The discussion revolves around the effects of running at near-light speeds (v=0.99c) on the perception of one's reflection in a mirror. Participants explore concepts related to relativity, reference frames, and the nature of light travel time in this context.
Participants express differing views on whether the reflection would appear different at high speeds. While some assert that there would be no change, others contend that the perception of the reflection could be affected by the time it takes for light to return, indicating unresolved disagreement.
There are limitations in the assumptions made regarding the reference frames and the effects of light travel time versus time dilation, which remain unresolved in the discussion.
fusi0n said:
According to relativity, all the laws of physics should work the same way in every inertial (non-accelerating) reference frame--this includes the fact that the speed of light is the same in every inertial reference frame. Another way of saying this is that if you were in a windowless box moving at constant velocity, you would get the same results for any experiment you could do inside the box (including measuring how fast light moves from your face to a mirror) regardless of the box's velocity relative to the earth. So, even if you are moving at 0.99c in the Earth's frame, you can just as well look at this problem from the point of view of a frame where you are at rest and it is the Earth that's moving at 0.99c away from you, and since the laws of physics all work the same in this frame, you won't see anything different when you look in the mirror. Keep in mind that there's no such thing as absolute velocity in relativity, an object's velocity depends on what frame you choose, so it isn't meaningful to say someone's velocity is 0.99c unless you specify what that speed is measured in relation to (but light moves at the same speed in every frame so that's the only case where you don't have to specify--if a light beam goes by the Earth at 186,282 miles/second and then you take off in a rocket which moves at 185,000 miles/second away from the earth, you'll still find that the light beam is moving away from you at 186,282 miles/second, not 1,282 miles/second as you might expect).fusi0n said:
No--like I said, since the laws of physics should work the same in every reference frame, you should see exactly the same thing in a mirror that's at rest relative to you regardless of how fast you and the mirror are moving relative to the earth.gurkhawarhorse said:
No. Any such observation can then be used to distinguish frames of referance which are in relative motion.fusi0n said:
In that case you were right, the image in the mirror would appear slowed-down, although as jcsd said this has nothing to do with time dilation, it's just because light is taking longer and longer to get from you to the mirror and back as you move farther away from it (so this would be true in classical physics too).gurkhawarhorse said:
