# Running out of time in a world where time has stopped, how to make it consistent?

When writing I always want the rules to be as consistent as possible for scenario’s that might be common or the reader might think about happening. But I’m not sure how to resolve some issues.

The fluff:

Someone in the universe has stopped all time. Humans, already space-faring with several planets colonized, noticed time shenanigans before hand and realized what would happen. This knowledge was limited so most people never even realized time was about to stop. Scientists managed to create time bubbles and create small communities within them before time truly stopped, leaving trillions to be frozen in time. They slowly build the energy and equipment to create more time bubbles, ironically a time consuming process. And unfreeze more people while balancing the energy and space they have (time shenanigans let them create more energy, just not much more).

The problem:

These people move through the timeless regions using special suits which have a time bubble that does not extend beyond the suit itself. They can move objects, damage them, throw them etc but anything not inside the timeflow of the suit will reset itself after a few moments. So if you see a coffeecup that was being dropped frozen in time and you move it, it will return to its original position a moment later. If you stand in that spot the cup will “wait” until your bubble of flowing time has moved on before returning to its position.

You are moving through the world in a suit, moving the air and objects out of the way which return to their position after you passed. Unfortunately your batteries are about to run out and you’ll be frozen in time until someone can power up your suit again.

Lets say you just opened a door and time runs out as you are standing inside the doorway. The door (and the air in that location) was waiting for your time bubble to move on so it could return to its position. Now that your time bubble has run out it could technically return to its position, but you are still in the same position.

The question:

How do I resolve the consistency problem of objects returning to their position if time runs out, without instantly killing the person by clipping matter through their bodies?

Some extra info:

• the suit is completely enclosed, you breathe from an air tank rather than time frozen air (which you couldn’t suck in anyway)
• The reason objects return is because they technically had no time to be moved, they were never actually unfrozen. This also means that if you move or harm someone frozen that they will be returned to their unharmed position after a moment. This also prevents easy unfreezing of people or objects, which is part of the narrative goal of having things return to their position.
• How do objects behave if you force them to collide while returning to their "original" positions? (Say you have two boxes stacked one on top of each other, and you switch their positions before leaving.) Do they collide with each other and stop, pass through each other, or something else? Commented Oct 7, 2023 at 9:40
• if you eat a apple digest it then poop, when the poop leave the suit does it turn back into a swiss cheese looking apple missing all the parts that became part of your body and didn't become poop? What happens to things that started in your body that leave your body, if you pee outside the suit does it teleport back inside you?
– John
Commented Oct 7, 2023 at 11:14
• @john fine questions but irrelevant to what I am asking here. Still: the apple will have to enter the time bubble of the suit, so it will be taken out of its “try to reach the original position” loop like any other person or object unfrozen from the timestop. At which point if you poop it, it will reach the stage that I am asking about: it is now occupying a space that air or an object tries to return too and it has no timefield, so what happens to the objects that can technically return to that location? Commented Oct 7, 2023 at 12:12
• I encourage you to read Sir Terry Pratchett's Thief of Time if you have not yet. A core part of the plot involves people who can ‘slice time’ (effectively making it so that they and their possessions experience many hundreds of seconds of time in only one ‘real’ second, making it seem to the rest of the world that they are speedsters), and most of the climax involves them dealing with restarting time after an extra-dimensional threat has stopped it. It’s mid-fantasy and not sci-fi, but they do discuss a number of the issues that the time shenanigans cause, so it may be good inspiration here. Commented Oct 8, 2023 at 4:51
• @U.Windl at that point you can look at LotR and say “but the square cube law forbids a creature like the Balrog and how can it be made out of fire and shadow so its not real and the story shouldn’t have been written”. Commented Oct 9, 2023 at 13:04

I'm answering with the assumption that moved items only teleport back to their original location, even though it looks like you imagine them doing some traveling through space back to where they were. I have trouble imagining the objects moving through space, so for the sake of this answer, I hope that's not a deal breaker.

# Quantum tunneling

In pop science, quantum tunneling is when particles can jump between two places, or even in some ways, occupy two spaces at the same time. Some recent science shows that tunneling might not be instantaneous, so this can handily explain why the objects eventually return.

I would also invent a similar principle for time (because it is a part of space-time), which can help explain the slow return, but also explains the ability to move things. Time isn't frozen, but is flickering between two near quantum-time states. You can now invent strange effects or sensations when an adventurer tries to move things (for plot), and you get to conserve mass, energy, and momentum. Objects move, as long as you're moving them, but the return is always quantum tunneling.

