Reply #12: pretty tricky... [View All]

As you approach the speed of light, time dilation kicks in and time starts passing slower (for you, as seen by the rest of the universe): If you were driving at the speed of light and switched the lights on, it would take until the end of time just to reach for the switch. Although things would appear 'normal' to you - the light would be moving infinitely slowly, but then so would you (I'm canceling infinities here, which is cheating :))

Moving that quickly, you'd also become infinitely thin and infinitely dense (think of Ann Coulter rushing round the chat-shows).

If you did manage to get that fast, light coming up behind you would red-shift to infinite wavelength and zero energy, so your rear view mirror would be totally black: Light from the front, on the other hand, would have zero wavelength and infinite energy. Take some sunblock. Light from the side would be normal, but since you'd seem to be moving infinitely fast (because of the time dilation) it would be a bit of a blur.

What things would look like moving faster than light would depend largely on what happens to time dilation past lightspeed: I don't think anyone's attempted that yet (in terms of maths), but Asimov's 1% faster = 1% slower that Geoff posted seems reasonable.

Good questions, btw :)