Speed and Spacetime Distortion

1. Jul 14, 2010

MikeCB

OK, i have just been watching a documentary about time (sorry if this is not allowed but it is here: http://www.youtube.com/profile?user=turxxx#p/c/B6BE0700688DBF9D/0/V3aYKAJEVfQ) anyway i think i now understand how time changes rate for a person (i am actually going to use time dilation and length contraction for this).

Imagine spacetime as a line with a start and finish the person in question is at the far left of this line connected to the start and finish of the line by what i will call elastic bands (they can expand and contract) both are straight, the one on the left is time, the one on the right space now if the person were to move towards the right end of the line, time would stretch at the same speed of the person and space would contract at the same rate.

Please tell me i'm right (in a sense) or at least close.

2. Jul 14, 2010

zhermes

You're definitely on the right track! Your analogy is a little confusing for me--we generally imagine time as running in a different direction as space, instead of time being like a 'band' in the same direction--so I'm going to look at it a little differently:

As you understand, when a person (observer) moves in space, their motion in time slows down (relative to an outside observer) and length contracts to account for the time difference. Everything in the universe moves at the same speed through space-time (the speed of light)! If you speed up in space (stretch out the space-rubber-band), you slow down your motion in time (contract the time-rubber-band).

3. Jul 14, 2010

MikeCB

different direction as in like x and y axises? so movement through it could be expressed with a linear equation? i also assume that the units on each axis are different to account for physical laws