I was surprised when I read the OG time machine story by Jules Verne and this was a main plot point, and only later stories hand-waived it. You'd think it was something from later analysis of the idea. Almost like that Verne dude was clever.
Clark Ashton Smith wrote a similar short story where the inventor failed to take it into account. Upon realizing his mistake he decided to just wait for another planet to reach him, turning his time machine into a spaceship.
That's actually a fascinating idea. All interstellar travel is based on the movements of the planets through space time. I bet it alternates between being technically faster and slower than FTL travel since you may have to wait for a time when your destination to pass into the planets past location.
Wow that's a fun thought hole. Constraint certainly breeds creativity!
One way to resolve this is to have some kind of multiverse theory where you don't travel back in time to your universe, but to a narrow slection of parallel universes that are also shifted slightly so that it spits you out in an analogous location to your initial departure.
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.
Tine machine probably moved in its own inertial reference frame. That will actually get you lost in space because the inertial frame does not orbit around, which involves rotation(rotation is intrinsically non-inertial, i.e accelerating). Time machine's frame will be moving in a straight line if its inertial
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.
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.
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.
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.
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?
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
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.
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.
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
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.
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.
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