There are many qusetions in science & cosmology which have degerate answers some of them are as follows: 1. In the presence of matter space get curved so massive particles as well as light photons do not move along stright line. Now one could always assume that photons also carry gravitational mass so they also get attracted in gravity in place of assuming that space get curved. Note that assuming that photons carry gravitational mass we are just postulating about photons but assuming that space get curved we are postulating about the behaviour of many unknown forms of matter. 2. Postulating that the space is expanding leads to the conclusion that remote galaxies are moving away from us. But assuming that these are actually galaxies which are moving away from us in a non-expanding universe also leads same conclusion as well as observation. I know, that assuming that galaxis are moving in a fixed background leads to many difficult questions but does the first option not ? i.e., what the space expanding into ? (nobody like to talk about this issue and says that this is not expanding into anything, my objection is that if this is not expanding into anything then this is not the type of expansion that we encounter in the daily life i.e., which always expands into something. If the expansion of the universe is not the type of expansion which we face in daily life then why we call it expansion at all). 3. In special theory of relativity postulating that nothing can travel faster than the speed of light we restrict the behaviour of that which have not been yet discovered (fastets than light signal). Note that in place of assuming that time interval get changed in moving frame we can always say there is a minium limit on the time interval which we need for communication.