What is light ? part 2 THEORY OF RELATIVITY

 Einstein's two simple statement

Is an experiment were conducted in a stationary laboratory of the Earth surface and then in an identical laboratory in a train moving with constant velocity along a level track  Newton's Law of Motion would apply equally well in both instance.

In 19 century the British physician James clerk Maxwell 1831 to 1879 demonstrated how electricity and Magnetism are related and show the light is an Electromagnetic wave scientist assume that waves could not travel through empty space so the existence throughout phase of the transparent medium called the either was suggested this could conceively be in the state of absolute rest suggested by neutral researchers conducted a number of experiments to find the velocity of earth through the either in 1887 to American scientist Albert nicholation and Edward Morley  use and optical device in such an atom but despite the accuracy of their measurement they were unable to obtain a result among the explanation for this was a suggestion that any object moving through the ether suffers as contraction in the direction of motion. 

Albert enistein two statements  1. The first is that the laws of Physics are same in all inertial (non accelerating) frames of the reference third passengers on a high speed train can for coffee and work about with an awareness of their Rapid motion unless they look out of the window.

Einstein special theory of relativity set out to agree with the experimental finding that the velocity of light does not depend on the motion of the observer is in so doing theory made several remarkable predictions two of these prediction concern changes in the observed mass and length of an object as its speed increases towards the velocity of light lens parallel to direction of motion but not those at right angle to it decrease or contract while masses increase this changes in length and moves make it impossible for anything to travel faster than the velocity of light.

An object mass is a form of energy in this  tracks in a  the collision of the single high energy proton with a stationary one create a spray of new particles as a kinetic energy Converse to mass energy.