View Full Version : Quick Question


KneeltoErasmus
10-06-06, 07:02 PM
In General Relativity the faster you go the slower time ticks right? So does that mean that our time ticks slower while standing still on Earth than if we were still somewhere in space that was barely effected by gravity? Like, since the Earth moves around the sun and it spins...that means the Earth itself has a speed and since we are on it we feel that time dilation of it's speed. So techincally, the fastest time could ever possibly tick would be out in space not moving at all as far away from any gravitational field as possible?

And would it be possible to be moving so fast near such a massive thing that time could actually go backwards? Or would time just stop?

imaplanck.
10-06-06, 07:24 PM
In General Relativity the faster you go the slower time ticks right? ?Nah thats SR.


So does that mean that our time ticks slower while standing still on Earth than if we were still somewhere in space that was barely effected by gravity? Like, since the Earth moves around the sun and it spins...that means the Earth itself has a speed and since we are on it we feel that time dilation of it's speed. So techincally, the fastest time could ever possibly tick would be out in space not moving at all as far away from any gravitational field as possible?Someone out in space as you described it, will see our clock tick slower relative to their clock(affected by both SR and GR).

And would it be possible to be moving so fast near such a massive thing that time could actually go backwards? Or would time just stop? NAh time can only stop like on the surface of a black hole.

cato
10-06-06, 07:37 PM
a more complete answer, though you should remember I am no physicist:

SR deals with relative velocity, GR deals with how mass/energy warps spacetime and how spacetime effects mass/energy.

now that we have that out of the way: time will always tick at the same rate in your frame of reference.

so, from the SR standpoint, any object that moves With Respect To (WRT) you will appear to have been slowed in the direction of time and contracted (thinner) in the spatial direction of their motion. conversely, the other object will see your clock slowed, and your length contracted, as there is no absolute frame of reference, and he can claim that he is still, and you are moving (reciprocity of special relativity).

from the GR standpoint, an object will appear to have its clock slowed if it is at a point with a greater curvature gradient of spacetime (nearer to a massive object).

KneeltoErasmus
10-06-06, 07:54 PM
Right you don't actually feel your own time being slower due to time dilation, you see others as being slower right?

cato
10-06-06, 08:02 PM
correct, because there is no absolute reference frame in the universe. imagine you and person X are out in deep space, you see that the distance between you is decreasing, how do you measure who is moving? you can't, if you take yourself as the reference frame, you are stationary, and X is moving towards you, but X can say that he is stationary and that you are moving at him/her, you would both be right as both of your frames of reference are equally valid.