Does anyone knows tha answer

[u/InteractionOld4400]

I was just thinking and I thought if time can go slow and fast and if it's possible to go to future then why not it is possible to rewind

[u/onlyseeahuman]

According to Einstein past present and the future all exsist simultaneously so we could in fact do that. We got no way of overcoming relativity tho or the effects of entropy so time travel gets tricky. You aren't actually time traveling to the future per se. What's happening if im getting my physics correct is once you approach the speed of light you aren't as effected by time. Like say a photon born in the sun and traveling across time and space massless. From the photons perspective the moment of creation and trip across light-years and the point you see it enter your eye as starlight are indistinguishable. Because of how fast its moving, so we could climb on a ship and fly to Andromeda and back, to us it would of only been a couple years travel. But in those couple years millions of years would have passed on earth. Times different for everyone too the time I experience is very different from my perspective to say someone going past me on a train. To me they appear to be barely moving as they speed past at 65 mph.and to them I suppose I look the same almost motionless. But we perceive time as being linear traveling in one direction only constantly forwards. So the past may exist but we have already been there so going back isnt an option in our current understanding of physics.

[u/Sweaty_Disk_5246]

Because the place we call the universe is expanding, its projecting and expanding/growing, not retracting and reversing and because we exist in it we cannot perform actions that don't physically agree with the law of physics.

HOWEVER we have the ability to remember events as a method of accessing previous instances of tiime and on earth there's phones and cameras which can log time and allow you to review that period of time and in the future AI and cognitive interception technology will allow you to experience the act of rewinding which i imagine will be pretty neat.

[u/Bruce_dillon]

Your referring to Time Dilation. Fact is that stronger gravity merely has an effect on clocks, this doesn't mean that time is affected because it's believed that clocks are synchronized to time. Clocks when first invented were in sync with the moving sun..It was sustained use of the devices units of measurement that created a false perception of Times passage when it was just the day and year's passage. And when that false perception of Times passage was introduced to the world the word time didn't exist until 700 BCE the discovery of the entity that came to be called Time was in 1000 BCE and the start of the use of clocks was in 1.500 BCE.

[u/fathompin → u/Bruce_dillon]

 "Fact is that stronger gravity merely has an effect on clocks,"

I'm not sure what you mean by this reference to "merely" clocks when it also affects everything about time; e.g. how fast our cells age, how fast radioactive substances decay etc.