t clean up too, production will simply shift to countries with lax regulation. One goal of the climate legislation that’s about to hit the Senate is to set an example; to show the world that the United States is ready to lead once again. With a firm domestic commitment to fighting climate change, Obama will have a more credible case to present at the Copenhagen Conference this December.

On a side note, have you ever checked out surfacestations.org? They make a pretty compelling case that the US temperature record over the last several decades is showing artificially high readings.

He’s saying that the surface temperature record is contaminated by the “urban heat island” effect– that temperatures are only rising around cities because of economic growth. One example he shows is that exhaust vents have been placed closer and closer to the sensors over the years.

This is a superficially compelling argument, but it’s also one that scientists have considered and rejected. One test is that the urban heat island effect should be less pronounced on windy days than calm days. That’s because if this warming is just caused by local exhaust vents, wind should carry that heat away whereas calm weather won’t. This doesn’t happen: calm and windy days have the same warming trend. This conclusion is from an article published in Nature by Dr. Parker in 2004; here’s a BBC article quoting it. Other studies have confirmed this result using different methods and data in 2003, 2006, and 2008.

NOAA recently published an answer to that specific website. They took the 70 stations that surfacestations.org designated “best” or “good” and created a time series based on them. Then they used all 1218 stations to create another time series. Both of those time series are plotted on page 3. They’re practically identical.

Also, scientists don’t blindly trust these sensors. Land temperature measurements are independently confirmed by sea surface temperatures, satellite data and proxies such as ice cores, boreholes, coral growth, tree rings, stalactites, fossil beds, ocean sediments and glacial deposits.

Update: Another paper casts doubt on the claims of surfacestations.org.

[Dumb Scientist]

I will say this: The EPA at its core is a political organization. EPA policies have quickly reversed under each new administration and I think this is an area where unfortunately the politics are very intertwined with the science. [Kyle]

Perhaps. But all I’m saying is this: we can agree that some types of pollution are bad, right? Sure, extremists like Earth First and Greenpeace give the whole notion a bad name, but I don’t think any of us want acid rain or smog. CO₂ is just a more subtle problem which is more difficult to explain to the public, but ultimately poses a bigger threat to humanity.

That, and they even admit that these policies will cause an immediate and substantial rise in US energy prices, which trickle down to every segment of the economy. I think the plan is guaranteed to do very tangible economic harm to people all over the US in the near term, and that left alone…

That’s probably true. It wouldn’t be much different than the harm that most other countries have experienced already, though. For quite a while, Europeans have been paying more than twice as much as we do for gasoline. As a result, their cars are smaller, their cities are much better for walking and biking, and their subway systems are better.

Would it hurt U.S. citizens? Probably a little. But it’s a much better idea to experience a little bit of pain now rather than a lot later. Frankly, we’re already far behind the Europeans in this regard. They’re not going to be hit nearly as hard as us when the shit really hits the fan because they’ve already been adapting to the post-oil era.

… companies will eventually develop cleaner technologies without having to be forced to by the government, because consumers want alternatives, and that to me is what it’s all about.

The keyword here is “eventually.” I doubt it would be soon enough, because every ton of CO₂ emitted into the atmosphere worsens the problem, and we still get half of our electricity from coal which needs to be changed to nuclear yesterday.

Liquid oceans had already formed 4 billion years ago, so Earth’s temperature must have been above the freezing point of water. A faint young Sun presents a paradox: how could a 25% dimmer Sun warm the Earth enough to develop liquid oceans?

First, note that the relationship between solar brightness and Earth’s temperature isn’t simple. A 25% fainter Sun only cools Earth by ~7% because Earth’s surface temperature is a balance between energy input in the form of sunlight and energy output from the Earth in the form of blackbody radiation. Further complications include feedback mechanisms such as greenhouse gas effects and changes in Earth’s albedo. Having said that, a 7% cooler Earth is enough to make the tropics as cold as the present-day Arctic which makes the evidence for a liquid ocean difficult to reconcile with the standard solar model.

I first heard about this paradox last December at an AGU talk given by Dr. Goldblatt. He pointed out that the early CO₂ partial pressure was ~25 times its current value (anyone have references for this?), but even this increase isn’t sufficient to guarantee the formation of liquid oceans. However, the total pressure of the atmosphere 4 billion years ago is unknown, so Dr. Goldblatt performed simulations with varying amounts of nitrogen.

Nitrogen isn’t a greenhouse gas, but its presence in the atmosphere causes CO₂ to act as a more effective greenhouse gas via pressure broadening. Dr. Goldblatt found that if the early atmosphere contained roughly twice as much nitrogen as it does today, this would raise the Earth’s surface temperature above the freezing point of water.

After his talk was finished, I asked: “You said that evidence constrains the early CO₂ concentration, but is there any experimental evidence which constrains the early nitrogen pressure?” He replied that there wasn’t, and then someone else in the crowd said that ongoing research is attempting to constrain the nitrogen budget through “raindrops.”

I’d like to find out what he was talking about. Do we have fossilized raindrop patterns in ancient rocks? If so, how do they tell us anything about the early nitrogen pressure?

To continue reading, please download the PDF version. I’ve also created a Powerpoint presentation that may help you understand the Boschi teleporation experiment described in the PDF. Make sure to watch the presentation in Slide Show mode (i.e. full screen) otherwise you’ll miss the animations which should make the experiment (a little) clearer.

Note: This post is unfinished. I intend to transcribe the latex that creates the PDF to HTML using TtH once I figure out how to use it.

Anyway, the gist of the argument is that special relativity divides the entire universe into three distinct regions as seen by any observer: the timelike future (which is the set of all points where you could be in the future if you could travel at any speed up to and including the speed of light), the timelike past (which is where all events that could possibly have an affect on you at the present reside) and “Elsewhere,” which is comprised of all other events. One example of an event in Elsewhere would be the status of the satellites orbiting Mars right now. I can’t possibly know their status at the moment because there’s about a 30 minute light travel time delay. It’s important to realize that FTL communication connects you to an event in Elsewhere in a causal manner.

Spacetime diagrams are just plots of any object’s position (in one direction only) versus time. I’ll call the object “Bob” and decree that he can only move to the left or right. Conventionally, these diagrams measure time on the vertical axis (which I call the time axis) and Bob’s position on the horizontal axis (which I call the space axis). This means that Bob’s speed in the left or right direction is expressed by the angle formed between the vertical (time) axis and the line he traces out on the diagram as he moves. Higher speeds translate into larger angles away from the vertical axis. Time and space are also conventionally measured in units chosen so that if Bob (somehow) manages to travel at the speed of light, his path would trace out a line that perfectly bisects the angle between the time and space axes. In other words, light beams trace out lines that make an angle of 45˚ with the time axis.

There are some important lines on the spacetime diagram that radiate out from the origin (the point where position=0 and time=0, otherwise known as “Bob’s current position”):

• Vertical lines represent Bob when his speed is zero- when he’s standing still. He’s not moving in space, but he is moving inexorably forward in time. Thus, the vertical (time) axis points up towards “the future” and is defined by the path traced out by Bob when he isn’t moving.

