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57 Responses to “A conversation regarding the “electric universe””

1. Dumb Scientist posted on 2009-04-04 at 16:40

   I’ve put some more thought into the idea that light travels faster outside our solar system. In order to allow us to see objects 13,000,000,000 light years away in the 6,000 years allowed by young earth creationism, light would have to travel ~2,000,000 times faster outside our solar system. But some young earth creationists assert that the universe is ~10,000 years old, so I’ll assume Marble means that light travels a mere 1,000,000 times faster in the outside universe.

   Total internal reflection imposes the strictest constraint on the size and geometry of the boundary layer between the external universe (where light travels a million times faster than we measure) and the region containing the solar system (where light travels at 299,792,458 m/s). If the boundary reflected any light from the sun, the solar system would be a super-heated pressure cooker due to all the trapped radiation. A gradual boundary layer like the one in a moth’s eyes would reduce this problem, but most boundaries reflect more light at higher incidence angles. A spherical boundary layer centered on the sun would minimize these reflections, so let’s examine the physical consequences of that particular geometry of the boundary layer.

   A point source in the exact center of a glass marble won’t undergo total internal reflection. But the sun isn’t a point source– it’s 700,000 km in radius. Using the small angle approximation, that means the boundary has to be at least 1,000,000 times larger than the sun so that light from the edge of the sun isn’t totally internally reflected. (A boundary this small would risk totally internally reflecting x-rays from the corona, but let’s ignore that problem for brevity’s sake.)

   A spherical boundary layer with an index of refraction of 1,000,000 would focus all EM radiation into the center of the sun. That means the earth can’t drift into the focus and be fried by radiation. But the extrasolar radiation would be intensified by a factor of ~20,000,000 at the earth’s orbit if the boundary is 1,000,000 times larger than the sun.

   Also, fish see the world above the water through “Snell’s Window.” The fact that light travels 25% slower in water than air refracts light from the sky as it enters the water, compressing the entire sky into a circular window 96 degrees wide.

   This effect will also occur in your scenario, but it will be much more pronounced because light travels a million times slower inside the boundary. Again using the small angle approximation, the “Snell’s Window” for your boundary would be 0.000000035 degrees wide. So light from the outside universe would be concentrated into a tiny, ultrabright spot in the sky directly opposite the sun.

   Finally, cosmic rays in the outside universe would be limited by the higher speed of light in that region, otherwise special relativity needs to be rewritten. The particles traveling faster than “our” speed of light would probably emit Cerenkov radiation upon crossing the boundary layer into our region, which would cause the entire sky to shimmer…

   Reply
   • Dumb Scientist posted on 2009-04-08 at 17:47

     A friend just reminded me that there are other questions raised by your proposal. The speed of light is tied to the permittivity and permeability of free space. Which is changing, and how? This would alter electrodynamics; wouldn’t the spectra of other stars look different than the sun’s?

     Reply
2. Marble posted on 2009-04-08 at 08:28

   I’ve been going through the crater formation links you provided and have been mulling them over. I must admit that the initial cement crater image is a good lookalike for some moon ones (although it’s a shame the image quality is so poor in that document). I have a couple of thoughts that I’m still pulling together on them and the other link that I’ll share soon.

   Here’s a couple of questions for you that you’ll have to suspend your disbelief filter to answer. I’ve been pondering these over the last couple of days – so I’d be grateful if you think about them seriously (and I suspect you will). I’ll mention now that this is the start of my 1000000 fold alteration of physics but with these questions – you’d expect nothing less ;) I think the theory should be easily falsifiable and of massive scientific & commercial importance if demonstrated to have merit. Text removed at Marble’s request.

   BTW – I didn’t know this before tonight…

   Anomalous increase of the AU

   The orbits of the planets are constantly expanding outward from the sun because the sun is losing mass by radiating away energy[3], which has led to calls to abandon the AU as a unit of measurement[4]. Now recent measurements indicate that the secular increase of the AU is larger than can be accounted for by solar mass loss[5][6].

   Reply
   • Dumb Scientist posted on 2009-04-08 at 16:30

     Reply text removed at Marble’s request.

     The truth is I don’t have enough time to look into these questions in detail. I’m struggling to phrase an answer to your last ID comment regarding HGT (it will probably require a new article) in between my research obligations. I also just wasted an entire day arguing climate change on slashdot, and this obsessive personality quirk is something I need to learn to restrain or I won’t have any time left for the stuff I’m getting paid to look at.

     Anomalous increase of the AU

     Yes, there are quite a few strange things happening in the solar system. The “Pioneer anomaly” shows that gravity may behave differently at extremely large distances (a type of MOND, I suppose, but the evidence is ambiguous) and the “flyby anomaly” which is even weirder.

     Reply
     • Marble posted on 2009-04-08 at 17:34

       All I’m asking for is the 1 minute to read it, say ‘rubbish’ or ‘there’s too many holes’ and that can be the end of it. Text removed at Marble’s request.
     • Dumb Scientist posted on 2009-04-08 at 19:13

       Text removed at Marble’s request.

       Reply text removed at Marble’s request.

       All I’m asking for is the 1 minute to read it, say ‘rubbish’ or ‘there’s too many holes’ and that can be the end of it.

       I think you’re seriously underestimating the time it takes to properly analyze these ideas. And as you’ve seen, I’m chronically unable to say ‘rubbish’ and leave it at that.

       Having said that, if you can summarize the ideas in a half-page or so, I’ll think about them. I can’t promise an immediate reply, but neither will I share it with anyone.

       I feel compelled to note that you’ll have to directly address the predictions I’ve made based on analyzing the boundary layer in order to hold my interest. You’ll have to show why “fast light outside the solar system” doesn’t lead to those physical consequences. Otherwise a simple glance at the night sky confirms that the speed of light is uniform.

       Maybe I’ve made some hidden incorrect assumptions in deducing those predictions, but I can’t find them. Refraction is all that’s being relied upon for most of the predictions, and refraction is a direct result of conservation of energy at the boundary layer. A spherical geometry of the boundary layer would imply a blank sky except for a solitary source of deadly radiation in the night sky directly opposite the Sun. Perhaps another geometry of the boundary layer would look slightly more normal, but I can’t think of any configuration that would match what my naked eye can see.
     • Marble posted on 2009-04-08 at 20:43

       Thanks.

       Hopefully it will hold your interest on its own merit.

       It does directly relate to the variability of light and yes – I agree, the concerns you raised need to be addressed. On that I’ll just note that there is no distinct boundary layer as such. I’ll be arguing that light speed (in a vacuum) is directly proportional to the absolute value of gravity at that point (the absolute summing of the scalar components of gravitational vectors). So, for example, I’m suggesting that the speed of light at Lagrange points will be slower because while the gravity vectors cancel out, it’s the absolute value that dictates the speed of light. (Note I’m not referencing the Doppler effect at all). So basically light speed is faster the further away it is from the (absolute) gravitational effect of mass.

       Falsifiable prediction #1: The speed of light (and hence atomic clock ticking) is slower at a Lagrange point.

       Falsifiable prediction #2: Atomic clock ticking will be appropriately slower at a Lagrange point, whereas relativity (I think – correct me if I’m wrong) would say that it should tick faster due to the low gravity environment.

       Falsifiable prediction #3: e=mc^2 will also reflect the lightspeed change etc.

       Of course of more interest / more importance is how gravity works – and my justification for why gravity and light are interrelated (yes – I think I can unify gravity & EM somewhat more than just the Doppler effect) as I have outlined above. I want to take a little longer to put down, but I haven’t seen it postulated as a theory on the web (at least in a format I understand). And (of course) it doesn’t need to appeal to complex mathematics for the basic concept of how it works.

       So anyway – I’m not sure if that alters some of your objections to the internal reflection argument. I’ve been trying to visualize the effect of internal reflection (and even the focusing of star light at the sun – that was a good one) and how that would look in the scenario above – but I think I’m going to have to put down some drawings and plot lines.
     • Dumb Scientist posted on 2009-04-08 at 21:35

       Thanks. Hopefully it will hold your interest on its own merit.

       You’re right, that was interesting. It’s definitely falsifiable science, too.

       It does directly relate to the variability of light and yes – I agree, the concerns you raised need to be addressed. On that I’ll just note that there is no distinct boundary layer as such.

       Which eliminates the problem of total internal reflection, but it’s a close enough analogy to the gradual lensing of the earth’s atmosphere that I don’t think any of the refraction related effects will change significantly.

       I’ll be arguing that light speed (in a vacuum) is directly proportional to the absolute value of gravity at that point (the absolute summing of the scalar components of gravitational vectors).

       Okay, so you’re talking about a general effect that applies to all stars. I previously thought you were singling out our sun alone for the region of slow lightspeed. In that case, all the weird effects I’ve described would be visible around other stars. Nearby stars would focus light from other, more distant stars in extreme ways (in the case of a slowdown of 1,000,000 around Earth relative to interstellar space).

       We do observe gravitational lensing around galaxies and (occasionally) black holes that drift directly in front of farther stars, but that’s a direct effect of the fact that general relativity bends light without slowing it down. It’s also a much smaller effect than a lens with an index of refraction of 1,000,000 would cause.

       I’m a little confused as to what you mean when you say absolute summing. Do you mean taking the lengths of all the vectors and adding them up separately? That would result in a value that would be positive everywhere (because it doesn’t depend on the direction those vectors are pointing, so doesn’t allow for cancellation).

       Falsifiable prediction #1: The speed of light (and hence atomic clock ticking) is slower at a Lagrange point.

       I think I have my answer: you probably do mean that the speed of light at any point is affected by the sum of all the lengths of the gravity vectors at that point, completely ignoring their directions. Perhaps the physical speed of light is determined by taking a theoretical “gravity-less speed of light” (which we don’t know because we’ve never measured lightspeed in a region with absolutely no gravity) and dividing that number by the sum of all those gravity vector lengths, which would imply that the speed of light is essentially infinite when you’re very far away from any massive body. The rest of my reply assumes that this paragraph is a correct summary of your idea.

       NASA has been sending probes into space for decades, and they’re linked to earth by radio signals. The delay in those radio signals is used to calculate an astounding number of subtle effects, and the delay is independently cross-checked with the Doppler-induced phase shift of the radio frequency.

       Anomalies have appeared, such as the “Pioneer anomaly” and the “flyby anomaly” (no time for links, but googling those terms should be effective). But they’re very small errors, and if I recall correctly they don’t show the type of effect you’re predicting. That’s because your effect would show up every day in missions like Cassini. Cassini regularly flies in between us and Lagrange points, and that means the radio delay would anomalously jump by some value because the speed of light would be lower in the region the radio signal passed through to get to us.

       I don’t think that’s the best test, though. That’s because Lagrange points are only special because the two strongest gravity vectors point in roughly opposite directions. Points slightly outside of Lagrange points have very similar absolute sums of the lengths of those gravity vectors, so your proposed mechanism has little to do with Lagrange points. Plus, gravity vectors only partially cancel even at Lagrange points– centripetal acceleration plays a large role which is more evident in L4 and L5 than in L1.

       A better test would be to say that Cassini signals that pass near Jupiter on its way back to earth would provide different delays than if it was at the same distance, but without a massive planet in between us. I don’t think that’s happened, but I haven’t checked in detail.

       Falsifiable prediction #2: Atomic clock ticking will be appropriately slower at a Lagrange point, whereas relativity (I think – correct me if I’m wrong) would say that it should tick faster due to the low gravity environment.

       Off the top of my head, I’m not sure. I’m familiar with special relativity, but general relativity is much more complicated and would require some deep thinking.

