Stephen Hawking was among the recipients at the White House today when President Barack Obama presented the National Medal of Freedom to 16 “agents of change.” Relatively few scientists win this medal, the highest civilian honor awarded in the U.S., particularly when the science is as removed from everyday life as the theoretical physics of black holes.

Hawking, of course, is no ordinary scientist, his wheelchair-bound figure having become an element of the zeitgeist (at least as measured by cameos in Star Trek and The Simpsons). Severely disabled for most of his adult life by a motor neuron disease (amyotrophic lateral sclerosis, or ALS), he has become emblematic of the human spirit pressing on against adversity. (In a Q&A on his web site, when asked about the study of physics taking him “beyond physical limitations,” Hawking answered, “The human race is so puny compared to the universe that being disabled is not of much cosmic significance.”)

PITTSBURGH—At a meeting of the American Physical Society (APS) here this past week, physical chemist W. E. Moerner of Stanford University presented a clever new trick for looking inside living cells. The technique allows views in three-dimensions and well beyond the so-called diffraction limit that ordinarily fuzzes up images at around half the wavelength of the light used. Moerner was this year's recipient of the APS's Irving Langmuir Prize in Physical Chemistry.

Techniques such as electron microscopy have long allowed exquisite imaging at the nanoscale, but they typically require careful preparation of the object to be imaged and are not practical for, say, looking inside living cells to see the processes taking place there. As physics students learn early on in optics, the best images usually obtainable using light can make out features no smaller than about half the light's wavelength, or about 200 nanometers using the shortest-wavelength visible light. (A nanometer is a billionth of a meter, or about 40 billionths of an inch.) Biochemical structures in cells are much smaller than that.

PITTSBURGH—Look in that lab: it's a gas, it's a solid, it's a superfluid—it's SuperSolid! Well, maybe.

The "it" in question is a collection of rubidium atoms cooled to within a whisker of absolute zero and the lab is physicist Dan Stamper-Kurn's at the University of California, Berkeley. His group is working on clouds of the ultracold atoms that exhibit properties of multiple states of matter at once. Stamper-Kurn announced the details of the research yesterday at the American Physical Society meeting here.

Ultracold rubidium has achieved fame before, being one of the gases first turned into a Bose-Einstein condensate in the mid-1990s (at that time Stamper-Kurn was a graduate student in 2001 Nobelist Wolfgang Ketterle's group at the Massachusetts Institute of Technology, but that is another story, involving rubidium's cousin sodium).

That's a seismograph in West Lafayette, IN. The online image gets updated every 10 minutes. If you click the ugly icon up at the top of this post (or click here), you'll see it at its proper size, or follow the link to the real thing.

It appears the seismograph flatlined shortly into the first quake, but stayed online while the second one decayed away.

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He had invited us to come over for a chat at his hotel, which happened to be the historic Hotel Chelsea, where he had stayed in the mid-1960s while working on his best known work, 2001: A Space Odyssey. (In the 1993 edition of the book, he wrote of "months of brainstorming with [director] Stanley [Kubrick]—followed by (fairly) lonely hours in Room 1008... where most of the novel was written.")

Clarke gently berated us for not taking cold fusion seriously enough. Most researchers had dismissed it a decade earlier, but he still believed that a revolutionary discovery could come from the experiments of the smattering of remaining devotees.

What is rational and what is irrational?

That question lay at the core of a mountain of letters we received about our June article "The Traveler's Dilemma" by Kaushik Basu. We ran a small selection of the letters here in the blog along with responses from Basu. A letter from Adam Brandenburger of New York University appears in the October print edition of SciAm. Here is a somewhat longer version of his letter:

In "The Traveler's Dilemma" (June 2007), Kaushik Basu describes an intriguing game he introduced into the game theory literature some years ago. (The Traveler's Dilemma bears some similarity to the famous Prisoner's Dilemma.) In the game, two players must each choose a number between 2 and 100. As Basu explains, the game is constructed

Last month marked the 50th anniversary of the launching of the "Many Worlds" Interpretation of quantum mechanics, in which parallel universes are constantly branching off from the one we experience, with different events taking place in them. The Many Worlds Interpretation competes with the Copenhagen Interpretation, championed by Niels Bohr, in which the quantum state of a system often abruptly changes when it is observed ("the collapse of the wave function"). One outcome is seen to happen and according to the Copenhagen Interpretation the parts of the quantum state predicting other possibilities simply vanish. Many Worlds says those other parts still exist, just not in our branch.

In a future issue we will have an article by journalist Peter Byrne about the author of the original Many Worlds paper—Hugh Everett III—including some little-known history of events around