This is a little thought experiment that has been bugging me, and I’d like to know if I’m even close:
Imagine a string tied between the Sun and Earth. You are holding this string.
You wiggle the string, generating a wave that travels from the Earth to the Sun, along the string. You watch this wave move along the string with a telescope.
When we look at the sun from Earth, we see it as it was 8 minutes ago, because it takes 8 minutes for the light to travel to Earth.
When the wave reaches the sun, you will see it 8 minutes after it has actually reached it. But you have watched it travel away from you in real time, uninterrupted. You have essentially watched the wave move backwards in time.
So my question is, how is causality and a present moment maintained in this scenario? Is it simply that, from the waves POV, time would move 8 minutes slower relative to the observer on Earth? The string isn’t actually moving backwards in time, but instead experiencing it at a slower rate, thus resolving the seeming paradox of watching the wave go back in time and preserving causality?
Let me know if this is stupid thank you <3
In: Physics
You don’t see the string in real time, the light it reflects still has to travel to you in order to see it. As the wave in the string gets further and further away, it’ll be further removed from your real time. When the wave reaches the halfway point, you won’t see it for about four minutes after that.
Essentially, the total time you see the wave traveling will be about eight minutes longer than the wave actually took to travel that distance. But its offset from your time while change continuously so you won’t notice a discrepancy.
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