Monthly Archives: June 2008

What Mr. Slack Got Wrong

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What neo-creationists get right

[I]n the debate over evolution, I also think creationists’ doggedness has to do with the fact that they make a few worthy points. And as long as evolutionists like me reflexively react with ridicule and self-righteous rage, we may paradoxically be adding years to creationism’s lifespan.

I think that the creationists’ doggedness has far more to do with the fact that their ideology comes first, and they mangle science to conform to that worldview. When “facts” are presented that can be falsified by just looking around, sometimes ridicule is the only option left. But there was much more in the article that bothered me, and to a greater degree.

Mr. Slack goes on to make four points. On the first two, I say this —
Yes, science is incomplete — I don’t think any competent scientist is claiming that there isn’t more to be found. This is true of all fields of science, and the “designer of the gaps” is a false dilemma. The complexity of the cell being unknown to Darwin also falls short and points out the misdirected nature of many arguments against “Darwinism,” (much like arguments against Einstein and relativity) because the theory has advanced quite far since the original proposal. I’ll get to the misuse of “faith” a little later on.

On to the third point
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Origin Not Originally Original

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On the Origin of a Theory

Darwin’s treatise on evolution wasn’t the first and wasn’t the only attempt to explain the diversity of life.

“The only novelty in my work is the attempt to explain how species become modified,” Darwin later wrote. He did not mean to belittle his achievement. The how, backed up by an abundance of evidence, was crucial: nature throws up endless biological variations, and they either flourish or fade away in the face of disease, hunger, predation and other factors. Darwin’s term for it was “natural selection”; Wallace called it the “struggle for existence.” But we often act today as if Darwin invented the idea of evolution itself, including the theory that human beings developed from an ape ancestor. And Wallace we forget altogether.
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[O]n November 22, 1859, Darwin published his great work On the Origin of Species by Means of Natural Selection, and the unthinkable—that man was descended from beasts—became more than thinkable. Darwin didn’t just supply the how of evolution; his painstaking work on barnacles and other species made the idea plausible.

It’s important to understand that last bit, and it applies in all of science. Saying, “I can explain that” isn’t sufficient. You need to amass scientific evidence in support of your claim — data that supports you and eliminates other explanations, along with predictions that would falsify your theory if they fail to come true.

Don't Wine About Your Carbon Footprint

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Calculating the carbon footprint of wine: my research findings

There’s a “green line” that runs down the middle of Ohio. For points to the West of that line, it is more carbon efficient to consume wine trucked from California. To the East of that line, it’s more efficient to consume the same sized bottle of wine from Bordeaux, which has had benefited from the efficiencies of container shipping, followed by a shorter truck trip. In the event that a carbon tax were ever imposed, it would thus have a decidedly un-nationalistic impact.

via Kottke

It's Not Gnu, But it's as Good as Gnu

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Plastics unite to make unexpected ‘metal’

Both TTF and TCNQ are electrical insulators. But Morpurgo’s team found that a 2-nanometre-thick strip along the interface between the two crystals conducts electricity as well as a metal.

So it’s “metal” in the sense that it’s plastic, but conducts very well along the interface. Apparently using “conductor” in the title would have broken some journalistic creed. Why go for accuracy when you can have imagery?

Neat result, though.

The Photon Push-Me Pull-You

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A few weeks ago, over at Built on facts, I threw Matt a bit of a knuckleball in the comments.

[C]onsider a solid bar of the same index [as water]. You send in the pulse of light (assume a really good AR coating so there’s no reflection). What happens to the speed of the bar?

This was sneaky because it is one of the unsolved issues in physics (I feel no remorse for doing this, and Matt realized that something was up) — the theory is complicated enough that it’s really easy to miss out on some of the subtleties and end up with an invalid answer. There are two schools of thought: Minkowski, who had taken the approach that the photon’s momentum in the medium should be nE/c, and Abraham, whose approach gave the momentum as E/nc. Clearly, the results are at odds, and this came to be known as the Minkowski-Abraham momentum controversy.

I found a number of articles on the topic, but perhaps the best one is a review article from Reviews of Modern Physics. Momentum of an electromagnetic wave in dielectric media by Pfeifer et. al, No. 4, October–December 2007 pp. 1197-1216. (link is to a pdf file) The article points out that this isn’t a simple problem, because a photon in a medium can’t be naively treated as just a photon — both solutions have merit, but must include the interactions with the medium, which are obviously different depending on the approach you take — in the end there can be only one you can only have one answer for the momentum of the system.
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Wisdom From Inigo

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You keep using that word. I do not think it means what you think it means.

Newly born identical twin stars show surprising differences

The identical twins were discovered in the Orion Nebula, a well-known stellar nursery, that is 1,500 light years away. The newly formed stars are about 1 million years old. With a full lifespan of about 50 billion years, that makes them equivalent to one-day-old human babies.
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By measuring the difference in the amount that the light dipped during the eclipses, the astronomers were able to determine that one of the stars is two times brighter than the other and calculate that the brighter star has a surface temperature about 300 degrees higher than its twin. An additional analysis of the light spectrum coming from the pair also suggests that one of the stars is about 10 percent larger than the other, but additional observations are needed to confirm it.
“The easiest way to explain these differences is if one star was formed about 500,000 years before its twin,” says Stassun. “That is equivalent to a human birth-order difference of about half of a day.”

So they have different brightness, surface temperature and possibly size. Maybe we shouldn’t be using the baby analogy (it’s not like they share DNA) and should stop calling them identical twins.

Update: Scientific Blogging does a better job, calling them fraternal twins, but the link has an auto-starting video with no means (that I can find) to turn it off!