[Physicist]

In other words, "in principle" (though not in practice) you can reduce it to a simpler problem which still captures the essence of the paradox, with a few simplifying assumptions. (Flat spacetime and no acceleration).

In practice, spacetime is extremely flat, and the real twins paradoxes we employ as tools in the laboratory--using time dilation to prolong the lifetimes of B mesons or pions, for example--don't typically involve accelerations.

The reason I simplified the problem is because people were distracting themselves with details that were irrelevant to the fundamental issue, which is that two observers at the same place, but in different frames, view different sets of events as being simultaneous. The differences are physically real, and can be huge.

[grey_whiskers]

In other words, "in principle" (though not in practice)

I was referring to the actual, literal twins of the paradox.

In practice, spacetime is extremely flat, and the real twins paradoxes we employ as tools in the laboratory--using time dilation to prolong the lifetimes of B mesons or pions, for example--don't typically involve accelerations.

I pinged you because I knew you'd used relativity it in your work, and that therefore you could explain the differences...

Thanks again for doing so.

Cheers!