Washington: Researchers are doing experiments to check if come particles can travel faster than the speed of light.
University of California, Berkeley, postdoc Michael Hohensee and graduate student Nathan Leefer`s first attempt to test this fundamental tenet of the special theory of relativity demonstrated once again that Albert Einstein was right, but Leefer and Hohensee are improving the experiment to push the theory`s limits even farther - and perhaps turn up a discrepancy that could help physicists fix holes in today`s main theories of the universe.
Hohensee of the Department of Physics said that as a physicist, he wanted to know how the world works, and right now their best models of how the world works - the Standard Model of particle physics and Einstein`s theory of general relativity - don`t fit together at high energies.
He said that by finding points of breakage in the models, we can start to improve these theories.
Hohensee, Leefer and Dmitry Budker, a UC Berkeley professor of physics, conducted the test using a new technique involving two isotopes of the element dysprosium.
By measuring the energy required to change the velocity of electrons as they jumped from one atomic orbital to another while Earth rotated over a 12-hour period, they determined that the maximum speed of an electron - in theory, the speed of light , about 300 million meters per second - is the same in all directions to within 17 nanometers per second.
Their measurements were 10 times more precise than previous attempts to measure the maximum speed of electrons.
Using the two isotopes of dysprosium as "clocks," they also showed that as the Earth moved closer to or farther from the sun over the course of two years, the relative frequency of these "clocks" remained constant, as Einstein predicted in his general theory of relativity.
Their limits on anomalies in the physics of electrons that produce deviations from Einstein`s gravitational redshift are 160 times better than previous experimental limits.
Compared with existing tests, the revamped experiment by UC Berkeley physicists will potentially be a thousand times more sensitive, the level at which some theorists predict special relativity might break down.
The findings have been published in the journal Physical Review Letters.