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I’m travelling at the speed of light. If I hold a mirror in front of me could I see my face?

Qmechanic
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Belisario Nieto
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If you're traveling at precisely the speed of light, you can't "hold" anything. In fact, you can't think either, much less see anything. This is because all of the above require that interactions happen between different parts of your body, or between your body and the environment. In order for two objects to interact at a particular moment in time, they must be lightlike or timelike separated at that moment (in other words, one must be reachable from the other using the fastest possible object). If you and a mirror are both traveling in the same direction at the speed of light, you could never interact with the mirror if it was in front of you, and the mirror could never interact with you if it were behind you. This is because nothing propagating from the object in back could ever "catch up with" the object in front.

probably_someone
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