Time travel doesn't exist because time travel wiped out the timelines where it did

[GreyLord]

So, it isn't the same spot, but you meant the same spot? You meant the thing that you say it obviously cannot be? What?



And you know the "only way"... how, exactly?
I mean, if you are a time traveler, and know, then tell us - we all stand to be able to live quite better using your unique abilities!



Why? You make this assertion, but give no reasoning behind it.

I will try to restate my previous note, and see if it helps.

Einstein tells us that there's no absolute measure of time, or of space. There is no one fixed inertial reference frame in which the laws of physics work differently than in any other, or that we can refer to for absolute truth. The best we can do is measure things relative to other things.

There is, to first approximation, no reason to choose a "farthest stars" frame, in which the Earth, Sun, and Milky Way are all moving, over a frame that happens to be fixed to the foot of the Eiffel Tower. The "farthest stars" themselves aren't actually fixed, even relative to one another - they only seem that way to us slow-moving, short-lived humans. Neither of those frames is particularly privileged - the only reason to pick one over the other is how hairy the math comes out.

So, if I am travelling in the lifespan of the Eiffel Tower, and start and end someplace mostly at rest relative to the Eiffel Tower, there's no reason the time machine cannot be working in that frame of reference, and it looks to everyone on the planet like the traveler moved in time, but not in space, relative to the surface of the Earth.

Now, yes, someone sitting around one of the farthest stars would say that the traveler moved in time as well as space. But, WE DO NOT CARE. His view of that isn't special, isn't privileged, isn't more true, than that of a person standing at the foot of the Tower. Folks not in the chosen rest frame of the machine can basically bugger off, we don't need to care about them.

I don't think you understand what I mean by the same spot.

I've tried to explain it.

Going to the same spot on earth today is like going to the same spot in the solar system today.
If it is relative to the solar system, it is relative to the Earth.

For example, the earth rotates. You put yourself stationary above the Earth for one hour, where you are not turning in rotation with the earth (aka, the same spot you are at right now but 100 feet up, but not turning in relation to the earth), you will find yourself a ways away from where you started.

Yes, it is relative, but we still have mapped it out on the Earth, and the same laws apply to the Earth as the rest of the universe (the Earth is not excluded from the laws of the universe as you seem to want to imply).

However, as you seem to want to twist the semantics and do no matter how simple I try to explain it, you do not wish to understand it, I have no idea how to explain what I am intending.

 

[GreyLord]

So, if I am travelling in the lifespan of the Eiffel Tower, and start and end someplace mostly at rest relative to the Eiffel Tower, there's no reason the time machine cannot be working in that frame of reference, and it looks to everyone on the planet like the traveler moved in time, but not in space, relative to the surface of the Earth.

That only works if you are using Newton's laws. It does not work with how we understand the laws of movement today.

If you THOUGHT the universe revolved around the Earth and the Earth did not move, it would work perfectly.

If you THOUGHT that you stay in the same frame of movement (as you would in a moving car) it would work perfectly.

However, when you involve time (which is relative) you are moving out of that substrate into something outside of time and space in order to go to another point in time and space.

This is how we can calculate relative movement in the first place.

It's why we could send men to the moon. It's how we send things to Mars.

If we sent the objects to the same spot (like you are asking us to) we would have our rockets, explorers, and other items go to a spot in space where the Moon or Mars no longer were at (because both those objects are constantly in motion).

Anyways, it's not worth the hassle on these forums to keep this up.