Are you in the mood for something truly inspiring, exciting and, um, spiritual? If not, why, you really ought to be! If yes, watch this short video of a speech by Neil deGrasse Tyson.

Awesome!

The spider-’silk’ produced by Spiderman about as thick as his arm — it’s more like ’spider-rope’. But, does it really need to be that thick? No, says this SciAm article on the wonderful combination of mechanical properties of real spidersilk.

The different silks have unique physical properties such as strength, toughness and elasticity, but all are very strong compared to other natural and synthetic materials. … The movie Spider-Man drastically underestimates the strength of silk�real dragline silk would not need to be nearly as thick as the strands deployed by our web-swinging hero in the movie.

Here’s a quick description of what makes up one of the several forms of spidersilk:

Dragline silk is a composite material comprised of two different proteins, each containing three types of regions with distinct properties. One of these forms an amorphous (noncrystalline) matrix that is stretchable, giving the silk elasticity. When an insect strikes the web, the stretching of the matrix enables the web to absorb the kinetic energy of the insect�s flight. Embedded in the amorphous portions of both proteins are two kinds of crystalline regions that toughen the silk. Although both kinds of crystalline regions are tightly pleated and resist stretching, one of them is rigid. It is thought that the pleats of the less rigid crystalline regions not only fit into the pleats in the rigid crystals but that they also interact with the amorphous areas in the proteins, thus anchoring the rigid crystals to the matrix. The resulting composite is strong, tough, and yet elastic.

Via an e-mail from Anant, we get this wonderful gem published in the New Yorker in 2003.

… I approached Miss Kelly’s gravitational field and could feel my strings vibrating. All I knew was that I wanted to wrap my weak-gauge bosons around her gluons, slip through a wormhole, and do some quantum tunnelling. It was at this point that I was rendered impotent by Heisenberg’s uncertainty principle. How could I act if I couldn’t determine her exact position and velocity? And what if I should suddenly cause a singularity; that is, a devastating rupture in space-time? They’re so noisy. Everyone would look up and I’d be embarrassed in front of Miss Kelly. Ah, but the woman has such good dark energy. Dark energy, though hypothetical, has always been a turn-on for me, especially in a female who has an overbite.

In an interesting piece in Chronicle Review, Mark Oppenheimer urges graduate students (and professors too!) to be interested in (and better yet, contribute to) the broader intellectual discussions and debates (in such magazines as NYRB and NYTimes Book Review, Dissent, etc):

The work of public intellectuals is important to young scholars partly because it helps us speak across disciplines. I, for example, was a student in a religion department, but my particular specialty, American religious history, gave me little common ground with classmates who specialized in Buddhism, New Testament criticism, or Islamic law. I had friends who were getting degrees in American studies, but if they were focusing on, say, material culture in the 19th century, their important professional journals were The Journal of American History and the Journal of American Studies, which I never read. Mine were Religion and American Culture and Church History, which they never read. If, however, we had all read one of the journals mentioned above, or maybe The American Scholar or The Wilson Quarterly — journals that include essays on a wide variety of topics in the humanities and social sciences — we could have had conversations with students who worked outside our immediate areas of interest.

Extracurricular reading would have produced social benefits as well. Graduate students, it’s well known, often feel isolated. On their bad days, they even feel that their lives are pointless, anomic, and worthless. It wears you down to spend years doing research on a topic that few people care about, greater knowledge of which will improve the world in no obvious way. But for graduate students to talk to each other, they need to have something to talk about — an obvious point, but one missed by administrators who try to foster camaraderie by scheduling grad-student movie nights. In unguarded moments, administrators will snicker that the controversial grad-student-union movement is fueled as much by the need for an improved social life as by legitimate gripes about working conditions. They have the ratio wrong — it’s more like 20 percent socializing, 80 percent genuine politics — but that’s a real insight. When I was in grad school, I could talk union politics with chemistry students and entomologists. I couldn’t talk about The New York Review with anybody.

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Link via orgtheory.net.

Aapparently, humans are hard-wired to enjoy music. What is the evidence?

Researchers at the Montreal Neurological Institute, for example, have scanned musicians’ brains and found that the “chills” that they feel when they hear stirring passages of music result from activity in the same parts of the brain stimulated by food and sex.

If something happens, scientists should be — and they are — asking questions like ‘how’ and ‘why’, and offering their versions of possible answers. What might they be?

Some evolutionary psychologists suggest that music originated as a way for males to impress and attract females. Others see its roots in the relationship between mother and child. In a third hypothesis, music was a social adhesive, helping to forge common identity in early human communities.

