15 March 2007 From New Scientist Print Edition. Subscribe and get 4 free issues. Zeeya Merali In 1998, just after he won a share of the Nobel prize for physics, Robert Laughlin of Stanford University in California was asked how his discovery of "particles" with fractional charge, now called quasi-particles, ...
| | #1 | ||||
| Last Starfighter Independent Northern California ![]()
| The universe is a string-net liquid
In 1998, just after he won a share of the Nobel prize for physics, Robert Laughlin of Stanford University in California was asked how his discovery of "particles" with fractional charge, now called quasi-particles, would affect the lives of ordinary people. "It probably won't," he said, "unless people are concerned about how the universe works." Well, people were. Xiao-Gang Wen at the Massachusetts Institute of Technology and Michael Levin at Harvard University ran with Laughlin's ideas and have come up with a prediction for a new state of matter, and even a tantalising picture of the nature of space-time itself. Levin presented their work at the Topological Quantum Computing conference at the University of California, Los Angeles, early this month. The first hint that a new type of matter may exist came in 1982. "Twenty five years ago we thought we understood everything about how matter changes phase," says Wen. "Then along came an experiment that opened up a whole new world." In the experiment, electrons moving in the interface between two semiconductors behaved as though they were made up of particles with only a fraction of the electron's charge. This so-called fractional quantum hall effect (FQHE) suggested that electrons may not be elementary particles after all. However, it soon became clear that electrons under certain conditions can congregate in a way that gives them the illusion of having fractional charge - an explanation that earned Laughlin, Horst Störmer and Daniel Tsui the Nobel prize (New Scientist, 31 January 1998, p 36). Wen suspected that the effect could be an example of a new type of matter. Different phases of matter are characterised by the way their atoms are organised. In a liquid, for instance, atoms are randomly distributed, whereas atoms in a solid are rigidly positioned in a lattice. FQHE systems are different. "If you take a snapshot of the position of electrons in an FQHE system they appear random and you think you have a liquid," says Wen. But step back, and you see that, unlike in a liquid, the electrons dance around each other in well-defined steps. Full article here: The universe is a string-net liquid - fundamentals - 15 March 2007 - New Scientist | ||||
| Register to Reply to This Post |
| | #2 | ||||
| Ron Paul '08 Libertarian Party Queens, NY ![]()
| Now I wouldn't go so far as to say "The Univserse is a String-Net Liquid". | ||||
| Register to Reply to This Post |
| | #3 | ||||
| ipsa Scientia Potestas est Pragmatist Greensboro, NC ![]() ![]() ![]()
| |||||
| Register to Reply to This Post |
| Register to Post a Reply |
| Bookmarks |
| Tags |
| state, new |
| ||||||
| Thread Tools | |
| |
| vBulletin 3.7.2 -- Copyright ©2000 - 2008, Jelsoft Enterprises Ltd. | Custom Artwork and Theme (TM) 2006, Liberty Lounge |