Thursday, May 6, 2010, 16:00
WHGA Auditorium
A. Peters, Humboldt University of Berlin
Abstract:
"The speed of light is finite and does not depend on the motion of
either source or observer". This is the fundamental statement underlying
Albert Einstein's theory of Special Relativity. First formulated early
in the 20th century, this theory now is one of the cornerstones of our
scientific understanding of the world and tightly woven into the fabric
of modern physical theories. It also has become more and more relevant
for daily life - timekeeping using modern atomic clocks and navigation
using the global positioning system are just two examples. Due to this
outstanding role, it always has been of prime importance to
experimentally verify the validity of the underlying theory. Today,
further incentive for such tests is provided by new theoretical attempts
- such as string theory or loop quantum gravity - aiming at unifying the
forces of nature, which indeed suggest small violations of
Lorentz-Invariance.
This talk will discuss modern tests based on optical methods, which are especially well suited for the task at hand. A specific example is a modern version of the classic Michelson-Morley experiment testing the isotropy of light propagation, where the measurement is performed by monitoring the resonance frequency of an optical resonator continuously rotating on a precision turntable. This currently allows a sensitivity at the Δc ⁄ c = 10-17 level for a direction dependent variation of the speed of light, with the potential for improvements in precision by up to three orders of magnitude in the near future.