That time IFLScience wrote about my field

As you can see, I took a brief blogging break… and during Asexual Awareness Week too.  But I don’t believe in apologizing for that sort of thing.


Two years ago, I spotted an IFLScience article about my particular field of research.  The article’s title?  Crucial Superconducting Theory Confirmed.  I remember chortling over the absurd idea that superconductivity would be solved, and that the first place I’d hear about it would be IFLScience of all places.

As I read the article, I realized how familiar I was with the research being discussed.  I knew Chandra Varma, a famous superconductivity theorist.  I had already read the scientific article they were talking about.  And one of the authors on the paper was a close colleague.  Small world, eh?

Anyway, I found the article interesting as a tiny little case study on science popularization.  Let’s go through the article, starting with the title.

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Explaining the light mill

 

A crookes radiometer, as described in the text

Image source: Wikipedia

The light mill, also known as the Crookes radiometer, is a little curiosity that can be found in stores at science museums, or in the offices of physics professors. It consists of four vanes, each painted white on one side, and black on the other. The vanes are placed in a bulb, under partial vacuum. When you shine light on the radiometer, the vanes spin around, with the white sides facing forward (counter-clockwise in the above image). A demonstration is shown in the video below.

Supposedly, the Crookes radiometer is an educational tool, but I can’t for the life of me determine what lesson it’s supposed to teach. Because if you ask how it works, the correct explanation is far beyond the ability for most people to understand. I have a Ph.D. in physics, and I still couldn’t understand it! There are numerous internet sources that identify “thermal transpiration” as the correct explanation, but fail to explain what that means or why it happens. So instead I found explanations in scientific literature,1 and now I will share the explanation with you.

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FTA part 4: Anthropic reasoning

This is the fourth and final part of a series discussing the Fine Tuning argument (FTA). The outline is here.

Mundane multiverses

A “multiverse” is a set of multiple sub-universes, which together comprise a single super-universe. The idea is that the universe that we know is a single sub-universe, and there are multiple other universes like ours. So we can imagine another sub-universe where everything is the same, except that ever coin flip comes up on the opposite side.  Or a sub-universe where everything is the same, but we’re all evil and have goatees. Or another sub-universe where

Typically, when physicists talk about parallel sub-universes, what they mean are non-interacting sub-universes. So, you can’t ever talk to the evil goatee’d version of yourself. Although, people sure like to imagine that sort of thing in sci-fi.  So let’s talk about the kind of parallel universe that we could, in principle, interact with. What if I told you that this kind of parallel universe is one we already know exists?

To travel to a parallel universe, just hop in a space ship, and travel 4 lightyears over to Proxima Centauri. You will find a universe exactly like ours, except that the sun is different, and the planets are different, and the constellations are different.

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FTA part 3: Ignorant hypotheses

This is the third part of a series discussing the Fine Tuning argument (FTA). The outline is here.

Uncertainty vs Ignorance

Earlier, I showed this plot showing probability distributions for three possible hypotheses of the universe. The FTA contends that the naturalism hypothesis predicts distribution A, and the God hypothesis predicts distribution B.

A graph showing three possible probability distributions. A is a very broad probability distribution. B is a sharp probability distribution centered at x_0. C is a sharp probability distribution centered away from x_0.

Three possible probability distributions. x0 marks the parameters of the universe that we have in the real world.

I will refer to a distinction that is commonly made between “uncertainty” and “ignorance”. “Uncertainty” refers to a situation where you don’t know what’s going to happen, but you at least have probabilities, a way to quantify how much you don’t know. “Ignorance” refers to a situation where you don’t know what’s going to happen, and you don’t even know how much you don’t know. When we compare probability distributions in the FTA, the probability distributions are just cartoons.  We don’t have any real probabilities.  We’re operating from a state of ignorance, not uncertainty.

Or, in other words, we pulled these probability distributions out of our asses.

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FTA part 2: Prediction distributions and inflation

This is the second part of a series discussing the Fine Tuning argument (FTA). The outline is here.

Comparing Hypotheses

Previously, I explained how the Fine-Tuning argument assumes this kind of picture:

A graph showing the probability of life vs the parameters of the universe. The probability is sharply peaked at x_0.

The probability of life is sharply peaked. x0 marks the parameters of the universe that we have in the real world.

Does this graph mean that life is unlikely? No, not necessarily. It depends on the probability distribution of the parameters of the universe. For example, here are three possible probability distributions A, B, and C. Under probability distribution A, or C, life is very unlikely. Under probability distribution B, life is much more likely.

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The Fine-Tuning Argument: A walkthrough

The Fine-Tuning Argument (FTA) is one of those standard arguments for the existence of God. The argument goes that humans can only arise when the parameters of the universe are tuned exactly right. And while it’s possible that we just got lucky, the argument goes that it’s far more likely that God did the tuning.

The standard way to talk about the FTA is delve into a bunch of math equations.  Not that there’s anything wrong with math, but here I wanted to write an in-depth overview that doesn’t talk about the math.  There will, however, be a lot of physics.  The goal here is not to refute the FTA (although refutations will occur incidentally), but to explore it, and to understand how we test hypotheses about the universe.

Outline

(Links to be added later)

1. The Fine-Tuning Argument: A walkthrough
2. Prediction distributions and inflation
3. Ignorant hypotheses
4. Anthropic reasoning

Perma-link to entire series

The parameters of the universe

The core premise of the FTA is that the universe is fine-tuned. Which is to say, the probability of life looks like this:

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The Second Law and its misuses

An OrbitCon session brought to my attention to the fact that Steven Pinker spouts a lot of bullshit about the Second Law of Thermodynamics. (The Second Law is, “entropy cannot decrease over time in a closed system.”) In Pinker’s book, Enlightenment Now, he begins by refuting the creationist argument that the Second Law contradicts the theory of evolution. This is easy to do, you just say that the earth isn’t a closed system, and dramatically point at the sun. But Pinker then proceeds to forget about the sun, and argues that the Second Law of Thermodynamics explains poverty. I don’t have the book available, but Pinker has written an essay along similar lines:

Poverty, too, needs no explanation. In a world governed by entropy and evolution, it is the default state of humankind. Matter does not just arrange itself into shelter or clothing, and living things do everything they can not to become our food. What needs to be explained is wealth.

Here’s the thing: creationists are really really wrong about the Second Law. There’s plenty of room to be less wrong than creationists, but still really really wrong. For those of us who have taken an interest in fighting creationism, we know we can just point at the sun and be done with it. But just because you’re familiar with this argument, please don’t mistake that for an understanding of the Second Law. Don’t be like Steven Pinker.

Here I will state and explain a few basic principles about entropy, with the goal of going beyond a mere refutation of creationist arguments.

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