       So anyway – I’m not sure if that alters some of your objections to the internal reflection argument. I’ve been trying to visualize the effect of internal reflection (and even the focusing of star light at the sun – that was a good one) and how that would look in the scenario above – but I think I’m going to have to put down some drawings and plot lines.

       It eliminates the total internal reflection objection, but all the other refraction related effects should be unchanged. It would take a while to calculate the changes to my predictions based on this new gradual effect, but I don’t see them changing significantly.
     • Marble posted on 2009-04-08 at 21:48

       Just a thought – how would the lensing affect parallax measurements of stars? I’m still of the opinion that the speeding up of light causes us to overestimate how far the stars actually are. So also any calculations based on their ‘known’ distances are doomed to failure because of the constant c assumption. Likewise with probes & satellites – aren’t the distance measurements to those relying on a constant speed of light too? (Radar/radio signals etc) Anyway – don’t spend too much time on that. Part 2 is yet to come.
     • Dumb Scientist posted on 2009-04-08 at 23:15

       Just a thought – how would the lensing affect parallax measurements of stars? I’m still of the opinion that the speeding up of light causes us to overestimate how far the stars actually are.

       It would… kind of. The problem is that a speedup of 1,000,000 would produce such a bizarre night sky that I have trouble even thinking about it. Suppose, instead, that light only speeds up outside our solar system by 0.03% (same as the gradual air-vacuum boundary layer).

       This would indeed make stars appear to be farther away. That’s because parallax measurements create a triangle with the base being defined by the positions of earth at opposite sides of the sun, and the top being defined by the other star. The angle at the other star is tiny– less than a thousandth of a degree. The parallax measurement is only possible because our telescopes are precise enough to tell the difference between a 0.0000 degree angle (which would be infinitely far away) and a 0.0001 degree angle (which would be merely far away). This technique simply yields an angle of 0.0000– and thus a distance of infinity which is interpreted as “too far away to tell with parallax”– for objects that are very far away, such as objects that are entirely outside our galaxy.

       If light was faster outside the solar system, the light wouldn’t travel in a straight line from the other star. It would be focused by the gradual boundary layer. This means our telescopes would record the path the light took after being bent, so the triangle would appear to have a smaller angle- and thus the distance to the stars would be artificially increased. The real triangle (measured with straight lines) would have a larger angle so the real distance to the star would be smaller. The apparent triangle (as drawn by our scientists based on the directions the light rays had been curved into) would have a smaller angle and imply that the star was farther away than it actually was.

       But even such a small (0.03%) increase in the speed of light would have baffling consequences. Increasing lightspeed above a small threshold (which I don’t have time to calculate) wouldn’t result in a triangle at all when the measurements were made at 6 month intervals. In other words, the star’s light would appear to be coming from two completely distinct places in the sky. For an extreme case, remember that a 1,000,000x increase implies that the star’s light would hit earth from completely opposite directions!

       This wouldn’t look even remotely like a parallax effect– it would clearly be a lensing effect. There’s a big difference between diverging light (which can yield a parallax distance), plane wave light (which is too far away for parallax) and converging light (which makes no astrophysical sense without a giant lens around the Sun).

       So also any calculations based on their ‘known’ distances are doomed to failure because of the constant c assumption. Likewise with probes & satellites – aren’t the distance measurements to those relying on a constant speed of light too?

       That’s a little complicated. The scientific definition of a “meter” was changed in 1983 to the distance that light travels in 1 / 299,792,458 of a second. But that doesn’t mean physicists have written this assumption into stone. You can find papers exploring speed of light variability in the journals (billions of times smaller than your variability, but variability nonetheless).

       Instead of removing this subject from the bounds of scientific discussion, it’s simply changed the language. In modern physics, speed of light variability is expressed as a variation in the index of refraction of free space. All experiments performed to date agree that the vacuum in every place we’ve looked has an index of refraction that is indistinguishable from “1.00…”

       So scientists performing these distance measurements are well aware that lightspeed may not be constant. The engineers working on the probe missions may not care about this rather esoteric debate, but what I’m trying to say is that a deviation from constancy would stand out in their data in an obvious manner. Like I said, probes that appear to pass behind Jupiter would send radio signals implying that the probes moved in ways not predicted by their gravitational calculations (because the radio signal would be focused by the change in lightspeed around Jupiter) and the radio delay would suddenly change (a direct result of the change in lightspeed around Jupiter).

       I’ll stress that these two anomalies are evidence that the engineers working on these probe missions aren’t making any foolhardy assumptions. I have enormous respect for the work they do, and I’m continually surprised by the subtle anomalies they’ve brought to the attention of the physics community. But I think gravity-dependent lightspeed would create totally different anomalies which haven’t been seen.

       That said, I do think it’s an interesting idea. It might even be true on a very small scale- lightspeed might change by something like a millionth as gravity decreases to zero in intergalactic space. My only real concern is with the scale you’re proposing for the increase in the speed of light, and the mind-twisting effects it would have on the night sky.
     • Marble posted on 2009-04-09 at 00:11

       BTW – I’m not attached to this 10^6 number for increase c – I think that got munged into our discussion somewhere back a bit – but that wasn’t a figure I ever had in mind. I’d like to think that mon 838 nova is still dust expanding rather than a light echo for example – so what ever is required for that to be true is where I’d be heading.

       We’ve got the Easter holidays this weekend (4 day weekend) – so I should get that final part to you in the next couple of days.
     • Dumb Scientist posted on 2009-04-10 at 16:17

       All those bizarre effects would show up even in the case of a slowdown much less pronounced than the one you’re describing. Just pick any slowdown factor and redo the calculations (like Snell’s window) that I did in my first comment to prove this to yourself.
     • Marble posted on 2009-04-11 at 07:59

       Prologue

       Basically I’ve never been able to go past the fact that light waves behave so much like sound waves – I find it too hard to believe that light is anything but a wave propagating through some medium (at least too hard to believe when I’m not convinced the alternatives have been fully explored).

       But then you encounter the empirically confirmed behaviours of General & Special relativity. Which generally provide no ‘real’ explanation of their behaviour, but instead are more a mathematical description. I include space-time in general as this aspect is a more abstract invention to aid the calculations. And so while some people claim that the aether then falls to Occam’s razor, I disagree in that they are not fairly applying the rule. A mathematical description without an accompanying explanation of the underlying reality is only half the story and the razor must be stayed because it can only be applied when comparing like to like.

       Text removed at Marble’s request. These particles have a size around the order of magnitude of the size of electrons.

       A proposed alternative explanation for gravity, removed at Marble’s request.

       Moreover, I postulate that this aether described is also the medium that the light travels through as waves. The ‘quantized’ component of light and its particle nature coming from the discrete nature of the aether particle itself.

       A connection between the Casimir effect and aether, removed at Marble’s request.

       More Casimir effect and aether discussion removed at Marble’s request.

       As the medium supports light, it also is the source of magnetic fields. Text removed at Marble’s request.

       This is why magnetic fields ‘saturate’, as there is a limit on the number of aether particles in a particular area. Text removed at Marble’s request.

       I could go on with a number of other ‘high level’ explanations of other phenomena, and there’s a stack more interesting observations that can be made from this as a base. Text removed at Marble’s request. My favoured thought on this is that light is a longitudinal wave of aether particles Text removed at Marble’s request.

       Anyway – now you can see my thoughts on the variability of the speed of light. I’ve got more thoughts on all of this I’d like to burble on about – but I’ll leave it there for now.
     • Dumb Scientist posted on 2009-04-11 at 17:31

       Basically I’ve never been able to go past the fact that light waves behave so much like sound waves – I find it too hard to believe that light is anything but a wave propagating through some medium (at least too hard to believe when I’m not convinced the alternatives have been fully explored).

       Everyone else found it difficult to believe in the 1890s too, but Michelson-Morley showed that any aether theory has to be really weird. The aether has to be dragged by the earth so that our velocity isn’t apparent. It has to be the most rigid substance ever (wave frequency is proportional to the medium’s rigidity) but not exert any force on the earth as it moves through the aether. Otherwise we’d have spiraled into the sun eons ago.

       Furthermore, speed of light tests performed across the solar system show no absolute velocity effects, which is essentially a repeat of the Michelson-Morley experiment, but across interplanetary distances. Dragging the aether is no longer as simple as Stokes and Miller once thought.

       Physicists abandoned the aether for good reasons nearly a century before I was born.

       But then you encounter the empirically confirmed behaviours of General & Special relativity. Which generally provide no ‘real’ explanation of their behaviour, but instead are more a mathematical description.

       I think that’s a misconception. Lorentz transformations contain nearly all the math of special relativity, and were developed as a “real explanation” of Michelson-Morley’s results. They claimed that nature conspired in just the right way to fake the Michelson-Morley result, squishing objects and making clocks run slow when moving through the aether.

       This math is identical in special relativity, but Einstein gave it a different “real” explanation: the structure of our universe is such that there is no aether, and no need for an absolute frame of reference. The speed of light is the only constant- every observer in the universe measures it to have the same value of 299,792,458 m/s. In order for everyone to measure lightspeed to be the same value, one aspect of Galilean relativity had to be altered.

       I don’t see how this explanation is any less “real” than Lorentz’s explanation. It’s less intuitive, but so is the fact that orbiting spacecraft need to slow down in order to speed up (yes, you read that right). Doesn’t make either fact any less true.

       Text removed at Marble’s request. These particles have a size around the order of magnitude of the size of electrons.

       Reply text removed at Marble’s request.

       Also, the size of the electron is a very tricky thing to define. Unlike a proton which is made up of 3 quarks and thus has substructure, experiments with electrons have never revealed substructure so they’re probably fundamental particles. As a result, electrons don’t really have a “size” in the normal sense of the word:

       • A free electron’s DeBroglie wavelength at experimentally accessible momenta is much smaller than the wavelengths of visible light. That’s why electron microscopes have much higher resolution than light microscopes.
       • An electron bound to a proton has a characteristic size known as the Bohr radius.
       • The Compton wavelength describes the length scale at which non-relativistic quantum mechanics breaks down and relativistic quantum electrodynamics is necessary.
       • The classical electron radius isn’t defined by quantum mechanics but rather uses classical electrodynamics to estimate the size an electron be if its mass is due entirely to electrostatic potential energy.

       A proposed alternative explanation for gravity, removed at Marble’s request.

       Scott Adams once said that there is no gravity, it’s just that all the objects in the universe double in size every second, so when we jump into the air the expanding earth pushes against our expanding bodies in such a way that we appear to fall down to the ground. We don’t notice this constant expansion because everything grows at the same rate, including our rulers.

       His idea was cute, and it was interesting to play around with it for a couple of minutes. But he didn’t seem to realize that gravitational physics is 300 years old. He not only needed to explain how that resulted in an inverse-square approximation, but he also needed to explain Lagrange points, the precession of Mercury’s orbit, and the orbital decay of binary pulsars due to energy loss from gravitational waves. He also needed to explain the gravitational deflection of starlight, and why it matches general relativity rather than a combination of Newtonian gravity and special relativity.

       A connection between the Casimir effect and aether, removed at Marble’s request.

       Reply text removed at Marble’s request. Since the Casimir effect only works with conductive matter, it seems like these new particles of yours depend on the conductivity of the matter Reply text removed at Marble’s request.

       Experiments have ruled out that idea.

       More Casimir effect and aether discussion removed at Marble’s request.

