Gravity & Time Travel

[Anaraxes]

Originally Posted by Brett

Are you absolutely positive about that?

Don't you have to ask "rate as measured by whom?"

[teviet]

Originally Posted by Anaraxes

Don't you have to ask "rate as measured by whom?"

You do. The rates are measured by two clocks: one at the bottom of the gravity well and one at the top. (Assume they are stationary.)

The sender at the bottom sends pulses of 400 nanometre (violet) light every second. If the gravitational redshift factor is 1.5, then the receiver at the top receives pulses of 600 nanometre (orange) light every 1.5 seconds.

TeV

[Agemegos]

Originally Posted by Anaraxes

Don't you have to ask "rate as measured by whom?"

Yes, and for exactly the same reason that you have to ask "frequency as measured by whom?"