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The experiment of Michelson and Morley



The experiment of Michelson and Morley

When you are inter­ested in physics you must read “Unbe­liev­able”!

The death of the ether hypoth­e­sis was, after the unjus­ti­fied denial of dragged ether, the exper­i­ment of Michel­son and Mor­ley. The dragged ether already being rejected by sci­ence the only ether thought pos­si­ble was the absolute ether. Sci­ence saw only pos­si­bil­i­ties in the absolute ether; an ether that is not influ­enced by anything.

All light, from any source in any direc­tion, has to move in absolute ether inde­pen­dently of the source. The prob­lem was how to prove the exis­tence of the absolute ether. In those days this was a very dif­fi­cult task because the speed of light is so immense. Michel­son how­ever devised an exper­i­ment that made it pos­si­ble to detect this ether by means of the orbit speed of the earth around the sun. The prin­ci­ple of the method by Michel­son and Mor­ley is the same as Fizeau’s exper­i­ment. The dif­fer­ence is mea­sured by means of the shift in lines of the inter­fer­ence pat­tern. The dif­fer­ence in time or dis­tance trav­eled by light is mea­sured in inter­fer­ence lines. The dif­fer­ence between extin­guish or for­tify inter­fer­ence lines is 140 of mil­lionth meter.

The earth moves in an ellip­tic orbit around the sun with a speed of more than 100,000 km/​h. This very high veloc­ity is not achiev­able in any other way on the Earth, because there is no pos­si­bil­ity accel­er­ate an exper­i­ment to such a high speed and this speed is still only 1/10,000 of the speed of light.

An observer on the earth can never be at rest with the absolute ether dur­ing the whole year when the earth is orbit­ing the sun. Michel­son had the bril­liant idea that one would not have to mea­sure the alter­ing of the inter­fer­ence pat­tern dur­ing the whole year to see whether that would be the case. He reflected that the equip­ment only had to be turned 360 degrees to obtain results. Then the light source can never be at rest with the ether all the time dur­ing the 360 degrees turn. When there is absolute ether, not influ­enced by any­thing, then the accu­racy of the exper­i­ment would be suf­fi­cient to deter­mine the exis­tence of absolute ether.

The time nec­es­sary for the light to travel right-​angled oppo­site to the ether would be t1. For the light beam to travel with or against the ether is t2 (fig­ure 7).

The the­o­ret­i­cal line shift should be:

With λ the wave­length of the light, v the speed oppo­site to the ether and L the length of the path with and against the ether. Only if there is no absolute ether the line shift is zero, because we argued before that if the absolute ether existed the Earth mov­ing around the Sun also must move in respect to the absolute ether and there­fore induce the the­o­ret­i­cal line shift.

In 1881 Michel­son con­ducted this exper­i­ment on his own for the first time. The accu­racy was how­ever not suf­fi­cient to prove with­out doubt there was no absolute ether. In 1887 Michel­son repeated the mea­sure­ment with Mor­ley with much more accu­racy. The shift, with absolute ether, should be 0.40 lines. The mea­sured shift was only 0.01 lines.

Fig­ure 7. The exper­i­ment of Michel­son and Morley.

Many oth­ers con­ducted the same exper­i­ment later on and always with the same result that only a small frac­tion of the the­o­ret­i­cal shift was mea­sured. The con­clu­sion was, with­out doubt:

The Michel­son and Mor­ley exper­i­ment did not pro­vide any exper­i­men­tal evi­dence for the exis­tence of the absolute ether. The rejec­tion of the hypoth­e­sis of absolute ether appears to be correct.

Next chap­ter: But what now?!


When you are interested in physics you must read “Unbelievable“!

The death of the ether hypothesis was, after the unjustified denial of dragged ether, the experiment of Michelson and Morley. The dragged ether already being rejected by science the only ether thought possible was the absolute ether. Science saw only possibilities in the absolute ether; an ether that is not influenced by anything.

All light, from any source in any direction, has to move in absolute ether independently of the source. The problem was how to prove the existence of the absolute ether. In those days this was a very difficult task because the speed of light is so immense. Michelson however devised an experiment that made it possible to detect this ether by means of the orbit speed of the earth around the sun. The principle of the method by Michelson and Morley is the same as Fizeau’s experiment. The difference is measured by means of the shift in lines of the interference pattern. The difference in time or distance traveled by light is measured in interference lines. The difference between extinguish or fortify interference lines is 1/40 of millionth meter.

The earth moves in an elliptic orbit around the sun with a speed of more than 100,000 km/h. This very high velocity is not achievable in any other way on the Earth, because there is no possibility accelerate an experiment to such a high speed and this speed is still only 1/10,000 of the speed of light.

An observer on the earth can never be at rest with the absolute ether during the whole year when the earth is orbiting the sun. Michelson had the brilliant idea that one would not have to measure the altering of the interference pattern during the whole year to see whether that would be the case. He reflected that the equipment only had to be turned 360 degrees to obtain results. Then the light source can never be at rest with the ether all the time during the 360 degrees turn. When there is absolute ether, not influenced by anything, then the accuracy of the experiment would be sufficient to determine the existence of absolute ether.

The time necessary for the light to travel right-angled opposite to the ether would be t1. For the light beam to travel with or against the ether is t2 (figure 7).

     

The theoretical line shift should be:

With λ the wavelength of the light, v the speed opposite to the ether and L the length of the path with and against the ether. Only if there is no absolute ether the line shift is zero, because we argued before that if the absolute ether existed the Earth moving around the Sun also must move in respect to the absolute ether and therefore induce the theoretical line shift.

In 1881 Michelson conducted this experiment on his own for the first time. The accuracy was however not sufficient to prove without doubt there was no absolute ether. In 1887 Michelson repeated the measurement with Morley with much more accuracy. The shift, with absolute ether, should be 0.40 lines. The measured shift was only 0.01 lines.

Figure 7.   The experiment of Michelson and Morley.

Many others conducted the same experiment later on and always with the same result that only a small fraction of the theoretical shift was measured. The conclusion was, without doubt:

The Michelson and Morley experiment did not provide any experimental evidence for the existence of the absolute ether. The rejection of the hypothesis of absolute ether appears to be correct.

Next chapter: But what now?!


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