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Position isn’t absolute so if this happens this means you knowingly made the time machine memorize position relative to e.g… the sun rather than the earth.
incorrect, that is not what this means. They could have forgotten about the position setting all together. Also why the suns position? it is also moving and non absolute, just like earths. Makes no difference in this meme
They could have forgotten about the position setting all together.
You’re assuming that the time machine would just change the time and keep the position but there is no absolute reference frame, so the time machine should use some reference frame in which it keeps the position constant. It would then be common sense to have the time machine keep the position relative to the earth. Anything else would be pretty dumb, unless you want to use your time machine also for space travel to other planets.
why the suns position
That was just an example. It’s either the sun or the center of our galaxy, or some other reference point so if it wasn’t the earth then the sun is the next most logical option.
What you’re describing is a machine which moves both in time and space. A machine which only moves in time would result in this meme no matter how you twist it.
You’ve got to entangle the same machine first over a massive macro quantum space-time superposition.
I remember reading about this concept as a kid in a short story Neal Shusterman wrote called Same Time, Next Year. Blew my mind
If space is always expanding, I’d really like to know if a time traveler would experience issues existing in a universe where the space between atoms is different from the one they left.
They wouldn’t; the expansion of space isn’t strong enough to change the distance between atoms; the force holding them together overcomes it.
I was under the impression that gravity was a constant force keeping the atoms closer together
More importantly it’s the electromagnetic force that keeps atoms together. Gravity only keeps planets and stars together and also solar systems and galaxies, but in ordinary objects it’s totally negligible.
“Weaker than Weak”.
Space itself is constantly expanding. Theories of the Big Rip predict the space between atomic particles could become vast enough to rip them apart.
The big rip scenario happens in the case where the rate of space expansion is increasing. It’s possible, but we haven’t seen any evidence of it yet, so far the rate appears constant, which means a heat death scenario.
The big rip concept comes into play when the expansion rate starts to become faster than the forces holding molecules and atoms together. As far as current cosmic expansion goes, it only applies to space between galaxies. The current expansion rate is so weak it’s not enough to overcome forces that hold galaxies together.
Should have watched Tom Scott
I know we’re in a meme community but this did get me thinking… Not only is the Earth spinning but it’s also in an orbit around the Sun which is also orbiting around the center of the Milky Way which is moving through space relative to other galaxies and so on.
Do we have enough information to calculate a position in space in the future for Earth without a fixed reference other than current point?
That’s what einstein said. There is no fixed reference frame, but only relative ones. Every “inertial”(meaning, motion without any external force) frame of reference is equally valid as any other inertial frame movibg with respect to it.
But for sure we can tell earth’s orbit is not inertial since circular motion occur, which is due to external force of gravity.
Edit:typo
Shouldn’t it be (at least theoretically) possible to find some sort of geometric center where - on average - the rest of the universe is expanding away from?
Turns out, no; every point is expanding away from every other point, so every point sees itself as the center of expansion.
No, for the same reason you can’t find a point a balloon is expanding from on its surface. Everything is expanding everywhere.
I’m not sure if I follow the balloon analogy. Sure, you can’t find the center on it’s surface. But somewhere within the balloon, there is a center. It might be virtually impossible to determine the center while actively inflating the balloon, but that doesn’t mean there isn’t any center? What makes the rest of the universe fundamentally different from an inflating balloon? I’m genuinely curious.
It’s not, because the space itself is expanding
There is not central point in the universe, and no way to calculate a position. Everything is relatove
Here, that might be interesting to you.
This is why Doctor Who has a time and space machine. Also because the BBC didn’t have the effects budget to show him flying around.
We also get a few glances of the coordinate system that the time machines use in doctor who. It appears to have enough digits for a date/time as well as an X/Y/Z grid coordinate.
I don’t think we have a relative fixed point to go off unless you choose the centre of the big bang. It’s all relative to other things around us which are also moving lol
There actually isn’t a center of the big bang, every point is expanding away equally.
Isn’t everywhere kinda the center?
Effectively, yes
I think you’ll run into the three body problem.
It’s just another problem with the mechanics of the snap at the end of Avengers: Endgame
Magic exists in that universe though and they’re using some of the most powerful objects in the universe. So like if it’s granting a wish, you just wish that everyone comes back to earth or whatever. It’s not even really a suspension of disbelief. It feels more silly to think that genius scientists using wish granting artifacts wouldn’t remember to account for the movement of the earth through space.
I cant watch that movie without thinking of all the unintended consequences. Pilots on planes snapped out, plane goes down, when pilot is snapped back, where plane use to be, but is now free falling.
It should be illegal to remind people (me, particularly) about Steins;Gate while they’re at work
I can’t be fucking crying on the clock, dawg
This blew my mind. All those movies!
So, Back to the Future’s a bunch of bullshit?!
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It’s possible to assume that the professor did the math.
But yeah any time machine would also basically have to have space travel built in to compensate.
They knew that when they wrote Dr Who (IE the time travel machine is called a TARDIS (Time and Relative Dimension in Space).
Nah, this thing with the planet moving under you is stupid because it assumes a fixed reference frame which is not a thing in our universe. Any movement is always relative to something. You can’t just “stay in place”. Having the Earth move from under you is very arbitrary.
Yeah, these jokes always assume a jump back in time, not some sort of rewinding for just the traveler.
There’s a ton of issues with time travel. That could be one, but most fictional time-travel devices can be said to accommodate for the difference in distance. It would just be boring to explain on-screen.
floating astronaut with pistol always has been
That’s why doctor who works, its very clear about the fact that TARDIS travels in spacetime, it can do only time, only space or both space and time and they can get away with time traveling and still staying on earth
It could be explained as a time and space machine but just saying time machine is easier.
That’s how ive always thought of these things in my head.
but imagine if you could set it to the same time but different distance, it would allow you to teleport, that might be too strong.
Sounds like a good tech concept for a story
Wow, I never thought about that.
It’s even cooler if you remember we send something to the moon even with all this variables and no calculators humans were able to know where the moon would be
Of course the moon is relatively close but still
Math is hard.
Oooohh. Thanks for the tip, just added that into my time travelling port o pottie’s destination algorithms. Gotta respect the earth be moving and shit.
Also, the earth will never be in the same place twice. So it’s not even like you can only jump increments of a solar year.
And its not like there even is a same place. Position is relative, but to what in this case? Doesn’t even make sense
well it’s likely the big bang has a central point, no?
Imagine the universe as the surface of a balloon. The Big Bang Theory stipulates that at one point, the balloon was extremely small, like a single point. But now that the balloon is bigger, you can’t find a particular spot on the balloon where that point was, because everywhere was that point. No matter where you are in the universe, if you turned back time and shrunk the balloon back down, you would be at the point of the Big Bang. Nowhere is closer or farther away from it.
would not the fact that blue shifted galaxies being rare, mean that in general all galaxies are red shifted from the perspective of all galaxies, thus they are expanding away from a point on a similar vector, and thus have a central point?
And a balloon does have a vector of direction: the mouth piece
No central point there
Also ghosts likely wouldn’t be affected by a gravitational pull, so the concept doesn’t make sense and there’d just be a trail of ghosts in space.
Can’t they just float and follow the Earth? Or would it be too fast? What’s the terminal velocity of a ghost?
What is this comment in response to?
Glad I’m not the only one confused. Who’s talmbout ghosts
I also think about this a lot.
See, that’s a problem they always skip in time-travel movies.
At least in Doctor Who, the T.A.R.D.I.S. can’t teleport through space as well as through time, solving that problem. But most time machines don’t
Heyy this property features in the accidental time machine by Joe Haldeman
