To look at it another way. If I build a time machine on the 10th floor of a building, and travel back to a time before the building existed, even if the Earth is in the same spot, the machine will appear, in that time, in the air at a height equivalent to 10 floors, wouldn't it?
I get the posed problem. And there is a potential way to get around it and explain it. At least for science fiction purposes of not actual theoretical physics.
In General Relativity, Space and Time are not seperate things but one thing known as Space-time. Mass warps space-time and thus we perceive that as gravity.
With other forces, we can actually measure the strength, such as a magnetic field. We not only observe and measure its effect, we can measure the field itself.
With Gravity we can only measure the effects. We cannot measure gravity itself. We know two masses attract each other and the strength of that attraction is bassesd on the masses and the distance between them. but we cannot detect the actual force itself interacting between them.
That is because gravity is only our perception of warped Space-time.
Ok... So to the problem at hand.
When you consider the problem of WHERE the other point of your timetravel comes out, not the when... You have to consider it "relative to what?"
Relative to the sun and the Earth is not in the same place of its orbit?
Relative to the galaxy as the whole solar system move about it?
Relative to some arbitrary fixed point in the universe as the galaxies themselves move?
See the problem? Relative to WHAT?
So here is how you fix it.
Any method of "Time Travel" Be it some artificial machine, or sone wierd natural ohenomena as in this film... Will be mass-locked to the largest gravitational mass.
Since time and space is the same thing and warped by the presence of a mass, this makes sense.
It does not matter how many years you go back and that Earth itself is not at the same point of its orbit around the sun. you Physical point of travel in time is fixed relative to Earth's mass and moves with it in Space-time.
Depending on where you travel, you may still have the same problems. Jump back 40 years in a time machine on the 10th floor and discover the building didn't exist 40 years ago... you're gonna have one hell of a fall. You're fixed relative to Earth so while you may fall from a nonexistant building, you're not going to appear in space because the Earth is not there.
Jump back far enough, Millions of years, and tectonic movement may have you appear in a mountain that has worn down to plains in your time, or an ocean where there was dry land. But you'll still be in the same relative spot on Earth.
Do the same in a Spaceship in Interplanetary Space, and your timetravel will be mass-locked to the sun and you will appear in the exact same spot relative to the sun. In this case I hope you did calculate the movement of Earth so that you dont appear in its core as it orbits about.
A sort of opposing problem was argued on the board for
Terra Nova some time back. But rather than a problem with the WHERE you appear in time travel, the problem of WHEN was discussed.
In Terra Nova there was discovered a fixed rift in time that goes back 85 million years to the time of the Dinosaurs. Earth in the future was dying of Environmental and ecological collapse. So several waves of settlers were being sent into the past to start over. The problem being posed was
"Why isnt all these people appearing on top of each other at the same moment if the rift is fixed to exactly 85 million years ago?"The answer here is that they failed to grasp that it isn't a fixed date in time the rift transports them to, but a fixed length of time that it transports back.
Not to a fixed date, hour and minute. But to a fixed distance in time from the time you stepped into the rift.
Person A steps in and goes back 85 million years.
Person B steps in 5 minutes later.
Person A and B do not both appear at a fixed moment 85 million years in the past, they each travel back 85 million years from the moment they stepped in, meaning Person B appears 85 million years in the past, 5 minutes after Person A did.
I joined the Navy to see the world, only to discover the world is 2/3 water!
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sir rooke
7 years ago
You're fixed relative to Earth so while you may fall from a nonexistant building, you're not going to appear in space because the Earth is not there.
Yes, you maintain your "frame of reference" -- consider: you're on a train going 60mph & you jump up -- you come back down in the same spot, even though the train has moved forward at 60 mph while you are in the air -- but you are ALSO moving at that rate, even though you don't realize it. The train & it's motion are your frame of reference. If you jumped OFF the train (out of the frame of reference), that spot where you would have come down will have moved away from you (and you are now in a new frame of reference!)
The earth (like the train) is moving but you are carried with it, so neither you nor the Nimitz re-materialize in empty space...
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