28.1 The Reality of Past, Present, and Future: Math Details
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Martin Spina
My previous comment leaves me wondering, though. Can it possibly be that standing on a moving conveyor belt with your telescope would allow you to see a distant cosmological phenomena’s past. Then stopping and reversing the conveyor belt’s direction and waiting for the conveyor belt’s speed to become constant but in the opposite direction, you would see it’s future? So if moving toward a dying massive sun would allow you to see a supernova, but then reversing your conveyor belt, you could see the dying sun still intact?
I understand this is a conceptual question since the myriad motions of obits, galaxies etc, would skew everything and render this experiment logistically challenging…
Then one can imagine placing a telescope on a large, fast(ish) spinning merry-go-round and observing a supernova happening and unhappening over and over again. Yes this is accelerated motion but unlike twin paradox, the acceleration effects might be considered negligible since the speeds in this problem are very low?
Would love some feedback on this question. Thanks!
Rhetorical question: Is 46 years old too late for an engineer with a Master’s degree to embark upon a Physics PhD? This stuff is fascinating and I have become a YouTube—binging astrophysics videos junkie thanks in large part to Dr. Greene’s magnificent pedagogy.
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Martin Spina
Well, maybe I should hold off a few minutes on my dreams of a Physics PhD… hahaha
I will visit Dr. Green during his upcoming Office Hours, and realize that my earlier comments are false. Dr. Greene will help me understand that my motion won’t change what I see when I look up at a star.
Instead my motion will only make me (or my similarly moving descendants) seeing ONE supernova, carve up SPACETIME differently than if I (we) were motionless. My (our) motion versus my (our) lack of motion will simply change what I (we) perceive (post-process) as simultaneous events here on Earth and at the star.
Still fascinating!
Jack Jabez
There is practical application in simply understanding what it must mean to exist in a block Universe.
Firstly, a block Universe can also be thought of as super-determinism, or designed. Secondly, life is unfair.
So if the Universe is designed to be unfair than that would mean that; the purpose of life must be to intentionally elicit negative emotions.
The purpose of life is to harm us.
Roelof Vuurboom
First off, it is MY past and MY future. There is no THE past. If I move towards or away from the star my now timeslice is changing. I will see exactly the same phenomena but what I say is occurring now you will say may be occurring in your past or in your future. However realise that neither of us can see those events at this point in time. The information (light) of the events still needs to travel to us. There is no free lunch here: you cannot see events that are in your future. The statement that past, present and future are equally real is a metaphysical one. You would need to define what "real" means first.
John Lee Farnsworth Sr
if you are standing on a treadmill it would be the belt that is moving not you you would be still because you are walking at a speed equal to the motion. same on the turntable relative to the far off star your not moving unless the whole turntable is
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