       That’s very similar to the mainstream explanation, except virtual photons aren’t able to exist inside the gap because of Maxwell’s equations. It doesn’t require new particles, and the conventional explanation accounts for the conductivity dependence.

       Moreover, I postulate that this aether described is also the medium that the light travels through as waves. The ‘quantized’ component of light and its particle nature coming from the discrete nature of the aether particle itself.

       As the medium supports light, it also is the source of magnetic fields. Text removed at Marble’s request.

       This is why magnetic fields ‘saturate’, as there is a limit on the number of aether particles in a particular area.

       Saturation is just a ferro-magnetic thing. It depends on the properties of matter, not space. For instance, magnetars have magnetic fields hundreds of thousands of times stronger than anything we’ve made so far.

       I could go on with a number of other ‘high level’ explanations of other phenomena, and there’s a stack more interesting observations that can be made from this as a base.

       Yes… I’m sure you could. But high level explanations are the “pointy haired boss” of the physics community. The pointy haired boss doesn’t know what those funny squiggles and semicolons on your monitor mean. They’re ridiculous gibberish to him, which is why he talks endlessly about anything but real, technical matters. He demands that programmers speak in simple English and avoid talking about the internals of their programs.

       This is okay in one sense because people shouldn’t need to understand pointers to use MS Word. But it’s dangerous to take this approach too far because eventually the pointy haired boss comes to believe that the high level explanations contain the same information content that the programmers get from their source code.

       They don’t, not by a long shot. Low level explanations are necessary, such as details of memory management techniques, or which algorithm will provide logarithmic rather than quadratic scaling for a database search. Even lower level explanations like the best method to code a search algorithm from scratch are sometimes necessary if you think that existing search algorithms aren’t good enough. But the pointy haired boss can’t possibly program that, because all he understands are the high level explanations. He just wants the program to be shiny and run fast, so he thinks it’s bizarre that those simpleton programmers can’t just finish it in an afternoon.

       A programmer can’t get away with that level of abstraction, though. If you need to search a database, you carefully look at all the search algorithms available at a low level. Then you (probably) choose one of those algorithms or (less likely) write one from scratch. What you don’t do is sit down at the computer for the very first time, grab an introductory copy of VisualBASIC, and start coding a brand new search algorithm for serious commercial use. You might out-do every other search algorithm on the planet if your name is Linus Torvalds, but it’s more likely that you’ll reinvent the wheel. A slightly crooked wheel, too, compared to modern algorithms.

       Don’t do that. Life’s too damned short to reinvent the wheel. Look at the last century of physics at a low-level perspective, and look at all the work that’s been done by people who had very similar ideas to yours. You were right to suggest that this will require a physics B.S., but it will likely require more than that- some of these topics definitely require graduate math and physics classes. This is a HARD task, but I’ve found it very rewarding (albeit after leaving many head-shaped holes in my wall because of Jackson’s homework problems…)
     • Marble posted on 2009-04-20 at 10:23

       Sorry it’s taken me so long to reply – but having said that I’m sure you’re putting your time to better use rescuing your PhD ;)

       Text removed at Marble’s request.

       Replying to one other of your points -

       It has to be the most rigid substance ever (wave frequency is proportional to the medium’s rigidity) but not exert any force on the earth as it moves through the aether. Otherwise we’d have spiraled into the sun eons ago.

       Given that the planet’s orbits are unexpectedly increasing (earth’s at 10m/cy according to this article), we’re certainly in no danger of spiraling into the sun. So I’ll point out that any drag upon the earth via aether could be masked by this phenomena. (As an aside – if I’ve got that unit right (cy = calendar year?), and making the large assumption of no change to the radial increase, 4 billion years ago the earth would have been at Venus’ current orbit. Life is postulated to have appeared around 3.5b years ago – so I guess extremophiles starting up give more complex life bit more breathing space allowing the earth to come to a more hospitable distance… Ahh – but wouldn’t the oceans have been ‘boiled off’ before then? Surely they couldn’t form so close to the sun – even if the earth is forming from orbital particles – approaching ice particles would have been vaporized right? – so where’s the primordial ooze? I didn’t realize they meant the ooze was molten lead ;)…sorry – got more distracted there than anticipated.

       Correction by Marble – I now realize that cy stands for centuries – which means I’m a factor of 100 off on my orbital distance calculations. However, it will be interesting to compare the corrected orbital variation with the circumstellar habitable zone taking into account solar luminosity variation.

       The orbital resonance is also an interesting feature of the planets as well that may point to a drag of some description too (otherwise you have a very weak electrical charge / dipole that keeps one half of the moon facing the other way etc – if you want to adhere to a previously more chaotic solar system within the last 10k years.).

       For the sake of closing this already delayed email; I was about to suggest that e=mc2 is not a reflection of matter being created or destroyed Text removed at Marble’s request.

       As far as I can tell – this isn’t an already existing wheel created by somebody else (aether wind is though). I do keep debating within myself whether this is a worthwhile expenditure of time… being naturally drawn to solving problems (particularly those not yet solved by anyone – rather than those designed to be solved just for the sake of it) I’ll probably never abandon it completely unless all my angles of attack end up in defeat. The reality is I need to get cracking on my own software so I can put it to a more certain financially productive use. ;)

       Harking back to an earlier conversation – here’s the picture I had in mind when I said that it doesn’t matter how much math you throw at gravity – it won’t do ‘that‘. You may want to check the quick time link on that page as well. Of course I’ll admit that if you (not you specifically of course) could model that behavior in a simulation – I’d be convinced it was gravity doing that. My intuition about gravity thinks it’s unlikely though – but of course, it is fallible.
     • Marble posted on 2009-06-24 at 06:13

       BTW – I saw the slashdot article on the model predicted gravity affect of Saturn’s moons causing ripples in the rings. Sounds like another chink in the EU’s armour – however I’d love to understand why (as seen in this image) the waves are not appearing on both before and after the moon on both the inner & outer rings at the same time. I.e. what makes the waves switch sides as the moon passes by? (Rhetorical question BTW).
3. Marble posted on 2009-05-05 at 22:34

   BTW I’ve stumbled across the Bohm interpretation for QM from a forum thread and was quite happy to see these guys had already headed down the same conceptual path I am want to go.

   I was very excited to see their explanation for the 2 slit experiment, because I already had come to a similar conclusion – although only a ‘pointy haired high level one’ of course- but effectively I would have explained it as something like a 3d standing wave effect (?-field they call it / pilot wave by another name I think) of aether particles caused by the emitter leading up to the expulsion of each photon / electron etc.

   I also came across Citation #2 (PDF) in wikipedia’s Bell’s Theorem entry ‘An intuitive analogy for EPR experiments’. Which is also very interesting and worth me trying to wrap my head around. But I’m glad to see there are (more knowledgeable) people who aren’t fond of the ‘collapsing wave function’ view of reality and despite the consensus view opposes them, I intuitively have to throw in with them. (Like I do with those pesky CO2 global warming skeptics ;)

   Reply
4. Dumb Scientist posted on 2009-06-05 at 10:21

   (Note by Marble: This conversation has been an extract of a private email conversation held with Dumb Scientist and originally was not intended for publication. Subsequently – some parts had been removed at my request that I didn’t want to see published in a public forum at this time.)

   (Ed note: I opposed the text removals but eventually decided to release some of the conversation rather than none of it. During the course of those negotiations, I made the following comments which I believe motivated Marble’s question.)

   I’m going to have to think about this. Your version cuts out topics I had been collecting notes on for use in my reply… (Ed. note: I went on to describe topics that were removed.)

   I was uncomfortable with this lack of openness from the beginning, but this has thrown me into a moral quandary. I really don’t know what to say- you clearly put a lot of time into all this at my request, but if I let my principles slip even a little I’m not sure where that will lead me.

   I’m probably going to be leaving the mainstream scientific field even if I manage to graduate, but that’s because I’m appalled at the closed-source habits and the unspoken requirement to publish in journals that charge $20 per article per person rather than returning the knowledge as open-source software/papers to the people who funded it in the first place: the taxpayers.

   Dumb Scientist is my personal refuge from all that. I’ll have to put some serious thought into how much I want to compromise on the original vision in order to continue this conversation.

   Reply
   • Marble posted on 2009-06-09 at 10:24

     From something in your last email – how/why do you view Open Science so passionately? I have a concern about open science being unwaveringly seen as an exclusively a Good Thing. I definitely think people should be educated / critical thinkers – but for example say truly strong AI is eventually created and is ‘open sourced’. Strong AI in my opinion would make unscrupulous governments near omnipresent/omnipotent with regards to controlling their populations including censoring all media. Not to mention the impact it would have on warfare. Now I seriously do not want particular countries to get their hands on strong AI (ignoring MAD which fails against suicidal attacks anyway) just taking into consideration their own oppressed populations. I’m not saying democracy is the be all and end all, obviously it isn’t – but I’d rather a democracy rise to global power over other forms of government because I think that’s the best bet of AI ending up being used altruistically. And for that to happen – (strong) AI at least shouldn’t be open science (and definitely not open source ;) ) Along those lines – I have similar concerns if a large enterprise invents AI (eg Sony for arguments sake) which could easily then corner many many markets on their terms. I’m not sure how that’d play out in the end – but you’re relying on the benevolence of the shareholders then – who are generally in it for maximal profit anyway…

     Reply
     • gkai posted on 2009-08-13 at 13:49

       Hum, a thought about strong AI: What are the chances for an oppressive (or a democratic, I think it would not make a big difference) government or a greedy corporation to keep a very intelligent (like, much more intelligent than them) slave in an obedient state? Hell, even a cooperative one? Just keeping it from doing whatever it just want?

       Slim, imho…

       True strong AI is, I think, synonymous from almost completely uncontrollable. The best one can hope is, at the initial building stage, add a set of core instinct that will turn out to make humans look like enjoyable pets, or interesting endangered species, or just so cute that they are impossible not to love, or like some slightly senile parent that nonetheless merit respect and love, and should be helped out of what he did when we were small and defenseless (I talk from the point of view of the AI here). And hope that those instincts are sufficiently self-consistent, entertaining and bring more joy than constraints and discomfort so that they are not worth being circumvented/rewritten…

       It could look like the strong AI is a exploitable prisoner at first. I do not see how this could continue for long if the intelligence gap is significant, i.e. it is a true strong AI qualitatively different from a team of very intelligent humans. Imho it makes as much chance as a pack of very intelligent wolves keeping a human slave to help them beat the other packs and devise clever tactics to bring those big mooses down without getting gutted like last winter…Then, as he was very helpful, why not a wife and children, so that we really become the uber-pack…then…. oups, we have become dogs ;-)
5. Someone posted on 2010-03-28 at 19:10

   (Ed. note: these comments were copied from a conversation about a map of dark matter from Hubble.)

   Nice pretty picture… especially when you consider it’s a picture of something that very possibly doesn’t even exist. …

   Reply
   • Abcd1234 posted on 2010-03-28 at 19:44

     It exists. Educate yourself.

     Reply
     • Dumb Scientist posted on 2010-03-28 at 19:57

       Thanks. It’s worth noting that the Bullet Cluster results you linked to are only the most recent development in dark matter’s nearly 80 year history:

       1933 – Zwicky studies the Coma cluster of galaxies and is surprised to find that these galaxies are orbiting each other much faster than he predicted based on their visible mass. He proposes that each galaxy actually contains much more mass than is visible.

       1959 – Measurements of galactic rotational velocities conflict with expected velocities based on the amount of matter observed to be present. The dark matter concept proposed by Zwicky is found to solve this problem too.