# Frozen in time, but out of place

But what happens to the adventurer caught outside his time bubble, right in the doorway? Will the door dissolve into him? Will he dissolve back to where he was pre-bubble? Will the door be prevented from moving back at all? I think you can pick here, for story needs. Any make sense to me with a little handwaving. However, if your characters entered their bubbles before the universe froze, it does not make sense for them to return to anything. If entering a bubble has no effect on a non-frozen universe, then leaving the bubble into a frozen universe should do nothing too.

I like the idea that he is frozen in the new place, and the moved object is in a perpetual state of being moved out of the way. But, to make it fun, it creates a unique phenomenon. I like that both the adventurer and the moved object flicker alternately between the two places, again, because of tunneling. By entering the quantum space and the quantum time that is occupied by another particle, the two particles are now locked into a quantum pair, which sure sounds a lot like quantum entanglement. The only way out would be through whatever technology creates a bubble. What would happen to this adventurer if the universe unfreezes while he is in this quantum lock is probably not very good.

This also explains how your time bubbles work, and why the dropped coffee cup waits for you to leave before it returns. They take advantage of the quantum flicker, solidly sitting in one portion, and forcing the objects into the other. The technology prevents entanglement that would otherwise naturally occur. Maybe this also ties into your energy generating "time shenanigans". I have a few ideas, but if you don't you can ask another question.

## The matter does clip, but it's not an instant-kill

Stuck Buck will have a door materialised in his body, but there's plenty of space between the atoms, this doesn't violate laws of physics just yet. Having an internal door interrupts Buck's bloodflow and air and such, but that's the thing - those effects do not get realised until when the heart attempts to pass blood through the obstructed veins. And the heart is not beating, he's stuck in time! So until his batteries are powered back up, there's no time for any harm to come to him.

Now rescuing such a person would be a trick and a half. As soon as you move part of Stuck Buck within Saving Jane's time bubble, that body-part will start demanding oxygenated blood that the still-frozen heart is not providing, and this will cause damage in minutes. So Jane needs to interact only with the extremities; hopefully the power socket is on a hand or foot. Once the time bubble is restored, the door will return to its moved state and Buck will be free.

## The matter doesn't clip, it applies pressure

Where is the door coming from when it materialises? Not out of thin air - it needs to come from some direction that's neither up, down, left or right. It can only come from a fourth spatial axis. The time bubble shoves the true door into this direction, and it falls back when the bubble runs out. So it "falls" and it would be no different from dropping a door atop Buck from any other direction. It may hurt and bruise but his body resists it. So saving him will require pulling him out from "under" the door; it'll form in place whenever he's pulled free.

• I like the latter answer. Commented Oct 7, 2023 at 20:30
• But pressure can't exist without force, which can't exist without time. There is no pressure. There's no movement of the door, it just is where it is. If it has to return to location when the field goes away, then you have to not be there. Commented Oct 10, 2023 at 3:52
• I really like the second solution. But I suggest that rather than a fourth spatial axis, the movement is along a temporal axis. The door wants to "fall" backwards in time to it's original "temporal ground state" after having been disturbed by the time bubble which "pushed" it forward in time. But it gets stuck against Buck's body, which is occupying the space-time that the door needs to pass through in order to get back to it's original space-time location. Buck is tempospatially in the way, if you will. Only after Buck's body is removed would the door fully restore itself.
– Gene
Commented Oct 13, 2023 at 20:40

The whole idea is delightfully silly, and like any good sci-fi B movie, it requires the reader to take out their brain, with everything they know about science, and just leave it on the coffee table and just enjoy the narrative.

That means, it doesn't matter. Do whatever the heck you like. You're in the realm of "space opera" here, having left the "hard science" far behind you. They can see, so clearly photons are traveling from lightsources outside their suits, bouncing off objects outside their suits, all in the frozen-time space, and then are reacting with and being destroyed by their retinas inside their suits. And if they stand in one place, they don't use up all the photons that were in that space, so clearly light sources continue "working", sending out streams of photons. So you can do whatever works under the rule of cool. Have the bad guy killed by a returning mug to the head as his suit runs out. Have the good guy survive the same fate.

The rationale is fairly obviously "I want them to be able to explore the frozen world and manipulate arbitrary stuff in it as if it had the mass and momentum it'd have in their own time stream, but I don't want them to be able to unfreeze arbitrary people", handwaving away all the physics effects they're relying on like light and gravity, and blithely ignoring the fact that they can just put a suit on someone and have them walk to the bubble-towns.

