The michelson interferometer among other interferometer configurations is employed in many scientific experiments and became well known for its use by albert michelson and edward morley in the famous michelsonmorley experiment 1887 in a configuration which would have detected the earths motion through the supposed luminiferous aether. The michelson interferometer equipment preparation goals of. Ligo we have to mention here that the most spectacular realization so far of michelsons interference techniques is the successful detection first in 2016 of gravitational waves by a scaledup version of the interferometer. This controls the length of the ac arm of the interferometer and hence the path di. The 1887 experiment was looking for a variation of 29 kms along the surface of the earth. Michelaon and morleyrelatiqm motion of the 885 the of this oversight and of the entire experiment forms the subject of a very searching analysis by h. The michelson interferometer fall 2008 to better understand the interferometer used by michelson and morley, we will use a simpli. Special and general relativity notes on the michelsonmorley interferometer how it works a monochromatic light wave has one frequency or wavelength. Michelsonmorley experiment american physical society. It was reasoned that, if the speed of light were constant with respect to the proposed ether through which the earth was moving, that motion.
The set up a light source, mirrors, and a telescope on a big slab of stone. The michelsonmorley experiment was an attempt to detect the existence of the luminiferous aether, a supposed medium permeating space that was thought to be the carrier of light waves. Data analysis calibration with hene laser below is a plot of the data taken with the hene laser light injected into the michelson interferometer. Perhaps the key experiment which led to einstein postulating his theory of relativity in 1905, in particular the invariance of the speed of light and the complete absence of a medium the aether for light being a wave, was the michelsonmorley interferometer experiment of 1887 see image above. Figure 1 10 5 laser mirror 1 fixed mirror 2 movable. It was developed by albert michelson and used, in 1893, to measure the standard meter in units of the wavelength of the red line in the cadmium spectrum. Semitransparent mirror sm splits the beam into two ones perpendicular to each other, propagating in the two arms. Michelsonmorley experiment mme is one of the great est failed experimen t ever carried out by humankind. Since then, interferometers are used for many purposes, e. M1 and m2 are two plane mirrors silvered on the front surfaces. They are conveniently divided into two main classes. The michelson morley experiment was designed to measure the extra time it took a light beam to travel thereandback against the ether wind, compared to a light beam travelling sideways across the ether wind.
An introduction to the experiments of michelson and morley that threw doubt on the aether theory and led to einsteins theory of special relativity. Special and general relativity notes on the michelson. Naturally, something that allows solid bodies to pass through it freely is a little hard to get a grip on. Lengths or displacements in terms of wavelengths of light. Experiment o6 michelson interferometer abstract a michelson interferometer, constructed by the student, is used to measure the wavelength of hene laser light and the index of refraction of a flat transparent sample. Shown in figure3, a michelson interferometer uses optical interference to detect the length di erence between. General article the experiment of michelson and morley. If the system is rotated, then the influence of the ether wind should change the time the beams of light take to travel along the arms and therefore. One beam wave 1 goes through path l 1, and is incident on the mirror. Note that the citing of these various websites does not necessarily imply the authors agreement with all. Cahill, the michelson and morley 1887 experiment and the discovery of absolute.
Introduction the michelson interferometer is the fundamental form of a large variety of twobeam interferometer con. Illustrating the michelsonmorley experiment bernhard rothenstein1, stefan popescu 2 and george j. Though often called the michelson morley experiment, the phrase actually refers to a series of experiments carried out by albert michelson in 1881 and then again with better equipment at case western university in 1887 along with chemist edward morley. Considering that the rays in the michelson morley interferometer. The michelson interferometer is the best known of a class of mirrored interferometers known as amplitudesplitting interferometers. Originally michelson designed his interferometer as a means to test for the existence of the ether, a hypothesized medium in which light propagated. Michelson morley experiment and the second postulate of str vesselin c.
Using a beam splitter, a light source is split into two arms. Michelson interferometer is best known for its use in the michelson morley experiment, which disproved the existence of the luminiferous ether and paved the way to the development of the theory of relativity 2. References taylor, zafiratos and dubson, modern physics, second edition, section 1. Aug, 2015 an introduction to the experiments of michelson and morley that threw doubt on the aether theory and led to einsteins theory of special relativity.
