ABSTRACT
As we discussed previously, Einstein discovered the theory of special relativity when he tried to answer the following question. Would it be possible to find a frame of reference of space and time coordinates, moving along with the speed of propagating light, such that the light would be seen to be stationary from this frame? From a close examination of Maxwell’s equations-the physical laws that explain light-Einstein discovered that indeed these equations have no solutions, expressed in any frame of reference, in which light would be at rest, or propagating at any speed other than the speed c (thirty billion centimetres per second)—the speed of light in a vacuum. (Recall that light propagates at slower speeds than this in material media. This is because of the delaying action of its being absorbed in the matter, thereby increasing the energy of this matter as it becomes ‘excited’. The light is then emitted again later, when the matter returns to its ground state-i.e. when it ‘de-excites’ in the characteristic ‘lifetimes’ of the light-conducting matter.)
Einstein’s conclusion about the constancy of c in all reference frames was based on his tacit assumption that the form of Maxwell’s equations must be preserved in all relatively moving reference frames. He was not willing to give up this assumption-even to preserve common sense-because it seemed basic to the meaning of the phrase ‘law of nature’. Thus he was led to a shocking conclusion that indeed defied common sense.
