If I were to travel tword earth from a distant star at .9 C, I would see that earth would be experiencing more time than I would, but does this mean that I would see earth approaching at more than the speed of light? I see everything on it move faster, but would the earth move faster as well? Would I see myself as going faster than light? (Still perceiving every photon as going at C relative to me)
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Qmechanic
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No, but geometry can make it look like things are moving faster than light https://en.wikipedia.org/wiki/Superluminal_motion – John Doty Dec 07 '22 at 16:02
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Why is this not the case if even everyone on earth looks like they are moving faster? – ACertainArchangel Dec 07 '22 at 16:09
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Time dilation doesn't apply to you, it applies to things moving relative to you. So, when Earth is moving at .9 c, it's Earth time that dilates. – John Doty Dec 07 '22 at 16:23
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But is everything not moving relative to me? Why does the apparent increase in velocity due to increase in time not apply to my velocity if motion is relative? – ACertainArchangel Dec 07 '22 at 16:30
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Because your motion relative to yourself is zero. – John Doty Dec 07 '22 at 16:39
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You can't do this analysis in terms of "your velocity". – John Doty Dec 07 '22 at 16:41
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But if the people walking around on earth look like they are going faster to me, then why does the earth not? – ACertainArchangel Dec 07 '22 at 16:45
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Let us continue this discussion in chat. – John Doty Dec 07 '22 at 16:51
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If your assumption is that you are travelling towards Earth at 0.9c, then you perceive Earth as coming at a speed of 0.9c towards you. How else could it be? Although, I may be misunderstanding the question, what I think you may be doing is using the time coordinate of the reference system on the earth and the distance coordinate of your reference system to calculate a "velocity". But that is not what is meant by velocity when we state that nothing can go faster than c. When calculating a velocity as v=Δx/Δt, one has to use the same reference system to calculate Δx and Δt.
Hmmmm
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I am trying to get an apparent velocity in my time by multiplying .9C by earth time and then dividing again it by my time. There is probably something wrong with this but I want to find out what. – ACertainArchangel Dec 07 '22 at 16:39
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@NæveßtTheQuasar you might be interested: https://physics.stackexchange.com/questions/711233/can-one-record-a-speed-faster-than-c – Allure Dec 08 '22 at 02:21
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