Instruments
Michelson Interferometer
my-KEL-suhn in-tur-fuh-ROM-uh-tur
Citation Formats
General Reference
APA Style
BibTeX
The Michelson interferometer splits a beam of light into two paths at right angles, sends each along its own arm to a mirror, and recombines them, so that any difference in the distance the light travelled shows up as a shift in the interference pattern. Albert A. Michelson built the device in 1881, and used it with Edward Morley in 1887 in an attempt to detect Earth's motion through a supposed luminiferous ether; the experiment's null result helped clear the way for Einstein's special theory of relativity.
Facts
Invented Year MeasuresInterference patterns arising from the path-length difference between two recombined light beams, used to measure distance, strain and wavelength with extreme precision. 2 Operating PrincipleA beam splitter divides a light source into two perpendicular arms, each reflected back by a mirror; the two beams recombine at the beam splitter and interfere, and the resulting pattern depends on the path-length difference between the arms. 2 ResolutionPrecise to the scale of a light wavelength; coherent laser sources can resolve path differences of millions to billions of wavelengths. 2 Operating RangeNot a single fixed range; scale depends on the light source's coherence length, from micrometers for ordinary white light up to kilometer-scale arms in the largest gravitational-wave detectors, such as LIGO's 4-kilometer arms. 2 Cross-Tradition Connections
Invented By
Built the interferometer in 1881 to detect minute differences in the speed of light travelling in perpendicular directions, then used it again with Edward Morley in 1887 in the famous null-result experiment.
Used In
Sources
Reader Challenges (0 open reader challenges)
No disputes yet. Spotted an error or a better source? Open the first one.
Sign in to dispute this or suggest a correction.
View At A Past Year
The atlas records no dated fact of its own for this entry, so there is no other year to choose.