• The lines at 45˚ away from the vertical (time) axis represent the path traced out by the light from Bob’s flashlight as it raced down the corridor to the left or right.

• Lines at smaller angles- much smaller angles- might represent Bob when he’s running to the left or the right.

• Lines at angles greater than 45˚ away from the time axis would represent something going faster than the speed of light, such as the proposed FTL signal.

• A horizontal line pointing along the space axis represents infinitely fast motion, such as the signal from an instantaneous communication device. It’s more useful, however, to think of the space axis as the set of all events in the universe that are occurring right now. In other words, the horizontal (space) axis defines what Bob considers “the present.”

Imagine Bob is standing at the origin of the spacetime diagram. His timelike future on the diagram looks like an inverted triangle. Its sides are physically defined by the path traced out by light (headed to the left or the right) that leaves Bob’s flashlight at time=0. Bob’s timelike past is an upright but otherwise identical triangle. His timelike past is physically defined by the path traced out by the light (from lamps set at regular intervals to the left and the right) that happened to hit Bob’s eyeballs at time=0.

So far, so good? Good. Here’s where it gets weird.

According to relativity, every observer in the universe has to measure the speed of light (in vacuum) to be exactly the same speed regardless of the observer’s velocity. Although this may seem like an innocuous statement, it’s not hard to come up with a scenario where the consequences of this little rule can blow your mind. For instance, imagine Bob is in a spaceship traveling away from Alice at half the speed of light and shines a flashlight back towards her. He measures the speed of the light leaving his flashlight to be the speed of light- a sensible result. But consider this: when the light from Bob’s flashlight reaches Alice and she measures its speed, what speed will she measure? Most people (myself included) want to say that Alice’s measured speed will be “missing” the relative velocity that Bob had- that her measurement will reveal the light to be traveling at half the normal speed of light. This sensible, intuitive answer is simply wrong; she measures the light to be traveling at exactly light speed. How is it possible that both Alice and Bob measure exactly the same speed of light in this situation?

In order to answer this question, it’s important to realize that in special relativity all motion is relative. Bob can draw a spacetime diagrams with axes that center on him, but so can Alice. The diagrams they make will be different, but keep in mind that they’re both correct. Alice and Bob have equally valid claims^[1] to being “at rest” once Bob’s spaceship stops accelerating and starts coasting at constant velocity, so neither of the diagrams is “the right one.” This means Alice has to be able to draw a spacetime diagram for herself that explains why she measured the speed of light to be the correct value, but she also has to draw Bob’s spacetime diagram from her perspective in a way that explains why Bob measured the speed of his flashlight beam to be the same correct value she measured.

So, what would Bob’s spacetime diagram- his particular set of time and space axes- look like from Alice’s perspective? To start with, she’d draw her time axis as a vertical line, and her space axis as a horizontal line. She can draw her own axes however she wants, but these are the simplest choices. Now suppose Bob’s spaceship is heading to the right. When Alice draws a spacetime diagram, Bob’s position at various times traces out a line that makes an angle of 22.5˚ to the right of her time axis (because he’s traveling at half the speed of light, and half of 45 is 22.5). But when Alice draws Bob’s time and space axes, how should she draw them?

When I first tried to draw Alice’s version of Bob’s spacetime diagram, I simply drew a vertical line through Bob’s position and called that his time axis, then I drew a horizontal line through Bob’s current time and called that his space axis. Basically, all I did was redefine the zeros of Bob’s coordinate system so that he was at the intersection of the two axes. But then I slowly remembered that Bob defined his time axis by the line he traced out when he wasn’t moving. It also dawned on me that he’s perfectly justified to consider himself “at rest” as long as he’s sitting in his chair in the spaceship which is traveling at a constant velocity. Therefore, Bob’s time axis is actually tilted to the right of Alice’s time axis by exactly 22.5˚. From Alice’s perspective, Bob’s time axis is the same as the path traced out by his position at various times. I didn’t see any reason to alter Bob’s space axis, though, so I left it perfectly horizontal at first.

The insight that Bob’s time axis as drawn by Alice is tilted by his velocity is a form of relativity, but it’s commonly known as Galilean relativity because Galileo published it in 1632. Unfortunately, allowing Bob’s time axis to tilt from vertical (as Alice defines her time axis) towards the 45˚ line that represents light speed implies that Bob measures light speed to be different than what Alice measures it to be. This discrepancy occurs because an observer measures an object’s speed by the angle it makes with the time and space axes. Since Alice’s and Bob’s time axes are no longer parallel, they no longer agree on the speed of light. Based on experimental results available as early as 1887 which showed that all observers must agree on the speed of light, this disagreement is a serious theoretical problem.

Einstein’s famous solution- special relativity- was to tilt Bob’s space axis “counter-clockwise” by 22.5˚, the same angle that Bob’s time axis tilted. In other words, Alice tilts Bob’s space axis towards the light speed line by the same angle that Bob’s time axis tilted towards the light speed line. By applying a tilt to Bob’s space axis that’s equal and opposite to the tilt of his time axis, Alice has insured that the line representing light speed perfectly bisects the angle formed by Bob’s time and space axes. As a result, Bob measures the speed of light to be “light speed” because the line representing light speed is midway between his time and space axes. Thanks to Einstein, Alice and Bob agree on the value of the speed of light.

Unfortunately, as a result of this small change, Alice and Bob now disagree about something more fundamental. That is, they disagree about what set of events constitute “the present.” Remember that each observer’s space axis effectively defines what they consider “the present.” When Alice tilts Bob’s space axis in order to draw his spacetime diagram from her point of view, she is implicitly saying that his definition of the present is different than hers!

It may seem like Einstein solved a small problem (that Alice couldn’t draw Bob’s spacetime diagram in a way that allowed them both to agree on the speed of light) only at the cost of creating a bigger problem which violates common sense so thoroughly that Einstein simply must have been mistaken. And it’s certainly true that relativity violates common sense in other ways. The important point to remember is that special relativity has been making these extravagantly nonsensical claims for over a century, and so far every experiment performed supports special relativity’s bizarre predictions.

Anyway, exactly how can an FTL signaling device be used to send a message to the past? Well, suppose Alice and Bob both have FTL communications devices, and Bob has a spaceship with powerful sublight engines. In this scenario, Alice could stay on Earth and send a message to her own past. Here’s how it would work:

1. Bob gets in his spaceship and travels directly away from Earth at 90% light speed. He travels for, say, one year. The time and speed aren’t really important; increasing either of them just sends the message deeper into the past.

2. Alice, on Earth, sends Bob an instantaneous message using her FTL communication device. It travels to Bob along Alice’s space axis – the line in her spacetime diagram that goes through her present position and on through Elsewhere, to define “the present.” It’s not necessary for Alice’s communication to be instantaneous, but I think it makes the argument a little clearer. Instantaneous signals might seem more outlandish than signals traveling just slightly faster than light speed, but there’s no qualitative difference according to special relativity.

