I was thinking about a scenario where time in one section of a ship has stopped. Everything (including people) that happened to have been caught in that section are also frozen. People outside the affected area have to find a solution. They walk to the time-frozen section to get a better look, entering one of the corridors where one part is untouched and the other is frozen. A person, not knowing where the dividing point is, tries to reach one of their frozen crew mates, and walks right into the temporal anomaly. Or, they stick their hand/an object out to see what happens if they were to cross that barrier.

I'm wondering what would happen to them. If they walked in face-first, how far in could they actually go? Every particle in their body that hit the frozen point would literally stop in place. Would the entire front half of their body be stuck, and their back half frozen? Would they die, as half of their body is working and half is not? If they just stuck, say, a metal rod through the barrier, would the rod be held in mid-air?

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    $\begingroup$ Is there a smooth transition into the frozen time, so the person would walk in, be gradualy "time frozen" becoming slower and slower for outside observer? Or is narrow border size of say 1 atom? (1 atom inside frozen, 1 atom outside moving) I would say walking into such hard border would stop you as if you would hit a brick wall, with 1 atom wide layer of your sking being frozen, not letting rest of the body move forward. Backing off would mean you lose the one atom layer of the skin, which would not be so bad - falling of bike and sliding across street would scratch your skin WAY more. $\endgroup$
    – p4ulie
    Commented Feb 6 at 23:47
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    $\begingroup$ In fiction it's generally not that the time has truly stopped, only flows very slowly. Otherwise you get AlexP's scenario, which is even more problematic than it seems. $\endgroup$
    – Mithoron
    Commented Feb 7 at 14:26
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    $\begingroup$ It's a hypothetical scenario where the behaviour of the objects/people encountering the "zone" would depend on the rules you set. You've not told us the rules. Voting to close as need details and clarity. $\endgroup$ Commented Feb 7 at 17:48
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    $\begingroup$ @Mithoron We were incorrect, sir. I have determined that time is moving forward at an infinitesimal rate....The motion of the cloud is within my visual detection threshold. At its current expansion rate, it will consume the Enterprise in approximately nine hours, seventeen minutes. $\endgroup$
    – Michael
    Commented Feb 7 at 21:09
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    $\begingroup$ @p4ulie Chances are you wouldn't even be able to land 1 atom into the "time frozen" zone, because to move in, you need to push through floating molecules, which you may not be able to. $\endgroup$
    – Clockwork
    Commented Feb 7 at 21:16

8 Answers 8


"A person, not knowing where the dividing point is, tries to reach one of their frozen crew mates, and walks right into the temporal anomaly":

And he bounces right back. No part of them, not even a single atom, can cross the barrier. Why? Because movement happens in time, and time beyond the barrier has stopped.

Let's look at the situation closely:

  • Beyond the barrier, time has frozen at some value $t_f$ ($f$ for freeze).

  • At some later time, somebody tries to insert even a single atom into the region where the time is frozen.

  • But time beyond the barrier is frozen at $t_f$, so that no change is possible. Not even a single atom of the rescuer can pass the barrier, because if it did there would be a change in the state of things, and change cannot happen when time is frozen.

The barrier is impenetrable. Nothing can go through it. Nothing, not even light, can enter. Nothing, not even light, can exit.

But that's not all.

The worst thing is that the frozen-in-time region can never be unfrozen. Why? Because in the frozen-in-time region time is frozen. The time is always $t_f$. Since time does not flow, there can be no change, no modification, nothing.

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    $\begingroup$ Not convinced about the defrost impossibility, but the fact that light cannot exit has an interesting implication: the characters cannot see their frozen comrades, or anything else in (or beyond) that area, all they see is complete utter darkness. $\endgroup$ Commented Feb 7 at 10:14
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    $\begingroup$ Wouldn't some sort of mirror effect be more likely than darkness? If border of region is perfectly smooth it would be perfect mirror. Or if imperfect it would scatter incoming light. That is if light can't enter, it means that it it must reflect light. $\endgroup$
    – Ekaros
    Commented Feb 7 at 12:45
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    $\begingroup$ @Ekaros I feel like this is actually a major problem. A person would bounce on the air particles inside (or he would leave an atom thin barrier on the side when attempting to enter perhaps?), but there's nothing to stop photons from entering, since they don't collide with each other. And having a place where photons keep entering indefinitely but cannot leave sounds like a recipe for disaster. $\endgroup$ Commented Feb 7 at 13:12
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    $\begingroup$ @Ekaros: Yup, Larry Niven's statis fields work that way: perfectly reflective mirror while time is stopped. larryniven.fandom.com/wiki/Stasis_field $\endgroup$ Commented Feb 7 at 14:29
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    $\begingroup$ @GoingDurden Can't move relative to what, though? There's no preferred reference frame. $\endgroup$
    – Idran
    Commented Feb 7 at 17:17

This is world-building, not physics, so I'll approach the question as a storyteller, not as a scientist. I'll set up something that is plausible enough for suspension of disbelief.

