[PatrickHenry]

Me:
But the time dilation is real, as they would learn if they could return home

You:
Actually, that's a popular misconception. The reason that the time dilation appears real when they return is because the rocket ship is ACCELERATING.

Yes, that's why the ship is the frame that undergoes the time dilation, and not the earth, even though from the ship's viewpoint, the earth is seen to be accelerating away from the earth. But it's really the ship that experiences acceleration.

Nevertheless, even for non-accelerating frames of reference that are in motion with respect to each other, the Lorentz transformation applies to observed differences in time, length, etc. Or so I've always understood. That's how the two frames can make sense of their otherwise incompatible observations.

[2ndreconmarine]

Nevertheless, even for non-accelerating frames of reference that are in motion with respect to each other, the Lorentz transformation applies to observed differences in time, length, etc. Or so I've always understood. That's how the two frames can make sense of their otherwise incompatible observations

A fun discussion, gentlemen. This stuff blows my mind.

I pity the poor Creationists and ID'ers, I really do. They will never enjoy any of this. They will be stuck in the prosaic and mundane view that ignores the majesty of God's great creation.