3. Bob receives the message at the exact instant (according to Alice’s timeframe) that she sent it, even though he is almost a light year away. He then immediately sends the message back to Alice using his copy of the FTL device. The difference is that Bob is traveling at 90% of the speed of light, so his space axis is sharply tilted away from vertical- it actually intersects Alice’s “timelike past.” Bob’s “instantaneous” signal- which travels along his space axis- actually arrives at Alice’s location before she even sends the message to Bob in the first place.

As a result, Alice has sent a message to her own past using Bob’s spaceship as a relay. In practice (if such a thing is ever possible), Bob’s spaceship would probably be replaced by a series of expendable communications satellites launched through some kind of space-based electromagnetic cannon.

Notice that this argument doesn’t refer to the particular method of FTL signaling. The FTL communications device could be literally anything- a tachyon transceiver, a traversable wormhole, a ship with an Alcubierre drive, or something more exotic. The details simply don’t matter- any FTL signaling device can be used to send messages to the past. This argument can only fail if special relativity is wrong. For instance, the existence of a preferred frame would cause this argument to break down. Eventually, I plan to significantly expand this article with spacetime diagrams, but in the meantime the best tutorial my quick google search has returned is Wikipedia’s article. Anyone seen any better spacetime diagram tutorials?

Footnotes

1. Objection: Alice and Bob were originally at rest on Earth, but Bob definitely felt the ship pushing against his back as it accelerated up to its high speed, so he must know that he’s the one who’s moving, not Alice. Alice’s diagram is therefore correct, Bob’s is wrong, and special relativity is just nonsense.
   Response 1: Why choose Earth as the official “rest frame” of the universe when there are better choices? For instance, Bob could determine Earth’s velocity (~370 km/s) relative to the CMB (loosely translated: “echo of the Big Bang”). By accelerating in the opposite direction of that velocity, he seems to have a more valid claim to being at rest, because the CMB is a relic of creation itself. But, if relativistic effects actually depended on which direction Bob accelerates, those effects should exhibit anisotropy (which hasn’t been observed).
   Response 2: Somewhat more whimsically, Bob could claim that he was only firing his engines to counteract a powerful but brief gravitational field that pulled every object in the universe in the same direction. Bob noticed this field (somehow) and accelerated in the opposite direction just to “stay at the same point.” Note that Alice wouldn’t have felt any effects because the field would affect everything at once, the same reason weightless training flights are possible.
   …anyone have a better response?↩ back

While the resulting conversation didn’t shed any light on the purported FTL implications of the no cloning theorem, DrVomact asked a question that eventually led to an enjoyable discussion (edited for clarity) about quantum entanglement and parallel universes.

Written by Dumb Scientist on June 04 2007, @03:34PM

I am a physicist, and I haven’t heard of a connection between the no-cloning theorem and using entanglement for FTL communication. Can anyone explain how they’re connected?

Before learning about entanglement, it’s necessary to understand a concept known as a quantum “superposition.” A quantum superposition is a bizarre state in which particles occupy two or more mutually incompatible states until they’re observed. For example, a particle can be in a superposition where it exists in both New York and Los Angeles at the same instant. But as soon as someone looks at the particle it ‘collapses’ so that it exists in only one city, not both. Quantum mechanics very explicitly states that you can’t predict which city the particle will appear in, even in principle. The exact city in which the particle exists prior to being observed is thus literally unknowable. (This paragraph wasn’t in the original post. Dumb mistake- I should have remembered to define ‘superposition’.)

Now consider two particles which are both in superpositions of being either horizontally or vertically polarized. The “spookiness” of entanglement lies in the fact that the two particles can be created in a state where (for example) their polarizations have to be opposite (perpendicular). Thus even though each particle is in a (literally unknowable) superposition of horizontal and vertical, if you measure the first particle and find that it’s horizontally polarized, that automatically means that a measurement on the second particle will show that it’s vertically polarized. This correlation occurs even if the second measurement is made so soon after the first that light doesn’t have time to travel from the first particle to ‘tell’ the second particle which way the first particle collapsed. There also doesn’t seem to be any distance restriction- the two particles could be on opposite sides of the galaxy and still be correlated.

At first glance, this seemed remarkable. At second glance, it just seemed like conservation of momentum. For example, suppose the two particles are formed by the decay of another particle that initially had zero angular momentum. Then the sum of the two resulting particles’ angular momenta needs to be zero so the final and initial momenta are the same (this is the same reason that guns have recoil). As a result, the polarizations must be equal and opposite- for a fairly mundane reason. The “spookiness” Einstein talked about lies in the fact that quantum mechanics says that both particles are literally horizontally and vertically polarized, up until the point where the first one is “collapsed” onto horizontal. Then the second particle instantly collapses onto vertical, which occurs even if both particles are separated by a great distance. Einstein took this spookiness to mean that quantum mechanics must be incomplete– that each particle really did have a well defined state before the collapse, but current quantum theory simply can’t describe it.

Amazingly, in 1966 a physicist named John Bell found a way to experimentally test the issue using “Bell inequalities”. Quantum mechanics correctly predicted the outcome of these experiments- carried out mainly in the early 1980s- up to high sigma values. In other words, the experiments convincingly proved Einstein wrong.

So we have to adjust to the reality of absurdities like ‘spooky’ FTL correlations. The problem with using these correlations for FTL communication is that each measurement just gives you a random horizontal or vertical outcome. In fact, the only “interesting” feature of making these measurements is that when you finally compare your results with the person who has the other entangled particles, you find that your results correlate perfectly. This isn’t useful for communication, though. Entanglement could only be used for FTL communication if quantum mechanics had small nonlinear terms which would allow one party to “bias” the collapse preferentially onto horizontal or vertical. This would allow for the transmission of binary data or Morse code. Unfortunately, decades of testing have shown that any nonlinearities in the Schrodinger or Dirac equations underlying quantum mechanics are very, very small. (Note that even though entanglement isn’t useful in an FTL sense, it can be used to facilitate teleportation.)

Bummer. On the other hand, I think the existence of FTL communication would automatically lead to the feasibility of backwards-in-time communication, so at least we don’t have to worry so much about being killed by assassins hired over the time-phone by future versions of our own grandchildren…

Written by DrVomact on June 04 2007, @07:36PM

Interesting, but I’m afraid that your explanation is far too clear…and it’s typically a bad sign when I understand something that’s supposed to be as complicated as quantum mechanics…in other words, I’m probably not understanding it. Let me put it this way: I need some help to see the “spookiness”. You say:

…Thus even though each particle is in a (literally unknowable) superposition of horizontal and vertical, when you measure the first particle and find that it’s horizontally polarized, a measurement on the second particle will show that it’s vertically polarized….

