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If we were to travel almost at $299\,792\,458~m/s$, or the speed of light, what would happen to the human body? Would the human body stay the same or would there be consequences that would harm the person? Would our body shut down? I've been looking for an answer but could not find one.


marked as duplicate by user10851, Jim, John Rennie, Emilio Pisanty, Kyle Kanos May 20 '15 at 19:28

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Although the most common answer to questions like that is "relative to what?", there are possible side-effects. If I recall correctly, the earth's velocity relative to the cosmic background radiation is on the order of a mere 600km/s. If we were to be travelling arbitrarily close to the speed of light as compared to our current motion, part of this background radiation could be blue-shifted to such an extent as to be harmful to us.

The answer remains: it depends, relative to what you will be travelling at the speed of light to. But if it's relative to now (as in "current state"), there are plenty of things in the universe that you wouldn't want to interact with.

  • $\begingroup$ :-) Somewhere in Gene Roddenberry's notes for the original "Star Trek" TV show, he wrote that the ship would need a navigational deflector---a sort of "force field" that would extend in a narrow cone in the ship's direction of travel to clear the path of all of the tiny particles of matter that otherwise would appear as harmful radiation to the crew of a ship that was passing through at relativistic speeds. $\endgroup$ – Solomon Slow May 29 '15 at 18:21

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