# Does Time Dilation Make Me See More?

1. Jul 12, 2004

### omin

I have heard that if I were traveling at the speed of light, things I'd see would appear longer along the horizontal axis. Does this mean I see more of what they are?

2. Jul 13, 2004

when you travel close to thh speed of light, objects do become elongated relative to you by a factor of: L / (sqrt(1-v^2/c^2)). The objects you observe will seem to be elongated but you do not see more of them, you see the same amount, since space/time starts to elongate relative to you, the object actually does not, so you actually see the same amount.

3. Jul 14, 2004

### LURCH

Although I have heard that you would see different parts of each object, which would not be visible at slower speeds. For example, a square or rectangular object would appear to you as though you were seeing the far side of it; "seeing around the corner" so to speak.

4. Jul 14, 2004

### Moose352

I'm not sure if I'm misunderstanding something here, but I was pretty sure that the length contracts along the direction of motion. Also about the phenomenon LURCH mentioned, I'm not entirely sure, but I think that is due to the length contraction. Because the length contracts, the light rays from the far side can reach the observer.

5. Jul 14, 2004

### Staff: Mentor

Right. The measured length of a moving object is shorter along its direction of travel by a factor of $\gamma = 1/\sqrt{1 - v^2/c^2}$ than its so-called proper length. Thus $L = L_0/\gamma$.
Pretty close. This issue here is what you see, as opposed to what you measure. Rather than a shrunken object, what you would actually see (or photograph with a really high-speed camera) would be a rotated object. This apparent rotation is called the Penrose-Terrell rotation.