In order to be able to see into the frozen region and allow any interaction at all, we have to make a few assumptions that will be important later on:

a) photons can enter the region, bounce off something, and exit the region to enter an observer's eye. Since time is frozen, I will postulate that the photons bounce off, but do not get absorbed, which means: No colours inside the frozen area and all surfaces seem smooth and glassy. That may not be scientifically correct, but it's cool so I'll go with that. I will handwave the thing by saying that photons, moving at the speed of light, don't really experience time.

b) the frame of reference inside the frozen region remains local, so it continues to move with the ship. If I didn't assume that, the region would freeze not just in time but also in space and we'd simply have a section of the ship ripped off and left behind.

c) the freezing effect continues to affect matter that moves at sub-lightspeed, but the freezing does not occur instantly. Otherwise there would be a hard barrier and entering the region would be utterly impossible. That would not be interesting since as the storyteller, you want someone to enter the region.

d) there is a "thawing" effect for matter that is in contact with unfrozen matter. Density of matter plays a role here. You'll see in a second why that matters.

With these assumptions in place, the following would happen: As the crew member enters the time-frozen region, he pushes against molecules of air that are frozen in time. Due to d), and his body mass being considerably higher than the mass of air he is pushing, he can push somewhat into the region, but the deeper he goes, the more resistance he encounters and the more he will be subject to the time-freezing effect from c). This can be as fast (a second should be time enough for him to walk entirely into the region) or slow (time enough to walk a few steps, notice what's going on, and run out in a panic) as you wish or your story demands. Pushing out against the time-frozen air that's begun to close the hole he left, combined with the fact that it's really hard to breathe that air and going back the same way means stepping through a vacuum can make his escape as dramatic as you need. If your story needs it, he can even die in that vacuum, or time-freeze on the verge of death.

  • $\begingroup$ Due to your suppositions, though, wouldn't the ambient temperature of all matter contained within the field be 0K (absolute zero)? If so, even in the second it takes for someone to walk into the space and realize they've made a mistake, they would likely have severe biological/physical damage from such a vastly low temperature/energy. $\endgroup$ Commented Feb 7 at 17:04
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    $\begingroup$ @JesseWilliams it would take more than a few seconds to be damaged by still, 0K air - air does not conduct heat very well. It also depends on how frozen particles interact with non-frozen particles because the frozen particles haven't actually lost their heat. $\endgroup$
    – Rob Watts
    Commented Feb 7 at 20:32
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    $\begingroup$ Regarding (b), there is no such thing as absolute motion/non-motion, so you don't need to make any assumption there. The question is what happens to the frozen section if the ship attempts to accelerate/decelerate, and you could have it go either way (ripping apart, or accelerating together). I think inability to accelerate (or at least doubts about whether it would be safe to do so) is more interesting. $\endgroup$ Commented Feb 8 at 2:02
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    $\begingroup$ @JesseWilliams that's an interesting question. We don't have experimental evidence on how heat works in time-freezes, so we can make something up that makes somewhat of a sense. I would posit that like in a vacuum, the time-frozen matter does not actually conduct heat away, so you only lose heat to radiation. $\endgroup$
    – Tom
    Commented Feb 8 at 8:00
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    $\begingroup$ +1 for putting the emphasis on the narrative aspects rather than strict adherence to (unrealistic) physics. $\endgroup$ Commented Feb 8 at 14:00

Many bad things

If time is frozen within an area, it is frozen for all particles, which includes photons. Photons won't move and when you look at a time-frozen place you will see nothing.

To make matters worse, it it is most likely that these particles would stop exerting fundamental forces on their environment, like gravity. Because of this the time-frozen region will be like a complete vacuum. Air will quickly rush towards it, and when time is unfrozen you will have absurd amounts of air crammed into the same space. When time is unfrozen, this will not be fun either.

The Earth is also moving. If the time-freezing doesn't work right, when it is unfrozen it could be in space or the center of the Earth.

