Category Archives: Popular Science

Liquid Metal? In A Watch?

Yes. In a watch. Not just any watch, but an Omega.

In any case, watch. I mean the video at that link, and you’ll love the slogan: “Sometimes, the most unlikely partnerships are the most enduring.” And I guess we could add, “the most expensive.”

Here’s the short description from that page on the bulk metallic glass that goes by its trade name “Liquidmetal®”:

Liquidmetal®: seamless bonding, remarkable hardness

The Liquidmetal® alloy is an amorphous metal – a metallic material with a disordered, non-crystalline atomic structure. Its fusion temperature is half that of conventional titanium alloys but when it is cooled, its hardness is three times as great as that of stainless steel. Its amorphous structure allows it to bond seamlessly with the ceramic bezel.

The Liquidmetal® is a bulk metallic glass alloy consisting of five elements: zirconium, titanium, copper, nickel and beryllium. A bulk metallic glass can, by virtue of its low critical cooling rate, be formed into a structure with a thickness of more than a tenth of a millimetre. Zirconium is an important constituent part both of the Liquidmetal® alloy and of the ceramic material which is made of zirconium dioxide (Zr02).

Thanks for the pointer to my friend and colleague Ram (Prof. U. Ramamurty), who is well known for his studies of mechanical behaviour of bulk metallic glasses.

* * *

BTW, this blog has had a chance to post about Liquidmetal® sometime ago.

Mechanics of superheroes

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.

Woody Allen does deep physics

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.

Intellectual commons

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.

* * *

Link via orgtheory.net.

Evolutionary relevance of music

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” …

Different meanings of the word ‘replicate’

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.

What is so great about the proof of the Poincaré conjecture?

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.

The expert mind

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.

* * *

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.

Nikola Tesla

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 …

Sociophysics

After writing this post about economics, physics and econophysics, I was poking around the web, looking for Philip Ball’s articles. Ball is the author of the piece that I linked to in my post, and has written quite enthusiastically about “sociophysics” which seems, to me, to be mostly simulations in which independent entities (particles, people, institutions) act and react according to specific rules. From statistical physics simulations of interacting particles, we know that complex behaviour could emerge even with simple interactions among the particles, and I guess the hope in sociophysics is to show a similar correspondence between simple interactions among entities (‘agents’ seems to be the preferred term in sociophysics) and (emergence of) complex behaviour in the aggregate.

Philip Ball has a huge footprint on the web, a testimony to his prolific output, not only as a regular columnist for the Nature group of publications, but also as an author of quite a few books. Check out his website. One of his recent books, Critical Mass: How One Thing Leads to Another has specifically been about sociophysics. Some of the ideas appeared earlier in the form of a short article with a catchy title Physics of Institutions (pdf); see also this rather nice popular science piece titled Utopia Theory in PhysicsWeb.

Here are some of the reviews of this book: Bruce Edmonds, James Buchan for the Guardian, Steven Strogatz for Nature, and Tamás Vicsek for PhysicsWeb. The ‘Reviews’ section of Ball’s website has links to more of them.

Let me quote from Bruce Edmonds’ review:

… It is, in its way, the first “popular science” book covering a substantial section of social simulation, and talks about many of the main figures up to about 1990 (it does cover later work but not so comprehensively, which is understandable). Thus the work of Thomas Schelling, Ilya Prigogine, Brian Arthur, Alan Kirman, Robert Axtell, Joshua Epstein, Robert Axelrod, Paul Omerod, Martin Nowak, Per Bak, Duncan Watts, are all discussed.

In all of this the book is quite careful as to matters of fact – in detail all its statements are cautiously worded and filled with subtle caveats. However its broad message is very different, implying that abstract physics-style models have been successful at identifying some general laws and tendencies in social phenomena. It does this in two ways: firstly, by slipping between statements about the behaviour of the models and statements about the target social phenomena, so that it is able to make definite pronouncements and establish the success and relevance of its approach; and secondly, by implying that it is as well-validated as any established physics model but, in fact, only establishing that the models can be used as sophisticated analogies – ways of thinking about social phenomena. The book particularly makes play of analogies with the phase transitions observed in fluids since this was the author’s area of expertise.

