A bit late I’ll remind people that the first of the “BrisScience” lectures is on tonight. The lectures will involve a number of excellent scientists giving lectures on their topics of interest for the general public. The website is here. All of the lectures are free, there is one talk a month, and they will all be held in the Judith Wright Center of Contemporary Arts in the Valley.

The first lecture is by John Mattick on “junk” DNA, which IIRC has been the subject of a very dubious intellectual property claim by an Australian entrepreneur. But the talk won’t be about IP, which should make it more interesting for about 99 per cent of the potential audience. John argues that the extra DNA is the opposite of junk: it may be ultimately responsible for the development of all life more complex than bacteria.

Occasional commenter “mick” has been in touch to advise me of a public lecture series to be held in Brisbane. The lecture series is entitled “BrisScience”, and will involve a number of excellent scientists giving lectures on their topics of interest for the general public. The website is here. All of the lectures are free, there is one talk a month, and they will all be held in the Judith Wright Center of Contemporary Arts in the Valley.

The first lecture is by John Mattick on “junk” DNA, which IIRC has been the subject of a very dubious intellectual property claim by an Australian entrepreneur. But the talk won’t be about IP, which should make it more interesting for about 99 per cent of the potential audience. John argues that the extra DNA is the opposite of junk: it may be ultimately responsible for the development of all life more complex than bacteria.

The latest evolutionary psychology[1] theory to do the rounds is that blondeness evolved as a selection strategem for women trying to attract scarce mates in the harsh and male-scarce conditions of Ice Age Europe. According to this report in the Times, the theory has been formulated by an anthropologist, Peter Frost. His supporting argument is that blondeness is a signal of high levels of oestrogen. I suppose I should wait for the article which is supposed to come out in Evolution and Human Behaviour, but I can’t resist pointing to an obvious hole and an alternative explanation.

The obvious hole is that blond(e)ness is not a sex-linked characteristic. If light hair colour signals high oestrogen, blond men should have a lot of trouble attracting mates. Tempted as I am by this hypothesis, I can’t say I’ve seen any evidence to back it up.

The alternative explanation (not at all novel) is that fair hair arose in conjunction with pale skin, as a straightforward physical adaption to the move away from the tropics – less need for pigment, or maybe more need to absorb vitamin D.
Read More »

The comments thread lately has been full of what might be called the “”ad hominem fallacy” fallacy”. This is the fallacy that, because a logical syllogism is equally valid or invalid no matter who propounds it, evidence in favour of a judgement about a matter of fact should be treated the same no matter who puts it forward. But classical syllogistic logic has essentially nothing to say in relation to reasoning about the plausibilty of judgements based on evidence.

No one sensible takes this idea seriously when, for example, money is at stake. A member of a board of directors who has a financial interest in a proposal is expected to declare it and withdraw from the discussion for example. By contrast, believers in the “ad hominem fallacy” fallacy would suggest that the director’s arguments were just as valid as anyone else’s, and they do not need to declare their interest before taking part in the discussion (though they should not vote).

The problems with conflict of interest are twofold. First, it is usually impossible to check every factual claim made by someone putting an argument. Second, even if all the facts asserted in support of some position are verifiable, they may have been selected (cherry-picked) to favour a case, while facts pointing the other way have been ignored. If you’re willing to go to the trouble of fully informing yourself about the topic using independent sources evidence from interested sources is redundant, and if not, it’s unreliable.

I had a lengthy go at this here, and for convenience I’ve reposted it over the fold.

There’s more from Don Arthur , Tim Lambert and Cathy Young
Read More »

Desktop manufacturing is one of those ideas that sometimes seems obvious and inevitable, sometimes a bit too good to be true and sometimes completely off the planet, depending on the angle at which you look at it. If it happened, it would certainly make a huge difference, creating up the potential for open-source everything.

David Pescovitz has the optimistic version of the story.

I was thinking about various forms of pseudo-science, and it struck me that the Gaia Hypothesis (in its strong version) is probably the most plausible version of Intelligent Design. Google reveals that this thought is far from original, and that something very like it has been pushed by some supporters of ID, such as Dembski.

In my view, the Gaia hypothesis is a variant on the anthropic principle. The fact that we’re here on earth implies that the planet must have developed in a way that sustains life, but this observation is, as Nick Bostrom says of the anthropic principle “too weak to do any real scientific work.”

Congratulations to Barry Marshall and Robin Warren, winners of the 2005 Nobel Prize for Medicine for the discovery that stomach ulcers are caused, not by stress as was formerly believed, but by a bacterium Helicobacter pylori. This is a classic Nobel-type discovery beginning with Warren’s acute observation, and continuing with Marshall’s work in culturing and identifying the bacterium.

It’s a striking observation that, thirty years ago, nearly everybody “knew” two things about stress: it was the primary cause of ulcers and it was particularly common among people men in executive jobs. Although widely held, these beliefs had never been properly tested by research and both turned out to be false. Surprising as it may seem, it’s more stressful to be ordered about than to order other people about. More precisely, the prevalence of stress-related diseases increases as you go down hierarchies of authority, status and so on.

The Nobel Prize for Economics[1] must be coming up soon. I have some ideas as to who should win, but as I’m very peripherally involved in the selection process, I’ll keep them to myself.

fn1. Strictly speaking, the Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel

The New York Times has an article by Brian Greene, a professor of physics and mathematics at Columbia about Einstein’s famous equation E=mc². In it he says:

The standard illustrations of Einstein’s equation – bombs and power stations – have perpetuated a belief that E = mc² has a special association with nuclear reactions and is thus removed from ordinary activity.

This isn’t true. When you drive your car, E = mc² is at work. As the engine burns gasoline to produce energy in the form of motion, it does so by converting some of the gasoline’s mass into energy, in accord with Einstein’s formula. When you use your MP3 player, E = mc² is at work. As the player drains the battery to produce energy in the form of sound waves, it does so by converting some of the battery’s mass into energy, as dictated by Einstein’s formula. As you read this text, E = mc² is at work. The processes in the eye and brain, underlying perception and thought, rely on chemical reactions that interchange mass and energy, once again in accord with Einstein’s formula.

I only did high school science, but I’m sure I remember learning the exact opposite of this claim, that chemical reactions like combustion leave mass and energy unchanged, only converting some of the chemical energy in the fuel into kinetic energy, and some into heat, with a net increase in entropy. Only nuclear reactions, I was taught, converted mass to energy. Wikipedia seems to back this up, though it isn’t absolutely unambiguous.

Can anyone set me (or, less plausibly, Greene) straight here?

fn1. As an aside, I also remember reading that a more correct version would be E=M. The term in c² just reflects a poor choice of units in the metric system. But maybe that’s wrong too.