Hi, I had a question on theory of relativity. It is more of a thought experiment. As per the theory of relativity, as the speed of an object increases time slows down. If any particle travels faster than the speed of light, theoretically it has to travel back in time. So from this we can deduce that when a particle is exactly at the speed of light t=0. Thought experiment- let's say a fly sits on a photon that is emitted by the sun. We know that from out standpoint of time, the photon takes approximately 8min 20 sec to reach earth. But let's say that the fly has a stopwatch and it starts the watch when it leaves the sun. As the photon and the fly are traveling at the speed of light, t=0, hence the fly clocks 0 seconds confirms that the photon traveled instantly from sun to earth. Concurring from this, even if the photon travels across the universe, the result i.e t=0 stands same. Also according to Einstin's theory, time and space are considered to be a single diminution called 'Time Space'. So as the speed of a particle tends towards the the speed of light, it is not just that time slows down but also space has to contract, eventually at exactly the speed of light space also become 0 (null). This brings us to Nothing. I am a novice. I would love your comments on the same. Thank you.