Not being a physicist, I have no clue what you mean by “superposition of horizontal and vertical” polarization. But that’s OK…you’re referring to some sort of property or properties that particles can have, and that can be measured. If I understand correctly, you are saying that pairs of these particles are created in such a way that these qualities (whatever they are) must be in a contradictory relationship. So if you measure the (whatever) of one particle, you know that the other particle has the opposite (whatever) quality. But why is that mysterious, or spooky?

Let’s say I have a magic particle maker. When I press the trigger, it emits two particles in opposite directions. The particle maker is constructed in such a way that each time I shoot off a particle pair, one of the particles must be blue, and the other white. However, the colors are assigned randomly so that I can never predict whether the particle shot off to the left will be blue or white–I just know that the particle shot off to the right is of the opposite color. Now let’s say that I’ve set up a game of catch-the-particle with Joe and Bill. Joe is standing a mile to my left, and Bill is a mile to my right. Due to the nature of my particle maker, I know that if Joe receives a blue particle, Bill has just got beaned by a white one, and vice versa. That doesn’t seem spooky to me…it doesn’t even seem particularly interesting.

I have a feeling that what I’m missing is tied up with the word “unknowable” that you used in your explanation. It’s not at all clear to me what you meant by that…if some object has a quality that can be measured, then that quality is not “unknowable” just because I haven’t measured it yet. I’m sure it’s not news to you that “unknown” is not the same as “unknowable”. So what did I miss? I think this is the crux of the matter…if you could make this clear to me, I’d be mighty grateful.

Written by Dumb Scientist on June 04 2007, @11:02PM

First of all, photons (particles of light) behave as though they’re waves. There’s a lot of subtlety hidden in this statement, but it’s not relevant now: just picture a single particle of light traveling into the screen while “waving” up and down pretty much like a water wave. This is a vertically polarized photon, and it can be easily distinguished from a horizontally polarized photon which travels into the screen while “waving” left to right instead of up and down. When I say “easily distinguished”, I mean that you can place a detector in the photon’s path that produces a “click” if the photon is horizontally polarized, and a “beep” if the photon is vertically polarized.

Now, according to the math of quantum mechanics, it’s possible for a photon to be in a “superposition state” of horizontally and vertically polarized. This is sometimes described by saying that the photon is traveling into the screen while “waving” at, say, a 45° angle- somewhere in between horizontal and vertical. This isn’t wrong, strictly speaking, but describing the superposition state with a physical geometric angle is very misleading- it obscures the very strangeness we seek to understand. Instead, I’ll say that the math literally implies that the photon is in two states (horizontal and vertical) at once- but when the photon hits the detector it randomly “collapses” onto one of those states. The important point is that quantum mechanics says the photon was in two states at once before the collapse, and that it’s impossible- even in principle- to say which state the photon was in before it hits the detector. Theories which attempt to describe the state of the photon before the collapse (which would eliminate the spookiness and make the situation analogous to your blue-white particle maker) are known as “hidden variable theories.” I don’t think any physicists consider these theories plausible, despite their intuitive appeal.

This “superposition then random collapse” is a bizarre property of quantum theory. But it becomes even more bizarre when you create two entangled photons- two photons that are each in their own superpositions, but created such that if one photon is horizontal, the other is vertical. Now, a measurement performed on one particle doesn’t just collapse its polarization down to vertical or horizontal, it also collapses the other particle into the opposite polarization.

Again, calling this phenomenon “spooky” depends on you believing me when I say that the photons are in a literally unknowable state before they are measured. Before the 1980s, it was plausible to believe that the whole concept of a “superposition” was mere fiction: the misguided result of equations that produced good answers for some problems, but implied a nonsensical property like entanglement in other cases. This is certainly the opinion Einstein held, so you’re in good company.

The problem is that in the 1980s, Aspect et. al. performed a series of experiments that have (nearly) conclusively proven that quantum mechanics is correct: particles do not have precisely determined states before they are measured. The details of these experiments are horrendously complicated (I don’t understand the nitty gritty of them myself, to be honest).

So we have no choice but to abandon the picture that each particle is like a pair of particles which are produced by a machine in pairs of “blue and white.” Each particle is literally blue and white, and there is no way for anyone- no matter how advanced their technology- to be able to tell which is which before they’re measured. It’s not a matter of our inability to describe the situation fully, it’s because the particles are literally in both states at once. Seem a little more spooky now?

Written by DrVomact on June 05 2007, @01:33AM

Thank you for that very lucid explanation, Dumb Scientist.

I should lay my cards on the table. I’m not a physicist, I am something far worse: a philosopher. No I’m not kidding, I have a degree that proves that I, for at least a very short time (my dissertation defence took 3 hours), managed to convince 3 other philosophers that I was right about something. (You have to have spent some time around philosophers to understand why that’s considered a noteworthy achievement.)

Anyway, words like “knowability” and claims about “reality” are the sorts of words that get philosophers excited (well, as excited as they get), so I’ve spent a large portion of my life in sort of a stand-off with the quantum mechanics. A lot of them are plainly fools who write popular books to make money…it’s pretty easy to pick them out. However, there are also some obviously very intelligent and serious people who talk about this stuff, who devote their lives to studying it, and yet utter what appear to be completely crazy propositions, propositions that should clearly be dismissed out of hand as nonsense.

Though I’d like to, I can’t do that–I can’t simply dismiss what appears to be the dominant opinion among the leading scientific luminaries of the day. On the other hand, I can’t bring myself to agree with it either, because I don’t really understand it. Call me stubborn, but I cannot, in good conscience, agree with anything I don’t understand.

I must admit to a major handicap that colors my understanding (or lack of it) of this subject: acute dysmathia. Math and I have never gotten along…I can handle logic (deduction, argument, that sort of thing) just fine; I can use words like razors (especially when I’m more awake than I am now). But numbers and funny squiggles have never meant anything to me. It’s much the same with music; they tell me that there are different notes, that they are called “A” and “G” or whatever, but I can’t repeatably tell one from the other, nor can I recognize melodies–much less discuss the finer points of syncopation.

I have often resented the reliance placed on mathematics by today’s physics; it’s as though a mere tool had become an end in itself. As you mentioned, one opinion I have taken comfort in is that “well, this quantum wave collapse looks good in their mathematical equations, it makes for an internally consistent mathematical description of what they’re trying to explain, but it doesn’t have anything to do with the world I live in. If it did, they could show it to me, and explain it in real words and not mathematical squiggles. But now, you’re telling me, there’s evidence to support the assertion that an object can be in two mutually inconsistent states at once. That is disturbing.

The immediate reply that pops into my head is that if you are empirically demonstrating this “45 degree” spin state, then isn’t that itself a measurement that should precipitate the quantum collapse? –But I’m sure someone’s thought of that.

For the sake of argument, let’s assume that you perform the experiment for me, and I not only understand it, I’m convinced that it shows what you say it shows. You have demonstrated that a “particle” can have two contradictory characteristics (or states, or whatever) at once. In other words, you’ve demonstrated what appears to be a paradox.

