Sunday, 6 November 2016

NOBEL PRIZE-2016

This year’s Nobel Prize in physics goes to three men, who, in their work in the 1970s and 1980s, explained the very weird thing that happens to matter when you squish it down to a flat plane, or cool it down to near absolute zero.

Half the prize goes to David Thouless of the University of Washington, and the other half is split between Duncan Haldane of Princeton University and J. Michael Kosterlitz of Brown. All the laureates were born in the UK.

The prize is a reward for their theoretical work, said Thors Hans Hansson, a Nobel committee member, at the Nobel announcement. “It has combined beautiful mathematics and profound physics insights, and achieved unexpected results that has been confirmed by experiments,” Hansson said.

So what, exactly, did Thouless, Haldane, and Kosterlitz prove?

In essence, they showed that the bizarre properties of matter at cold or condensed states — for instance, when super-cold materials conduct electricity without resistance — could be explained by the mathematics of topology.

Topology is a branch of math that studies what properties are preserved when objects are stretched, twisted, or deformed. Hansson, apparently anticipating our total ignorance of topology, helpfully brought along a cinnamon bun, a bagel, and a pretzel to explain it at the prize announcement.

You can describe the number of holes in each shape topologically, he said. A bun has zero holes, a bagel has one, and a pretzel has two. There are no half holes. And the number of holes in these objects stays the same if you stretch or twist them.

Here he is explaining:

Using topology, Thouless, Haldane, and Kosterlitz were able to elucidate mysteries like how super-cold films of helium change their phase of matter, and how those phase transitions then change their properties (like how conductive they are to electricity and magnetism).

Beyond theory, the research has also led scientists to develop new materials with novel properties, said Nils MÃ¥rtensson, acting chair on the Nobel committee on physics. Some of these materials are called “topological insulators,” which conduct electricity solely on their surface.

These topological insulators haven’t made it into any commercial products yet, but the Nobel committee and the scientists are still excited about the possibilities for using them in quantum computing and other yet-to-be discovered applications. One of these insulators,called stanene — basically a one-atom thick layer of tin — will conduct electricity at high temperatures with little resistance. One day, scientists hope stanene could perhaps replacecopper components in computers.

That this work on topological insulators won the prize is a bit of a surprise. The detection of gravitational waves at LIGO was one of the most stunning physics announcements of the year, confirming a prediction made by Einstein more than 100 years ago. Many predicted the scientists who led that work would win.

Why wasn’t LIGO selected? One answer: The discovery, announced in February, missed Nobel’s deadline for consideration in January. The Nobel Committee also typically awards scientific discoveries many years after they are first shared — after they’ve truly changed the field.
Source: www.vox.com, www.nobelprize.org

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