Perception while traveling

[Grizwold]

Suppose you can travel at the speed of light. What do you see when you travel? If you travel away from earth, and look back at it, do you see a still image (which is panning out)? What if you are looking ahead? Do you see the past occur at double speed? What if you look to the side?

Suppose you can travel faster than the speed of light. If you travel away from earth and look back, would you see reality in reverse/rewinding? What if you look ahead?

[Siegmund]

Lots of... well... singular things, would happen if you could move AT the speed of light.

But there are various ways one can visualize how things change as you approach that speed. The links, with animations, at http://www.fourmilab.ch/cship/cship.html are a good place to start.

[madnak]

[ QUOTE ]
Suppose you can travel at the speed of light. What do you see when you travel? If you travel away from earth, and look back at it, do you see a still image (which is panning out)? What if you are looking ahead? Do you see the past occur at double speed? What if you look to the side?

Suppose you can travel faster than the speed of light. If you travel away from earth and look back, would you see reality in reverse/rewinding? What if you look ahead?

[/ QUOTE ]

You would see the universe collapsing into you.

Jokes aside, what you would "see" from behind is nothing - it would probably just look black if you could do it. Sight is what happens when light hits your eyes - basically when electromagnetic particles excite receptors on your optic nerve. If you're moving at the speed of light, the speed at which electromagnetic fields propagate, then the "bits of light" or photons coming from Earth aren't moving fast enough to catch up with you. In front, the view would be pretty normal - you'd intercept any photons in the intervening space as usual. On the side you'd probably get distortion fading to black - the stars might just look more and more scattered, it wouldn't be too spectacular. Imagine a room with stars on one side of the wall, pure blackness on the other side, and a mix in-between.

But don't try to take this too far - space doesn't work in a way that makes any normal sense when you deal with large distances and high speeds. Everything sort of warps and twists according to special relativity, even time, so there isn't really such a thing as "traveling at the speed of light."

[Roy Munson]

Most likely I would see my already eaten lunch all over the front of my shirt.