Inspired by this question.

Suppose we can get a container strong enough to withstand the force needed for the vibration, and the human or clock within is able to survive the duration of the experiment. Of course, anything else, like energy needed, is also provided.

The experiment involves putting the container with the human or clock in a constant near light speed vibration or short circular motion.

Why not sub lightspeed travel? Because we can't observe what's going on. With this we can observe the time dilation because the container is more or less stationary.

Is this even possible? Is there any repercussion doing a near light speed motion on earth? (I'm imagining maybe it will deform space, or such)

In my story this is used as some sort of punishment to criminals (to separate them from loved ones)

Note : I've read most answers on the original question. I'm mainly looking for why and how does this possible/not.

  • 1
    $\begingroup$ It's worth noting that not only will the acceleration be crushing, but the acceleration means you probably wouldn't be in an inertial frame (or even approximately in an inertial frame!) if you were on a small circular track going that fast, so special relativity would not be too helpful for calculations. I'm don't think any of it would hold, really. $\endgroup$
    – HDE 226868
    May 31, 2017 at 22:21
  • $\begingroup$ Even if you could overcome the minor technical problems, it wouldn't prolong life at all. The person(s) in the container would still (barring accidents!) live their alloted four score and ten or whatever, they would just see the rest of the universe being fast-forwarded. $\endgroup$
    – jamesqf
    Jun 1, 2017 at 5:34
  • $\begingroup$ @jamesqf the goal is not the prolonged life, but rather punishing the convicted by separating them from their loved ones $\endgroup$
    – Vylix
    Jun 1, 2017 at 6:10
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    $\begingroup$ Seems like a much easier way to do this is with cryogenic hibernation, like in Demolition Man. Same effect, you go in, and when you come out it's many years later, even though almost no subjective time has elapsed. The big problem with this compared to normal prison is that while it does have punishment in that you lose time with loved ones and society, it doesn't give the prisoner any time to reform. So there is punishment without behavioral correction. $\endgroup$
    – AndyD273
    Jun 1, 2017 at 19:51
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    $\begingroup$ @jamesqf it is used to punish white collar criminal (corrupt politicians, and such). Something that is inspired from the high rate of corruption in my country, you see, since it is possible that in the future capital punishment is banned. $\endgroup$
    – Vylix
    Jun 1, 2017 at 20:02

6 Answers 6


The acceleration will be crushing.

Either you are on a circular track, or you slow down stop turn-around on each swing.

On the back-and-forth linear track, your average speed will be low, and the track can’t be long enough as it takes months to get up to relativistic speeds using only a few g of acceleration.

For the circular track, you feel the inward acceleration continuously. Centrafuges for training pilots reach human limits and are only a few hundred miles per hour.

human or clock

Now if you want to observe time dilation, that is a real thing and has been for the better part of a century. Individual subatomic particles can be sent along a circular track at close to light speed. Particles like muons have half-lives and act as clocks.


Would tiny high-speed motions cause an object to effectively travel to the future?


The mathematical principles that describe time dilation are well established, and you can use them to calculate the difference between proper time (that observed by the thing moving) and coordinate time (that observed by the thing not moving).

For an object rotating about an origin given its orbital distance $r$ and angular velocity $w$, the proper time $\delta T$ can be calculated like so:

$$ \delta T = \Delta T \sqrt{1-(rw/c)^2} $$

Can we do that to a container with a human being in it?

Not without killing that human being. You'll run into problems with friction, compression, and inertia such that you'll open the container and find your prisoner smeared and crispy.

So then how can we do it without making a mess?

The problem is reliably moving individual atoms around in the first place without destroying the body they comprise.

But let's handwave that concern and imagine you've got some miraculous tech that somehow tractor beams onto every atom in a person's body and shakes them each around in a small circular rotation at near light speed.

Let's keep the diameter of rotation so small that we can minimize concerns about macro-scale effects like friction and compression. Under the assumption that you don't want any of the individual's particles to be displaced any farther than the diameter of a hydrogen atom (53 × 10−12 meters), you'll need incredibly high angular velocity to see any significant time dilation... which sadly means we'll have to either address or handwave concerns about how to deal with the accelerative radiation produced (see also Bremsstrahlung).

Doing some quick calculations, an angular velocity of 50 × 1017 radians per second would result in time dilation such that 100 years would pass on the outside for 47 years as perceived by the time-traveling prisoner. But we can do better than that...

The large hadron collider can accelerate protons at 0.999999990$c$ (over 299,792,455 meters per second). If your future tech can match that velocity for all the atoms in a person's body simultaneously within the tiny rotational diameter of a hydrogen atom to prevent molecular dissolution, as given above, you can expect time dilation such that a year in coordinate time will pass by in less than 74 minutes of proper (subjective) time.

So a bit over an hour in the clink equals a year in coordinate time, and a bit over 5 proper days (124 hours) in the clink would remove your dastardly criminal from all friends and loved ones by 100 years.

Is it feasible?

The large hadron collider is probably our best example of artificially accelerating subatomic particles, and it's 27 kilometers long.

Accelerating particles in tiny (submolecular) loops at such speeds has obviously never been accomplished, and I can't even imagine a mechanism for doing so.

Your impressive magical future technology will need to be capable of the following feats:

  • accelerating billions of particles simultaneously (uniformly) without destroying the body they comprise
  • accelerating particles with extremely high angular velocity over incredibly small distances (such small distances should prevent negative chemical reactions such as friction heating)
  • keeping the subject alive, addressing potential problems with respiration, hydration, and ingestion (would this mean accelerating air, food, and water molecules simultaneously?)
  • prolonged continuous operation (presumably on the scale of years in coordinate time)

This seems like it would take an incredible amount of energy over an extremely prolonged period of time (presuming the machine will be running continuously in coordinate time, not the prisoner's proper time).

Some of the concerns might be addressed by delivering the punishment in small "doses" instead of all at once, such that the prisoner won't require food and water for the relatively short proper time experienced, simultaneously reducing the duration (and therefore the power consumption) of the continuous treatment in coordinate time.

However, if you've already assumed that this magical technology exists, there's no reason not to overcome its challenges completely unless such problems make your story more narratively interesting.

  • 1
    $\begingroup$ So a bit over an hour in the clink An hour of his subjective time. He'd still be in the clink for a hundred years as far as the rest of us are concerned. Which means having to store a guy moving at the speed of light in a box somewhere until his sentence is up. And that has got to be downright annoying. $\endgroup$ Jun 1, 2017 at 15:41
  • 1
    $\begingroup$ @Draco18s I agree, it certainly seems like a lot of expense and trouble for someone who's presumably contributed more harm than good to the futuristic society. $\endgroup$
    – Thriggle
    Jun 1, 2017 at 16:00
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    $\begingroup$ Not to mention the fact that they're only an hour older and will likely have learned nothing. "Meh, my family and everyone I knew is dead. So what? I didn't like 'em much anyway. Time to go a murderin'!" $\endgroup$ Jun 1, 2017 at 16:04
  • $\begingroup$ « keep the diameter of rotation so small that we eliminate any concerns about … acceleration» That's not right. A small rotation will have enormous acceleration. The LHC has a Large diameter to minimize the centrifugal forces. And you neglected to cover the fact that charged particles will radiate energy when you accelerate them in a tight circle… $\endgroup$
    – JDługosz
    Jun 1, 2017 at 23:36
  • $\begingroup$ @JDługosz Ha! Good catch... I don't even know what I was trying to say there, in retrospect. I guess I was trying to logically eliminate macro-scale effects (hence the friction and compression). Thanks, as always! $\endgroup$
    – Thriggle
    Jun 2, 2017 at 1:35

The big problem will be creating a uniform acceleration. If you could somehow accelerate every single atom in the body on exactly the same circular path, then it would not strain the body at all. However, doing that is tricky. If you tried to apply the force on the surface of the body, the result would be a resounding squish. You have to apply to the force to all atoms in the body at once, not just the ones on the outside. However, all known forces which can do this are not uniform. Their effect varies by the square of the distance. This would cause tidal forces which rip you to shreds, akin to spaghettification from a black hole. The faster you go, the higher your momentum, and the greater the forces.

Creation of a field which is incredibly uniform and high power would be the essential key to making this work. I'm reminded of the Helmoltz Coil, which is known for creating a remarkably uniform magnetic field in its core. I highly doubt the coil on its own would be enough to do what you need, but it could be a piece of the puzzle.