       1970s – Big Bang nucleosynthesis has trouble reconciling observations of high deuterium density with the expansion rate of the universe. Non-baryonic dark matter solves this problem as well.

       At this point, dark matter was simply an hypothesis. MOdified Newtonian Dynamics (MOND) was another hypothesis with equal weight. But then in 2006 measurements of the Bullet Cluster supported the dark matter hypothesis over the MOND hypothesis.

       Simultaneously, WMAP (2001-present) measured the microwave background radiation and independently confirmed the existence of dark matter. It also revealed an even larger amount of “dark energy” which confirmed the 1998 discovery that the expansion of the universe is accelerating.
     • painandgreed posted on 2010-03-29 at 10:03

       At this point, dark matter was simply an hypothesis. MOdified Newtonian Dynamics (MOND) was another hypothesis with equal weight. But then in 2006 measurements of the Bullet Cluster supported the dark matter hypothesis over the MOND hypothesis.

       I don’t think you could really say MOND had equal weight until 2006. I got my physics degree in the late 80′s/early 90′s and while MOND was often mentioned along with dark matter, it was usually as a footnote of other possibilities. Very few considered it a serious contender as it was complicated and failed to describe all but ideal models. Physicists like elegant physics which is the ability of simple equations to describe a complex situations. MOND required complex equations to describe simple situations.
     • Dumb Scientist posted on 2010-03-29 at 10:04

       (Ed. note: actually posted on 2010-04-06 at 10:59, but my limited comment nesting puts this out of logical order if the actual date is used.)

       I finished undergrad in 2004, and my experience was similar to yours. I was being overly conciliatory to MOND because in my experience non-physicists aren’t swayed by issues of elegance and simplicity.
     • Someone posted on 2010-03-29 at 12:34

       However, just this last year it was found that prior surveys of background radiation had missed the mark widely. Further, there is strong new evidence contradicting the assumption that we are in a “typical” region of the universe, simultaneously calling into question whether expansion is actually accelerating.

       Gotta keep up with the news, man!
     • Dumb Scientist posted on 2010-03-29 at 13:22

       However, just this last year it was found that prior surveys of background radiation had missed the mark widely.

       Huh? What “mark” did WMAP or COBE miss widely? Says who?

       Further, there is strong new evidence contradicting the assumption that we are in a “typical” region of the universe, simultaneously calling into question whether expansion is actually accelerating.

       WTF? The 1998 supernovae measurements I cited were measured over billions of light years, and have been confirmed by more recent measurements with higher precision. They’re confirmed by WMAP’s measurements of the background radiation, which encompasses nearly the entire observable universe. They’re also confirmed by Chandra data of galaxy clusters.
     • Someone posted on 2010-03-30 at 16:12

       My mistake. I was thinking microwaves, but it was gamma rays.
     • Dumb Scientist posted on 2010-03-31 at 05:42

       As you say, unidentified gamma ray sources aren’t relevant to the galaxy collision observations or dark energy acceleration observations in question. You’ve demonstrated true scientific spirit here by admitting a mistake. Kudos.
     • Dumb Scientist posted on 2010-04-09 at 09:24

       I am curious about something: since dark matter has to be strongly interacting enough to account for the anomalies observed in the rotation of galaxies (which is why it is presumed to be the majority of the gravitationally-interacting mass in the universe), how does that fit with the gravitation that we observe locally, in our solar system? And please don’t try to tell me that the gravitational interaction is too weak to notice on that scale, because if it did, then it would not have the requisite effect on galaxies, either. (If it interacted on weakly gravitationally, then there would have to be even more of it to have the observed large-scale effects, so that’s not an answer.) [Someone]

       The key is that most dark matter candidates don’t strongly interact, as shown by the Bullet Cluster observations. In fact, that’s what WIMP stands for: Weakly Interacting Massive Particle. Since dark matter only interacts via gravity, it only clumps together on the largest scales of galaxies; at the scale of individual solar systems most WIMP candidates should have a fairly uniform density. Depending on whether we’re dealing with cold or hot dark matter, clumping may occur at scales smaller than galaxies but to the best of my knowledge this hasn’t been confirmed experimentally.

       Locally uniform dark matter exerts no detectable gravitational force on planetary orbits because they’re much smaller than the typical distance between stars. This conclusion follows from reasoning similar to that used to solve the famous sophomore-level physics problem where one proves that gravity everywhere inside a hollow uniform sphere is identically zero.
     • Dumb Scientist posted on 2010-04-09 at 09:24

       What about the dark matter inside a sphere defined by the radius of a planet’s orbit? Doesn’t it exert a gravitational force which should show up in careful measurements of that planet’s orbital period? [Someone]

       Yes, but dark matter’s locally homogenous distribution means that the amount of dark matter in this sphere is very small compared to the mass of the Sun, so the corresponding force is also very small. Gauss’s law for gravity shows that the force due to this sphere increases linearly with respect to distance from the Sun, as opposed to point source gravity which has inverse square dependence. Incidentally, that’s similar to the gravity inside a spherical planet with uniform density.

       More specifically, the gravitational acceleration due to dark matter is g_dark = BigG*rho*radius, where BigG is Newton’s gravitational constant (6.67*10^-11 m³*kg^-1*s^-2, rho is the density of dark matter in kg/m³, and radius is measured from the center of the Sun in meters.

       A rigorous estimate of rho would start with a plausible total mass of the Milky Way’s dark matter halo, then use something like the NFW profile to predict the density at the Sun’s distance from the center of the Milky Way.

       But I’m pressed for time, so the standard density of dark matter at the Sun’s location is quoted as 0.3 GeV/cm³ (with an uncertainty of ~3x), and relativity says 1 GeV/c² = 1.78*10^-27 kg, so rho = 5.3*10^-22 kg/m³.

       Since the dark matter acceleration grows linearly with distance from the Sun, let’s examine its value at the maximum distance of Pluto from the Sun: 7.38*10¹² m. In that case, g_dark = 2.6*10^-19 m/s², which is less than a billionth of a nanometer per second squared. Compare that to the Sun’s gravitational acceleration at that distance: 2.5*10^-6 m/s². Even at the orbit of Pluto, the Sun’s gravity is 10 trillion times stronger than gravity due to dark matter.

       In contrast, the orbit of the Sun around the center of the Milky Way is affected by all dark matter in the sphere defined by the Sun’s orbit. Since the radius of this sphere is ~30,000 LY (which is much larger than the average distance between stars), the non-clumpy distribution of dark matter is irrelevant on that scale so it exerts a measurable gravitational force. As a result, a smooth galactic dark matter halo affects the velocity curves of stars vs. galactic radii, but has no significant effect on planetary orbits.
     • Dumb Scientist posted on 2010-04-09 at 09:25

       The Pioneer anomaly exhibits anomalous acceleration toward the Sun at an extremely large radius, which seems to match the effect due to a uniform dark matter distribution in the Solar System. [Someone]

       That’s probably not related to dark matter because the effect doesn’t show up in the orbital periods of the outer planets, and the equivalence principle holds that dark matter should affect planets exactly the same as probes. Plus, even after accounting for local enhancements in the density of dark matter around the Sun, dark matter is too weak on this scale to explain the Pioneer anomaly.
     • Dumb Scientist posted on 2010-04-09 at 09:27

       Most of your derivation assumes local uniformity of the dark matter halo, which might not be a good approximation if dark matter is cold enough to clump together on smaller scales. [Someone]

       Yes, but WIMPs don’t interact via the electromagnetic force. This makes them invisible (dark) but also means they can’t run into each other (“solid matter” is only solid because the atoms’ electron shells repel each other).

       As a result, most astrophysicists believe that normal matter (with its unique clumping ability) acts as “seeds” for dark matter clumping. That’s the case on galactic scales, and maybe stars and planets can capture sufficiently cold (i.e. slow) dark matter. But there probably aren’t any planets or stars made entirely out of dark matter, which (if in the solar system) would be detectable using ranging measurements to Cassini and other probes.

       Of course, physicists are studying the issue of small-scale dark matter clumping. For instance, the flyby anomaly might be related to earth-bound dark matter, and a bound on the dark matter density in the solar system has been derived from planetary motions.

       A significant amount of earth-bound dark matter would imply that our measurements of the density of the Earth via GRACE, GOCE and Gravity Probe B (all of which include dark matter) and seismic data (which don’t include dark matter) should disagree. As far as I know they don’t show significant discrepencies, so this places an upper bound on the mass of Earth’s hypothetical dark matter core.
     • Dumb Scientist posted on 2010-04-09 at 09:27

       What about the Cuspy halo and missing satellites problems? [Someone]

       I study spatio-temporal gravity anomalies on the surface of the Earth, which is a radically different subfield than dark matter astrophysics. The basic principles are similar, though. We both use natural laws (Newtonian gravity or GR) to predict the effects of all known masses on observations. Then we subtract these known effects from the observations and study the nature of the residual errors.

       My experience is that when new observations examine the background model (i.e. the “known masses”) at finer spatial and temporal resolutions, a number of strange anomalies appear. Most of these anomalies only end up requiring minor tweaks to the model, though. The general public rarely hears about these “boring” anomalies and tweaks, so they tend to believe that every new anomaly precedes a revolution on par with the discovery of the precession of Mercury’s orbit.

       The missing satellites problem looks like an interesting problem for people who study galactic evolution on a very fine resolution. The missing cusps at the centers of galaxies are also very small features compared to the galactic halos, and might be related to the ubiquitous super-massive black holes in the same places.

       In contrast, MOND’s problems are at the largest scales. The existence of at least some CDM appears to be virtually unchallenged at galactic cluster length scales, though (like all models) its smaller scale features are still being explored and may eventually help determine which varieties of dark matter exist. MOND proponents have to include hot neutrinos, which are a form of non-baryonic dark matter. Also, MOND requires dark matter to avoid predicting radial temperature profiles which disagree badly with observations.

       Update: A new technique uncovers at least one of those “missing satellites.”
     • Dumb Scientist posted on 2010-04-09 at 09:28

       MOND explains the Bullet Cluster’s collision velocity better than DM. [Someone]

       Actually, the Bullet Cluster’s velocity isn’t extraordinarily high in the Lambda-CDM model, even though it’s higher than average.
     • Dumb Scientist posted on 2010-04-09 at 09:28

       MOG and TeVeS are claimed to reproduce Bullet Cluster observations. [Someone]

       Dark matter explains the Bullet Cluster observations using both Newtonian gravity and general relativity. As a result, I’m suspicious that modified gravity can only explain these results by modifying general relativity. TeVeS also doesn’t explain Boomerang data and requires some dark matter to simultaneously fit lensing and rotation curves.
     • Dumb Scientist posted on 2010-04-09 at 09:29

       Here’s a counter-example to the Bullet cluster. [Someone]

       Yes, Abell 520 doesn’t have the same angular separation between the x-ray emissions and the mass inferred from weak lensing observations. But this may simply mean that the galaxies in Abell 520 have a lower ratio of dark vs. normal matter than the galaxies in the Bullet Cluster.

       That’s something MOND or TeVeS or MOG can’t easily explain, because modified gravity should be universal so it should always imply the same ratio of “dark matter” to normal matter (although not all normal matter is equally visible). Therefore dark matter more easily explains the dark galaxy called VIRGOHI 21 which might have ~1000x as much dark matter as visible matter (compare to ~10-20x for the Milky Way’s ratio). Dark matter also explains the apparent lack of a universal dark matter density profile better than modified gravity for similar reasons.