Considering that the rays in the michelsonmorley interferometer. Theres an interference pattern which was expected to be shifted when the system was rotated 90 degrees. Morley at what is now case western reserve university in. The active surfaces of the optical components must never be touched with the. Experiment o6 michelson interferometer abstract references. Michelson and morley built a michelson interferometer, which essentially consists of a light source, a halfsilvered glass plate, two mirrors. The basic idea of the interferometer is shown in fig. When set up correctly the michelson interferometer is used in conjunction with a gas cell and vacuum pump to. The michelsonmorley experiment was an attempt to detect the existence of the luminiferous. Jan 26, 2012 michelsons interferometer consists of one semitransparent mirror and two mirrors.
But there was no shift in the interference pattern. Spix 3 1 politehnica university of timisoara, physics department, timisoara, romania 2 siemens ag, erlangen, germany 3 bsee illinois institute of technology, usa abstract. Michelsonmorley experiment, which disproved the exis tence of the. The michelsonmorley experiment was an attempt to measure the motion of the earth through the luminous ether.
In their experiment, a variant of the device used in this experiment was employed. First performed in germany in 188081 by the physicist a. The surprising results of the michelsonmorley experiment. It is the most common design for optical interferometry and was invented by albert abraham michelson. Michelson, the test was later refined in 1887 by michelson and edward w. When set up correctly the michelson interferometer is used. Undoubtedly the most critical turning point in the history of physics was the michelsonmorley experiment which was carried out by albert michelson and edward morley in 1887 and repeated by many others since then with increasing accuracy but ongoing misleading conclusions. The definitive experiment was carried out by alvager et al. A simplified diagram of a michelson interferometer is shown in the fig. This interferometer, used in 1817 in the famous michelson morley experiment, demonstrated the nonexistence of an electromagneticwavecarrying ether, thus paving the way for the special theory of relativity. A quantumoptical approach article pdf available in international journal of optics 2012 may 2012 with 393 reads how we measure reads. The hoek experiment, for example, was intended to detect interferometric fringe shifts. Michelson interferometer definition and applications.
The michelsonmorley experiment 1887 doug marett 2010 in the later part of the 19 th century, the undulatory theory of light assumed the existence of a medium called the ether, whose vibrations produce the phenomenon of heat and light, and which is supposed to fill all space. The optics and electrodynamics of moving bodies pdf. A light source is split into two beams by the beam splitter s. Screws are provided in front of the holders, adjusting of which. Experiment 8 michelson interferometer 1 introduction the michelson interferometer uses light interference to measure distances in units of the wavelength of light from a particular source.
This is known as interference by division of amplitude. Motion, progress in physics, october 2005, volume 3, pp. Michelsons interferometer wavelength of laser beam theory. It can be used to carry out the following principal measurements. Not only that, one will further learn and most cer tainly. That is, the interference displacement fringe ratio must be at least 0. Morley at what is now case western reserve university in cleveland, ohio, and. Special and general relativity notes on the michelsonmorley. Analysis 1 note that the citing of these various websites does not necessarily imply the authors agreement with all. In descriptions of the experiment, the two arms of the interferometer have the same length. The magnitude of the phase shift was far beyond the sensitivity in the historical 1887 michelsonmorley experiment and is still just beyond the sensitivity of turntable rotated optical resonators used in present tests of lorentz invariance. Michelson interferometer lab report robert clancy 04329741 november 9, 2005 abstract in this experiment the famous michelson interferometer and some of its uses are investigated.
Reanalysis of michelsonmorley experiments reveals agreement. The michelsonmorley interferometer experiment of 1887 is often cited as one of the cornerstones and perhaps the cornerstone upon which einstein built his theory of special relativity. Details in the other arm of the interferometer, the total velocity must be perpendicular, so light must propagate at an angle. The objective of this experiment is to observe the interference of light by combining coherent monochromatic light beams using a michelson interferometer. Schematic illustration of a michelson interferometer. Michelson interferometer is best known for its use in the michelsonmorley experiment, which disproved the existence of the luminiferous ether and paved the way to the development of the theory of relativity 2.