Also, make sure that whatever you are using to force the individual into a circle is very conservative. The amount of energy pent up in a structure vibrating as you say will be incredible. Even a tiny fraction of energy could be incredibly destructive if emitted as waste rather than feeding back into the system.

  • 1
    $\begingroup$ Ok, so a thought struck me. There's a demonstration of an effect called Laminar Flow. It was colored dye added to a container of corn syrup, which then had a rod in the middle that was rotated. It applied the force non uniformly over the liquid, stretching out the colored dye, smearing it all over the inside of the container. But when the rod was reversed and rotated the same number of times back, the dye reformed back where it had been inserted. I could imagine some handwavium to do that to a human and not kill them. At least, not permanently... $\endgroup$ Jun 1, 2017 at 15:46
  • 1
    $\begingroup$ @Draco18s Laminar Flow in High-Acceleration Humans. Never do I ever want to see the defense of a thesis with that title! $\endgroup$
    – Cort Ammon
    Jun 1, 2017 at 15:55
  • $\begingroup$ Ba hahaha, I died. I would enjoy seeing that as a thesis or white paper (maybe not "humans" but some analog). It would amuse me greatly. ((((I may also be a sociopath)))) $\endgroup$ Jun 1, 2017 at 16:02

Take look at Oscillation. Hertz.


Nanotechnology. (We can even today do molecular thin layers of things)

Our computer processor today run at 3000000000 Hertz. Thats the amounts of times up and own/on and off/circular motion.

I guess the big problem is to put everyhing back into place. And how to activate a brain dead person? Maybe you could tune the mind in after some time. The brain waves have to be the same. Maybe a computer program will preform a proxamiation that will in the end be so close to the original mind that it dosen´t matter. The character might experience this as dreams - that suddenly crashes - A new dream will start to continue a bit longer but only to crash again - with no memories of the former dream.

The original mind prior to the whole process was saved. The brainwaves results of countless of small expriments (brain reaction to events) made by the computer - and longterm memory. When the brain starts to work - it compares it to the saved brain data (and brain wave functions) - and shut down - to redo process until it is on a whole the same as the original.

When it comes rematerizaltion. Thats a tough one. There is extreme amounts of atoms in a human body. It would be near impossible if not impossible to save such data - of how they are built up. After all life is quiet old. And I guess our atoms is as many as planets and stars in our universe or something like that.

I suggest the character (characters mind) would have to be inserted in a new body - or a clone (that have gotten through similar life events in a simulated enviroment). If you want more realism I think you might want to skip the container. If you stay with the container - maybe the atoms and molecules are used (turned into water and oxygen - and cole to to CO2 - for plants to breath to become food for the clone). Basically you characters materia would be recycled into a clone tha becomes himself again.

You could also take a look at this and use it somehow. https://en.wikipedia.org/wiki/Isotope_separation


Yep, there's at least one obvious repercussion. Moving at fractions of the speed of light in Earth's atmosphere will cause the air to undergo nuclear fusion, which would overall be bad for everyone involved.

  • $\begingroup$ So do it in a vacuum chamber. $\endgroup$
    – JDługosz
    May 31, 2017 at 21:19
  • $\begingroup$ So energy isn't a problem, acceleration issues aren't a problem, and nuclear fusion isn't a problem? $\endgroup$ May 31, 2017 at 21:24
  • $\begingroup$ Acceleration is not in your Answer. Fusion is a result of moving in air. And note that energy is stipulated in the OP. So what’s the point of your comment? $\endgroup$
    – JDługosz
    May 31, 2017 at 21:35

If it was physically possible to accelerate an individual in a perfect vacuum (or near perfect such as a particle collide) you may be able to remove the crushing force of the acceleration. However, even assuming that, it would not account for particle decay-time dilation. It's possible, but that would be more influenced by gravity, in which case it may be more likely possible to extend life if one could be moving at this speed, instead of outside the edge of the expanding universe.

  • $\begingroup$ «you may be able to remove the crushing force of acceleration» how do you accelerate but remove the crushing force of acceleration? «assuming that it would not account for particle decay-time dilation is possible but that would be more influenced by gravity,» I don’t understand that one bit. “it” would not account? It = The high speed? The acceleration without acceleration? «IT would not account for (particle decay-time dilation) is possible» does not scan as a grammatical sentence — so what? I cannot understand what you wrote. $\endgroup$
    – JDługosz
    Jun 1, 2017 at 23:29

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