January 30, 2012
California Researchers Hoping To Reveal Secrets of Anti-Gravity
A team of researchers from the University of California, Riverside (UCR) say they are close to determining whether or not anti-matter exerts a sort of "anti-gravity" in much the same what that ordinary matter exerts regular gravity.
In an article published Friday, BBC News reports that, while it is well known that normal matter attracts all other matter in the universe, scientists currently do not know if anti-matter would attract other matter, or repel it.
Writing in the journal Physics Review Letters, authors D. B. Cassidy, T. H. Hisakado, H. W. K. Tom, and A. P. Mills, Jr. discuss producing "Rydberg positronium (Ps) atoms" -- pairs of electrons and positrons that maintain stable orbits around each other, without colliding and destroying each other.
The researchers say that they accomplished this via a two-step, experimental process that uses "incoherent laser excitation, first to the 2“3P state and then to states with principal quantum numbers ranging from 10 to 25."
They add that the excitation of these atoms "occurs very efficiently," and that, combined with their longevity in a high magnetic field, could "make it possible to perform direct measurements of the gravitational free fall of Ps."
According to the BBC, the majority of scientists believe that anti-matter will be attracted to normal matter. Some argue, though, that anti-matter might actually repel ordinary matter, causing it to effectively fall upwards.
While testing these conflicting theories has not yet been possible, by Cassidy, Hisakado, Tom, and Mills hope to expand their method to allow their Rydberg positronium atoms to reach higher energies, then using them to crease a beam comprised of the particles and observing "which way they fall," up or down, according to BBC News.
Image 2: Allen Mills, professor of physics and astronomy. Credit: Mills lab, UC Riverside
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