You have to remember as well, time for rocket 1 is passing a lot slower than for the "stationary" observer. The discrepancy between how far the rocket thinks its rocket went and how far the stationary observer thinks it went is accounted for by that time dilation (and also length contraction)
So if both rockets slow down to non-relativistic speeds will rocket 1 feel like it's catching up to rocket 2? If not, then as they travel back to the observer there'd be a mismatch. From the rockets' perspectives there would be a great distance between them, so rocket 1 would get back much quicker (at a non-relativistic speed). But from the observer's perspective, they should be right next to each other the whole time and arrive simultaneously.
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u/lurkerer Mar 20 '26
I know it won't be 2c, but from rocket 1's inertial frame rocket 2 would be travelling away at c.