Viewing a single comment thread. View all comments

above_average_magic t1_j0zmti3 wrote

Earth rotates the sun at speed, but that doesn't mean you would be 67,000 miles away because it would be a radial distance traveled. The chord* line would be the distance away plus the total distance traveled by the solar system/galaxy in that time

But yes on top of that, the earth (and sun and solar system) have traveled through space-time for eons ... and going back in time but NOT space would mean you would be billions, trillions, uncountable miles from where the earth was when* e.g. ancient Rome, or dinosaurs existed.

It would have to be positional time travel

65

FLGamerDad t1_j0zn1bw wrote

that is super interesting actually, never thought of that.

14

DropsTheMic t1_j0znwia wrote

This is why some people say a time machine would also have to be a teleportation device. Consider the inverse of this, if you could calculate a precise coordinate of time to travel to you could also precisely coordinate a point in space to land in.

18

Spookimaru t1_j0zr8yg wrote

I've argued this very same point many late drunken hours, but no one listens to me

2

stout365 t1_j0zouqg wrote

you'll probably enjoy this kurzgesagt

that out of the way, to address your original question, there's virtually no distinction between time and space, they are for all intents and purposes, the same thing. therefore, any sort of feasible time machine will also be a space machine, meaning the machine, to be functional, will need to be able to calculate both the when and where you'll end up traveling to (that is grossly over simplified).

11

thegabe87 t1_j0zq1wr wrote

If you fix the position issue you just invented long distance space travel IMO.

7

above_average_magic t1_j0zqy1c wrote

Ha yes!

However personally I think any two way time travel has to be "gate to gate." So if ever invented it would only work for periods of time which are forward in time, from the time of the invention/installation/go-live. Which would also be positional in a sense but wouldn't really be more broadly usable like you want to hack it

3

willtantan t1_j0zrph6 wrote

This is a good point, since spacetime is a thing. If you can travel time, you will definitely be able to travel space. The wormhole concept has to apply for spacetime together.

2

anxious1975 t1_j0zo4ad wrote

Plus the universe is moving too

4

IllustriousCookie890 t1_j0zqz9u wrote

Besides the expansion of space - all things moving apart from each other that are not bound by gravity.

2

Cetun t1_j0zrfmp wrote

Do we know the universe is moving? We don't even know how big it is

0

silhouetteofasunset t1_j0zs25t wrote

The theory is that it's always expanding at an increasing rate, I thought

1

Cetun t1_j0zx1lj wrote

The expanding doesn't necessarily mean moving, the distance between gravitationally unbound objects is increasing, but those objects aren't "moving" in the classical sense because at some point they will be "moving" faster than the speed of light, which is impossible. So I think within this discussion, If you were to build a time machine that would disappear at one time and reappear in the same coordinates, You wouldn't end up in a void your galaxy "moved" while you stayed stationary, your Galaxy stayed in the same "place" just the space between the galaxies increased in size. But from your galaxy's frame of reference the other galaxies that are not gravitationally bound are moving. Which movement in the universe depends on your frame of reference so conversely the other galaxies would see you moving away also. But you didn't "move" relative to those galaxies, though you may have moved relative to the surrounding galaxies that you are gravitationally bound to.

1

ingleacre t1_j0zse26 wrote

My smartass friend in school was annoyed by this when watching Back To The Future.

"88mph? Relative to what?"

2

slothsupervisor t1_j0zqyoc wrote

I’ve also read that “which supports your statement in an obtuse way” that if we created a Time Machine at some point in the future the issue would be that the same as if traveling in space you would need to have coordinates essentially and the coordinates of time and space would not be accurately defined until the point in time the machine was created. You could pinpoint the exact position of the destination based on the time machine’s position therefore could return to THAT moment in time but would not accurately be capable of returning to a time before the machine was created.

Therefore all time travel could only be coordinated to the point in time after the creation of the machine. It would essentially be a waypoint in which any future time travelers could come back to but traveling farther backwards would maybe not be impossible but it would be nearly if not completely impossible.

I guess another way of looking at it is if/when time travel is created in the ideology of a quantum universe where there is a future generation which already would have this technology they have not been able to return to times beforehand and “correct” timelines to suite their own needs.

Maybe I am talking absolute nonsense but it makes sense to me.

1

above_average_magic t1_j0zr4hx wrote

I literally posted a very similar reply to another redditor this very second, so which of us is the time traveler hmmm??

1

slothsupervisor t1_j0zw4xy wrote

I feel like I am far too poor to have that technology and not utilize for my own needs honestly.

1