But some people are not convinced that there is any evolutionary purpose at all.

… [A] few leading evolutionary psychologists argue that music has no adaptive purpose at all, but simply manages, as the Harvard psychologist Steven Pinker has written, to “tickle the sensitive spots” in areas of the brain that evolved for other purposes. In his 1997 book “How the Mind Works,” Pinker dubbed music “auditory cheesecake” …

In the rough-and-tumble world of science, disputes are usually settled in time, as a convergence of evidence accumulates in favor of one hypothesis over another. Until now.

On April 10 economist John R. Lott, Jr., formerly of the American Enterprise Institute, filed a defamation lawsuit against economist Steven D. Levitt of the University of Chicago and HarperCollins, the publisher of Levitt’s 2005 book, Freakonomics. At issue is what Levitt meant when he wrote that scholars could not “replicate” Lott’s results …

That’s from Michael Shermer’s Skeptic column in Scientific American. Shermer is “executive director of the Skeptics Society, bold debunkers of all things supernatural”, according to Salon which has a long interview with him [free, if you are willing to watch an ad]. I don’t know if artificial intelligence would be considered ’supernatural’, but here is an interesting article in the Skeptic magazine (flagship of the Skeptics Society) debunking the lofty claims made by AI enthusiasts.

Jordan Ellenberg has a truly wonderful article in Slate.

The entities we study in science fall into two categories: those which can be classified in a way a human can understand, and those which are unclassifiably wild. Numbers are in the first class—you would agree that although you cannot list all the whole numbers, you have a good sense of what numbers are out there. Platonic solids are another good example. There are just five: the tetrahedron, the cube, the octahedron, the dodecahedron, and the icosahedron. End of story—you know them all. [...]

In the second class are things like networks (in mathematical lingo, graphs) and beetles. There doesn’t appear to be any nice, orderly structure on the set of all beetles, and we’ve got no way to predict what kinds of novel species will turn up. All we can do is observe some features that most beetles seem to share, most of the time. But there’s no periodic table of beetles, and there probably couldn’t be.

Mathematicians are much happier when a mathematical subject turns out to be of the first, more structured, type. We are much sadder when a subject turns out to be a variegated mass of beetles. [...]

[...] [Perelman's proof of the conjecture of Poincaré] means … that we can think about proving general statements about three-dimensional geometry in a way that we can’t hope to about beetles or graphs.

In the latest issue of Scientific American, Philip E. Ross presents an overview of what we know about the Expert Mind, culled from decades of research on chess (which he calls the Drosophila of cognitive science). Here are some of the key conclusions:

The better players did not examine more possibilities, only better ones…

… [T]he expert relies not so much on an intrinsically stronger power of analysis as on a store of structured knowledge …

… [E]xperts rely more on structured knowledge than on analysis …

… [A]bility in one area tends not to transfer to another.

… [I]t takes enormous effort to build these structures in the mind. [Herbert] Simon coined a psychological law of his own, the 10-year rule, which states that it takes approximately a decade of heavy labor to master any field. Even child prodigies, such as Gauss in mathematics, Mozart in music and Bobby Fischer in chess, must have made an equivalent effort, perhaps by starting earlier and working harder than others. …

… [K. Anders] Ericsson [whose views on expertise was linked to here] eargues that what matters is not experience per se but “effortful study,” which entails continually tackling challenges that lie just beyond one’s competence. …

… [M]otivation appears to be a more important factor than innate ability in the development of expertise. It is no accident that in music, chess and sports–all domains in which expertise is defined by competitive performance rather than academic credentialing–professionalism has been emerging at ever younger ages, under the ministrations of increasingly dedicated parents and even extended families. …

… [S]uccess builds on success, because each accomplishment can strengthen a child’s motivation.

All of which lead to the ultimate conclusion:

The preponderance of psychological evidence indicates that experts are made, not born.

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See also After the Bell Curve by David Kirp in the NYTimes Magazine, and the comments on this article on the blogs of Mark Thoma and Brad DeLong.

Couturnix has a great post — no, make that an absolutely great post — on Nikola Tesla in celebration of the latter’s 150th birthday on July 10. You’ve got to check out that post to see why I’m amazed …

Still, at least the first two commenters on that post were left rather underwhelmed by Couturnix’s link-fest. Hmmm, such is life …

Why do Mentos and Diet Coke produce such a wonderful effect? The short answer is surface tension and nucleation. For a long answer, go read David Biello’s post over at the SciAm Observations.