That's all OK. It'll bug people, but all frozen-time-based sci-fi is criminally stupid. It seems to be a necessary thing for the genre, because there's just no way to write it intelligently.

...But we can TRY! We can take the premise, move as few mental mugs out the way as possible, and try to make the story still work.

Let's look at "Time", first, and how to freeze it.

Someone "stopped" time... what does that even mean? It doesn't really mean anything. That's like saying someone stopped West, or someone stopped Up. You can't stop a dimension, it makes no rational sense. Causality just stopped causing? This also creates a "bad guy" that can never be reached and defeated, unless they are somehow also unfrozen and in the same instant of stopped time.

From your narrative, it seems that the people in these frozen bubble-towns are the ones who froze time, for themselves, by creating these bubble times that have time passing for themselves while no time is passing outside. They made themselves a time-tangent. They separated themselves from the flow of time. It was all them!

So a more believable rationale would be "the world is gonna end, because [arbitrary disaster scenario, gamma ray burst or whatever], so we need to pause time for ourselves, so we can at least continue to live in a tangential time, hopefully long enough to figure out a way to save our entire solar system from getting destroyed."

Think of time like a ruler, running from south (past) to north (future). Every mark on that ruler represents one second. At a certain second-marking, let's arbitrarily say the 10ft point, someone creates a time bubble, which we can think of as another time-ruler which now branches off at a right-angle, with their "future" being to the East. But no matter how far East they go, they will never change their position in the main timeline's ruler: they're still frozen at 10ft in that main time-stream's timeline.

If they leave their bubble and their suit runs out, they will resume their path along the original ruler, flowing in the original time-stream.

Note that if two bubbles were created at a tiny fraction of a second apart on the main ruler, they would be unaware of each other: they would have different tangential rulers starting from slightly different places in the main time-stream's ruler, and never touching. Only realities created instantaneously with each other would share the same bubble-ruler and be able to see each other. Easiest way to enforce this would be one person in only one bubble town start theirs, then walk in their suit to all the others and press the "on" button on their machines.

That 'tangential ruler" approach is a fairly rational approach to handling stopping time for others while still having time passing for yourself. There are other ways to do it, but this way avoids the most major "WTF?" moments.

So, for the suits that let you continue moving along the tangential timestream even outside a bubble, there's still the problem that you can move stuff, see stuff, etc.

One possibility is the suit's power-down isn't instantaneous. Well, not from their perspective, at least. So as their stuff returns to its position by moving there in a straight line, at a velocity proportional to the distance moved. So if the suit takes five seconds to power down, and you are standing in an open doorway, then it's no different to real life where you are standing in a doorway and a door takes five seconds to close on you: you get pushed aside.

But what if you take a mug and tape it into a box? The mug will try to move in a straight line towards where it came from, the box in another, the tape in a third... it'd be silly.

So another option is that time "unwinds": the tape comes off and reconnects and rewinds onto the dispenser, the box opens, the mug comes out and returns to its position, the box goes back to its own original position, everything moving along the path it was moved through, in reverse.

This means that some stuff will be trying to move back into the space they are occupying. The important thing is how much force it's trying to move back with.

I would say: if moves with the same kinetic energy it was moved with, since it's moving at the same speed, but in reverse. So you can have the air just gently pressing around them. If they are not rescued, and instead return to the main timestream, they'll seem to those in that timestream to appear with a bang of pressurized air. They'll know that they can't ever return to their time-bubble, and that they were never rescued at any point in the time-bubble's "future", because by the time they hear the bang of their own appearance, they'll be past the tangential "ruler" of their time-bubble. They will have to hope that someone in the time-bubbles solved the problem, because they'll be permanently out of the fight.

But how's about a third possibility, a frame challenge? Rather than freeze time, how's about we really, really slow time down? Say, one then thousandth of the speed. So instead of having six months until the end of the world, they have five thousand years to try to figure it out?

This is the same as above, but instead of being entirely tangential, their timestream is slightly angled relative to the first one, with a 1:10,000 slope.

You also then remove the problem of two time bubbles created a second apart. To the first time bubble, it would just seem like the other one took a few hours to appear, rather than it never appearing.

Light outside the bubbles becomes MUCH darker as there are fewer photons per second: at one ten-thousandth-speed, things would be only one-ten-thousandth as bright, but you can say the suit amplifies the light.

