Is the speed of light measurement dependent on the tick rate of different clocks?

[kmarinas86]

Hello I want to ask the following questions:<br /><br />If Clock A is undergoing only a natural gravitational time dilation, and possesses 0 rate of change in time dilation, and if it is measuring seconds at a different rate than Clock B, which for our purposes is a clock at higher gravitational potential where the seconds are different - what if:<br /><br />Clock A was used in a measurement of the speed of light, and the value for this clock reads 1 second within which light travelled 299,792,458 meters. However, Clock B, which we will assume to have 0 relative velocity with Clock A, being in a higher gravitational potential, reads 1.000001 seconds passed.<br /><br />If you take the "distance traveled by light / the time passed for Clock A", you will get a different value than "distance traveled by light / the time passed for Clock B".<br /><br />Of course, you could take the reverse, where you have, say, 1 second passing for Clock B and .99999 seconds for Clock A<br /><br />Am I getting this right?

 

[rpmath]

<font color="yellow">Clock A was used in a measurement of the speed of light, and the value for this clock reads 1 second within which light travelled 299,792,458 meters. However, Clock B, which we will assume to have 0 relative velocity with Clock A, being in a higher gravitational potential, reads 1.000001 seconds passed.<br /><br />If you take the "distance traveled by light / the time passed for Clock A", you will get a different value than "distance traveled by light / the time passed for Clock B".<br /></font><br />The point here is how can you measure the distance between A and B...<br />To get the right value for a speed, you need to measure both time and distance in the same reference frame...<br />The standard way is: put a mirror in the other point send a ray of light get the time it needs to get back and multiply by 299,792,458 m/s / 2.<br />If you send the light from A to B and back, Clock A would measure 2 sec, so the distance is 299,792,458m.<br />If you send the light from B to A and back to B, Clock B would measure 2.000002 sec, and the distance is 2.000002 * 299,792,458 / 2 = 299,792,<font color="red">7</font>8 m (300m more than the other measurement). <br />You would not say light speed is different, but that distance measurement is different.<br />You will see the space below you expanded.<br /><br />There is an alternate way to do the measurement:<br />You can use the local reference frame of each point to measure distance and get a value of distance between the 2 values we got with A and B...<br />The conclusion for this alternate test is that speed of light is faster for points above you and slower for points below... and... if you go further below... speed of light is 0 at the event horizon of a black hole...<br />But for relativity this point of view is not valid because you are mixing reference frames.

 

[alokmohan]

In theory of relativity there is no absolute time.Things depend on frame of reference.