Hi guys, Firstly apologies if this question has been asked before (or are stupid questions) or better explained elsewhere. I'm not studying physics nor pursuing a scientific career, just curious about the following questions. The questions I have are regarding the speed of light. Firstly if an object travelled at the speed of light or close to it, there would be two different speeds? One speed from a perspective outside the object and a second one from inside the object as the time travelled would be different? Secondly, if two objects were travelling apart at 50.01% speed of light, would I be correct in assuming the object would not be visible from spectating from one object to the other? e.g. if the Earth was travelling in one direction at 50.01% the speed of light and the Moon in the opposite direction at the same speed, the object would not be visible from Earth? Following on from that if two objects were travelling towards each other at 50.01% the speed of light would I be correct in assuming that object would also not be visible? Lastly, going back to two objects moving apart at 50.01% the speed of light, could one object be used as reference at looking at the other object travelling at 100.02% the speed of light?