Posted February 9th, 2013 in Science. Tags: Climate, Diagrams, Graphics, Introductory-Science, No Equations, Pedagogy, Physics.
Before the Industrial Revolution in the 1800s, the concentration of carbon dioxide (CO2) in the atmosphere was about 280 parts per million (ppm). This means that for every million molecules in the atmosphere, about 280 of them were CO2.
However, climate.nasa.gov shows that we’ve burned so much coal and oil that atmospheric CO2 is now approaching 400 ppm. It hasn’t been this high for millions of years. The last time Earth’s atmosphere had this much CO2, our species (and many others) hadn’t yet evolved. (more…)
Posted July 22nd, 2012 in Relativity 3. Tags: Advanced-Science, Conversation, Equations, Physics.
Reythia asked me to write something uplifting, so I copied a recent conversation about general relativity and hypothetical sources of energy. (more…)
Posted April 7th, 2012 in Physics. Tags: Climate, Diagrams, Intermediate-Science, No Equations, Pedagogy, Physics, Quickie.
The overwhelming majority of scientists endorse this statement:
“Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.” [IPCC Summary for Policymakers, 2007]
Here, “most” means at least 50% of the 0.55°C rise since 1950. Some mistakenly call this an “alarmist exaggeration” but it actually understates the human contribution because it’s easy to incorrectly conclude that the other 50% of the trend might be caused by natural forcing variations: (more…)
Posted December 31st, 2011 in Psychology. Tags: Introductory-Science, No Equations, Pedagogy.
When I mention Dumb Scientist, a common reaction is “Wait… you called your website WHAT?” I usually deflect this question by joking that irony is all the rage these days, but the truth is that I chose this pseudonym because I think many people accidentally imply that intelligence is fixed at birth. For instance, many parents praise their children by saying they’re smart, but this tactic backfires:
Since Thomas could walk, he has heard constantly that he’s smart. … as Thomas has progressed through school, this self-awareness that he’s smart hasn’t always translated into fearless confidence when attacking his schoolwork. In fact, Thomas’s father noticed just the opposite. “Thomas didn’t want to try things he wouldn’t be successful at,” his father says. “Some things came very quickly to him, but when they didn’t, he gave up almost immediately, concluding, ‘I’m not good at this.’” With no more than a glance, Thomas was dividing the world into two- things he was naturally good at and things he wasn’t. [The Power (and Peril) of Praising Your Kids]
My early education was similar to Thomas’s, and it seems we’re not alone: (more…)
Posted October 17th, 2010 in Math. Tags: Graphics, Introductory-Science, No Equations, Quickie.
Dr. Benoît B. Mandelbrot passed away last Thursday at the age of 85. He’s best known for coining the term “fractal,” so it might be appropriate to remember him by looking at some pictures of the Mandelbrot set. He discovered this hauntingly beautiful fractal shape while exploring the mathematics of imaginary numbers. His discovery inspired generations of scientists and mathematicians, some of whom have recently found a 3D version that they call a Mandelbulb. (more…)
Posted July 19th, 2009 in Physics. Tags: Climate, Conversation, Diagrams, Intermediate-Science, No Equations, Physics, Pseudoscience.
One part of a recent survey caught my attention:
The strongest correlate of opinion on climate change is partisan affiliation. Two-thirds of Republicans (67%) say either that the Earth is getting warmer mostly because of natural changes in the atmosphere (43%) or that there is no solid evidence the Earth is getting warmer (24%). By contrast, most Democrats (64%) say the Earth is getting warmer mostly because of human activity. … The divide is even larger when party and ideology are both taken into consideration. Just 21% of conservative Republicans say the Earth is warming due to human activity, compared with nearly three-quarters (74%) of liberal Democrats. [Pew Research Center] (Skip to videos, data, index.)
In other words, most of the general public appears to believe that the existence of abrupt climate change A large-scale change in the climate system that takes place over a few decades or less, persists (or is anticipated to persist) for at least a few decades, and causes substantial disruptions in human and natural systems. (formerly known as anthropogenic ‘Human-caused’ global warming) is a question of politics rather than science. (more…)
Posted May 24th, 2009 in Physics. Tags: Intermediate-Science, No Equations, Physics, Quickie.
According to the standard solar model, the Sun’s brightness steadily increases because helium ash slowly builds up in its core. The introduction of heavier elements like helium forces the Sun to fuse hydrogen faster in order to prevent gravitational collapse, so it shines brighter as it ages. The Sun was ~25% dimmer 4 billion years ago compared to now.
