Who Ordered That?

2010-02-28

Elegance is for the tailor and the shoemaker.

— Ludwig Boltzmann, a pragmatic mathematician and theorist. Via Boltzmann’s Atom: The Great Debate That Launched a Revolution in Physics by David Lindley, Free Press, 2001.

2010-02-27

Music is the pleasure the human mind experiences from counting without being aware that it is counting.

— Gottfried Wilhelm von Leibniz

2010-02-26

Royal Society Michael Faraday Prize Lecture 2010

Marcus Du Sautoy, Simonyi Professor For The Public Understanding of Science at Oxford, gives the 2010 Michael Faraday Prize Lecture at the Royal Society.

In the talk, titled The Secret Mathematician, Du Sautoy debunks the ‘arts versus sciences’ dichotomy with heaps of examples of mathematics being used directly in the arts — in music by Messiaen and Schoenberg, in the architecture of Palladio and Le Corbusier, in the writing of Borges, and in the art of Dali and Picasso.

Artists are constantly on the hunt for interesting new structures to frame their creative process. From composers to painters, writers to choreographers, the mathematician’s palette of shapes, patterns and numbers has proved a powerful inspiration.

I never considered L’Arche at La Defence, as being a shadow of a 4D hypercube, but I’ll appreciate it even more next time I’m in Paris.

2010-02-13

Early Galaxies Formed Stars Fast Because They Had More Gas | Wired Science | Wired.com

Wired Science explains results showing that early galaxies had more hydrogen to fuel star-formation:

Ultimately, the team wanted to know how much hydrogen filled these early galaxies, because it is by far the most abundant element in the universe and in interstellar gas clouds. But hydrogen emissions from these distant objects are simply too hard to detect, Tacconi said.

Instead, they measured the light emitted from carbon monoxide molecules. As these molecules rotate, they shift from one energy state to another. As they shift, “they emit photons, and that radiation is what we see as an emission line at a specific wavelength,” Tacconi said.

The amount of light emitted from these spinning molecules revealed the fraction of each galaxy made up of carbon monoxide. Carbon monoxide and hydrogen are found in almost the same ratio in many parts of the universe. So, they used this ratio to extrapolate the amount of hydrogen present in these early galaxies.

2010-02-10

Helium clue found in echo of the big bang - space - 08 February 2010 - New Scientist

New Scientist reports on a combination of results from telescopes including the Wilkinson Microwave Anisotropy Probe:

A trio of telescopes has found helium’s signature in the cosmic microwave background, radiation emitted some 380,000 years after the big bang. The patterns in this radiation are an important indicator of the processes at work at that time. Helium affects the pattern because it is heavier than hydrogen and so alters the way pressure waves must have travelled through the young cosmos. But helium’s effect on the CMB was on a scale too small to resolve until now.

2010-02-07

The biomechanics of barefoot running : Nature

A paper in Nature on the mechanics of human running. In the study, runners tended to land on the ball of the foot or flat when barefoot but on the heel—with a greater impact— when shod in modern running shoes.

A comparison by Daniel Lieberman and colleagues of the biomechanics of habitually shod versus habitually barefoot runners now suggests that the collision-free way that barefoot runners typically land is not only comfortable but may also help avoid some impact-related repetitive stress injuries. Kinematic and kinetic analyses show that modern shoes allow runners to land on the heel, as they do when they walk. Runners who don’t wear shoes land more often on the ball of the foot or with a flat foot.

2010-02-04

Technology Review: Blogs: arXiv blog: How to Build a Dark Energy Detector

The arXiv blog on a suggested experiment for detecting dark energy:

Of course there are some important differences between an electric field and the dark energy field that make measurements tricky. Not least of these is that you can’t turn off dark energy. Another is that there is no known reference against which to measure it.

That leaves the possibility of a gradient in the dark energy field. If there is such a gradient, then it ought to be possible to measure its effect and the best way to do this is with atom interferometry, say Perl and Mueller.

2010-01-31

It all works because Avogadro’s number is closer to infinity than to ten.

— Ralph Baierlein, American Journal of Physics 46, 1045 (1978).

2010-01-29

Giant laser reaches key milestone for fusion - physics-math - 28 January 2010 - New Scientist

New Scientist reports on progress at Lawrence Livermore National Laboratory, using the world’s largest laser to compress a spherical pellet in order to ignite a fusion reaction:

The team used targets that did not contain the key ingredients for fusion – two isotopes of hydrogen known as deuterium and tritium. But the symmetrical implosion of the targets suggests that NIF should be able to ignite fusion with laser pulses of 1.2 to 1.3 megajoules – well below its full 1.8-megajoule capacity.

Researchers spent last year slowly cranking up the output of the laser, ultimately reaching a total energy of more than 1 megajoules. Now they’re pausing to mount new instruments on the 10-centimetre-thick aluminium target chamber and to install giant concrete doors to contain neutrons they expect to produce in future fusion experiments.