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I'm trying to understand the twin paradox and time dilation.

Someone told me that if observer A and observer B are traveling apart from each other with each having a uniform speed of .4c they will have the same age when they return back at the point of origin. Even though I'm unsure of this outcome, because observer A would think he's standing still and B is moving away and so when B returns at the origin A should be older, but I'm going to assume what this person told me is right and they both will be the same age when they return at point of origin because they changed directions.

I'm assuming they are moving with uniform speed and that no acceleration is involved. They are traveling in complete vacuum.

To extend this I'm adding an extra observer C who is standing at the point of origin. I'm assuming that observer C will see both A and B with the same age when they return from this trip.

If observer A was standing still and observer B was the one moving, when B comes back he would be 8 years and observer A and C would be 10 years old.

Now I will change the original example so observer A is traveling at a much slower speed. To be annoying lets say he moves a total of 1 meter back and forth in the 10 year duration. So the first 5 years he moves away from the origin with a uniform of .1 meters per year and then the next 5 years he will move back with the same uniform velocity.

Traveler B on the other hand moves with very fast speeds so that together they move apart with a combined uniform velocity of .8c. Just like the above example, they are both traveling apart at .8c and they both change their directions. So just as the above example, due to the principle of relativity they should be the same age when they return at the origin. I'm assuming they both get there at the same time.

Will observer C see them both being the same age as in the above example? For example both will be 8 years instead of just B being younger and A being 10 years old?

I assuming the second example is identical to the first example.

Thanks!

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# B Twin Paradox with different speeds

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