This is completely unsurvivable and more useful as a weapon than anything else. Unfortunately, you probably don't want a weapon. Because of this, you should make your time freezing work however you want it to work.

What I suggest

You probably want to be able to see inside the time-frozen area, which is problematic in a few ways. An easy solution is to allow some surface matter, along with other transparent matter, to interact with things. The boundary between surface matter and inner matter would effectively tie surface matter to the locations of inner matter. Fortunately, it appears that this solves all of the problems I outlined above.

As for light, this question has an answer with several possibilities.

  • $\begingroup$ Read a book way back where they could make a stasis bubble around a region. In the book the stasis bubble was given a mirror surface because what does a black hole look like. $\endgroup$
    – KalleMP
    Commented Feb 7 at 15:19
  • $\begingroup$ "it it is most likely that these particles would stop exerting fundamental forces on their environment, like gravity." – Is it? My first assumption would be that the various fields surrounding the matter inside there would be "frozen" and remain constant, rather than suddenly changing to 0. $\endgroup$ Commented Feb 7 at 15:22
  • $\begingroup$ @TannerSwett You are right. I had the (bad) assumptions when writing this that slowing time completely is equivalent to stopping it, and that fundamental forces are applied less when time is slowed. $\endgroup$
    – Jakav
    Commented Feb 7 at 21:46
  • $\begingroup$ Air would not rush towards the region, because it cannot enter the region in the first place and therefore its a perfectly solid barrier. $\endgroup$
    – Seggan
    Commented Feb 8 at 16:57

Depending upon the interaction between time-stopped space and normal space, light may either be absorbed or reflected on interacting with the interface between the two zones, so the interface should either look black or reflective respectively. Such an interface would be impassable as previous answers have indicated. However, this is probably narratively uninteresting... if this situation has a solution, it can only be because the mechanism of stopping time within the zone is external... unless there is some other handwavium device that would allow the passage of time to be restored in a smaller volume. Exploring the interior of a timeless zone would then require moving that volume of restored time around and looking at what became visible as the field interacted with it.

However, if the interior of the 'time frozen' area is visible such that a person on the outside can see in and want to rescue someone they see inside it, then that indicates the occurrence of something other than that time is not passing at all inside the zone. It would seem to me that in such circumstances, the ratio of $T_{Inside}:T_{Outside}$ is something other than 0:1. That light would leave an object inside the 'time stopped' zone and be visible outside the zone would indicate that at the interface, particles and energy switch from being time-slow to time-normal or vice-versa. Therefore, the ratio of $T_{Inside}:T_{Outside}$ must be 1:N, where N is some large number, such that to the external observers, those inside appear to be frozen. That would also have the effect of reducing the apparent illumination of the area within the slow-time-zone (STZ) to 1/N of normal, since by the perspective of the outside, the lights are emitting 1/N fewer photons per second.

Let us suppose, then, that Adam, outside the STZ, sees Betty inside the STZ, apparently not moving, and attempts to go into the STZ to investigate. If Adam is moving at 1 m/s as he attempts to cross the boundary, the parts of him that attempt to cross first would react as if they were moving at N m/s where $T_{Inside}:T_{Outside}$ is 1:N. Since N is so high that people inside appear to be frozen, it would likely be in the thousands at least. Hitting the surface of a volume of air at 1 ATM at, say, 10,000 m/s, would be like walking into a wall. It would hurt, and Adam would be no more able to push through that surface than he would be able to push his way through a block of glass.

However, there are other ways to investigate the STZ than physically. By shining a light into the STZ and waving it around, the value of N could be determined by seeing how far the light reflected from objects within the STZ lags behind the notional position of the light within the STZ if it was not slow-time. Knowing that light travels at 299,792,458 m/s and that the far wall within the STZ is 10 metres away, if N is 10,000, the time it would take for light to be reflected from it would be the same as if it were 100,000 metres away. However, that light would also act upon the STZ as if it were N times brighter...

So, if a Plot Device at the centre of the STZ caused the STZ, those outside need only wait until the person who turned it on decides to turn it off... which they may do 'almost' immediately, in perhaps as little as one second, which at $T_{Inside}:T_{Outside}$ of 1:10000 would be 2h 46' 40'... or they may have decided to leave it on for a while so they can investigate it further. In the latter case, we're back to either waiting it out or handwaving a Second Plot Device that generates a field that allows someone to move at $T_{Inside}:T_{Outside}$ 1:1 inside the STZ.

