Month: September 2007

Graphene is Forever

Carbon flatland
This article originally appeared in the September 25, 2007 issue of Science News magazine.

“Graphene has always been before our eyes, but no one ever tried to look,” says Andre Geim, a physicist at the University of Manchester in England. A single-atom-thick, chicken wire web of carbon atoms, graphene forms the layers that stack up to make the graphite found in pencil lead and carbon soot.
However mundane the stuff may be, physicists have long predicted that if it were possible to isolate single graphene sheets, they would be sturdier than diamond and would have almost preternatural abilities to manipulate electrons. That could make graphene a better material than silicon for making computer chips. Until recently, though, no one had been able to isolate graphene sheets, let alone do anything useful with them.
In 2004, Geim and his collaborators startled the physics community by announcing that they had peeled graphene layers off graphite using common adhesive tape. The discovery raised a buzz in physics circles reminiscent of the excitement that greeted carbon nanotubes a decade ago.
Continue reading “Graphene is Forever”

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Classic Weinberg

While calling NASA’s “manned” space flight programs (such as [the International] Space Station) worthless with regards to science, Steven Weinberg calls NASA’s “unmanned” space flight programs (such as Martian robots Spirit and Opportunity robots and Hubble Telescope) very important to the advancement of science.

Steven Weinberg stated at the Tuesday, September 18, 2007 Science Writers’ Workshop called “Dark Energy: A Decade of Discovery and Mystery” at the Space Telescope Science Institute [home of the Hubble Space Telescope] in Baltimore, Maryland, U.S.A., “The International Space Station is an orbital turkey. No important science has come out of it. I could almost say no science has come out of it. And I would go beyond that and say that the whole manned spaceflight program, which is so enormously expensive, has produced nothing of scientific value.”

(From Nobel Laureate Weinberg calls space station an “orbital turkey”)

Taming Antimatter

Dance of death. Credit: Allen Mills/UC Riverside

By soaking a silica sponge with antimatter, physicists have made the first matter-antimatter molecules. With further refinement, the technique might be used to briefly condense antimatter into fluid or solid states or even to create the first gamma-ray laser.

About 10 years ago, researchers created atoms of antihydrogen by combining antiprotons and positrons, the antimatter equivalents of protons and electrons. By itself, antihydrogen is as stable as hydrogen, though it’s difficult to store in our matter world because of antimatter’s propensity to vanish in a flash of gamma rays as soon as it comes into contact with matter.

For more than 50 years, however, physicists have been able to create nucleus-free “atoms” consisting of one electron and one positron. Attracted by their opposite charges, electrons and positrons will orbit each other, as the stars in a binary system do.

Unlike antihydrogen, however this unusual matter-antimatter hybrid, called positronium, is unstable. It enjoys just a brief dance of death as the two particles spiral in toward mutual annihilation.

(Read the rest of my article Alliance of Opposites, freely available on the Science News Web site)

Can Network Theory Explain Why Some Developing Countries Stay Poor?

Making the world flat
The economies of poor and developing countries often depend almost exclusively on a single product—perhaps timber or coffee—or on a handful of products at most. That’s hardly a startling observation, but what’s puzzled economists over the years is why it’s been so difficult for these countries to start up new activities in the hope of spurring economic growth and lifting themselves out of poverty.

While there have been a few success stories, such efforts have often ended up consuming heaps of money to little lasting effect.

A team of economists and physicists [led by network theory expert Albert-László Barabási and by former Venezuelan Minister of the Economy Ricardo Hausman] is now proposing a new way to look at development. The researchers have shown that a country’s competitive edge can spread from one kind of product to another along a well-defined network of links, much as disease epidemics tend to spread among people who are socially connected.

The newly charted map of products could help countries design good policies by indicating the most promising paths to creating new industries. The network’s structure also presages the hurdles that many developing countries will face along that path.

Continue reading “Can Network Theory Explain Why Some Developing Countries Stay Poor?”