Answer to Question #156353 in Mechanics | Relativity for Shailendra kumar

Question

 What will be the expected fringe shift on the basis of stationary ‘ether’ hypothesis in 

Michelson -Morley experiment if the effective length of each path is 8 m and wavelength of 

light used is 8000 Ả

Answer 1

The essence of the Michelson-Morley experiment itself is as follows. Scientists hoped to detect the movement of the Earth relative to the stationary ether, according to the idea that Maxwell had expressed earlier. In this experiment, the Michelson interferometer was oriented in such a way that one of its arms, for example, PM1, is parallel to the speed of the Earth's orbital motion, and the other, PM2, is perpendicular. It was assumed that the time intervals it takes for light to travel back and forth the same distance along the arms PM1 and PM2 will be different. As a result, the screen should have been observed, in the opinion of the experimenters, a displacement of the interference pattern. However, observing for a year, Michelson and Morley came to a negative result of the experiment. This was the starting point for denying the existence of the ether.

The conclusions drawn from these experiments are based on scientific concepts that existed both at the turn of the 19th and 20th centuries and today. But these are just concepts that, due to lack of knowledge, maybe erroneous or incomplete.

$$PM=\frac {8000}{8}=1000$$