28 research outputs found
A Review of One-Way and Two-Way Experiments to Test the Isotropy of the Speed of Light
As we approach the 125th anniversary of the Michelson-Morley experiment in
2012, we review experiments that test the isotropy of the speed of light.
Previous measurements are categorized into one-way (single-trip) and two-way
(round-trip averaged or over closed paths) approaches and the level of
experimental verification that these experiments provide is discussed. The
isotropy of the speed of light is one of the postulates of the Special Theory
of Relativity (STR) and, consequently, this phenomenon has been subject to
considerable experimental scrutiny. Here, we tabulate significant experiments
performed since 1881 and attempt to indicate a direction for future
investigation.Comment: Updated Fig. 7 and references; Revised sections 3.2 and 4. Accepted
in the Indian Journal of Physics on March 30, 201
The Confrontation between General Relativity and Experiment
The status of experimental tests of general relativity and of theoretical
frameworks for analysing them is reviewed. Einstein's equivalence principle
(EEP) is well supported by experiments such as the Eotvos experiment, tests of
special relativity, and the gravitational redshift experiment. Future tests of
EEP and of the inverse square law are searching for new interactions arising
from unification or quantum gravity. Tests of general relativity at the
post-Newtonian level have reached high precision, including the light
deflection, the Shapiro time delay, the perihelion advance of Mercury, and the
Nordtvedt effect in lunar motion. Gravitational-wave damping has been detected
in an amount that agrees with general relativity to better than half a percent
using the Hulse-Taylor binary pulsar, and other binary pulsar systems have
yielded other tests, especially of strong-field effects. When direct
observation of gravitational radiation from astrophysical sources begins, new
tests of general relativity will be possible.Comment: 89 pages, 8 figures; an update of the Living Review article
originally published in 2001; final published version incorporating referees'
suggestion