# Near light velocity.

1. Mar 6, 2007

### duordi

If I attained a speed close to the speed of light the distances between all objects in front and in back of me would shorten causing the universe to appear to flatten out like a disk from my perspective.

Is this true?

On the other hand I have heard that the universe would seem to converge in front of me.

Can these both be true?

2. Mar 6, 2007

### anantchowdhary

Well,it really depends on your direction of relative velocity.Say ur going past an object with relative velocity only in the x direction.Then you would see that if the proper length of the object is $$L_0$$ and ur relative velocity is $$\vec v$$ then

the length $$L$$ perceived by you will be

$$L_0_x=\frac{L_x}{\sqrt{1-{v^2/c^2}}}$$

Last edited: Mar 6, 2007
3. Mar 6, 2007

### duordi

If I have a velocity with respect to objects B and C.
When B and C have no velocity with respect to each other would they appear to get closer together?
Would the distance between them seem to shorten to me because of my velocity?

It seems you are saying yes.

4. Mar 6, 2007

### pervect

Staff Emeritus
You have to be a bit careful to distinguish between what you see with your naked eyes, and what you measure (after taking into account propagation delays).

Both of your statements are true under diffrerent interpretations of your question. See for instance http://www.exo.net/~pauld/stars/PD_images_relativ.html for the visual appearance of "convergence to a point". (It is apparently taken from http://adsabs.harvard.edu/abs/1979AmJPh..47..309M

You might also want to read about "Terrell rotation" as far as visual appearances go, for instance in the sci.physics.faq "Can you see the Lorentz contraction"

http://math.ucr.edu/home/baez/physics/Relativity/SR/penrose.html

Last edited by a moderator: Apr 22, 2017
5. Mar 6, 2007

### anantchowdhary

yes if U are moving with respect to both of them.And if YOU are measuring the length between them while you are moving

6. Mar 7, 2007

### tehno

I remember I watched once simulation on the internet as how enviroment appears to the observer when he/she travels at velocity near c.
I don't know of site URL any more but I remember it was damn cool to watch.

7. Mar 7, 2007

### pervect

Staff Emeritus