       But here’s another cluster that confirms the Bullet Cluster isn’t just a fluke.
     • Dumb Scientist posted on 2010-04-09 at 09:29

       But we haven’t detected any WIMPS or axions, despite decades of attempts. [Someone]

       Yes, it’s difficult to tell which varieties of dark matter are prevalent in our galactic neighborhood. Many groups are working on this problem, and some recent papers seem interesting. But, as you say, at the moment no unambiguous detection events have risen above the signal to noise ratio.
   • ShakaUVM posted on 2011-01-17 at 20:39

     (Ed. note: these comments were copied from here.)

     There was an interesting musing by the author of a recent Scientific American about how dark matter may interact with its own kind by forces other than the ones that cause normal matter to interact with its own kind. According to the musing (which the author rejects), dark matter operating under such forces could form complex systems, maybe even an unseen parallel universe where “people” live lives like ours, as unaware of us as we are of them. All undetectable, except by their gravitational attraction on us. [Black Parrot]

     This is something I’ve been musing on recently. What if there were, say, 4 or 5 universes all operating in the same “space”, but invisible to each other because they’re in another parallel dimension or 3-brane or something like that? According to string theory, pretty much nothing can escape from a 3-brane except gravity – which might explain why gravity is so weak, as it could diffuse in more directions than EM radiation. Since EM radiation can’t escape, these things would be effectively invisible, as it appears to be.

     It could also explain that Dark Flow thing.

     Reply
     • Dumb Scientist posted on 2011-01-17 at 21:49

       Last year Tanuki64 asked a similar question, and I referred him to an anecdote from my senior year of physics undergrad. In 2004, I presented a similar idea to an astrophysicist in my department:

       I wonder if “dark matter” is the result of gravitational interactions with galaxies in parallel universes. Suppose parallel universes exist in the same physical “space” we inhabit, and only interact with each other (and us) via gravity. The galaxies in different universes would then clump together, but their disks wouldn’t necessarily be aligned. So the total gravity would appear similar to a spherical halo of dark matter. This would explain the too-high velocities of stars at the edges of galaxies and the too-high velocities of galaxies in superclusters.

       In 2004, I didn’t have enough experience to understand why that astrophysicist rejected my idea by saying that I was trying to explain something we don’t understand by invoking something else that we understand even less. Several years later, though, I started to see some cracks in this idea:

       2009-07-25 Update: I don’t think my hypothesis is consistent with the Bullet cluster data.

       2009-07-27 Update: Also, I wonder if galaxies in my imaginary parallel universes really would clump together. They’d certainly be gravitationally attracted to each other, but if each universe has roughly the same density of galaxies, they’d typically have a long way to fall towards each other. As a result, they’d be moving so fast that I doubt any damping mechanisms could have brought them to rest in ~13.7 billion years. But… what if they formed in the same place initially? That would make sense because supermassive black holes likely play a large role in proto-galaxy formation. Gravitational collapse in one universe would trigger collapses in other universes leading to galaxies with small relative velocities. But in that case, it seems like the disks would be aligned because disk formation probably doesn’t involve a large percentage of actual physical collisions (any actual astronomers want to help me here?). I think this would result in the wrong velocity profile for stars versus distance from the center of the galaxy? Oh, and all these stars in different universes would cause gravitational lensing events to occur with a much greater frequency than has been observed by the OGLE. Galaxies with non-aligned disks would look even weirder- that implies lensing with bizarre relative velocities.

       It could also explain that Dark Flow thing.

       Perhaps. But given the above problems with such an idea, it’s more likely that the Great Attractor is simply a massive supercluster in our own universe, even if it’s already passed over the horizon.
     • ShakaUVM posted on 2011-01-17 at 22:26

       Interesting, Khayman. Why do you say it’s inconsistent with the Bullet Cluster data? It seems to me that if you had two clusters on top of each other, one in our 3-brane, and one in a neighboring one, and they collided with a cluster just in our 3-brane, that the result would be more or less consistent with the result of the purported dark matter separating from the normal matter.
     • Dumb Scientist posted on 2011-01-17 at 23:22

       First, note that dark matter halos have always been observed around normal matter galaxies. Your example should therefore involve at least four galaxies- two visible colliding galaxies in our own universe, each with a counterpart galaxy that occupies the same physical space in the other universe/brane, which are therefore colliding in that other universe too.

       In conventional theory, dark matter interacts with normal matter and with itself only through gravity. These dark matter halos would fly right through each other in a galactic collision, whereas normal matter can’t because it also interacts via other forces, most notably the electromagnetic force. That’s why the Bullet Cluster’s separation of x-ray vs. matter distribution tends to support dark matter rather than MOND.

       But if these dark matter halos are simply made of ordinary matter in another universe, they would collide with each other in that universe in the same way that ordinary matter collides in our universe. Thus I don’t believe that our hypothesis would result in the same separation of x-ray vs. matter distribution observed in the Bullet Cluster.
     • Dumb Scientist posted on 2011-01-17 at 23:38

       Aside from the fact that I’ve never seen evidence of a galaxy without a dark matter halo, the Bullet Cluster has two opposing lobes of dark matter, indicating that each galaxy in the collision had a dark matter halo that flew right through the other dark matter halo. Another similar collision also has two opposing lobes of dark matter. If a collision is ever observed with only a single lobe of dark matter, that would be consistent with our hypothesis. (Though the other objections I raised would still apply.)
     • Dumb Scientist posted on 2011-01-18 at 01:52

       Well, okay, rarely seen a galaxy that might not have dark matter.
     • ShakaUVM posted on 2011-01-19 at 13:17

       That’s a very good point. Though I suppose if there were lots of parallel dimensions connected by gravity, they could exhibit similar behavior, if the matter was distributed throughout the dimensions so that they couldn’t collide, and only interact through gravity.
6. Dumb Scientist posted on 2010-10-12 at 18:12

   (Ed. note: this comment was copied from here.)

   There’s yet to be any evidence the universe doesn’t run on very specific mathematical rules. For example, there’s a very good reason for inflation having to do with the ‘pressure’ at high energy states. [ShakaUVM]

   Huh? Your customarily vague but authoritative comment which doesn’t include an “IANAP” disclaimer will just reinforce the disturbingly common impression that physicists are bullshitting about concepts like inflation and dark matter.

   The cosmology course I’ve mentioned was taught by Dr. Nanopoulos using Kolb’s The Early Universe. He pointed out that physicists have known for decades that something like inflation is required to explain the isotropy of the cosmic microwave background radiation. Kolb disusses these topics in chapter 8, though his overview is somewhat dated now. WMAP has since observed temperature fluctuations on the 10^-5 level, which matches predictions based on modelling quantum fluctuations in the early universe. More precisely, inflation predicts that these fluctuations would deviate slightly from the perfect scale invariance expected in a universe without inflation. After 7 years, WMAP can exclude the possibility of a scale invariant spectrum by more than 3 standard deviations. The WMAP results also show that the universe is perfectly flat, at least to within the limits of measurement. Inflation isn’t necessary for the universe to be perfectly flat, but it’s sufficient to explain what may seem like “fine-tuning” at first glance.

   That’s why physicists think inflation happened, but it’s an argument based on how relativistic causality affects the large-scale thermodynamics of the universe, not pressure. Pressure is at least tangentially relevant to almost every physics problem imaginable, though, and inflation is no exception. I’ve explained that dark energy’s negative pressure acts as a kind of anti-gravity. Later, Dr. Stoeger (Jesuit priest, astrophysicist working for the Vatican Observatory) observed that “There is, of course, a much deeper connection between inflation and dark energy. The only way we can really conceive of inflation occurring in the early universe is under the influence of a large amount of vacuum energy, which is a type of dark energy. This dark energy must be quickly transformed into the particles and radiation at the end of inflation. So, it’s not at all clear if there is a relationship between the dark energy which drove inflation and the dark energy which we have evidence is driving the gentle acceleration of cosmic expansion now. It may be that the dark energy now may be a remnant of the dark energy left over from the very early universe.”

   Then there’s the problem of heavy exotic particles predicted by most GUT’s; the only one I’m familiar with is the magnetic monopole. In my senior year, I took electrodynamics using the standard Griffiths 3rd ed. Page 327 shows how symmetric Maxwell’s equations appear in the presence of magnetic monopoles, and Griffiths opines that they “beg for magnetic charge to exist.” My fondest memory of that class is problem 8.12 on page 362, along with footnotes 11 and 12 on the same page. Griffiths guides the reader through a proof that quantization of electric charge can be deduced (rather than assumed a priori) if the universe contains just one magnetic monopole. Years later in graduate electrodynamics, the standard Jackson 3rd ed covers magnetic monopoles in a similar fashion in sections 6.11 and 6.12 on pages 273-280.

   A period of rapid inflation after the universe becomes too cold (i.e. not energetic enough) to create magnetic monopoles would greatly reduce their initial density, which in turn would explain why they’re so hard to find (Kolb p239,266). Thus there’s a decent reason for believing that inflation took place at comparatively low energy states.

   There’s been occasional theories tossed about with C (or other cosmological constants) changing values, but there hasn’t been any actual evidence for it. [ShakaUVM]

   First, variations in dimensionful constants are very difficult to interpret, so most of these theories concern variation of dimensionless constants. In fact, Dirac’s original argument was specific to dimensionless constants. Second, physicists discuss the possibility of the fine structure constant varying over cosmological time because “actual evidence” was published in 2001. I previously called it “weak evidence” because it hasn’t been reproduced. But glossing over its publication isn’t helpful.

   Third, I’ve explained that the 1983 redefinition of the meter means that physicists now talk about varying the index of refraction of free space rather than varying the speed of light. Oddly, varying speed of light (VSL) theories seem to use the old terminology. Fourth, notice that these VSL theories are designed to replace inflation as the explanation of the CMBR’s isotropy. However, if the fine structure constant changed the universe would look different, so in VSL theories other physical “constants” have to vary in just the right way to agree with experiments.

   However, my understanding of it is that there’s a rather large asymmetry between the amount of energy needed to create a matter particle vs. a much higher number to create an antimatter particle. Not the 1% they were talking about, but something like an order of magnitude more free energy. [ShakaUVM]

   Roger W. Moore was right: your statement is incorrect. In 1930, the Dirac equation hinted at the existence of what would later be called holes in the Dirac sea after their experimental discovery in 1932. Dirac postulated that the vacuum is filled with both positive and negative energy states, but that almost all of those negative energy states are filled. Positive energy states are familiar particles of matter like electrons, while the corresponding negative energy states are antimatter particles like positrons. Creating an electron requires filling a state with energy E, while creating a positron requires emptying a state of energy -E… which is exactly the same amount. They’re not even 1% different; the asymmetry mentioned in the article is that of CP violation which is now well established thanks to experiments like BaBar. CPT symmetry isn’t violated, though, which is more relevant here. As Kolb says on page 160: “… particle and antiparticle masses are guaranteed to be equal by CPT invariance.”

   So there are very strong theoretical reasons to believe that matter and antimatter particles have the same masses, and thus require the same energy to create. But what about experimental evidence? Well, remember that the spectrum of the hydrogen atom is derived in undergraduate quantum mechanics. The proton is ~2000x more massive than the electron, but a common homework problem (#3) replaces the proton with a positron to form positronium. Any imbalance between the masses of electrons and positrons would have been detected in experiments decades ago. As you can see, physicists showed in 1984 that any imbalance must be less than 1E-7. Then in 2008 you claimed that the imbalance was ~10, which means you’re only off by a factor of ~100 million compared to research performed 24 years earlier. If “being off by two orders of magnitude is just ignorant” then you must have gone to plaid. Smoke if you got ‘em…

   … Not the 1% they were talking about, but something like an order of magnitude more free energy. Hence the free energy ended up mainly creating bosonic matter. [ShakaUVM]

   Huh? Papers exploring bosonic matter do exist, but they don’t seem relevant. Given the context, you appear to be saying that creating antimatter requires ~10x more energy than creating matter (false), so the free energy would end up mainly creating matter rather than antimatter.

