ICANT in Message 29 writes:
Hi Percy,
Percy writes:
The runner and the time keeper are in different frames of reference. If they both have a clock, then their clocks will show different times after each trip. The time differences might be too tiny to measure for such tiny speeds, but we've measured the difference for spacecraft many times. For example, an astronaut living on the International Space Staion (ISS) for 6 months ages about .005 seconds less than people on Earth.
Are you saying his physical body would age five thousands of a second or his clock would be five thousands of a second different than one on earth?
Neither one. Reread for understanding and try again.
Why would duration/existence change anywhere in the universe?
I don't know why you're suddenly introducing existence into the discussion, but speaking only about duration, you aptly described it in terms of clocks measuring time. The amount of time measured is subject to relativistic effects
It would not be affected by gravity as clocks are.
Incorrect. Assuming your use of the pronoun "it" refers to duration, clock measurements of time are affected by relative velocity, gravity and acceleration.
--Percy