Isn’t a such a paradox cause to re-examine our fundamental assumptions, to ask ourselves whether it’s not time to take a totally new view of the universe? I’m not qualified to do that, though I have some vague intuitions about what might have gone wrong. For a couple of hundred years, physicists have vacillated between describing light–and then matter–alternatively in terms of either waves or particles. Mathematical models–and observed results–seemed to support both hypotheses in turn. But aren’t both particles and waves merely metaphors? We derive the notion of a wave from watching ripples in a pond. Then we find that we can apply this mental model of a wave to both sound and light. But not even sound is exactly like a ripple on the surface of a pond–it’s three dimensional, and consists of pulses of compressed and relatively rarefied air. Light “waves” truly have a merely metaphorical connection to water ripples. (Especially since we gave up on the aether.) And particles…well one is tempted to imagine them as little tiny solid balls whirling around in space…but of course any physicist will tell you that’s a ridiculously naive way to think about, say, electrons.

Where am I going with all this? Well,I think I’m going to bed…I’m currently being possessed by the demon of insomnia, and no doubt I’ll rue tomorrow what I wrote today. But I’d like to throw out this one suggestion: if we don’t stick to trying to understand the subject of your “45 degree” experiment as being something like a little marble or a ripple, does this change our understanding of the experiment? Could it be that the experiment says, “throw away your notions about particles and waves”, instead of “the universe is really crazy”? (Yes, I realize that both could be true.)

Goodnight

Written by Dumb Scientist on June 05 2007, @10:44AM

However, there are also some obviously very intelligent and serious people who talk about this stuff, who devote their lives to studying it, and yet utter what appear to be completely crazy propositions, propositions that should clearly be dismissed out of hand as nonsense.

I agree, as do most physicists. Quantum mechanics is difficult to learn, not only because the math is complicated, but also because it’s seemingly nonsensical. If it’s any comfort, every quantum physicist since the 1920s has gone through the same stage of incredulity that you find yourself in now. In fact, that very incredulity has caused physicists to test quantum mechanics to a greater degree of precision than any other theory I can think of off the top of my head. In every experiment, designed to disprove every bizarre property of quantum mechanics, quantum theory has prevailed…

Though I’d like to, I can’t do that–I can’t simply dismiss what appears to be the dominant opinion among the leading scientific luminaries of the day. On the other hand, I can’t bring myself to agree with it either, because I don’t really understand it. Call me stubborn, but I cannot, in good conscience, agree with anything I don’t understand.

It took me a long time to believe in black holes (even after most physicists thought they were conclusively proven to exist) so we agree on this principle.

I must admit to a major handicap that colors my understanding (or lack of it) of this subject: acute dysmathia. Math and I have never gotten along…I can handle logic (deduction, argument, that sort of thing) just fine; I can use words like razors (especially when I’m more awake than I am now).

I’ve always found math and logic to be extremely similar, if not synonymous. They both start with a small collection of axioms and use deductive (and occasionally inductive) logic to arrive at a conclusion. Have you ever tried to learn symbolic logic? If so it’s quite similar to math, and I suspect it would lessen the transition shock because it encodes information into symbols in similar ways.

As you mentioned, one opinion I have taken comfort in is that “well, this quantum wave collapse looks good in their mathematical equations, it makes for an internally consistent mathematical description of what they’re trying to explain, but it doesn’t have anything to do with the world I live in.

Interestingly, wave function collapse is not an internally consistent description of reality. The inconsistency arises because the “collapse” of a quantum state is a completely different process than the normal time evolution of a quantum state; physicists say that it is a “non-unitary” process because it annihilates some of the quantum state (a state which is originally horizontal and vertical collapses onto vertical only, thus annihilating the horizontal part of the state). This is opposed to ordinary “unitary” processes that occur at all other times which don’t affect “how much” of the state exists.

This paradox was resolved (in my opinion) by Everett and Wheeler when they reformulated quantum mechanics without the “collapse” axiom- instead of collapsing onto horizontal or vertical, the entire universe splits in two. In one universe, the observer sees the collapse result in a horizontal state, while the other universe sees a vertical state. This is sometimes referred to as the “many worlds interpretation” of quantum mechanics. It involves fewer axioms, has no internal mathematical inconsistencies such as those created by the notion of wave function collapse, and results in the same physical predictions. The only caveat is that it predicts a nearly infinite number of parallel universes, leading some physicists to say that the many worlds interpretation is cheap in terms of axioms, but expensive in terms of universes.

I mention this only because I find it interesting, but it really doesn’t change any part of the argument here. We still can’t predict what polarization will be observed, it’s just that the many worlds interpretation explains that unpredictability by saying that we can’t be sure which universe we will find ourselves in after the measurement splits the universe into two copies.

The immediate reply that pops into my head is that if you are empirically demonstrating this “45 degree” spin state, then isn’t that itself a measurement that should precipitate the quantum collapse? –But I’m sure someone’s thought of that.

A horizontally polarized photon will definitely produce a click, and a vertically polarized photon will definitely produce a beep. A photon in a 45° spin state will click or beep randomly but over many measurements 50% of the photons produce clicks and 50% produce beeps.

But that doesn’t make the 45° spin state different or special. The exact same random click/beep phenomenon would occur with horizontally polarized photons if you tilted the horizontal and vertical detectors by 45° so the “horizontal” detector clicks when a +45° photon hits it, and the “vertical” detector beeps when a -45° (perpendicular to the +45° state) photon hits it. In this case, horizontally polarized photons would randomly click or beep.

The measurement of a photon’s polarization depends on the relative angle between the polarization and the detector’s orientation. The photon is always detected if the relative angle is 0. If the relative angle is exactly 90°, it will never be detected. For intermediate angles, the statistical odds of a detection are higher when the relative angle is small, and the odds are 50/50 when the relative angle is 45°.

For the sake of argument, let’s assume that you perform the experiment for me, and I not only understand it, I’m convinced that it shows what you say it shows. You have demonstrated that a “particle” can have two contradictory characteristics (or states, or whatever) at once. In other words, you’ve demonstrated what appears to be a paradox. Isn’t a such a paradox cause to re-examine our fundamental assumptions, to ask ourselves whether it’s not time to take a totally new view of the universe?

No more so than time dilation and relativity of simultaneity are proof that we should re-examine the assumptions that went into special relativity. Quantum superpositions are weird, sure, but what would you expect? Our intuition is based on instincts inherited through countless generations of creatures who interacted with the world on a length scale from 0.1 mm to 100 km (the smallest visible dust grain size to the distance to the horizon as seen from the top of a mountain), and at speeds of up to ~200 m/s (approximate tornado windspeed). We shouldn’t necessarily expect our intuition to apply to a radically smaller domain (quantum mechanics becomes important on very small scales like a millionth of a meter) or very fast speeds (where time slows down and simultaneous events are different for different observers).

