The Stardust probe returned to Earth safely after a seven-year mission to collect comet dust. The return capsule landed safe in the Utah desert with about a teaspoon of the fundamental matter of the solar system, and is en route to Johnson Space Center.
Science update
Read this. New study on the effect of the paleocene/eocene thermal maximum on ocean currents. (About 55M years ago, a 7-degree rise in temperatures basically caused the entire world’s climate to flip) If you haven’t been following this story carefully, you should — people are finally starting to discuss in public the big secret of climate change, which is that it’s a great deal more serious than anyone’s wanted to talk about in public.
Science list: Things that don’t make sense
New Scientist has an interesting little article about “13 things that do not make sense” — basically, odd experimental results from the past couple of years that nobody really feels comfortable explaining yet.
Now, the crackpots will be out in force saying “See! Science is at an end! There are things it can’t explain! There therefore must be an intelligent designer intentionally confounding the attempts of humans to tinker with Things Man Was Not Meant To Know…” et cetera. I’ll just leave them out in the pottery shed; these thirteen things are really interesting, and while most of them probably won’t pan out, if any of them do then there’s some damned interesting advances going on. These are all under fairly active research (for the theoretical ones and the more well-understood experimental ones [like cosmic rays] people are working hard on them, and for the stranger experimental ones [like tetraneutrons, or one they forgot, the magnetic monopole] people are still waiting for experimental confirmation).
Two bits of science
Creativity determines sexual success
Atlantic warm-water currents are weakening
The latter article is actually fairly important.
A possibly controversial question
I’ve been re-reading Jared Diamond’s Guns, Germs and Steel, and finding it very thought-provoking; it’s a good book to come back to after a time, and if you haven’t read it (and his more recent book, Collapse) I recommend it highly.
But here’s a question that popped into my head while reading it: (This will probably make a bit more sense to those who have read the book) Why did England successfully invade and colonize India, and not the other way round? I’m curious both about the proximate causes (my lack of Indian history is showing through) and the deeper reasons, if any can be traced back. Diamond’s analysis doesn’t seem to carry over unmodified to this case; India certainly had no shortage of intensive agriculture, nor a late start in developing it, and at times in its history was a large empire. Had the two countries been neighbors, the outcome might have been very different; similarly if they had come into contact a thousand years earlier. Nor was the battle completely one-sided; the Sikhs twice managed to field a very impressive army and pose a real challenge to British domination. Yet despite all of this, the British managed to basically set up shop and run a country many times their size, and hold that empire for over a century; so there must have been some major fundamental asymmetry.
Thoughts?
Just in from Saturn
New results: Enceladus, one of Saturn’s moons, apparently has an atmosphere and liquid water beneath the surface. WP article gives a summary of this and other recent discoveries from the Cassini mission.
Science News: Apocalypse Real Soon Now
The Independent is reporting that a new report indicates that polar ice melting may have just passed the critical point. I think this is something worth taking very seriously: I’ve been expecting a report that says this for a few years. Note that this may trigger a very large-scale change soon, such as a shutdown or other significant change in the Gulf Stream thanks to the change in thermal absorption due to having fresh instead of saltwater in the northern Atlantic.
When evolution is outlawed…
Apparently, our President wants equal time for intelligent design in American schools, saying that “both sides ought to be properly taught” so “people can understand what the debate is about.”
It’s probably not really worth too much discussion in this forum, but it’s fascinating to see how this culture of false debate has emerged. If a public figure were to go out and say that the sky is green, the press would simply report it, and then ask someone else what color they say the sky is, satisfied that by presenting “both sides” of the issue they’ve discharged their duty, and (seeing that there are clearly two sides who disagree) now being able to describe it as a disputed issue. What you won’t hear is the press actually checking the facts themselves; such things are “not their department.” This is especially true when there are a large number of people who, for one reason or another, feel strongly about backing whomever it was who made the false statement; the media are really averse to flat-out contradicting someone when that may alienate readers.
But if a political movement grows, and out of fear of contradicting them nobody ever says they’re wrong, where do we end up?