   But what could you possibly have meant by inserting the word “bosonic” in a sentence where it doesn’t seem to make any sense? Bosons and fermions are both types of indistinguishable particles in quantum mechanics. Fermions have half-integer spin, like protons, electrons, antiprotons and positrons. Bosons have integer spin, such as photons and mesons. Some implications of this distinction can be deduced using nonrelativistic quantum mechanics, such as the fact that fermions obey the Pauli exclusion principle while bosons actually attract each other into the same state (Griffiths 1st ed p179). The connection between these statistics and spin is simply assumed in nonrelativistic quantum mechanics, but it can actually be deduced using relativistic quantum field theory.

   Perhaps you’re trying to say that most of the energy ended up creating bosons like photons? That’s true, and in a sense WMAP sees the echo of these photons from when the universe was only ~400,000 years old. But these photons were created in such profusion because in the early (10^-6 seconds) universe, matter and antimatter were almost exactly balanced. There were only 30,000,001 quarks for every 30,000,000 anti-quarks (Kolb p159). This conclusion is motivated by evidence like the observed baryon-to-photon ratio of the universe, and the extraordinary stability of the proton (p157,158) which suggests that baryon number is conserved. Cosmologists seem to prefer theories which dynamically evolve this imbalance around the GUT epoch (10^-34 seconds old) from perfect symmetry at the Big Bang through processes like “sphalerons” (p184) which might be capable of violating baryon number, and/or other processes capable of CP violation on the required scale.

   Whatever caused this slight imbalance, all the antimatter and nearly all the matter were quickly annihilated, releasing exactly equal amounts of energy for the matter and antimatter particles. Most of this energy was released in the form of gamma rays that stretched over the eons to become what we now call the cosmic microwave background radiation.

   … For scientific theories at the forefront of technology, there have been a tremendous number of mistakes made, as in, ALL the scientists were wrong. Remember the Michelson-Morley experiment? It invalidated basically every theory and model we had to that date. The notion that inertia somehow doesn’t apply to light — even though light is sorta a particle, or rather, has particle-like traits — was completely unexpected. [ShakaUVM]

   Huh? The Michelson-Morley experiment has nothing to do with your “notion that inertia somehow doesn’t apply to light.” Inertia wasn’t the problem, galilean relativity was. Light most certainly does have inertia in special relativity, as anyone who designs solar sails could tell you. If you don’t know any, just open Jackson 3rd ed to page 259, calculate a Poynting vector as in equation 6.109, divide by c² as in equation 6.123, and remember that non-zero inertia is necessary for non-zero momentum. Griffiths 3rd ed makes a similar point in equation 8.29 on page 355 using different units.

   As the story goes, Einstein first conceived of special relativity based on his daydream of racing a beam of light, which uncovered a fundamental inconsistency between Maxwell’s equations and Newtonian mechanics. Also, as I’m explaining to Marble, physicists had recognized serious problems with the luminiferous aether decades before the Michelson-Morley experiment. In other words, Einstein’s discovery of special relativity was based on pre-existing considerations; the Michelson-Morley experiment just confirmed his hypothesis and made it more accessible to the average scientist.

   well that’s ok, because the study was about Electromagnetic fields, not magnetic fields, which are two different things. As far as I am aware, there is absolutely nodanger to humans from a magnetic field. [miro f]

   Wrong. All Electric and Magnetic Fields are the same thing. They are components of the same EM field Tensor. … Thus, if you have a pure magnetic field (like that of the earth) with the 3 E’s in F being 0, it is always possible to construct an L st F` has nonzero E’s. L is a Lorentz Transformation, so the physical significance is that you can always transform relativistically to a frame of reference where a magnetic field picks up an electric field and even radiation EM fields (such as Lienard-Wiechert potentials), making it an “electromagnetic” field. [XchristX]

   Just recalling my high school physics, if I’d have written it (and you were responding to a troll, IMO), I’d just have said that all electrical waves are electromagnetic in nature. Maybe talked about the history of ether, and how the electrical and magnetic components provide the medium for each other. [ShakaUVM]

   Oy vey. You propose to replace an overcomplicated but correct explanation with vague gibberish about aether? Trust me, there are enough people babbling about aether as it is. Before he debuted as a climate change contrarian, Marble repeatedly stressed that relativity wasn’t a “real” explanation, and that aether was more compatible with his young-earth creationist cosmology. After appearing as a climate change contrarian, gkai endorsed einsteinhoax.com… which should be self-explanatory to anyone who doesn’t think relativity is controversial. Instead, try this:

   Einstein’s theory of special relativity shows us that space and time aren’t separate entities, but are instead two sides of the same coin that we call spacetime. In exactly the same way, electricity and magnetism are two sides of the coin called electromagnetism. Even a purely magnetic field will behave like an electromagnetic field if you’re moving relative to it.

   Or, more relevantly:

   Electromagnetic fields (otherwise known as “light”) are made up of chunks called “photons” which carry an energy inversely proportional to their wavelength. In other words, small wavelength photons like gamma rays can kill you because each photon carries a lot of energy; large wavelength photons like microwaves barely interact with the human body at all because each photon carries a very small amount of energy. Interestingly, quantum mechanics says that multiple photons are absurdly unlikely to “gang up” on any molecule in your body, so mutations and cancer aren’t a concern as long as each photon has less energy than would be needed individually to damage molecules in our bodies. The only other effect we need to worry about is thermal dissipation of microwaves in water and fat molecules (i.e. the reason microwave ovens make tasty burritos.) But I don’t see how that’s significantly different from worrying about getting too close to a caveman’s fire. You might as well worry about spooning.

   Besides, conservation of energy doesn’t apply across very short time scales – you can borrow energy from the future as long as you pay it back quickly. That’s how nuclear decay works – the radioactive atoms are trapped in an energy well; if they couldn’t borrow energy from the future they’d never decay. But their energy levels fluctuate, and depending on how deep the well is is how long the half-life of the atom. A shallow well will decay rapidly, a deep well can do a really long time before decaying to a lower energy state. What happens is the atom borrows energy from the future and then immediately repays it when it transitions to a lower energy state. [ShakaUVM]

   When I was in high school, I used to read a lot of pop-science books about physics which claimed that energy conservation is uncertain on short time scales. Then in my junior year of college I took quantum mechanics using Griffiths, though the 1st edition was standard back in 2001. Imagine my surprise when I made it to page 115:

   … It is often said that the uncertainty principle means that energy is not strictly conserved in quantum mechanics– that you’re allowed to “borrow” energy deltaE, as long as you “pay it back” in a time deltaT ~ hbar/(2*deltaE); the greater the violation, the briefer the period over which it can occur. There are many legitimate readings of the energy-time uncertainty principle, but this is not one of them. Nowhere does quantum mechanics license violation of energy conservation, and certainly no such authorization entered into the derivation of Equation 3.151. But the uncertainty principle is extraordinarily robust: It can be misused without leading to seriously incorrect results, and as a consequence physicists are in the habit of applying it rather carelessly. [Griffiths, Intro to QM, 1st ed]

   I’d recommend working through example 3 on page 114; it describes the relationship between spontaneous decay and the energy-time uncertainty principle. Also, chapter 8.2 discusses tunneling in the WKB approximation and alpha decay on page 281 and problem 8.4 on page 283. Notice that these explanations don’t misuse the energy-time uncertainty principle by invoking it the way you do.

   My first research advisor explained this issue by saying that the position-momentum uncertainty principle is subtly but crucially different from the energy-time version because there is no “operator” for time in quantum mechanics. Position/momentum/energy operators exist in the sense that those properties can be measured in the lab, but time can’t be measured in the same way. In fact, John Baez shows that there can’t be any such time operator.

   A much better example of the energy-time uncertainty principle can be seen through a spectroscope. The spectrum of any atom corresponds to the energies of photons falling from one electronic state to another. Given that quantum mechanics only allows electronic states to exist at certain quantized energy levels, one might assume that the spectra would be infinitely sharp. In other words, photons emitted when an electron falls from level 2 to level 1 might seem like they should always have exactly the same amount of energy and thus the same wavelength. But in fact, the photons will have slightly different energies, and this broadens the spectral peak.

   The exact degree of broadening turns out to be directly related to the “lifetime” of the transition between the two states in question. Due to the energy-time uncertainty principle, a transition with a short lifetime will have a large uncertainty in energy and thus have a broader peak (Sakurai 1st ed p341-345).

   Later, I took another year of nonrelativistic quantum mechanics using Sakurai 1st ed as a physics grad student, but never took relativistic quantum field theory. However, most physicists seem to agree with this wikipedia summary:

   One false formulation of the energy-time uncertainty principle says that measuring the energy of a quantum system to an accuracy deltaE requires a time interval deltaT > h/deltaE. This formulation is similar to the one alluded to in Landau’s joke, and was explicitly invalidated by Y. Aharonov and D. Bohm in 1961. The time deltaT in the uncertainty relation is the time during which the system exists unperturbed, not the time during which the experimental equipment is turned on.

   Another common misconception is that the energy-time uncertainty principle says that the conservation of energy can be temporarily violated – energy can be “borrowed” from the Universe as long as it is “returned” within a short amount of time.[13] Although this agrees with the spirit of relativistic quantum mechanics, it is based on the false axiom that the energy of the Universe is an exactly known parameter at all times. More accurately, when events transpire at shorter time intervals, there is a greater uncertainty in the energy of these events. Therefore it is not that the conservation of energy is violated when quantum field theory uses temporary electron-positron pairs in its calculations, but that the energy of quantum systems is not known with enough precision to limit their behavior to a single, simple history. Thus the influence of all histories must be incorporated into quantum calculations, including those with much greater or much less energy than the mean of the measured/calculated energy distribution.

   Do cows use quantum entanglement? no. Do sheep? no. Plants do. Why would I eat the *smarter* lifeform?

   Depending on your theory of quantum mechanics, you might believe that all systems are entangled. So yeah, they all do. [ShakaUVM]

   There are many theories of quantum mechanics: Bohr’s early theory is used as a high school teaching aid, Schrodinger’s theory is taught in undergraduate physics and widely used in industry while relativistic quantum field theory is unwieldy but even more accurate.

   But that’s irrelevant to entanglement, so presumably you’re talking about one’s interpretation of quantum mechanics. That term is preferred because different interpretations of the same theory are mathematically identical and (probably) experimentally indistinguishable.

   Either way, you seem to be talking about the many worlds interpretation, which in the most pedantic sense possible implies that all systems are entangled. Well, not exactly all systems, just those within each others’ past light cones. Relativity is a harsh mistress.

   I shouldn’t have to mention that something which can explain everything explains nothing. Physicists reserve the term “entangled” for systems that violate Bell’s Inequality because such systems are entangled regardless of one’s interpretation of quantum mechanics.

   I’ve previously pointed out that “some physicists propose that the brain is a quantum computer rather than a classical analog computer, but I’m heavily skeptical of this claim because a quantum computer’s inherent vulnerability to decoherence effects seems to make it more complicated. …”

   Here I’m mainly referring to Roger Penrose and Stuart Hameroff’s proposal that microtubules in human neurons are sufficiently well-isolated that quantum entanglement lasts long enough to play a role in human thought before decoherence takes effect. If true, this bold idea could revolutionize the fields of neurobiology, artificial intelligence, quantum computing, and possibly others. For instance, a whole brain emulation project would suddenly have to deal with the no-cloning theorem from quantum information theory.

