A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. The best ones are thoughts that many people can relate to and they find something funny or interesting in regular stuff.
I've begun thinking that time travel can only be possible if all of time were to exist simultaneously. Like a singularity. Then with complete knowledge and ability to influence matter you can rewrite time anyway you would like.
Like spreading the frames of a film out and altering them as you see fit.
Yeah but is there evidence to suggest that this is not the case? My understanding is that we don't really understand time.
I think, lots of people these days have an inflated understanding of time, because of the time travel trope in pop culture, as well as videos and simulations with time sliders being readily available.
Without getting into Einstein's theories for a moment, time is something we measure, we never modify time in reality.
In particular, we measure the progression of causality. Say, you kick a ball, then the atoms in your foot push the atoms in the ball, the whole ball rapidly accelerates and then takes 0.6 seconds to hit a wall.
You can't just set the whole process to -1x speed and expect it to happen in reverse. That breaks causality. The ball would need to fly towards your foot without anything giving it a push.
With our time sliders, this may seem like a small difference, but it's just completely different from anything we've ever observed in the universe.
Now, about Einstein's theories, all of the above is still true. However, Einstein has discovered that travelling through time is possible, but only going forward in time, at a different speed than everything else.
Basically, causality has a speed limit, which happens to be the speed of light. (We believe photons to be massless, so with our usual acceleration formula, any acceleration would make them go at literally infinite speed. They don't, which is why a speed limit for causality is assumed.)
Gravity and your own speed can influence this speed of causality for you, meaning at a lower speed of causality, things happen less quickly for you and you'd age more slowly.
So, theoretically¹, you can get into an extremely fast spaceship, spend 5 years-as-perceived-by-you in there and then land on an Earth that's in the year 3000.
That is a one-way trip, though, because going backwards is not a thing.
¹) In practice, you need to go at speeds for this, that are magnitudes higher than anything humanity has ever achieved.
If the Multiverse is a thing, then that timeline has happened somewhere and our future selves visited us. Ahahaha. That would be trippy.
In this Multiverse though, it looks like we become the Borg, so they would have already collected all the info they needed and thus have no need to go back in time.
also because it is genuinely impossible to move faster than light as matter, let alone survive it
That's why you make the space move around you instead.
https://en.m.wikipedia.org/wiki/Alcubierre_drive
That's not related to time travel though, but that's a link to an actual irl concept of a warp engine.
that's so cool
All those random scraps of metal you find lying are just the end result of someone trying to travel back in time and the time machine not surviving
Now I just wanna watch Primer again.
Incorrect. The child support liability on multiple timelines could no longer be insured.