Dying stars in a grain of sand
Wednesday 13 February 2013
Scientists led by Professor Ben Murdin at the University of Surrey have been able to reproduce the conditions in one of the most hostile environments in the galaxy.
Near to the surface of a white dwarf star, the dead embers left after Sun-like stars have exhausted their fuel, there are very high gravitational forces, very high temperatures, and occasionally very high magnetic fields. Sometimes these fields are thought to reach levels a billion times stronger than the Earth’s.
The rules of chemistry completely changes in this environment so atoms that did not previously stick together can become bonded, while previously bonded molecules change their size and shape.
Extreme environments like this are common in space but often difficult or impossible to reproduce on Earth. The team of scientists discovered that ordinary silicon crystals of the same type used to make computer chips are so sensitive to the effects of a magnetic field that they could achieve the same conditions as on the most magnetic white dwarf.
They found that in these conditions, the electron cloud around a hydrogen atom was changed to a variety of patterns from fans to highly elongated lumpy pencil shapes.
Dr Ellis Bowyer, a researcher at the University of Surrey, who did the experiments, said: “It’s not just about astronomy. There are also practical implications. Learning how to control the shapes of tiny electron clouds in silicon chips is letting us design new kinds of computer chips, called quantum computers, where the transistors contain just one atom”.
Professor Paul Murdin, of the Institute of Astronomy in Cambridge, one of the co-authors of the work said: “The theory predicting the behavior of Hydrogen atoms in magnetic fields this high has been around for just under a century, but until now, no one was able to test it right up at the limit seen on white dwarfs.
“We are looking forwards to using the principle to see what happens to molecules where the theory is almost impossibly hard.”
The team is now looking for signs of a helium molecule, predicted to exist there but never before seen.
You can read the full research paper in Nature Communications See: http://www.nature.com/ncomms/journal/v4/n2/full/ncomms2466.html
Media Enquiries
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