   But your definition of “entangled” reduces that bold idea to meaningless gibberish. Because if everything is entangled already, there wouldn’t be anything special about the brain using quantum entanglement. Oh, and since our brain structure is so similar to other mammals, the quantum brain idea would also apply to sheep and cows.

   And, importantly, it’s not a matter of “whatever universe you can imagine is out there somewhere!”–the possibilities are strictly limited by deterministic evolution of the wavefunction and the initial conditions of the universe. [kebes]

   There may be no married bachelors in any branch of the multiverse, but there’s one right now where all the atoms of oxygen in my room spontaneously moved into a corner and I’m suffocating to death. That’s a lot of possibilities. There certainly could be a dimension without shrimp. [ShakaUVM]

   Ever since that cult’s movie was inflicted on the public, physicists have been overwhelmed trying to explain that the many worlds interpretation (MWI) isn’t the license to speculate wildly that most people seem to think it is. As kebes said, there are more constraints on what can happen than merely “no married bachelors” which would allow for anything except for logical contradictions.

   Even in classical statistical mechanics, the probability of all the oxygen in a room moving into a corner isn’t zero, just absurdly small. In the MWI, this fact is explained by saying that the relative amplitude of this “suffocation” branch of the wavefunction is absurdly small. The absolute square of this relative amplitude is proportional to the chance that we find ourselves in that branch.

   At first glance, it might seem like the fact that the suffocation branch has non-zero amplitude really does mean that you’re experiencing such a confusing death right now. However, there’s a subtle problem having to do with wave function collapse. In the Copenhagen interpretation, it’s easy to explain why measurements of a photon’s polarization are only ever horizontal or vertical. The photon’s superposition “collapses” onto one or the other. In the MWI, this doesn’t happen. Instead, we say that the photon’s superposition becomes entangled with its environment. More melodramatically, the entire universe splits in two, and in each branch I find either horizontal or vertical polarization.

   So far, so good. But there’s no “preferred basis” in quantum mechanics. So why don’t we ever measure a photon to be in a superposition of horizontal and vertical? In other words, if wave functions don’t collapse, why do we experience the world as though it’s classical and not quantum mechanical all the way up like the MWI says it is?

   I’ve briefly addressed this issue while debating an atheist. Most physicists think that “decoherence” is a good explanation. Dr. Zurek calls this “environment-induced superselection” (einselection). The really short version is that only certain superpositions consistent with classical physics are observable.

   Unfortunately, I don’t understand this topic well enough to make it more comprehensible. Anyway, what I’m trying to say is that I doubt your suffocation branch would be robust against einselection. Thus there probably isn’t a version of you suffocating in your room right now.

   Of course, none of that implies Anya was lying about the possibility of a dimension without shrimp. A few improperly bonded amino acids at exactly the right time certainly could have changed evolutionary history without that branch having an absurdly small relative amplitude or conflicting with einselection. The world with nothing but shrimp, on the other hand, seems less plausible. That said, I could easily understand why Illyria would tire of it quickly… if it actually existed.

   … To use your own words, it’s like a modified Salem Hypothesis that lets non-physicists like climate scientists think that their hand-waving is a legitimate form of argumentation, whereas everyone else is an anti-scientific nutjob. It probably comes from their field being only tenuously considered a science. … [ShakaUVM to me on 2010-05-22]

   Oh, I guess you don’t fucking know what you’re talking about, do you? [ShakaUVM to me on 2010-05-19]

   I was just annoyed that you called me a non-physicist. I let it pass once with your rather insulting Salem Hypothesis thing, but I don’t let things go twice. To re-iterate what I said before, you don’t know what you’re talking about when you’re trying to insult me like that. If you label me a non-physicist, then I’ll have to start calling you a weather man. [ShakaUVM to me on 2010-05-22]

   … please feel free to continue deluding yourself that scientists are the shining beacon of logic in an otherwise inhospitable world. [ShakaUVM to Dumnezeu on 2010-07-25]

   When you say “research” do you mean enrolling in graduate physics courses at an accredited university to learn about the radiative physics of the atmosphere? (This would involve some kind of objective measure of your ability to construct and solve equations.) … [~30 pages later] … Like before, you seem to mistakenly believe that you’re being insulted by angry climate scientists. For instance, you claimed to be insulted when I implied that you were a non-physicist… just because you don’t have a graduate (or even undergraduate?) physics degree. … [~15 pages later] … Your error analysis seemed to repeatedly assume that climate models are empirical, not dynamical… among other mistakes which would be inexplicable for someone with a graduate or undergraduate (?) degree in physics. [Dumb Scientist]

   Two years of physics as an undergraduate … [ShakaUVM]

   Yes, I find it easy to believe that you’ve taken freshman and sophomore level undergraduate physics. This is where your list of accredited physics courses stops, which I also find easy to believe. Among many other things, it explains why you later repeated gibberish from your confused high school biology teacher regarding thermodynamics.

   What I don’t understand is why you’re posing as a physicist when your answer to my first question clearly should have been “no” (but technically still isn’t.) Perhaps you’re thinking two years of physics courses is roughly half of a four year physics bachelor’s degree? Hardly. Two years of lower-level physics at a semester-based school is a grand total of 4 courses. During my first two years of college I also only took 4 physics courses at a semester-based school because during that time I was an aerospace engineering major. Then I switched to physics and took 8 more physics courses before the siren song of the real world called to me. Years later I moved to a quarter-based school and finished my physics bachelor’s degree by taking 11 physics courses. However, I retook the first quarter of quantum mechanics and all three quarters of electrodynamics, so those don’t count. Since 3 quarters = 2 semesters, that’s a grand total of ~16 semesters of physics.

   So two years of physics courses is roughly 25% of the way to a physics bachelor’s degree which is basically only useful for getting into physics graduate school. For me this involved taking a further 12 physics courses that made the previous ones look like kindergarten coloring tests. Your mileage may vary, but you’re likely ~15% of the way towards starting the research which will eventually lead to your physics PhD. It would be prudent to wait until you have a little bit more experience before slandering an entire subfield of physicists.

   … I also read a great deal. … [ShakaUVM]

   After reviewing the surfacestations FAQ (where he fumbles with that lid) and comparing it to your claims, I’m inclined to agree with you. But I’ve already addressed that kind of “research.” Remember that pop-science books aren’t the same as a structured education with TAs who beat the subject-specific stupid out of their students, impart subject-specific background and make them prove that they’ve learned subject-specific somethings at a certain level. Your graduate physics education sounds like a “recipe for disaster.”

   … perfect score on the SATII Physics Test, 5 on the AP Physics test … [ShakaUVM]

   I googled the SATII Physics test (called the SAT subject test after 2005). It’s taken by non-physicists like pre-medical students because it covers algebra-based introductory physics. The AP Physics test is taken in high school, which reminds me of Walter Wagner. He accuses physicists of dishonesty and/or incompetence when they point out that the LHC isn’t going to destroy the world. To back up his claims, Wagner repeatedly stresses that he got a perfect score on the math portion of a high school teacher’s exam. He doesn’t seem to understand that he’s babbling about a topic far more advanced than anything on that test. Maybe a good score on the physics GRE would be relevant, but even it only tests senior-level undergraduate physics without testing graduate-level physics understanding at all.

   I taught methods in solving physics problems, etc., including an undergraduate quarter spent on error analysis. [ShakaUVM]

   Hmm… instructors teaching physics courses are usually required to at least have the bare minimum physics bachelor’s degree. Even teaching assistants are required to be at least two years ahead of their students, which means most physics TA’s start teaching during their third year of physics-track (not algebra-based) physics courses. I hope for the sake of UCSD’s reputation that you’re not talking about courses offered by the physics department. Possibly you’re referring to computer science classes, which you would indeed be qualified to teach.

   … what am I missing? [ShakaUVM]

   A graduate physics education, or the disclaimer “IANAP”. Take your pick. Either one would be a massive improvement over the current situation where you repeatedly pose as a physicist while spouting vague gibberish.

   For example, when VShael joined the chorus of slashdotters accusing cosmologists of incompetence and/or unscientific dogma, you agreed with him. As I’ve shown, there are many reasons why cosmologists favor dark matter over MOND. Just because other scientists don’t agree with Dr. McGaugh doesn’t mean they’re falling prey to dogma, acting unscientifically, or ignoring him. In fact, McGaugh published several papers asserting that the ratio of the first two CMBR peaks definitively rules out cold dark matter. As of 2010-10-10, those papers were cited 11 times, 47 times, 33 times, and 4 times, respectively. Furthermore, I’ve repeatedly linked to Dr. McGaugh’s website even though I don’t endorse all of his conclusions.

   Reply
   • Dumb Scientist posted on 2010-10-13 at 17:23

     Stop copying my posts onto Dumbscientist.com. [ShakaUVM]

     Nah.

     Perhaps you got confused because both of our usernames start with ‘S’? … Especially since your ad hominem includes assigning me claims of “gibberish” by linking to posts that aren’t even by me. If you want to argue a particular topic, do so – but by this laughably dishonest (did you think that people would just never bother to check your references?) attempt at discrediting someone on the internet, you’re just exploding any cachet you had with anyone who cares. [ShakaUVM]

     That link defines the word “gibberish” as I mean it in this context:

     What you need to understand is that what you said, while sounding philosophical to the uneducated is gibberish. To a scientist what you said sounds something like “What if what I thought was my hand was actually an ardvaark in disguise”.

     I’ll see your Griffiths and raise you a Feynman, Greene, and Gershenfeld. … If your interpretation of your introductory textbook was correct, semiconductors wouldn’t work. Read up on them some time.

     Sure. Just quote the page numbers and passages (like I did) which support your claim that conservation of energy doesn’t apply across very short time scales. Make sure that you’re not misinterpreting the concept of quantum foam to support a confused pop-science notion that energy conservation is violated by much slower processes like nuclear decay or anything happening in semiconductors.

     The fact that you’re taking seriously Penrose’s idea means that you have no fucking idea what you’re talking about.

     I guess I should’ve mentioned that “I’m heavily skeptical of this claim.”

     You might want to read up some time on baryogenesis, CP violation, and the big question about why there’s more matter in the universe than anti-matter.

     Ironically, the reference I gave to Kolb p157 is the first page of chapter 6… which is called “Baryogenesis.” I suppose I should’ve mentioned (twice) that CP violation is considered along with baryon number violation caused by processes like sphalerons.

     … Khayman, you’ve gone completely off the deep end … If you’re a scientist, as you purport to be, you’re a very bad scientist. … Since you state with such certainty you know the answer, I suggest calling Stockholm and letting them know you’ve got all the answers. It’ll make a nice break from your work studying clouds. … the ad hominem from you is getting intolerable … you sound more like the unibomber than a physicist. … If you want to keep writing these long, unibomber-like screeds …

     That’s Mr. Unabomber to you.

     Update: ShakaUVM isn’t the only contrarian comparing scientists to the Unabomber.

     Reply
   • Dumb Scientist posted on 2010-10-14 at 18:05

     Light has *momentum*. Technically, it’s just p = hf. I’m not sure why you need to reference a textbook, but you seem to go about everything in bizarre and unproductive ways. [ShakaUVM]

     Because that’s from early 1900′s quantum theory, not classical electrodynamics. My point is that even in the 1800′s, it should’ve been clear that light has momentum and thus inertia just by examining Maxwell’s equations.