  • $\begingroup$ Light travels at the same speed in all reference frames (it's the core tenet of Einstein's theories), so you cannot figure out the slowdown speed using your method. $\endgroup$
    – Seggan
    Commented Feb 8 at 17:34
  • $\begingroup$ @Seggan This isn't a matter of different inertial reference frames, it's supposedly an alteration of the flow of time in a volume. Speed is distance travelled divided by time elapsed. If you change time outside of relativity then you change the speed of light. Stop time completely and photons will be suspended in space. It's not science though, this isn't something you can actually do, so don't expect scientific principles you hold dear to have any meaning. $\endgroup$
    – Corey
    Commented Feb 10 at 2:15


I would split this into two forms of time freeze: Volumetric and by Logical Unit.


This one makes slightly more "sense". The whole area is frozen, no light can pass in or out, no interaction at all. Maybe also all the physical horrors that other commentors have mentioned.

Logical Unit

This is the interpretation I would prefer for worldbuilding purposes. It requires some form of cognition from whatever caused the timefreeze in the first place.
In this, it wouldn't be the whole area that is frozen, but rather the area would define the space where every individual logical unit is frozen in time. So, people, along with the clothes they are wearing etc. would be frozen as one unit, the floor would be frozen as one unit, etc.
If you are lucky, the area is in vacuo, so you could still move around in it. If it has an atmosphere, every last molecule of air is now a tiny, tiny immovable object. Walking speed might be fast enough to kill you if you walk into it.

This would get interesting if the time freeze caught something like a laser pointer being turned on; the beam could be frozen midway.

As a side note, the second form can be somewhat nicely experienced in Fallout 4 (and maybe other Bethesda games) using the SetGlobalTimeMultiplier console command.

  • $\begingroup$ Instead of "logical unit" you can simply say "every atom is suddenly cooled to absolute zero and stays that way" $\endgroup$
    – Seggan
    Commented Feb 8 at 17:11
  • $\begingroup$ @Seggan but that is not actually the same. The “logical units” stay in their own isolated frame of reference and stay fully coherent. That wouldn’t happen if you just froze every individual atom $\endgroup$
    – MarsMagnus
    Commented Feb 8 at 22:25

Given that you can't see into a zone that has zero time progression, can't interact with it or its contents in any way and generally can't predict what's going to happen, this is already a bad idea.

Let's ignore all that for a moment and consider a very different question: how believable is this? How much am I - and anyone else with even a layman's knowledge of physics and a bit of rational thinking ability - going to have to suspend disbelief to swallow the idea?

A lot.

Like a lot.

But this is happening in your story and you want it to look a certain way, and I don't want to take that away from you. Let me propose a solution to our little problem:

Volumetric Fields

I loved this one from Greg Bear's 'Anvil of Stars'. The idea is that you have a forcefield that gently encapsulates every part of the content down to the molecular level and moves things around in an emulation of 'normal' physics. With this a crew of relatively normal young humans is able to withstand accelerations in the hundreds of Gs without having their insides turn into a complex organic soup.

(Gotta love the fact that Bear describes these things in some detail rather than just writing "inertial dampers" and leaving it at that.)

Of course the computational complexity of such a thing is mind boggling, but with a little hand-waving we can come to a compromise that lets us both walk away happy.

Let's say that your people are working on an inertial dampening field projector that would let them operate normally during acceleration. Maybe it's a standard part of the ship technology these days, but someone tinkered with this one and now the device that's supposed to ensure that your molecules keep doing the dance that keeps you alive has gone haywire.

From the outside this looks just like you've been frozen in time. And you can see it because the field has little or no effect on photons and other stray particles. What you can't do is get inside the field yourself. The field volume is, to all intents and purposes, a perfect but massless solid. If it affects photons at all you might see some distortion or refraction, but it's probably just an impenetrable wall from your side.

Not to worry though. All you need to do is cut power to the field and pray that the sudden collapse of the field is enough to let things return to normal. Let's hope the collapse happens uniformly across the whole field rather than shrinking the volume over time, because that's not the sort of thing that an organic can survive. But that sounds like an engineering problem to me.

It's a pretty problem to solve. Hope for your sake that your engineers are on their game that day. Get it wrong and your people are dead in some fairly permanent ways. Even getting it right is going to be medically... interesting. Might want to have a few medical staff on hand to revive the crew when they're released.


