What sort of universal reference frame do you seem to be assuming? All location is relative to other things, and keeping your location relative to, say, the Earth would be a lot more convenient that making it relative to some arbitrary star or something.
Op thinks the universe is built with some inherently absolute positioning method. Thanks for writing this
Use the time and space machine on a ruler and send it back in time a pico second, then a millisecond, then a thousand, then a second, then a minute. You just have to calibrate with measurements first.
But if you’re in a moving car and “pop” back a few seconds while the car doesn’t you won’t be in the car anymore. If it worked more like rewinding a video you wouldn’t need to do much, but I’m assuming OP means literally going “poof” and now you’re back in time. If that’s the case, you would still need to know how Earth is moving through spacetime. If you don’t know your relativistic relationship to the Earth and every other object in the universe then how would you know where you are or your own relativity compared to the Earth?
Their point is that (as per relatively), all movement is relative to something. So if the earth moved away then you must be measuring in relation to some other reference point. There is no absolute positioning system. So when you say the earth is moving, what is it moving in relation to? And why did you pick that reference point instead of having a time machine that uses earth itself as a reference point?
But that’s the thing though. How can you determine the Earth as a reference point without knowing how it relates to other objects in space? “Here” is as useful a coordinated system as a fake absolute positioning system. “Here” is just your relation to other objects. If you don’t know what your relation to those objects is you can’t determine where “here” is, or the Earth for that matter. Whether it’s the machine or the person operating it, something or someone has to calculate where the Earth is in order to use it as a reference point.
If you are driving away from your friend at 20 mph, from your perspective they are moving away from you at 20 mph while you are the one that’s stationary. The only thing determining your location, or reference point, is your relation to each other.
You’re still thinking in a context where the earth is travelling around the sun, etc etc.
If you assume the Earth as the reference point, then that is fixed, absolutely frozen, doesn’t move at all. That’s point zero.
You cannot calculate where the earth is. What you do is calculate where everything else, the universe itself and even other dimensions, are with regards to your fixed point.
This can feel counterintuitive, but here’s a random visualization: https://youtube.com/shorts/UZyuZVvCE78
Note that, in that video, only the perspective has changed. The solar system is moving as usual.
That video is super, super wrong, and nowhere even close to “just a different perspective”. To demonstrate, Mercury and Venus should periodically come between the Sun and Earth, but that’ll never happen in that model.
But that’s the point that I’m trying to make. It’s probably my fault as I’m not very good at explaining things like this, and I’m not disagreeing with at all. I’m just saying that there is no way to have a machine or method of travel with a fixed point without knowing its relation to other objects. Just like you can’t know the trajectory of the Earth through space without knowing its relation to other objects. What I’m saying is that regardless of your “fixed point” you will have to do the same math, just in a different order depending on your point of reference. We are dealing with relatively here so the only variable that changes is your point of reference while the math stays the same.
Exactly, and due to earth’s rotation you don’t even need the car.
I get that people just refer to them as time machines, but they’re actually space-time vehicles.
Before your first journey, you calibrate it to a reference point (mine already had Earth mapped out, with a gravity well depth monitor as a fail-safe) so that you lock your target coordinates in space and time.
But no, it’s not teleportation. You’re still just travelling to your destination, you just get there as quick as you want and without the need to be disintegrated.
Just want to leave it here
I…I need the template for that meme :o
For science?
Space and time are the same thing. Spacetime. Time travel would necessarily also by teleportation if you are traveling instantaneously through spacetime. Unless of course your travel is continuous like it is currently for all of us, just sped up, slowed down or reversed.
Also there is no objective point of reference for location in the universe, only relative points of reference. In other words, you are always some distance in some direction from some thing. But you never have objective stable coordinates relative to the universe itself. There is no “center” or other fixed point of the universe. So the earth is moving, yes, but only relative to other independent celestial bodies. And those bodies are moving, too, relative to other bodies. Their movement is always relative to a non-absolute frame of reference. No movement is objective to the universe, it’s all relative.
So it would be illogical to expect the earth to have moved X miles away in Y direction if you teleported one second into the past/future because that would presuppose that your location was objective and absolute in the universe at the point of time traveling and the earth moved relative to your absolute location. It would break known physics if that were the case, as much as time travel itself would.
🤔
If only there was some kind of theory that could explain relativity.
