I read popular physics: Explosions at the edge

This is part of my series where I read physics articles in Scientific American, and rant about barely related tangents in order to provide “context”.

After the November issue, which didn’t really have any physics articles at all, the December issue has two major articles! One is astronomy, the other one is about the fusion reactor, ITER. But, after complaining about how all the physics articles are about astronomy, it looks like I’m still choosing the astronomy article. The ITER article is just a bunch of photos of the engineering, and I don’t have much to say about that.

So, the astronomy article is “Explosions at the Edge” (or that’s how it’s titled in print). It’s about the surprisingly diverse ways that massive stars can go supernova. For example, rather than simply exploding, a star may first shed a layer of gas, and then the subsequent explosion will collide with that gas, producing a prodigious burst of light.

[Read more…]

I read popular physics: Orbital Aggression

This is part of my series where I read physics articles in Scientific American, and publicly ponder what choices in life brought me to this point. This month’s “physics” article is not really about physics at all, but that’s the bed I made.

The article is titled “Orbital Aggression” (paywalled), and it’s about the possibility of space war. Space war refers not to war rained down from space, but rather war that targets satellites. Especially in the US, satellites play an important role in communication and imaging, such as transmitting credit card transactions or monitoring weather. They’re also used by the military, again especially the US military, which occupies every corner of the globe.

[Read more…]

COVID and perspectives on causality

Recently, people have been circulating a statistic from the CDC that says 94% of death certificates listing COVID-19 as a cause of death also list at least one other cause of death. For instance, if someone catches COVID, can’t breathe anymore and dies, perhaps the doctors would also list “Respiratory failure” as one of the causes of death, in addition to COVID. Come to think of it, why do only a third of COVID deaths include respiratory failure as a cause, how exactly is COVID killing people if not by causing respiratory failure?  Before parading around this statistic, I have to ask, do we really understand what it’s even saying?

That misleading statistic came to my attention because a friend wrote a Vox article about it. He brings not a medical perspective, but a psychology perspective, discussing the cognitive biases that make people bad at understanding causation.

Causation is also a favorite topic of mine as well, although I come at it from a different set of perspectives: philosophy, physics, and law. And although I don’t have medical expertise, it’s not hard to find the medical standard of causation from google, so I include that at the end.

[Read more…]

Basic epidemic math

We are living in an epidemic of armchair epidemiology, and far be it for me to contribute by giving my own feverish take as an expert of an unrelated field. Therefore, I solemnly swear that I will make no predictions about the present pandemic. I am not paid enough to make such predictions–and if you did pay me I would consider it my professional duty to find you a better expert.

What I can do for free, is read up on basic epidemiology, and digest the maths for you, dear reader. My sources: Wikipedia’s article on mathematical modeling and compartmental models, and some lecture notes I found. My expertise: during my PhD in physics, I frequently worked models like the one I’m about to discuss, only with electrons instead of people.

The SIR Model

The very first epidemiological that one learns about, is the so-called SIR model. This model divides the population into three groups (“compartments”): susceptible (S), infected (I), and recovered (R). Susceptible people are those who could be infected; infected people are those who are currently infectious; recovered people are those who are no longer infectious, and are immune to infection. “Recovered” can be a bit euphemistic, since one method of “recovery” is dying. Another method of “recovery” is by developing symptoms strong enough that the victim knows to quarantine themself (becoming less infectious).

[Read more…]

MBTI: A lukewarm analysis

MBTI, or the Myers-Briggs Type Indicator, is probably the most popular personality test. It contains four axes: Introverted/Extraverted, iNtuitive/Sensing, Thinking/Feeling, Judging/Perceiving. If you take the test, you may be assigned one of 16 personality types, for instance I would be INTJ.

The MBTI is regarded as pseudoscience, perpetuated by the popular consciousness and HR departments rather than academic research. One time I asked a personality psychologist and she said it was just so far off from reality that nobody even bothered talking about it. Psychologists prefer to talk about another personality model, called the Five Factor Model, also known as The Big Five. This has five axes, labeled Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism (OCEAN).

I’ve often remarked that although the Five Factor Model is supposedly more scientific, it’s clearly a lot less compelling. And isn’t that something? I couldn’t honestly say that I find astrology compelling, or ear candles compelling, but the MBTI, now that’s some yummy pseudoscience. I have some remarks on what makes MBTI a pseudoscience, what makes it compelling, and what its problems are.

[Read more…]

“Cat Person or Dog Person?” survey explained

Picture of a cat with sciencey stuff. "Survey says 75% are cat people ... and 25% are wrong"

Several weeks ago, I published the “Cat Person or Dog Person?” survey.  It’s a silly survey that asks the same question over and over again in different ways, and then you see the results.  It’s basically an interactive art piece, and your interpretation of it is as valid as mine.

Now that several weeks have passed, I’m going to explain some of the thought process behind the survey.  This should be thought of as “explaining the joke”–the survey was funny, this explanation will not particularly (cat meme excepted).

[Read more…]

Stop supporting nuclear power

A powerful way to convince people of a policy, is to get them to believe they understand the policy’s disadvantages. People believe they understand the disadvantages of nuclear power: radioactive waste, and the possibility of catastrophe. Skeptical/sciencey people tend to think these disadvantages are small, because they know people often give too much weight to highly unlikely outcomes. But in fact, the main thing holding back nuclear power, is that it’s not economically competitive.

Public understanding of nuclear power is based on decades of political debate, with one side arguing that nuclear power is much cleaner than the alternatives, and the other side pointing to catastrophes like Chernobyl or Fukushima. I recall being taught these advantages and disadvantages in grade school science classes. They were also encoded into Sim City. But in the real world, the advantages and disadvantages of different energy sources are not timeless. They depend on the details of the technology. It is not possible to understand a complex and ever-changing issue based on what you were taught in grade school.

If you take nothing else away, I would like to at least persuade you of this: a) you don’t understand the disadvantages of nuclear power as well as you thought, and b) your position of “more nuclear power” should be updated to “nuclear power is an option that experts should consider”.  If you’d like to learn more, read on.

[Read more…]