Thread: the twin paradox and reletivity

Originally Posted by Joe McCarron

I apologize, I didnt really understand the complexity of my question. but you pretty much nailed it anyway. I still dont really understand Specail Reletivity. So reguardless of how fast i may be going, im always stationary to my own frame of refrence?

I never really thought about it that way. I always use my distance to other objects to get a sense of speed at any givin point when i'm driving.

You are correct that you are always at rest in your own reference frame. If you are driving at constant speed, then objects fixed to the ground like buildings, utility poles, and traffic signs appear to be approaching you at your vehicle's speed. Because they are moving, however, the distance between you and them will be contracted by the length contraction:

where is the proper distance between you , the object and is the apparent length, is your speed, and is the speed of light.

Originally Posted by Joe McCarron

I never really thought about it that way. I always use my distance to other objects to get a sense of speed at any givin point when i'm driving.

If you were kidnapped and woke up on a starship coasting at 0.5 c halfway between here and the nearest star, you might take a good look out the window. If you were to take another look out the window a week later, you would not be able to discern any difference. Yes, space is that big.

On the other hand, if the starship were to accelerate even slightly, say, at 1/10th of a g, you'd immediately detect the acceleration. That's one of the reasons they refer to it as an "inertial" frame of reference. The other is that it's the cumulative effects of acceleration which determine relativistic effects, namely because the cumulative effects result in relative velocities.