Especially in large celestial objects.
In a different position relative to what?
What point in space is the reference, where other things are placed relative to?
Any point you want, but likely the great attractor.
Tell me you didn’t pay attention in Spatial Distortion as Applied to Time Dilation class without telling me you didn’t pay attention in Spatial Distortion as Applied to Time Dilation class.
Forget the orbit… remember the song…
https://genius.com/Monty-python-the-galaxy-song-lyrics
“Just remember that you’re standing on a planet that’s evolving
And revolving
at 900 miles an hour.
It’s orbiting at 19 miles a second,
so it’s reckoned,
The sun that is the source of all our power.
Now the sun, and you and me,
and all the stars that we can see,
Are moving at a million miles a day,
In the outer spiral arm,
at 40,000 miles an hour,
Of a galaxy we call the Milky Way.”Teleportation or building your time machine into a spaceship so you can land.
Or stealing someone else’s spaceship time machine
Never go in against an Australian when death is on the line!
One of the best characters
Edit: autocorrect
That’s why I always liked approaches that use a physical machine that has to stay in one place for an extended period of time. Quantum Break’s hard sci-fi approach to this was fascinating and kept making me reconsider how the time loop worked. Highly recommended for time loop nerds like me.
I’m convinced that if there’s a way to build a time machine, it’ll probably work like Primer.
Space is full of time travelers that forgot to include the Zed access into their calculations.
Zed access sounds a lot cooler and more scifi than z axis.
Hahahahaha!!! Oh, man. Speech to text did not do me well earlier hahahahah
That’s correct. But if you’ve figured out how to travel through time, traveling through space should be easy.
Also, be sure to wear a hazard suit so you don’t die from any ancient/future diseases your body has no protection from.
A wormhole type time machine would leave the travel points A and B physically independent of each other. This opens up the option to change destinations… step in at New York, exit in San Francisco.
Due to the energies involved, creating a wormhole between two cities would probably leave you with a wormhole and no cities.
Those are just small issues that will be solved after few tries.
Maybe if you timed it juuuuuust right you could land somewhere on the planet as it orbits the sun and comes back to the same position once a decade or century or whatever? I mean I guess it depends on how you determine absolute location in the universe. Is that even possible with the universe constantly expanding?
Nope, not possible. The solar system itself is moving as is the galaxy… it’s useful to think of Earth’s orbit as spiraling around the sun in the direction our star is traveling. So 1 orbit later we have not come to the same location.
But moving relative to what?
Everything else.
Galactocentrism was established in 1925, which realised that our solar system is not near the center of the Milky Way. So, we are moving relative to the center of our galaxy.
In 1929, evidence was found that everything else is moving away from us. So we are moving relative to everything else.
In 1931, the Big Bang theory started superceding Galactocentrism, which was an acentrist model of the universe (where there is no center).
But what frame of reference?
Everything else. Or anything else, if you select a single quark (presuming we don’t split a quark).
If everything is moving away from us, then everything is moving away from everything else.
It’s just that some things are moving away from us faster than they are moving away from other things
Yep, and not to mention the position of our solar system in the Milky Way or our galaxy in the local cluster. In fact, without a specific reference frame you would have to make corrections very rapidly for even a tiny jump in time.
There was a not very good TV show Seven Days that used this well. They had a time machine that could go back in time seven days. The pilot had to fly the machine chasing the earth as he traveled back in time.
He would usually end up crashing it somewhere and have to find a phone to call for pickup.
Yep, and he had to also solve the problem of the week given everything they could figure out in the 7 days following it happening. A cool set of limitations for the writers, the execution was a little sloppy, but overall a cool idea.
This is interesting because the most “realistic” (i.e. still not realistic) depictions of time travel in fiction involve travelling through a singularity or wormhole. So you probably have to be in space to start with, but also both ends of the wormhole have mass so they can be orbiting a planet or star and stay within a stable distance of it. It solves this particular problem (just leaving the other usual problem of causality!) It also proves your point since it does allow travelling in space, in fact it allows travelling faster than light.
I think the converse is true as well, that if faster than light travel is possible then time travel must be possible, at least if you take relativity at face value. As others have pointed out there’s no universal reference frame, and for any journey that is faster than light in one reference frame, there is another frame in which the journey goes backwards in time.
