3 ms·

Yes the clock will indeed tick slower deep in the gravity well and that's the reason why from the point of view of the observer outside the gravity well the pho

Yes the clock will indeed tick slower deep in the gravity well and that's the reason why from the point of view of the observer outside the gravity well the photon will be red shifted! The speed of light is the same in both frames of reference. What you think is going affect the speed is actually the slowing of the proper time which effectively causes the photon to redshift.

cyberax 2y ago
> The speed of light is the same in both frames of reference. What you think is going affect the speed is actually the slowing of the proper time which effectively causes the photon to redshift. No. You can drop a ruler onto the surface of Earth and measure from the Moon the time it takes the light to travel from one end of the ruler to the other. It will be slower than the lightspeed from your point of view. This is a real effect, we've measured it. However, it will be lightspeed from the point of view of an Earth observer.
- ithkuil 2y ago
  Ok but that's exactly what it means when we say that clocks are ticking slower in a gravity well (after all you can implement a clock by bouncing light). And this effect falls out directly from the warping of space-time described by general relativity am I understanding correctly that you claim that the warping of space-time is just a mathematical trick and that the phenomena are better explained by just postulating they light slows down in a gravity well?
  - cyberax 2y ago
    > am I understanding correctly that you claim that the warping of space-time is just a mathematical trick and that the phenomena are better explained by just postulating they light slows down in a gravity well? Light slows down in gravity wells because the space-time is "denser" near massive objects. This is not a mathematical trick, this is actually a real effect. It's also the reason for gravitational lensing, as the shortest path through a gravity well is not a straight line. Light can avoid the slowdown near the massive object, if it instead "goes around" it. The curved path is longer, but faster lightspeed along it compensates for the additional length.

cyberax 2y ago

> The speed of light is the same in both frames of reference. What you think is going affect the speed is actually the slowing of the proper time which effectively causes the photon to redshift. No. You can drop a ruler onto the surface of Earth and measure from the Moon the time it takes the light to travel from one end of the ruler to the other. It will be slower than the lightspeed from your point of view. This is a real effect, we've measured it. However, it will be lightspeed from the point of view of an Earth observer.

ithkuil 2y ago
Ok but that's exactly what it means when we say that clocks are ticking slower in a gravity well (after all you can implement a clock by bouncing light). And this effect falls out directly from the warping of space-time described by general relativity am I understanding correctly that you claim that the warping of space-time is just a mathematical trick and that the phenomena are better explained by just postulating they light slows down in a gravity well?
- cyberax 2y ago
  > am I understanding correctly that you claim that the warping of space-time is just a mathematical trick and that the phenomena are better explained by just postulating they light slows down in a gravity well? Light slows down in gravity wells because the space-time is "denser" near massive objects. This is not a mathematical trick, this is actually a real effect. It's also the reason for gravitational lensing, as the shortest path through a gravity well is not a straight line. Light can avoid the slowdown near the massive object, if it instead "goes around" it. The curved path is longer, but faster lightspeed along it compensates for the additional length.