Liquid oceans had already formed 4 billion years ago, so Earth’s temperature must have been above the freezing point of water. A faint young Sun presents a paradox: how could a 25% dimmer Sun warm the Earth enough to develop liquid oceans? (more…)
Posted April 25th, 2009 in Politics. Tags: No Equations, Religion.
Many issues in American politics confuse me, but the widespread opposition to gay marriage truly boggles my mind. In a bizarre turn of events, California banned same-sex marriage, then Iowa struck down a similar ban. Until just recently, the U.S. was one of the few western nations that refused to decriminalize homosexuality. Miss California became a GOP star last week because of her opinion on this issue. My personal reaction, on the other hand, was similar to Jon Stewart’s: (more…)
Posted April 16th, 2009 in Science. Tags: Intermediate-Science, No Equations, Physics, Quickie.
I’ve previously called evolution and the Big Bang “theories” to confront widespread confusion regarding the differences between theories and hypotheses. However, using the word “theory” in these instances might be a subtle mistake. It may even be partially responsible for the systemic communications barrier between scientists and the general public. (more…)
Posted March 28th, 2009 in Astronomy. Tags: Conversation, Intermediate-Science, No Equations, Physics, Pseudoscience, Religion.
Marble and I have previously discussed creationism and evolution, but our conversation later centered on a non-standard cosmology known as plasma cosmology (popularized as the “Electric Universe”). (more…)
Posted February 26th, 2009 in Software. Tags: No Equations, Software.
As a computational physicist, I’m often running programs that consist of many nested for-loops. At the moment, my outermost loop cycles through millions of data points and various inner loops explore tens of thousands of parameters. I’m always fiddling with the settings on the inner loops in ways that cause the run time to vary between 10 seconds and 10 weeks.
Annoyingly, it’s not always easy to predict how long the program will run after each set of modifications. Also, my code occasionally has bugs which make it hang indefinitely. When a program’s expected run time is measured in weeks, it’s reassuring to see regular progress reports. Otherwise I worry that the program has silently crashed.
At first I just slapped a print statement into the outermost for-loop, encased in an if-then statement which only activated once every 1000 loops. The print statement used the time elapsed since the start of the loop and the progress made to estimate the time remaining. It looked a little like this (plus some type casting): (more…)
Posted February 19th, 2009 in Biology. Tags: Introductory-Science, No Equations, Quickie.
I used to go scuba diving, but I routinely got seasick on the boat. Since I had nothing better to do while leaning over the water, I wondered why I had to go through this wretched experience. I understood the origins of physical pain– an animal that didn’t realize it had sprained an ankle would likely hurt itself even more rather than waiting for it to heal. But why should I feel nauseous when on a boat? I wasn’t being hurt by the waves, so this incapacitating condition wouldn’t have provided any advantage to my ancestors and therefore shouldn’t have been favored by natural selection. (more…)
Posted January 6th, 2009 in Psychology. Tags: Introductory-Science, No Equations, Quickie.
As a young boy, I was often intimidated by beautiful women. I only began to conquer this social anxiety when I concluded that the situation was symmetrical; women probably thought the same thing about handsome men. Later, I began to notice that many women don’t agree with my early conclusion. As evidence, here’s a conversation from Seinfeld:
Elaine: “Whoa! Walking around naked? Ahh… that is not a good look for a man.”
George: “Why not? It’s a good look for a woman.”
Elaine: “Well, the female body is a… work of art. The male body is utilitarian, it’s for gettin’ around, like a jeep.”
Jerry: “So you don’t think it’s attractive?”
Elaine: “It’s hideous. The hair, the… the lumpiness. It’s simian.”
George: “Well, some women like it.”
Elaine: “Hmm. Sickies.”
Posted January 2nd, 2009 in Philosophy. Tags: Introductory-Phil., No Equations, Pedagogy, Quickie.
I have a tendency to get attached to my beliefs, because in a very real sense they’re the only possessions which can’t be taken from me. I’ve poured countless hours of effort into them, whether I derived the belief independently or found them in another person’s writings. I find it easier to be an intellectual parasite in this sense, because independently deriving beliefs is much harder. But some beliefs can’t be easily falsified, so critically examining them is often just as difficult as independently discovering them. Either way, the prospect of abandoning any of my beliefs is painful because it involves admitting I was wrong. I always find that difficult; the shame of admitting my mistake and the difficulty of re-aligning my worldview pose serious challenges. (more…)
Posted December 5th, 2008 in Biology. Tags: Introductory-Science, No Equations, Quickie.
My mother always tells me to bundle up before I go outside during the winter, because otherwise I’ll “catch a cold.” When I first learned about the germ theory of disease, I thought she was wrong. Cold doesn’t make you sick, I thought. Germs make you sick.
Recently, it’s become obvious that I was wrong and she was right. (more…)