If you were to actually break the speed of light under relativistic conditions, what would happen exactly? Would you go back in time? Would you cause a "light boom" like a sonic boom but bigger? I've been running some thought experiments in my head (with almost no formal physics training) and I think it's a possibility that by breaking the speed of light one would create a new speed of light that travels as fast as the fastest speed achieved by the speed limit breaker. Thus, when one starship breaks the speed of light, the speed of light for the whole of the universe changes. Is this mathematically possible? If not, what would happen if the speed of light is broken? I'm not asking if it's possible. I'm asking what would happen if someone--specifically an observer, not a tachyon--broke the speed of light under Einstien's rules.