[dleviwing]

Originally Posted by Profpat

"Time is constant; the measurement of time (clock) is relative."

Does that mean the twins are clocks David?

Pat;
Somewhere in another post I stated that the actual slowdown of the accelerated clock was not due to time dilation but to the effect of the increase in velocity that reduces the biological interactions of atoms and molecules. The accelerated clock also experiences this actual slowdown as does all physical entitles. If you wish to age slower, just travel at high velocities greater than half the speed of light.