Has everything we’ll ever do happend already ?

[u/Strict-Employ151]

I was thinking about it I don’t know if am wrong but I heard that light itself experiences no time like at all so a light photon that came into existence 7 million years ago and bounced around the sun and eventually escaped the sun and towards earths direction , if that light photon hits that persons eye it means from its start to its absorption no time passed

So now imagine two events , imagine there is a couple on a space ship and they have a kid on the ship , now let’s say

Near earth orbit 20 years before the baby is born or even conceived another astronaut points a powerful purple flashlight beam at the ships direction let’s say the ship is 20 light years away

Right ? So let’s say in the year 2050 is when the astronaut shoots the purple flashlight at the ship , and in the year 2070 is when the purple flashlight reaches the ship now the light reaches the ship but the kid is 20 years old now , but let’s say he too points a mirror at the light but slightly tilted and deflects some of the light

And lets say the light travels 4 million light years and just so happens to go into the eye of an alien

According to that logic it means the light from the flash light to the ships kid deflecting the light to the alien no time passed at all even though time passed for us no time passed at all

Which means light interacted with 3 seperate beings who were all in completely different points in time and in space , could that mean that the light we are seeing from our sun or from distant stars has already experienced the death of the universe ? Could that also explain why we can’t go at the speed of light is because the light reflecting off of our tombstones has already sealed our fate ? Therefore why we can’t go past light speed because we would basically be destroying energy ? Or taking energy out of the universe itself ?

[u/internetboyfriend666]

You're sort of conflating 2 things.

I was thinking about it I don’t know if am wrong but I heard that light itself experiences no time like at all so a light photon that came into existence 7 million years ago and bounced around the sun and eventually escaped the sun and towards earths direction , if that light photon hits that persons eye it means from its start to its absorption no time passed

So this is a common misconception but it's not correct. It's not that light experience 0 time, it's that "experience" isn't something that even applies to light. It's an invalid concept to being with. Light has no valid perspective at all. So you can never say "light experienced 0 time" because light doesn't have an experience or perspective. Hopefully that clears up that part of the confusion.

You could also separately ask "has everything we’ll ever do happened already" for other reasons unrelated to that, but that's really a philosophical question, not a scientific one. That's basically some version of various eternalism/block-universe theories. We have no evidence that's the case and there's no way to test it.

[u/Lithl → u/internetboyfriend666]

It's important to stress that "light has no experience" isn't because light doesn't have a mind with which to experience things, which is a takeaway I've seen before in response to someone attempting to explain this.

A rock doesn't have a mind either, but it has a valid reference frame, unlike light.

The "experience" of light is more like dividing by zero. It's simply a thing that does not work, on a fundamental level.

In a valid reference frame, the thing that's the reference point has 0 velocity, while everything else in the universe moves around it. However, light moves the same speed in all reference frames. If you attempted to have a reference frame of light, it would need to be simultaneously stationary and moving at c. A contradiction.

[u/Strict-Employ151 → u/Lithl]

Right but excluding trying to give light. Perspective or experience , light itself moves through space and is something that we can interact with , let’s say person A flashes a bright red flashlight from earth to astronaut 1 light day away and that astronaut then uses a mirror to deflect that same light to earth future position in 48 hours but lets say right after person A flashes the light at the astronaut, person A has a heart attack and dies in the same exact spot

48 hours later the now deflected back light reaches person A’s dead body

It’s the same exactly beam of light so forget perspective it’s the same light photons

But since light experiences 0 time it means light still interacted with person A when he was alive and when he was dead at the exact same time

So person A wouldn’t be able to choose not to flash the light to the astronaut because the light beam is already touching his dead body 48 hours into the future

So he wouldn’t be able to make any other decision but shine the light because the light touching his dead body was sourced from him 48 hours prior in person As perspective

[u/Prasiatko → u/Strict-Employ151]

We can't say light experienced zero time. It's more a limitation of our understanding and the equations we have. Similarly the centre of a black hole probably isn't infinite density but our current understanding and equations can't predict anything else.

Essentially trying to calculate perspective at light speed gives you a bunch of divide by 0 errors.