That’s not to say that this strangeness isn’t reason to go over the theory with a fine-tooth comb. Unfortunately, most of this work was done before I was born. From what I can tell, most 20th century scientists simply refused to believe in this nonsense, so they kept designing experiments to disprove it. Quantum mechanics kept stubbornly being right. After over 80 years of testing the basic theory, I think we have to accept that quantum mechanics reflects the way the universe works, at least until someone can come up with a better experiment.

Where am I going with all this? Well,I think I’m going to bed…I’m currently being possessed by the demon of insomnia, and no doubt I’ll rue tomorrow what I wrote today. But I’d like to throw out this one suggestion: if we don’t stick to trying to understand the subject of your “45 degree” experiment as being something like a little marble or a ripple, does this change our understanding of the experiment? Could it be that the experiment says, “throw away your notions about particles and waves”, instead of “the universe is really crazy”? (Yes, I realize that both could be true.)

We actually have thrown away the notions of particles and waves. Think of it this way: according to quantum mechanics, objects can occupy a continuous spectrum between “particle” and “wave.” Only extremely fast, massive “quantum states” have properties that look like particles. Very slow or very light quantum states have properties that look like waves. In between, they exhibit properties of both. But these extremes (particle and wave) do not define the situation very well; they are simply extreme limits.

Written by DrVomact on June 05 2007, @09:13PM

On my way home from work tonight, I remembered what really bothers me about quantum mechanics. (It’s a long commute.) I’m not really vitally worried about wave/particle stuff, or what the exact characteristics or behaviors of the quantum objects are. What bugs me is “collapse”. The way I understand what I’ve read about QM, I’m required to believe that quantum objects are in some sort of indeterminate state until they are observed. Observation works a change on the observed object (and if “entanglement” is true, it may change another object at a distance, but let’s not worry about that now).

I’ve never understood this. Sometimes, it seems as though the quantum mechanics mean that the change is strictly mechanical–that is, it’s a side effect of the instrument used to observe the object’s behavior–going through a detector somehow changes the particle. But that seems trivial to me–of course something really tiny is going to be affected in some way if you do something to measure it. At other times, it seems to me that the assertion of “collapse” is something much more mysterious, that it has to do with someone learning about the particle’s characteristics. I’ve read some QM articles in which the author seems to be asserting that the act of someone becoming aware of a particle’s behavior somehow changes that behavior. In other words, if the instrument is turned on, and nobody happens to be watching it, then no “collapse” takes place. It’s just when the physicist is paying attention that “collapse” happens.

That has got to be wrong, because nobody but a philosopher could possibly say anything so completely silly. (Like David Hume for example, who thought that the world might possibly go away when he closes his eyes, or Berkeley, who averred that the universe only exists because God pays attention to it.) So if it’s not a mere mechanical side-effect of instrumentation or a mystical by-product of the physicist’s careful observation, what causes quantum “collapse”? (In case you’re wondering, I am not pulling your leg–I am really this confused.)

Written by Dumb Scientist on June 05 2007, @10:01PM

I agree that quantum collapse is bizarre, and leads to paradoxes such as Schrodinger’s Cat and Wigner’s Friend. My personal answer is that there is no such thing as collapse. I use the term because it’s part of the standard “interpretation” of quantum mechanics, but I actually believe that the many worlds interpretation (that I detailed in my last post) is more likely to be true. I say this because:

1. Quantum collapse is introduced in the standard interpretation as an arbitrary axiom. Therefore, if any different formulation of quantum mechanics can eliminate this axiom while producing identical predictions about real experiments, we should choose the new formulation based on Occam’s razor.
2. Because quantum collapse is introduced as an axiom, it is not justified in any specific physical manner. In the many worlds interpretation, collapse is simply seen as “the decoherence caused by interacting with a system containing a very large number of particles.” This phenomenon, known as einselection, is rigorously described on a fundamental level. It is a purely mechanical process, not a mystical one. It has nothing to do with knowledge. In fact, it emerges as an obvious consequence of letting an individual particle interact with an object composed of a very large number of particles.
3. Quantum collapses are a fundamentally non-unitary process, as opposed to every other process in quantum mechanics. It’s inconsistent with the rest of the theory in that respect.
4. Abandoning quantum collapse by choosing the Many Worlds Interpretation of Everett and Wheeler (and more recently Deutsch) results in exactly the same experimental predictions as the “standard interpretation.”

Now, the many worlds interpretation is weird. It implies that a nearly infinite number of parallel universes exist, each representing the state of the universe if a particle had gone this way or that way, collapsed onto horizontal or vertical, etc. Because we humans are made up of particles, that means that there is a different universe for every possible event in history. There is a universe where the Nazis won WW2, where dinosaurs never became extinct, where Paris Hilton is a college professor, etc. But this weirdness is, in my mind, more than offset by the elegant way that it simplifies quantum theory. Not all physicists agree with me, but the many worlds interpretation is not a fringe view by any stretch of the imagination, and it seems to be growing more accepted with each year…

Written by DrVomact on June 07 2007, @09:02PM

As an enthusiastic fan of fantasy/science fiction from an early age, the “many worlds” (MW) hypothesis appeals to me; how nice, if it were true! However, as a fugitive philosopher, I must remain unsmilingly skeptical.

1. Quantum collapse is introduced in the standard interpretation as an arbitrary axiom. Therefore, if any different formulation of quantum mechanics can eliminate this axoim while producing identical predictions about real experiments, we should choose the new formulation based on Occam’s razor.

With all respect sir, I must frown on your uttering the name of Occam in the same decade of your life as the phrase “many worlds”. I truly cannot think of a more complex hypothesis! Perhaps the MW theory is no more strange than “collapse”, but it’s quite a bit more extravagant. I mean…all those universes!

2. Because quantum collapse is introduced as an axiom, it is not justified in any specific physical manner. In the many worlds interpretation, collapse is simply seen as “the decoherence caused by interacting with a system containing a very large number of particles.” This phenomenon, known as einselection, is rigorously described on a fundamental level. It is a purely mechanical process, not a mystical one. It has nothing to do with knowledge. In fact, it emerges as an obvious consequence of letting an individual particle interact with an object composed of a very large number of particles.

I am pleased to learn that there are no epistemic requirements for MW. That is, I think you’re saying that MW does not rely on the activity of observers–that the generation of new universes occurs whether or not someone is observing quantum events. Do I understand this correctly? If so, that is an improvement. I can’t, however, concur with your claim that MW is “obvious”.

4. Abandoning quantum collapse by choosing the Many Worlds Interpretation of Everett and Wheeler (and more recently Deutsch) results in exactly the same experimental predictions as the “standard interpretation.”

This sounds as though neither hypothesis is empirically verifiable; both explain observed phenomena equally well, correct? I suppose that is no reason to reject either theory; I don’t know what gravity “really” is, but Newton’s–and later, Einstein’s–theories of gravity both had “explanatory power”.

