Re: relativity and time at near-c?

Question

I understand most of relativity but one thing bugs me.
I can't figure out where my understanding is flawed in this one scenario:
If I head off at near-c, look around, and head back, then relative to you I've been travelling very quickly and will have experienced less time.
However, relative to ME you've been the one that travelled at near-c in one direction and then near-c in the other. If all perspectives are relative, then why when I came back would you have experienced more time than me?

This has been bugging me for over 4 years, but in trying to write out the question clearly and without confusion I figured it out. Now I'm going to ask it anyways since it's interesting and the answers might be insightful.

thanks, all.
I've been looking into the twin 'paradox'.
I realise that my mistake was the assumption of an absolute present.
It's not exactly intuitive the fact that two events can take place, each before the other, in their own inertial frame.

FYI they have tested the whole concept of time-dilation and many other aspects of relativity and such.
Experience shows that if you argue against Einstein, you're probably going to lose.

The gap in my previous understanding I found when writing the question was that from the frame of reference of the outward trip, your inward trip would be fast enough to explain the entire time difference, and from the inertial frame of reference of the inward trip, the outward trip would have been fast enough to explain the entire time difference.
I hadn't wrapped my brain around that before for some reason.

Answer 1

Excellent question. This is exactly the famous "Twin Paradox."

The paradox is: "If both observers 'do' exactly the same thing, why don't they both have the same experience?"

The answer is: both observers don't do exactly the same thing. Specifically, in order to "turn around and come back," you must change your inertial reference frame. Physically, you must apply a force, decellerate to a "stop," then push yourself back in the other direction.

The person you left behind, doesn't do this.

It can be shown that this difference (one of you "changes your motion" and the other doesn't) is enough to account for the fact that one of you ages and the other one doesn't.

Answer 2

This is just an educated guess...

The person that hasn't moved experienced more time because they have traveled a distance of 0....where-as the person traveling at near-c has traveled a given distance. I assume that the equations dealing with relativity take into account the distance traveled from one point to the next (given that c is a rate of distance/time). So regardless of the fact that relative to the person traveling..the stationary person is doing the traveling...the stationary person has moved a distance of 0 (no rate of change from one point to the next). Not having traveled a distance...the stationary person could not have "bent space" as the fast-mover did.

Answer 3

Your mistake is assuming that "ALL perspectives are relative"...That is not true, .....ALL INERTIAL FRAMES are 'relative'.

When you accelerated you entered a "non-inertial" frame.....that is equivialent to a gravitational frame and it is NOT 'relative'....to your buddy who sat still at home.

Answer 4

Relativity is still just a theory. Untill someone actually performs a real experiment that can be copied, they are all guessing.