     Also, you meant to say that momentum is p = h/lambda, right? E = hf is the undergraduate notation for energy.

     Update: Since the M-M interferometer didn’t use a single photon source (most affordable interferometers still don’t) the expression for a single photon’s momentum needs to be multiplied by the number of photons per unit volume in the beam. The classical Poynting vector approach isn’t counting photons and thus doesn’t require such a correction.

     … I only consider objects with mass to have inertia, as a massless object cannot have an inertial reference frame that makes any sense. A number of people agree with me. For example, Greene equates inertia with particles with mass.

     That’s an interesting definition; I’ve never heard of it before. Like Einstein, I prefer to call “E/c²” the “inertia” of light because that’s the conceptual breakthrough which resolved the original pesky factor of 4/3 that kept appearing in Lorentz’s derivation of “E=mc²“:

     And because the em-mass depends on the em-energy, the formula for the energy-mass-relation given by Thomson (1893) and Wien (1900) was m = (4 / 3) E / c² (Abraham and Lorentz used similar expressions). Wien stated, that if it is assumed that gravitation is an electromagnetic effect too, then there has to be a proportionality between em-energy, inertial mass and gravitational mass. However, it was not recognized that energy can transport inertia from one body to another and that mass can be converted into energy, which was explained by Einstein’s mass–energy equivalence.

     The idea of an electromagnetic nature of matter had to be given up, however, in the course of the development of relativistic mechanics. Abraham (1904) argued (as described in the preceding section #Lorentz transformation), that non-electrical binding forces were necessary within Lorentz’s electrons model. But Abraham also noted that different results occurred, dependent on whether the em-mass is calculated from the energy or from the momentum. To solve those problems, Poincaré in 1905[A 8] and 1906[A 9] introduced some sort of pressure of non-electrical nature, which contributes the amount − (1 / 3)E / c ² to the energy of the bodies, and therefore explains the 4/3-factor in the expression for the electromagnetic mass-energy relation.

     It also happens to explain the paradox discovered by Poincare regarding conservation of momentum in different frames when using Lorentz transformations to transform between inertial reference frames.

     In other words, the reason Einstein is a household name but Lorentz is known only to scientists can be traced back to the fact that Einstein recognized that light has inertia.

     You’re quite wrong that it was an expected result – read, and look at the number of times they kept trying to get the experiment to “succeed”.

     First, I just said that as the story goes, Einstein based special relativity on his daydreams and pre-existing problems with the aether. That’s the official story, but I find it hard to believe that Einstein really didn’t think about the Michelson-Morley experiment during this process. However, that’s what Einstein claimed and the story is at least remotely plausible given his stratospheric genius.

     Second, I didn’t say Michelson and Morley expected it. I just said Einstein claimed to not find it surprising or informative in his development of special relativity, and that aether timeline I linked should provide convincing evidence that the aether had already been shown to be logically inconsistent long before Michelson and Morley started their work. That same timeline also contains a handy list of all Michelson and Morley’s experiments, but thanks for the redundant link.

     Reply
     • ShakaUVM posted on 2010-10-15 at 01:58

       That’s the official story, but I find it hard to believe that Einstein really didn’t think about the Michelson-Morley experiment during this process. However, that’s what Einstein claimed and the story is at least remotely plausible given his stratospheric genius.

       There’s people on both sides of the issue. Some say he wasn’t aware, other’s that he was aware, still others that he was peripherally aware but relied more on his gedunkenexperiment.

       Personally, it doesn’t bother me that much, since either way Einstein had the genius to derive special relativity when other people were trying to figure out the experimental error in the M-M experiment. Really though, I think the overarching point here (as Kuhn makes) is that science can be wrong, but (if given enough evidence) will paradigm shift to a better, more accurate model.

       Naturally I’m sure you are going to mis-summarize this entirely reasonable statement of mine as saying that scientists are all lying liars who lie a lot, like my response to Vshael.
     • Dumb Scientist posted on 2010-10-15 at 02:02

       Actually, I’m ignoring it on dumbscientist altogether.
     • ShakaUVM posted on 2010-10-15 at 02:10

       Actually, I’m ignoring it on dumbscientist altogether.

       Naturally.

       Wouldn’t want to make yourself look bad, like last time.

       Shaka: Here’s four thesis statements, some of which I’ve never raised before. Please agree or disagree.
       Khayman: I already have answered them!
       Shaka: No you haven’t
       Khayman: I don’t have time to be your tutor!
       Shaka: Just answer yes or no to each of them.
       Khayman: I have a paper to write!
       Shaka: You’d save time by just answering yes or no
       Khayman: I’ve referenced 50 papers which contains my answer somewhere!
       Shaka: What’s your thesis statement? Answer yes or no to each, and why.
       Khayman: I’ve already answered them and I hate repeating myself! …and reading back through your Dumb Scientist blog reveals exactly that – that you never answered any of the questions before, and only one after.

       Thanks for making the record. You sounded just like the Creationists that get really evasive when pressed to explain some of their answers. In fact, saying that they don’t have time to educate people is one of their favorite lines.
     • Dumb Scientist posted on 2010-10-15 at 02:20

       Actually, it’s because you bore me when you stop talking about physics. Also, you previously seemed to want me to stop copying your statements. But I’m copying all of these right now.
   • Dumb Scientist posted on 2011-01-28 at 16:21

     (Ed. note: This comment was copied from here.

     … I’ve thought a bit more about that question of if photons of light have inertia. While they do have momentum, I am more convinced now that they don’t have inertia. One can define inertia as the resistance of mass to changes in velocity, right? The root cause of this classic Newtonian mechanic is the interaction of objects with the Higgs field, right? That’s what grants particles inertia. But photons do not interact with the Higgs field, so they don’t have inertia. [ShakaUVM]

     I’ve never taken graduate-level elementary particle physics, so I don’t know much about the Higgs field. My classmates who have taken those classes and moved on to work at the LHC tell me that most theorists consider the discovery of the Higgs boson to be very likely.

     Personally, I’m not sure how to rule out the notion that inertia is caused by viewing zero point energy in an accelerating reference frame. I’m sure the Higgs field really is more likely to be the cause of inertia, but right now I don’t have enough time to wade through the relevant literature to learn why.

     Anyway, you’re right to say that the “inertial mass” of an object can be measured by placing it in a container and determining how much force is necessary to accelerate the container. Or, rather, how much extra force is necessary compared to experiments performed when the container is empty.

     Now imagine a one dimensional container with perfectly reflective inner walls. I claim that if this container is filled with photons having total energy E, then more force would be needed to accelerate the container after filling it. More precisely, the experiment would show that the container has an extra “inertial mass” E/c² compared to its empty state.

     Here’s why.

     If the container isn’t accelerating, the trapped photons will exert equal pressure on both walls of the container as they’re reflected back and forth, just as with solar sails. Accelerating the container, though, will cause the mirror on the bottom to reflect those photons more often with more force than the mirror on the top. Thus on average the bottom mirror will experience more pressure than the top mirror, and this pressure asymmetry will mimic an “inertial mass” of E/c².

     In fact, I think any method of measuring inertial mass would conclude that photons have inertia. That’s because active gravitational mass in general relativity is defined by the stress-energy tensor, which includes the energy (and momentum) in electromagnetic fields. Active and passive gravitational masses need to be equal to conserve momentum, and the equivalence principle says that passive gravitational mass equals inertial mass.

     In other words, the container curves spacetime more when it’s filled with photons. Therefore its gravitational mass has increased, and via the equivalence principle so has its inertial mass.

     This depends on my interpretation of the equivalence principle (and the principle itself) being correct. It also implies that pressure has inertia, because pressure contributes to the stress energy tensor. Interestingly, that implies tension has negative inertia because tension is just negative pressure. Greg Egan uses this concept masterfully in a short story called Hot Rock.

     Reply
   • Dumb Scientist posted on 2011-01-31 at 17:27

     I no longer think the “inertial mass” of a container full of photons will be due to more frequent collisions with the bottom mirror. After further thought, that’s not true. But the second argument still seems compelling, so I wonder how the effect would show up in a literal container experiment. Perhaps the bottom mirror would reflect a slightly blue shifted photon, and the top mirror reflects a slightly red shifted photon? This might explain the pressure asymmetry but depends on quantum mechanics to show that the momentum change of reflecting a photon depends on the wavelength. I was hoping to come up with an explanation that depended only on special relativity, but no such luck.

     Reply
   • ShakaUVM posted on 2011-01-31 at 20:23

     Well, even though breathless science journalists report that the Higgs Field is “source of mass”, it’s not the only one. As you pointed out, E=MC^2, so any energetic entity has a gravitational mass under relativity. Nuclei of atoms get a significant fraction of their apparent mass from the nuclear binding energy from the strong force.

     I think the Higgs Field is better described as the “source of inertia”, as opposed to the source of mass, as the mechanism by which it operates is basically what we think of as the Newtonian definition of inertia at normal scales – particles that interact with it are resistant to changes in their velocity. Since photons do not interact with it at all, that’s why I was saying that you could argue that photons do not have inertia (on top of the fact that you cannot apply a force to them to change their velocity).

     It’s really just a semantic argument, though.

     Reply
   • Dumb Scientist posted on 2011-01-31 at 23:23

     Nuclei of atoms get a significant fraction of their apparent mass from the nuclear binding energy from the strong force.

     It’s true that an individual nucleon (a proton or neutron) gets a significant fraction of its mass not from its constituent quarks but from the strong force. For example, a proton’s mass is 938 MeV but its two up quarks and single down quark only sum to (at most) 12.4 MeV.

     But nuclei of atoms are actually slightly less massive than the individual neutrons and protons that comprise them. I believe this effect has a different sign than the binding of quarks into individual nucleons because quarks can’t ever be physically separated. It’s also much smaller; iron nickel has the most tightly bound nucleus, and its binding energy is only 8.8 MeV per nucleon. Though vastly larger than chemical energies, this is still less than one percent of its mass.

     As you pointed out, E=mc², so any energetic entity has a gravitational mass under relativity.

     … and thus also has an inertial mass through the equivalence principle. My failure to explain how the extra inertial mass of E/c² manifests in the container experiment doesn’t invalidate the equivalence principle. If light didn’t exhibit inertial mass in that sense, the container would be a magical fuel tank for a photon rocket. Most of the constraints of relativistic travel are related to the need to accelerate the reaction mass in the fuel tank. If the photons can simply be stored in a mirrored container and accelerated for free until they’re allowed to escape out the back of the rocket, that would constitute an unbelievably efficient space drive. And I mean “unbelievably” quite literally here.

     I think the Higgs Field is better described as the “source of inertia”, as opposed to the source of mass

     Photons don’t interact with the Higgs, and photons certainly have zero rest mass. Most of the introductory material I’ve read seems to use that terminology, but again I’m not a particle physicist.

     Since photons do not interact with it at all, that’s why I was saying that you could argue that photons do not have inertia (on top of the fact that you cannot apply a force to them to change their velocity).

     Velocity is a vector, so gravitational lensing and reflection are both examples of changing the velocity of light. Refraction is an example of changing the direction and the speed of light. In all these cases, equal and opposite reactions occur but are simply too small to observe. The sun is gravitationally attracted to a beam of light that it deflects, a solar sail experiences a force, and the material interface that refracts the light really does experience a force as it deflects and slows down each photon.

     Reply
   • Dumb Scientist posted on 2011-01-31 at 23:24

     It turns out nickel is most tightly bound. News to me.

     Reply

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