In the twin paradox, I can hop on a spaceship, cruise around at a high percentage of light speed, and return to Earth in a younger state than my twin. I want to do the reverse. I want to leave Earth, do something, and come back very much older than my twin. (I guess leaving Earth is optional, if I can pull this off on Earth somehow, that would be perfectly adequate.)
Hypothetically speaking, my reason might be that I know a terrible disease is about to destroy the human race in about 2 years. I can cook up a cure, but I need a few decades to make enough to save humanity. How can I squeeze those decades into the next year as measured on Earth?
And to anticipate the obvious question: Need answer fast.
There is no known way to do this. At best, you can go into orbit and stay there, freeing yourself from the gravitational time dilation at the surface of the Earth, but the Earth’s gravitational time dilation is tiny, and so freeing yourself from it makes almost no difference: It’s enough that the ultraprecise clocks on GPS satellites need to take it into account, but not long enough to come up with a cure for a disease.
Well, the obvious answer is for you to be the twin who is left behind. But that’s based on your first paragraph.
Your second paragraph throws in a monkey wrench. Now you want EVERYONE on Earth to age less than you do. Again, the simplest answer would be to put everyone on the spacecraft and start your research. Good luck!
Right. Just attach your reactionless drive to the Earth, send the whole Earth on a non-stop round trip to Fomalhaut at 0.9999999999 c, while you work on your cure for Space AIDS back home on Luna.
Better make the trip fast enough so it’s only a subjective day or two for the Earth, since they’re not taking the Sun with them.
Never really got into Relativity, with my minor in physics -but as I understand it - in the classical relativity, twin paradox, if two clocks are travelling past each other at the speed of light, each will see the other as going slower. Sounds weird, but that’s relativity - they are never standing still to compare. two frames of reference are functionally identical. So how does this reconcile with the OP’s question? Simple, it’s a question of special relativity. One twin undergoes acceleration and deceleration (i.e. more acceleration) and that’s the one who avoids the aging. Acceleration of a frame of reference is a special case, hence “special” relativity. So the simple answer is to send the one twin out into space, then accelerate the earth to an appreciable fraction of c, then slow it down again…
And just to confuse you, acceleration and gravity are indistinguishable in relativity IIRC.
A situation like this occurs in a Greg Egan novel. Fortunately, the characters live in a universe where the laws of physics are difference, so that the travelers have time to solve a problem and rescue the more slowly aging stay-at-homes Plus, Minus: A Gentle Introduction to the Physics of Orthogonal — Greg Egan
Assuming spacetime is simply-connected and complete then there is one thing and one thing only you can do to experience more time than an observer on the Earth and that is to make the minimum motion possible to free yourself from the Earth’s rotation about its own axis, excepting frame dragging. The difference though this would make over a two year period would be a tiny fraction of a second. Any motion you made to free yourself from the Earth’s gravitational field would have the net effect of decreasing the amount of time dilation, as in a simply-connected complete spacetime, free-falling observers always experience the maximum possible time between two events they are co-incident to.
If spacetime was not simply-connected, e.g. there were wormholes present, it may be possible there are other ways of increasing the time experienced, but not necessarily.
Moving very fast, close to the speed of light, is what you need the opposite of…
I have the answer. I operate very close to the speed of nothing. I can confirm that this method is not particularly effective for… well, much of anything.
Stay right here on Earth. Drink 2 fifths of whiskey a day, smoke 3 packs of cigarettes, commit to absolutely no exercise and a high stress job. You will age much faster than your clean living, stress-free twin.
Why can’t he go live on Pluto for awhile to do this?
Pluto’s orbital speed is lower than the earth’s (4.67 vs 29.78 km/s) and it had a lower gravity. Both should contribute to the clocks on Pluto running faster than those on Earth. Its rotational speed on its axis is slower too.
I realize the trip there would slow his clocks down but presumably we could account for this.
Now, if his clocks run faster on Pluto than on Earth why can’t we continue this slowing down clock trick (e.g. just stay in a rocket and adjust speed to orbit more slowly) and get greater and greater differentials in how fast the clocks are running?
Ok but if we use Pluto as a guide why can’t we keep extending that notion. Go slower and slower in comparison to the Earth to get a bigger and bigger difference?
Apparently, the Earth doesn’t have enough inherent motion to cancel out. That’s why I get suggestions about sending the whole Earth (or at least all the people) on one long twin paradox trip while I stay at home in the Solar System and work on the cure.
I expected that a reverse twin paradox scenario was impossible and that’s been confirmed.
Yes, the Earth’s gravity and the Earth’s orbit around the Sun mean that clocks on Earth go slower than objects in zero gravity and objects that don’t orbit the sun.
But that difference is what scientists call “very very small”. So small that you’d have to have an atomic clock to measure the differences. The Earth’s speed around the sun is only 30 km/second. The speed of light is 299,792 km/second. So the Tau factor is very very small. Going from 30 to zero doesn’t get you any more than a few microseconds advantage in your super-speed search for the cure for Space AIDS.
You’d need the velocity difference between you and Earth to be a very large fraction of the speed of light to get any useful tau factor, and since the Earth isn’t going particularly fast relative to interplanetary or interstellar space, and since the Earth is very large, the only realistic way to get a large tau factor is for you to travel at very high speeds while Earth stays where it is. As far as relativity is concerned, that’s just like the Earth zooming away at high speeds. The trouble comes when you want to go back to Earth to give them your cure for Space AIDS. You have to turn around and go back, and when you return home to Earth’s reference frame you’ll find that it was Earth that had the faster clocks, not you. That’s the opposite of what you wanted.
Pluto is slower than the earth and its clocks run faster.
Why not continue to maneuver to see what results in a faster clock? You fire your rocket and then match speed with Mars and compare clocks. Hey…clocks run faster on Mars than on Earth. Great!
Now do it again and match with Jupiter and Saturn all the way to Pluto. You stop at each planet and see your clocks are running faster still than they were on Mars. Each step gets you a faster clock than the one on Earth.
Or to put it a way that might be easier to understand. Suppose we construct a reference frame where Earth (and the Sun and the Milky Way Galaxy and the local cluster) are zooming through space at a hair less than light speed. To create a situation where you observe the clocks on Earth slowing down, you just jump in your spaceship and turn the engines on full blast so you can slow down relative to Earth.
You get out your Hyper Telescope, set the sights on Big Ben, and notice success! The clocks on Earth are going very slowly, since Earth is going so fast and you’ve managed to slow down. You get to work on your cure for Space AIDS, and after 20 years of backbreaking research you’ve done it. You look back at Big Ben, and since you’ve slowed down to near zero while Earth is screaming away at near light speed, it’s only been 2 weeks back on Earth. Time to head back to Earth and give them your cure.
Except, how do you do that? You’ve slowed down so much that Earth is moving away from you nearly as fast as light. The only way to do that is to reverse course and speed back up to even closer to light speed to catch back up to Earth. That undoes all your previous tau gain, and exactly reverses it. You catch back up to Earth only to find that your girlfriend is now in a nursing home.