However, I note that in your article, you call the “collapse” theory “bizarre” and MW “weird”. It seems that one sort of strangeness just appeals to you more than the other. (Do you like science fiction, too?) I’ve learned that when scientists (or philosophers) say such strange things, it’s usually because someone is holding a gun to their heads (at least metaphorically). They’re trying to explain something that is itself disturbing; if the explanation that occurs to them is also unpalatable, they may nevertheless be driven to embrace it, because they believe that any explanation is better than none at all

So here is where I am with respect to understanding Quantum Mechanics: something has been observed that is so extremely strange, that even two such strange theories as “collapse” and MW look like good life preservers in a stormy sea. My problem now is that I can’t properly appreciate the emergency–I can’t understand what’s been observed that makes apparently sensible people behave like this. It’s as though I were sitting in an excursion boat, enjoying the scenery, when suddenly a bunch of geeky-looking fellows jump overboard, clutching life jackets. I have the queasy feeling that maybe I should go looking for one of those jackets (preferably one labeled “MW”), but I don’t see any reason to jump overboard just yet.

Written by Dumb Scientist on June 12 2007, @04:16PM

As an enthusiastic fan of fantasy/science fiction from an early age, the “many worlds” (MW) hypothesis appeals to me; how nice, if it were true!

I, too, seem to have been born with the gene for “sci-fi fan” turned on. Unfortunately, as I continue to learn about physics, I find myself less able to suspend disbelief than in years past. As a result, I usually prefer shows that either skip the technobabble completely (such as Firefly and Battlestar Galactica) or manage to get their facts straight occasionally. Stargate Atlantis is the only currently airing show I can think of that even comes close, and it’s only reasonably correct 30% of the time or so…

With all respect sir, I must frown on your uttering the name of Occam in the same decade of your life as the phrase “many worlds”. I truly cannot think of a more complex hypothesis! Perhaps the MW theory is no more strange than “collapse”, but it’s quite a bit more extravagant. I mean…all those universes!

MW is extravagent, but only in the sense that it implies the universe is larger and stranger than we thought it was before. That’s been happening for millenia- every new paradigm in science (heliocentricity, relativity, the realization that our sun is just another star, etc) has shown us that the universe is stranger than we thought it was before.

So most physicists have stopped trying to apply common sense to physics theories. If Einstein had used common sense to say “Of course everyone experiences time at the same rate!”, then we wouldn’t have special relativity today. The only criteria I use are:

1. Does the theory match experiment?
2. Is the theory mathematically consistent?
3. Does the theory have fewer axioms than its nearest competitors?

In this sense, the MW interpretation wins. It is mathematically consistent, involves one fewer assumption than the conventional “collapse” interpretation of quantum mechanics, and it describes experimental results just as well. It’s possible that other interpretations are more accurate (such as Cramer’s “Transactional Interpretation”) but for now I’m leaning towards MW.

I am pleased to learn that there are no epistemic requirements for MW. That is, I think you’re saying that MW does not rely on the activity of observers–that the generation of new universes occurs whether or not someone is observing quantum events. Do I understand this correctly? If so, that is an improvement. I can’t, however, concur with your claim that MW is “obvious”.

Yes, the “collapse” effect in MW is a purely physical phenomenon. It’s difficult to translate the math into english, which is why I’ve said strange things like “generates new universes.” This is a clumsy (and probably overly dramatic) way of describing the process, but it’s the best I can do.

A more accurate way of describing the process would be to say that coupling an isolated quantum system to a much larger system (like a detector) dramatically reduces the off-diagonal terms of the density matrix describing the original quantum system. Since these off-diagonal terms describe interference between the various eigenstates of the quantum system (horizontal and vertical polarization, for example), this process effectively prevents the two eigenstates from interfering with each other. Because the two eigenstates no longer interact, some physicists interpret the resulting density matrix as saying that the two outcomes are now in two “parallel universes” which no longer interact.

But, as you can tell, it’s a lot easier to say “it splits the universe in two.”

This sounds as though neither hypothesis is empirically verifiable; both explain observed phenomena equally well, correct? I suppose that is no reason to reject either theory…

Yes. They’re simply interpreting the math of quantum mechanics in different ways, and the math always gives the same answer for real experiments.

However, I note that in your article, you call the “collapse” theory “bizarre” and MW “weird”. It seems that one sort of strangeness just appeals to you more than the other.

That’s true. The strangeness inherent to MW is of a variety that only contradicts “common sense.” The strangeness inherent to the collapse interpretation is of a variety that involves mathematical inconsistencies and additional (apparently unnecessary) axioms introduced to explain the “collapse” that the MW interpretation explains without any additional axioms.

They’re trying to explain something that is itself disturbing; if the explanation that occurs to them is also unpalatable, they may nevertheless be driven to embrace it, because they believe that any explanation is better than none at all

That’s certainly a possibility. My only real response is that I am willing to provisionally accept an explanation if it fits all available experimental data, is mathematically consistent, and involves the smallest number of arbitrary axioms possible. If an explanation with fewer axioms shows up, or if new experimental evidence contradicts the previous explanation, I’ll drop it like the proverbial hot potato.

I’d describe my application of the scientific method like this: sometimes I notice something strange in my environment, or take a fresh look at a ubiquitous phenomenon. My curiosity’s piqued, so I make at least a token attempt to explain the phenomenon. Historically, the most effective way to approach these problems has been to assume that the universe is governed by objective rules and try to guess a rule that explains the phenomenon in question without implying absurdities. In physics, this search for a mechanism generally involves postulating a general principle (for instance, “energy is conserved” or “objects at rest stay at rest”) and considering the consequences of that postulate. The resulting explanation is “scientific” if it makes predictions that can be verified. This is the primary characteristic of “good” science; not only do our models of reality have to be consistent with the facts at hand, they also have to predict new phenomena which can then be checked via experiment.

Do general physics classes in their current form actually teach students to think using this process? I don’t think so, mainly due to the focus of the course material. A typical problem in one of these classes is formulated like this: “Given this verified physical law, predict the behavior of the following system.” As an example, students are often told to assume Newton’s laws of motion and predict the path of a baseball after it’s thrown. This type of exercise tends to leave the student with the impression that science is a mechanical system of picking a set of equations and churning out an answer. Problems like these are certainly good practice for learning how to apply physical laws to obtain specific predictions, but that’s nearly irrelevant for a student who doesn’t intend to become a physicist.

A better approach would actually require the students to construct hypotheses regarding phenomena that seem confusing, and have them test these hypotheses by considering what they imply about the real world. Though we’re probably succeeding at teaching people the mechanics of working within a given scientific theory, it’s more important to show them how those theories were constructed in the first place. Students need to be shown how to take an explanation of a phenomenon and test it for validity.

We’re failing miserably at this goal.

