I want to start with a question that is universe is really expanding? According to my view it is to be like this: (To get this one should be well versed in Doppler’s effect) Suppose we had gone to mars & placed a light source there & came back. Now we know orbital velocity of earth is more than that of mars, so as a result earth moves away from it. Now observe the spectrum of the light of mars we will defiantly got red shift. Now suppose we do similar experiment with Venus we will get blue shift as earth is approaching toward it. Now similarly it can be assumed that galaxies in stead of getting away as we are assuming at present are also revolving around a centeral body of gravitational force which tends to infinity. So we are getting red shift as we are getting away from it (in our frame), also there will be a galaxy from which we are getting blue shift(just as in case of Venus). So we can assume that, universe is not expanding but galaxies are revolving around a body of high gravity. If, that was the practical which showed that Universe is epanding, so it may be wrong; or the method was different.