Over the age of the universe, it, like other universal constants, *may* have actually changed. There were/are? some astrophysicists who believe this to be possible. The important thing about the speed of light, however, is that it is believed to be the *universal speed limit*. i.e., light can travel slower than light speed when it passes through various materials.
Even the effects of gravity are limited to and travel at light speed. The Sun is about 8 light minutes away. And so if the Sun were to suddenly disappear, Earth wouldn't feel the gravitational effects for about 8 minutes.
“Even the effects of gravity are limited to and travel at light speed.”
I’m not sure that is the case. If it were then the gravitational force between the sun and planets wouldn’t be perpendicular to their orbits but have a component opposing their motion. The result would be (relatively) rapidly decaying orbits.
The ability of gravity to act instantly I think is one of the more baffling properties of the universe.
Well, not quite. I can think of at least one other thing that is faster than light that occurs naturally.
I read something a while back that would argue that case. Seems that devices that can detect gravitational effects show the sun where it actually is as opposed to where we see it (8 minutes in the past). I may have bookmarked the article. If I can find it I'll post the link to this thread.
AmP