For instance, if college graduates were randomly surveyed regarding the cause of the Earth’s seasons, I think a sizable percentage of them would say that the seasons are caused by variations in the Earth’s distance away from the Sun. This misconception only arises because students aren’t being taught to critically evaluate ideas in terms of their implied effects. Consider this: if winter occurs when the Earth’s farther away from the Sun, doesn’t that idea imply that winter should occur at the same calendar date everywhere on the globe? If seasons really were caused by the Earth’s distance away from the Sun, the seasons would be the same everywhere because the Earth as a whole would be closer or farther from the Sun. This isn’t true, though: in the southern hemisphere, summer occurs in January, and winter occurs in June (vice versa for the northern hemisphere). In other words, if you believe that seasons are caused by distances from the Sun, you’d be likely to pack completely inappropriate clothes for a “summer” plane trip across the equator.

What’s the actual cause of the seasons, though? More importantly, how do you determine that cause? I’ll answer that question with another question: Why do winters get colder as you move farther away from the equator? Is it because the distance to the Sun increases as you approach the planet’s poles?^[1] No, not in any significant sense; the Earth’s usually ~150,000,000 kilometers away from the Sun and the Earth’s only ~12,000 kilometers in diameter. So any movement you make on the Earth’s surface is an infinitesimal fraction of the distance to the Sun; it shouldn’t play a role in determining temperature.

However, the Sun is lower in the sky when you’re farther from the equator. This relationship’s easiest to see if you draw a picture of the Earth in its orbit with the axis of rotation of the Earth (roughly) perpendicular to the line that connects the Earth and the Sun. A person standing on the equator will see the Sun pass nearly directly overhead during the course of the day, but a person very far north (or south) of the equator will never see the Sun directly overhead. This means that less light intensity is reaching the Earth’s surface at those points far from the equator- less light per square meter is hitting the ground because it’s not shining directly vertically. Again, the best way to see this is to draw a picture and investigate the geometry of the situation on your own.

How does this explain the seasons, though? The seasons occur because the axis of rotation of the Earth’s actually tilted^[2] away from being perpendicular to the line that connects the Sun and the Earth. This axis stays in the exact same orientation (relative to the “fixed stars”) as the Earth orbits the Sun, so sometimes the northern hemisphere’s pointed towards the Sun (this produces a northern summer and southern winter) and sometimes the southern hemisphere’s pointed towards the Sun (which occurs during northern winter and southern summer).^[3]

The actual scientific process involved in this explanation is the recognition that a common misconception (seasons being caused by distance changes) predicts incorrect phenomenon (winter and summer occurring at the same time everywhere on the globe). This realization’s followed by a different model for the seasons (the tilt of the axis) and should then be followed by observations that confirm that model. For instance, you could observe the Sun staying lower in the sky during winter than during summer to verify the “axis tilt” model of the seasons.

This brings me to my next pet peeve. In the Simpsons episode “Bart vs. Australia,” the U.S. Embassy in Australia has gotten fed up with the way water drains in the southern hemisphere and installed a special device on the toilet to “make the water drain in the American direction.” I believe this scene’s representative of a widespread belief that water drains counterclockwise in the northern hemisphere and clockwise in the southern hemisphere.

The purported cause of this difference is a real phenomenon called the Coriolis effect. In order to understand the Coriolis effect, consider a person standing on the equator. Because of the rotation of the Earth, he’s actually moving in a large circle at a very high speed.^[4] A person sitting exactly on top of the North or South Pole, in contrast, would simply be spinning once every 24 hours- he wouldn’t be going anywhere. At intermediate latitudes the speed varies smoothly from a maximum value at the equator to zero at the poles.

Suppose you stand at the equator and fire a cannonball directly north. In addition to the northward velocity from the cannon, the cannonball has the high velocity of rotation of the equator, and as it flies north it retains that velocity.^[5] However, once the cannonball travels a significant distance, the ground underneath it isn’t moving as fast as the cannonball so its path will appear curved relative to the ground. Because the Earth rotates from west to east, the cannonball will appear to be “pushed” to the east by the Coriolis effect. This is the modern explanation for why hurricanes rotate in preferred directions in different hemispheres.

Does this explanation apply to toilet bowls and sinks, though? The cannonball’s path isn’t noticeably curved unless the cannonball travels very far to the north. That’s why hurricanes are affected by the Coriolis effect- they’re large enough so that the eastward deflection is sizable. But toilet bowls and sinks are millions of times smaller- the Coriolis effect’s way too small to have any measurable effect on them. The tiniest imperfection in the shape of a sink’s drain or random circulation of water flowing down it would completely mask any Coriolis-induced spinning.

That’s a physics explanation of why this “rotational drainage” myth isn’t true. I included it for completeness’ sake, but my main point is that physics education shouldn’t be about supplying explanations to students. Science education should teach students how to create and test their own explanations. Let’s say that I did believe that sinks drained in preferred directions. How would I test this belief for accuracy? Well, I’d just have to wash my hands in different sinks and see whether the water drained in a consistent direction in this hemisphere. Try it, and you’ll see that this simply doesn’t occur- water drains clockwise or counterclockwise in different sinks even when you’re far from the equator. Hint: if it’s difficult to see which way the water’s draining, try sprinkling some pepper on the water so you can see the circulation pattern more clearly.

Why do otherwise intelligent people believe in effects that can be disproved just by looking in the sink? I think it’s because no one ever takes the time to emphasize the importance of verifying beliefs through experiment. That’s what science classes should be doing, but instead they’re teaching medical students the arcane intricacies of Newtonian mechanics without even attempting to test whether or not those students understand how Newton discovered his theory in the first place.

It should now be obvious that there’s an inadequacy in our science education system. Why does this inadequacy exist, though? The obvious reason is that a mechanical, computational approach is easier to apply in larger classes, and it easily translates into an objective grading system. This is probably unavoidable in today’s large universities, but part of the problem’s due to the fact that general physics classes are treated as “watered-down” versions of the introductory physics courses that are intended for physics majors. This is convenient for the instructor, of course- the material’s easy to translate from one class to another. It’s inappropriate for the students, though, because the major-based physics courses are simply treated as the first stepping stone to building a scientific mindset. These first courses are where physics majors gain practice at mathematical computations; the real science actually comes into play much later. For general students, however, these few physics courses are the only glimpse of the subject they will ever see. We can’t afford to ignore the more important aspects of the scientific method, even if it means the class structure has to be changed significantly.

Footnotes

1. I mention this possibility because many students suggest it as a possible reason why winters are colder when you’re farther from the equator. ↩ back
2. The axis is actually 23.5° away from being perpendicular. ↩ back
3. Due to the geometry of Earth’s orbit around the Sun, northern winters occur when the Earth is closest to the Sun. ↩ back
4. A person on the equator is rotating on a circle of radius 6400 km (the radius of the Earth) and they complete one circle a day, so their speed is ~460 meters per second (greater than the speed of sound at standard temperature and pressure!). ↩ back
5. Ignore air resistance for the purposes of this explanation. The cannonball simply obeys Newton’s First Law: “Objects in motion remain in motion.” ↩ back

(Ed. note: This article was originally written on 2003-08-20.)