The rather simple problem with the “debate” over the teaching of evolution, which nobody ever seems quite willing to say, is that the reason we don’t teach “intelligent design” or other forms of ersatz creationism in school isn’t because there’s a secular humanist bias, or because we don’t want to favor one religion over another; it’s for the rather simple reason that these things are false, and known to be false. The fact that one group strenuously advocates for them doesn’t make them any more true, and no matter how loud these groups are, the fact that people are out there saying something does not make it true, nor does it make the debate legitimate or worth people’s time; if a thousand people claim the sky is green, even by divine revelation, the sky will still be blue, and trying to convince them will still be an elaborate waste of time.
Or to say this in a more religious context, we are given senses and a faculty of reason, and we do not derive our laws and our sense of the universe from omens and signs. As R. Jeremia said, the Torah has already been given at Sinai; that is, the set of divine interventions needed to create this world was done at the creation of the world, and so the world is complete within its own context: we can study it in its own right, without having to resort to revelations “explaining” for us things which our own senses can understand on their own. (Baba Metzia, 59a-b) (Yes, I realize that making a religious argument in this context seems odd, but I don’t believe there’s any fundamental contradiction between religion and reason; only when people start misunderstanding the difference between stories and the world around them, to the extent that they reject the evidence of their own senses.)
And now, our president has decided that he needs to weigh in on this issue, because without his wisdom and guidance, where would we be?
Reading material
[Edited: Link fixed]
I’ve been reading this article, and it’s quite interesting: Peter S. Bearman, James Moody and Katherine Stovel, Chains of Affection: The structure of adolescent romantic and sexual networks. The National Longitudinal Study of Adolescent Health, among many other things, did detailed surveys of behavior. This paper takes the data for a single large (~1000 people) high school, in which every student was surveyed and information about their romantic and sexual partnerships was acquired, and analyzes it in depth. The major conclusion is that the network structure of sexual relationships in high school is qualitatively different from the structure of such relationships in the world as a whole.
Specifically, other studies (I wish I had the reference next to me – will update if I find it) have shown that the sexual relationship networks of the general public are preferential-attachment networks, in which a new connection is most likely to form to someone who already has a lot of preexisting connections. (Not a big surprise, really…) This leads to a network of connected hubs, somewhat like American air routes. High school networks, OTOH, have a much more tree-like structure, with long branches and less clumping. The authors of this paper conjecture that this is due to a social norm against cycles of length 4 – i.e., against dating your ex’s current’s ex. They show that adding this assumption to ordinary models produces trees that look a lot like the ones they found experimentally. (Not too surprising, again – in a predominantly heterosexual network, if 4-cycles are excluded the smallest possible cycle is of length 6, which is already getting too big for real clumps to form)
Why is this interesting? Well, first of all there’s our usual prurient interest in who everyone else is shtupping. (cf. also this ScienceBlog entry, Monkeys will pay to look at porn) But the network of sexual connections is also the network along which STDs propagate, and so network interruption theory takes on serious public-policy implications. For example: In a preferential-attachment network, it turns out that the network is disproportionately vulnerable to interruption of its highest-linkage nodes. This means that sexual health programs aimed at the most active people will have a larger than expected effect, while broadly-aimed programs will be ineffective. In a less clumped network like the high school network, though, removing a random node is enough to disconnect major graph chunks, so a broadly aimed education program may be a lot more effective.
There are other interesting features of this, too, and for those I recommend you read this article.
Ethics of a copied cat
There’s a big ethical debate storming over the recent cloning of a pet cat. One line that caught my eye in this was from David Magnus, of the Center for Biomedical Ethics at Stanford: “It’s morally problematic and a little reprehensible… for $50,000, she could have provided homes for a lot of strays.”
This argument seems specious to me. For $50,000, she could also have provided homes for humans; does that also make the action reprehensible? Would it be less so had she spent it on a car? For that matter, a number of people persist in having biological children, even though there are plenty still available for adoption. Is he arguing that that’s morally problematic as well?
It seems to me that if there are ethical issues involved in this, the ones being discussed right now aren’t them – but I’m a bit surprised to see so many scientists and ethicists jumping on this bandwagon. Is it just me, or is some deep fear of “cloning” – not a fear of the actual procedure, but of something subconsciously associated therewith – taking over the discussion?
Does someone have a sense of what the actual underlying fears are?
Yonatan Zunger’s Blog 