What really is time?

Originally posted by Palynka
Bear with me, I think I'm getting close to understanding this.

Your example was somewhere along the lines of what I was expecting after I read about Minkowski spaces, but it seems that Lorenz Transformations are just rotations in a Minkowski space.

If this is correct, then the different treatment of time in LT comes naturally from the nature of Minkow ...[text shortened]... think this is key for me finally understanding why time is fundamentally different from space.

Hmm, I'm not so sure, I think in the end it boils down to the axiom in relativity that the speed of light is the same for all observers.

Originally posted by smaia
There is no such thing as "absolute" time. Generally, you cannot synchronize clocks based on an "absolute time" and time is relative to the observer.

There is no preferred time frame, but any event's time can be mapped to any arbritrary time frame at a different velocity using the Lorenz factor.

For example, if you sped up to a velocity where time passes half as quickly for you, then you could speed up the clock to twice the speed and it would be synchronized with a stationary clock.

What is relative to the observer is the rate of change of time.

Originally posted by KazetNagorra
In the context of special relativity, "same place" means the same x, y, z coordinates in some inertial frame of reference.

... in some inertial frame of reference? And where do you find something like that?

Originally posted by FabianFnas
... in some inertial frame of reference? And where do you find something like that?

An inertial frame of reference is one in which the laws of physics hold. So you can check it by checking if that is (approximately) true.