Category Science

Embryology and Programming Languages

If you’ve never thought that the way molars develop in mammalian fetuses is way cool, you should read this article by PZ Mhieares at Pharyngula. It’s all about one substance in the environment of the developing jaw saying “you are going to become a bit of enamel”, and then that turns on another substance that tells neighboring cells, “cancel that: you don’t want to become enamel after all”, and stuff like that.

One fascinating thing about embryology is that the way living bodies develop is completely different from the way you’d build a house, or a credenza, or a sewing machine. It involves working in different media, with different tools, and that affects the way you do things, sometimes radically.

To me, the shift in thinking about building furniture to thinking about embryology is like learning a new programming language.

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Retro-Toy

One of the departments at work is moving offices around, so there are piles of junk in the hallways, some of it cool, most of it not.

One thing I picked up was a Gerber Variable Scale, invented by H. Joseph Gerber as a more elegant solution to an engineering problem that had originally required the use of his pyjama elastic.

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Any Questions?

I just watched PZ Meiarz’s talk about mind and brain, and listened to Ron McLeroy’s talk at his church, about the evils of materialism and evolution. I’ve also listened to Kent Hovind‘s schpiel, and seen his show live.

One thing that struck me—and it’s a small thing, but I think significant—is that PZ took questions during the talk, while McLeroy and Hovind didn’t.

Yes, the last section of Hovind’s seminar is a Q&A session, but that comes at the end of 14 hours of Gish Gallop, while PZ’s audience asked questions while they were fresh in their minds, and while the relevant slides were up on the screen.

And again, to be fair, I’ve attended talks by scientists and researchers who asked that questions be kept until the end, but even there, this was considered unusual enough that it was announced at the beginning. Certainly, throughout school and college, it was the norm that you raise your hand when a question occurs to you, not at the end: if you don’t understand something at the beginning, you should correct that as soon as possible, otherwise you won’t understand the stuff that comes later.

Of course, the other difference is that PZ is trying to teach his audience, and explain why (he thinks that) something is true. McLeroy and Hovind, on the other hand, are telling their audience what to think.

Crippling Brains for Jesus

Does anyone need more proof that Ron McLeroy, the newly-appointed Texas State Board of Education Chairman, is a superstitious asshat who’s out to cripple the state’s education system? Here’s what he told his church in 2005:

“Whether you’re a progressive creationist, recent creationist, young-Earth, old-Earth, it’s all in the tent of intelligent design,” McLeroy said. “And intelligent design here at Grace Bible Church is actually a smaller tent than you would have in the intelligent design movement as a whole, because we are all Biblical literalists…. So because it’s a bigger tent, just don’t waste our time arguing with each other about…all of the side issues.”

“Modern science today,” McLeroy complained, “is totally based on naturalism,” thus “it is the naturalistic base that is [our] target.”

What’s frightening is that this assclown is in charge of education in Texas. And as bad as that is, the effect of his militant ignorance won’t be confined to one state: Texas is the second-largest market for school textbooks (after California). This means that publishers will tone down the science in their books if they think it’ll make them more likely to sell in Texas.

Maybe we need a new rule: that someone in charge of X must not be ideologically committed to destroying X.

(HT Texas Observer → Texas Freedom Network → Americans United)

Math for Middle-School Girls

HT to for pointing me at Math Doesn’t Suck, by Danica McKellar. It’s a math book aimed at middle- and high school girls. The main message seem to be a) math doesn’t suck, and isn’t as hard as you think it is, and b) if you’re smart, don’t hide it. Both worthwhile messages.

I haven’t read the book, so I don’t know whether it lives up to its hype, but if it leads to more women realizing that they can do math, then that’s all good.

Oh, and may I just point out, as a guy, that smart is teh sexy?

Lowest Common Denominator

I was just thinking of the phrase “lowest common denominator” in the sense of something lowbrow that appeals to the unwashed masses, rather than something refined. And it occurred to me that in math, the lowest common denominator of a group of (natural) numbers is always going to be 1. What’s more interesting is the largest common denominator: it’s more interesting to know that 12 and 20 are both divisible by 4, than that they’re both divisible by 1.

Admittedly, I didn’t learn this part of arithmetic in the US (or even in English), so it’s possible that the phrase “lowest common denominator” is commonly understood to mean 1/n. In the example above, 1/4 is < 1/1, so 1/4 could be viewed as the lowest common denominator of 12 and 20.

But another possibility is that the phrase “lowest common denominator”, as applied to marketing and popular tastes, was originally ironic: a filmmaker might want to make a movie that appeals to the largest common denominator, i.e., one that’s as highbrow as possible, while still appealing to everyone. A critic who said that a movie appealed to the lowest common denominator would be saying that the movie appealed to the public’s basest tastes and wasn’t even trying to be good.

I haven’t found an etymological reference to confirm or disprove this, but I think it’s at least possible that the phrase started out ironic, but that over time people forgot this.

Fundamentalist Math

(Update, Aug. 6, 2007: Hey, this post appears in the 51st Philosophers’ Carnival. And I didn’t even submit it. How cool is that?)

I didn’t think it was possible to write a Christian math textbook. I mean, math is math, right? But this comment at Pharyngula pointed to an article in Harpers that purports to give excerpts from just such a book, Precalculus for Christian Schools, published by Bob Jones University Press.

I don’t normally read Harpers, so I don’t know whether they publish humor. And the excerpts they quoted seemed just too wacky to be true. Or would be, if it weren’t for Poe’s Law.

So I decided to be a good skeptic and check it out. One Amazon reviewer quoted the Harpers excerpts, which most likely meant he was copying from them. Then I found that BJU Press has a sample chapter online.

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Fabric Brain Art

The Museum of Scientifically Accurate Fabric Brain Art.

Fabric brain

On one hand, people like this obviously have too much time on their hands. On the other hand, damn, that’s cool!

(HT Neurodudes,
Fresh Brainz.)

Evolution of Morality

The Post has an interesting article about the origin of morality (HT ). It talks about research showing that various moral impulses are hardwired into our brains by evolution.

This dovetails nicely with another bit of research I stumbled upon recently (but can’t find now) that showed that, when posed with a moral problem, people from all over the world pretty much agree on what the right answer is, though they offer different explanations.

What this suggests is that we dislike stealing because we’re wired that way, and any explanation, be it “It goes against the 8th Commandment” or something involving Rousseau’s social contract, is post-hoc justification of a chosen conclusion.

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Why Everything Good Is Bad for You

Imagine an animal that requires some substance, but that substance is scarce. Say, a mountain goat that needs salt, but lives in mountains where there’s hardly any around, unlike the seashore. In such an environment, it’ll need all the salt it can get, and natural selection will favor those goats that find salt tasty, since they’ll seek it out.

Obviously, it’s possible to have too much salt in one’s body, so ideally there ought to be a biological function that switches off this craving for salt. But in practice, if salt is that scarce, there’s no such thing as too much salt, so the mechanism that switches off salt’s tastiness can be horribly miscalibrated and still not be selected against.

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