On 30 Jul, Jack Lewis <jandj.lewis@xxxxxxxxxxxxx> wrote: > > > > Also, the stars would be travelling faster than light, which is > > impossible according to Einstein's theory of relativity. > Question 1 What was Einstein's basis for formulating his theory? Well, If I started now, and wrote about 100 Mb of text, I might begin to be able to explain it to you, but I suspect you might not understand it! Einstein was exceedingly brilliant! I suggest you buy a book on relativity. However, I will tell you that Einstein made several predictions in the theory of relativity which appear totally to contradict common sense (and all of them have been proved correct experimentally). He said that if a body approached the speed of light, its length in the direction of motion would shrink. Also that its timescale would slow down, so seconds would become longer, and also that its mass would increase, and become infinite at the speed of light. You can't accelerate a body with infinite mass, because it would require an infinite force, so therefore nothing can ever go faster than light. > > I suppose you will say that you don't accept Newton's laws, or > > the theory of relativity, (which have been supported by all the > > experiments so far carried out). > > Question 2 What are these experiments - are they to do with particle > physics? Well there are hundreds of experiments which confirm Newton's laws which can be carried out in a school laboratory. When it comes to Einstein, the speeds are so great that it is only possible to accelerate particles of low mass to these speeds, so yes, most of them are confirmed by particle physics. However, some are confirmed astronomically. Since Einstein's rules differ very slightly from Newton at lower speeds, it does have an effect on the orbits of the planets, but only very small. One of the other things which Einstein predicted is that light would be affected by a gravitational field, which was verified during a total eclipse of the sun just after the war, as the light from stars close to the sun was bent by the sun's gravitational field, and the stars appeared to be in the wrong place. Does this answer your questions? Alan