The michelson morley experiment was an attempt to measure the motion of the earth through the luminous ether. Michelsonmorley experiment and the second postulate of str vesselin c. Michelsonmorley experiment and the second postulate of st. Record of experiment actual notes from lab notebook shown on previous 4 pages. Michelson 18521931 designed a device known now as an interferometer. Interference of light in michelson morley interferometer. Cahill, the michelson and morley 1887 experiment and the discovery of absolute motion, progress in physics, october 2005, volume 3, pp. Figure 1 is a diagram of the apparatus, the pasco model os8501 interferometer. The experiment was performed between april and july 1887 by albert a. In this experiment, you will use a michelson interferometer to determine the wavelength of laser light, as well as to investigate the index of refraction of air and how it is affected by changes in pressure. They are mounted vertically on two rigid holders placed at the sides of a flat metal stand. For more information see optics, second edition by eugene hecht addison wesley publishing company, 1987, pp.
The procedure depended on a michelson interferometer, a sensitive optical device that compares the optical path lengths for light moving in two mutually perpendicular directions. We have to mention here that the most spectacular realization so far of michelsons interference techniques is the successful detection first in 2016 of gravitational waves by a scaledup version of the interferometer. Michelsons interferometer consists of one semitransparent mirror and two mirrors. The michelsonmorley experiment became what might be regarded as the most. In 1864 james clerk maxwell showed that light is an electromagnetic wave. The schematic of michelson interferometer is shown in fig. In this experiment, you will use a michelson interferometer made by r. Michelson morley experiment used an interferometric technique to detect this e. Two weights for all experiments with michelson interferometer and one weight more for experiments with fabryper. Jan 17, 2018 perhaps the key experiment which led to einstein postulating his theory of relativity in 1905, in particular the invariance of the speed of light and the complete absence of a medium the aether for light being a wave, was the michelson morley interferometer experiment of 1887.
Illustrating the michelson morley experiment bernhard rothenstein1, stefan popescu 2 and george j. The nature of light and its propagation through space and opti. Michelson morley experiment, an attempt to detect the velocity of the earth with respect to the hypothetical luminiferous ether, a medium in space proposed to carry light waves. Michelson morley experiment physics stack exchange. The main features of the interferometer are shown schematically in figure 1. Though often called the michelsonmorley experiment, the phrase actually refers to a series of experiments carried out by albert michelson in 1881 and then again with better equipment at case western university in 1887 along with chemist edward morley. The michelson interferometer equipment preparation goals. According to fresnel, the ether, which is enclosed in optical media, partakes of the motion of.
Interpretation of the slight periodic displacement in the. Undoubtedly the most critical turning point in the history of physics was the michelson morley experiment which was carried out by albert michelson and edward morley in 1887 and repeated by many others since then with increasing accuracy but ongoing misleading conclusions. Lo who finds that this effect can by no means be disregarded. Experiment 4 the michelson interferometer 2 figure 1. Mirror 1 m1 inside the michelson interferometer is being translated at a constant speed by a motor. In consequence, the quantity to be measured had in fact bat onehalf the value supposed, and as it was already barely be. Each of those light beams is reflected back toward the beamsplitter which then combines their amplitudes using the superposition principle. A deeper understanding of the mathematics of the michelson. Special and general relativity notes on the michelson morley interferometer how it works a monochromatic light wave has one frequency or wavelength. It was reasoned that, if the speed of light were constant with respect to the proposed ether through which the earth was moving, that. Michelson morleys interferometer together with einsteins theory of relativity helped in abandoning the concept of ether in the classical experiment performed in 1887. The michelson interferometer is a common configuration for optical interferometry and was invented by albert abraham michelson. Michelsonmorley experiment, interferometer, the theory of special relativity, single photon experiment.
Experiment 8 michelson interferometer 1 introduction. The michelsonmorley experiment is considered via a single photon interferometer and a hypothesis of the dragging of the permittivity of free space. Details perpendicular propagation vaether parallel and antiparallel propagation 2. Michelsons interferometer wavelength of laser beam. The michelsonmorley experiment seems to have taken many years, resources and a nervous breakdown to complete. Therefore it was assumed that there is an ether which propagates light waves. In the beck apparatus, m2 of the michelson optics is mounted on a carriage that is driven by a micrometer. Michelson interferometer is a tool to produce interference between two beams of light.
656 363 257 1412 1417 1193 555 235 1251 1128 183 694 61 1306 980 1446 752 1053 887 375 1482 1116 666 1437 681 690 23 1137 534 764 514