Making Light:  Tracking Nielsen Haydens in their habitat ::: August 16, 2004, 04:49 PM

Dan Blum:

  The Twins Paradox is in fact not actually a paradox, but a common
  misunderstanding of Special Relativity....

I understand it from a standpoint of Special Relativity.  But that
doesn't stop it from being a paradox, any more than Zeno's paradox
stops being a paradox when you understand continuity.  It's true,
it's explainable, it's understandable, but I call it paradoxical.

  To summarize - the twin on the spaceship definitely ages more slowly.

I don't believe that's an accurate summary.  From an SR standpoint,
the twin on the spaceship measures the Earther as aging more slowly,
then (in another reference frame) as being suddenly older, then aging
more slowly.  After the round trip, the Earther is older, but except
during turnaround he's going just as much slower with respect to the
traveler as vice versa.