You may want to take a look at World of Ptavvs by Larry Niven and The Peace War by Vernor Vinge (a short novel that's also collected with some other related stories in Across Realtime). Niven's novel has "stasis fields" that conform to the boundaries of the time-stopped objects, and Vinge's book has spherical "bobbles" for which time is stopped for everything inside the sphere.

Both authors assume that the objects themselves can move. It doesn't make sense to assume that a time-stopped region would have to be perfectly still in space because that's a meaningless concept.

Both authors also assume, as others have suggested, that the boundaries would be perfectly reflective. That pretty much has to be the case, because for them to be black would mean they absorbed light, which would involve changing the time-stopped region. However, if the boundary of the time-stopped region were rough or even fractal then it could be white like snow rather than shiny.


Caught in a black hole

First things first, no one has any solid idea about what goes on inside a black hole. There are some interpretations and speculations based on General Relativity. String Theory goes further and weirder by proposing that the inside of black holes doesn't even exist.

But we do have an idea of what happens as you approach the event horizon. From any external observer's point of view, a falling object seems to take literally forever to cross the horizon. In other words: stuff falling into the hole appears to be frozen in time - but only for those outside. An observer falling into a black hole will (theoretically) feel as if time is passing normally for them, though.

Your ship could be slowly falling into a very large black hole. Particles that have already crossed the event horizon measure their own proper time normally. But from the point of view of the parts that haven't crossed yet, the parts that are going towards the horizon take infinite time to reach it. They will seem like a paused movie.

If you try and cross from the region that "has time" to the other side, well... you join the other side forever. You cannot come back from a black hole anymore than you can come back from the grave.

And since particles inside cannot interact with particles outside ever again, every particle going in gets separated forever from its original body. Stick just a hand in, and it won't make it back - you will be left with a bloody stump of an arm.

Avoiding spaghettification

Read enough about black holes, and you'll learn about this. The gravitational tide forces on falling objects would tear their molecules, possibly even atoms apart before they come close to the event horizon.

That is true for possibly most black holes, but for really largest ones the tidal forces could be small enough to be even negligible. That's because the tidal forces get weaker as you get farther from their barycenters. For TON 618 or Phoenix A, you might not even feel it before you cross their horizons.

Avoiding excessive radiation

Very massive black holes have accretion discs that are hot enough to emit even x-rays. In the case of TON 618, the total radiation is enough to outshine its entire galaxy, with a total output (as seen from Earth) of about half a supernova worthy of energy per second.

You may have to handwave how the ship survives a thing like this. But hey, Gargantua (a fictional, and much smaller black hole) had a shiny disc too and the spaceship from the Interstellar movie passed through it just fine.

  • $\begingroup$ This clearly has nothing to do with black hole. Part of the ship is frozen, the rest is not. "Inside of black hole" is irrelevant. $\endgroup$
    – D'Monlord
    Commented Feb 7 at 18:58
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    $\begingroup$ @D'Monlord au contra. OP has literally described an event horizon. One of the few solutions to general relativity which includes an event horizon is called the Schwarzschild metric, or what is generally known as a Black Hole. There are other event horizons, but none I can think of which was universal to all observers outside of the affect area. $\endgroup$
    – Aron
    Commented Feb 8 at 5:22
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    $\begingroup$ @D'Monlord Are you really trying to explain to a Master's graduate in Physics what an event horizon is? That an event horizon is capable of spaghettification (as opposed to the gravitational tidal forces that a compact, super massive object would generate)? That time is not stopped within a blackhole from the pov of a distant observer in an inertial frame, outside of the event horizon (its in the name). Please, tell me how my entire education has been a lie. $\endgroup$
    – Aron
    Commented Feb 10 at 18:25
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    $\begingroup$ I never said anything about crossing an event horizon. An event horizon is literally a boundary where nothing happens on the otherside. That is literally the definition of an area of space which time has stopped wrt to an external observer. It does not necessarily require a blackhole. You are arguing with me without even knowing the words you are using. $\endgroup$
    – Aron
    Commented Feb 11 at 6:56
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    $\begingroup$ @D'Monlord Further more, not all Blackholes have an event horizon. It has been theorized that a spinning blackhole (see the Kerr metric for the full mathematics). Conversely, a spaceship under constant linear acceleration will experience an event horizon in its rear. In an expanding universe, stellar objects will accelerate apart and eventually be shrouded by an event horizon from the rest of the universe. See the Cosmological event horizon. $\endgroup$
    – Aron
    Commented Feb 11 at 19:34

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