When we think about teleportation, there’s always someone talking about how you should take into account the earth and the sun moving through space. Let’s step back a little (not so much) what if the galaxy we’re currently in is rotating really really fast around another, bigger, still unknown, spacial object?
You mean like the Great Attractor?
Oh my god that is so cool, thanks!
Appreciate the rabbit hole!
I mean motion is all relative anyway, right? So would teleportation be like throwing a ball on a train? That is, the ball’s motion depends on the frame of reference. So maybe teleporting would work that way if it were actually possible.
Now what about time travel?
Technically, Marty McFly should have appeared in space far from anything instead of old man Peabody’s Pine farm.
Should have why?
Earth itself is moving around the sun at about100,000 km/h and the sun is traveling through the galaxy st about 1 million km/h.
So if Marty went back/forward just one hour then he’d be about 1,100,000 kilometers away from Earth in space (or 900,000 kilometers, depending on the orbital direction of Earth relative to the sun’s direction of travel).
And then there’s the motion and speed of the Milkyway itself.
This is all assuming that the layout of the underlying fabric of spacetime is absolute (which it seems to be, outside of expansion).
Well the thing is the universe is so big that anything further than 14ish billion lightyears away from us basically doesn’t exist as any information from them woukd take longer to get to us thsn the universe has existed and due to cosmoc expansion, that linfkrmstion actuslly gets firther away from us over time, despite it traveling at the speed of light. And since the universe rotaing around a point would require a gravitstional onteraction that travels at the speed of light, we physically cannot be rotating around a point further away than that.
And since the same is true for any point in space, there can’t really be any centre to the universe.
The closest we could come to that is a point in the relative centre of the Virgo supercluster, which is the largest structure in “our” universe that are gravitational bound to us and won’t dissappear from our sight as the universe expands.
Yeah but since the speed of light is always relative to a reference frame, wouldn’t the distance to the beginning of the universe depend on the frame you use to measure it?
Currently the closest thing to a universal reference point we have is the cosmic microwave background. Relative to that we move at about 370 km/s ± 60 km/s, depending on the time of the year and day.
Hah now this is a great shower thought, if you want some existential dread you should watch this video from Kurzgezagt video about it called You Are Not Where You Think You Are about this idea, it’s great!
What if reference frames are the average of large mass, and that’s what they mean when they say “space time bending”.