This book is by no means unique in making these kinds of conflation – they are rife within the world of social simulation. The culture of physics is a complex of different attitudes, norms, procedures, tools, bodies of knowledge and social structures that are extremely effective at producing useful knowledge in some domains – it is not for nothing that physists have gained status within our society. However when this culture is transported into new domains, such as that of modelling social phenomena, the culture does not travel uniformly. Thus we have seen (and Critical Mass documents) an influx of simple, physics-style simulation models into sociology but they have arrived without the usual physists’ insistence that models predict unseen data. It is part of the culture of physics to aspire to the simplest possible model of phenomena but a model which only acted as a sort of vague analogy with respect to its phenomena would get short shrift in traditional physics domains. Yet frequently one reads social simulation work which takes the form of physics-style models and yet uses only vague, hand-waving justifications to justify its relevance (and, at best, a rough fitting of known, aggregate data). Models need to be constrained by the subject matter they are supposed to be about – there are two main ways of doing this: by ensuring the model is designed to behave as we know it should do (typically the parts of the model); and by checking the resulting behaviour against corresponding observed behaviour (often in aggregate). Sociophysics models tend to avoid either: they impose over-simple behaviour onto the design and don’t validate strongly against unseen data. Thus whilst such models may have interesting behaviour there is little reason to suppose that they do in fact represent observed social behaviour.

A point Edmonds makes is this:

[C]omplex behaviour can result from the interaction of lots of simple parts. This is now well established, but the implied corollary that the complexity we observe is a result of lots of simple interactions (or that it is useful to model this in this way) does not, of course, follow. Grounds for hope does not make it a reality.

This seems to be an intensely difficult ‘inverse’ problem, no? A related problem, which seems to be common to many ‘emergence‘ phenomena is the following: suppose you rig up a model with a certain set of rules (for interactions among the agents). And suppose that this model exhibits some complex behaviour. You are certainly within your rights to feel satisfied. However, how can we be sure that this is the only set of interaction rules that will lead to this ‘complex’ behaviour? If there are two (or more) sets of rules that give rise to (broadly) the same complex behaviour in the aggregate, which one should we choose? Even then, how can we be sure that that is the one that governs the real interactions among the agents?

Olivia Judson’s agony aunt column

Just take a look at the first Ask Dr. Tatiana column that appeared in the Economist. And, eventually, a book emerged with the same title. From the Economist review:

Olivia Judson’s funny and blissfully original new book …purports to be sex advice offered to the animal kingdom by a universal agony aunt called Dr Tatiana, and amply demonstrates the sheer unyielding ruthlessness of the business of procreation. … She responds with gusto to pleading letters from the Dandy on the Cowpat, a yellow dung-fly who wants to make his sperm more attractive, or Anxious in Amboseli, an African elephant who is diagnosed as possessing SINBAD (Single Income, No Babe, Absolutely Desperate). I-Like-‘Em-Headless-in-Lisbon is a praying mantis who asks Dr Tatiana if she also enjoys the thrilling mid-sex spasms of a partner who has just been decapitated; and we are introduced to a female midge who plunges her proboscis into her mates’ heads and turns their innards to a soup “which she slurps up, drinking until she’s sucked him dry…only his manhood, which breaks off inside her, betrays the fact that this was no ordinary meal.” There are several kinds of spiders, we learn further, “where there can be no doubting the females’ intention to take head, not give it.”

All this is from 2002. Just recently, I learnt that Olivia Judson has a blog, but alas, her blog is behind the NYTimes‘ paywall. So, all I can do is to just link to some extended excerpts in Mark Thoma’s blog: here, here, and here.

Science of cuteness

Cute cues are those that indicate extreme youth, vulnerability, harmlessness and need, scientists say, and attending to them closely makes good Darwinian sense. As a species whose youngest members are so pathetically helpless they can’t lift their heads to suckle without adult supervision, human beings must be wired to respond quickly and gamely to any and all signs of infantile desire.

From Natalie Angier’s piece in the New York Times.

Among the several examples of cuteness-filled 2005, I found this:

Women’s fashions opted for the cute over the sensible or glamorous, with low-slung slacks and skirts and abbreviated blouses contriving to present a customer’s midriff as an adorable preschool bulge.

Do you find this cute? What would be cute in male fashion?