Air out there becomes thick and viscous, but air that others have passed through is thinner for a bit: the well-traveled main routes out of the city could be cleared already by the passage of others, to be near-vacuum, so be easier to pass through. Or conversely, they may be more turbulent, and hotter.

Suits would need to be thermally heat-shielded because of the effects of friction, moving through the thickened air: walking at what, to them, was a normal walking pace of 3mph, they would moving at twice re-entry velocity in the normal timeline. They'd be running clad in haloes of flame!

You can handwave away kinetic effects from the momentum of the suited human bodies by saying the suit handles that. Or, especially as the suit's power is fading, you can play them up by having people having trouble slowing down or turning, their feet not gripping to the floor, slamming into and through walls, etc.

Gravity becomes MUCH lighter. Again, the suit can deal, or you can have them treat the world as zero-G, with jetpacks or something.

Even though it "floats" in the low gravity, everything is impossibly massive. At one-ten-thousandth speed, a 500g stoneware mug with 500ml (~1 pt) of coffee in would effectively have ten metric tonnes (10,000kg) of mass, making it next to impossible to move aside, and once it gets moving, stopping it is another challenge. Opening a door would require massive force. They would need to use jacks, time-bubbled explosives, and other tricks to apply enough force to explore. They would have to accept that some of the things they're moving will harm those who are in the regular timeline because of the ballistically insane velocities they're moving everything at just to make their way through the world.

This also explains why people can't be just pushed to a bubble: if you tried to push them at 10,000x speed, you'd liquify them with the acceleration, then ignite the liquid with the velocity. Even entering the room they're in would likely require destroying the door and risk killing them with the shrapnel.

• I haven’t read it all yet but absolutely not. No. Just because I have some fiction does not mean I can do whatever I want. This is why soft magic/sci-fi and hard magic/sci-fi exist. You have more wiggle room in one than the other. But a fire ball will heat stuff up, it won’t suddenly cool everything down. Its a logical consequence of the rule “I throw a ball of fire at you”. I have rules for how things behave when people move stuff that are time stopped, which creates a conflict when those people become time-stopped themselves. I cannot just go “well screw all those rules ignore it”. Commented Oct 8, 2023 at 11:21
• As for light, light tends to have this feature of going at the speed of light. Which causes technically no time for light (or gravity or any other lightspeed process) to pass by. Your reasoning here is basically “if you have any magical element at all you can do anything”. So even the Expanse could just randomly throw a Jedi and Cthulu having a tea party in there according to your way of thinking because they have FTL. And yes you can absolutely write intelligent time based stories. Commented Oct 8, 2023 at 11:25
• @Demigan Time does, in fact, pass for light, otherwise it would not have a finite speed, we wouldn’t have communication delays with distant spacecraft, and quite a few aspects of currently accepted physics would not be correct. It is, indeed, very fast, but it is not infinitely fast. So you do in fact need to account for it if you’re going to stop time. Same for gravity if you want to claim that relativity still holds true. Commented Oct 8, 2023 at 12:30
• @AustinHemmelgarn depends. As I understand the theory, the closer you get to the speed of light, the 'slower' you will go in time. If you could go faster than the speed of light, you would go back in time. That would mean that light in a way is on the edge of the two. That would intuitively mean that they experience no time. No idea how they resolve all the weirdness that comes from that conundrum. Commented Oct 8, 2023 at 13:18
• @Trioxidane That's only true in the inertial reference frame of light, which is academic to the eyeballs of the observers, the light source, and the illuminated surfaces, none of which are in that reference frame. In their reference frame, time passes, and the photons travel from one to the other in that time. Commented Oct 9, 2023 at 16:50

Nothing happens... honestly, nothing

You've set a rule for your world: people moving through the timeless condition push atomic objects out of the way without regard to inertia, energy, or anything else. By definition a door is as "light" as an atom because there is no gravity and mass has no meaning in a timeless condition where, due to your rule, they can be moved out of the way. This is incredibly important. Yes, your time-bubble professors could technically move planets, but we'll ignore that.

What does this mean to the unfortunate soul whose time bubble fizzles while walking through a door?

Nothing, absolutely nothing. They simply become part of the frozen milieu.

Why? Because there's no inertia, no energy, no nothing. The atoms fall back into place after the passing of a time bubble because once the disturbance has passed, they need to fill in the "time void" of the bubble's passing. But once that bubble ceases to exist, there is no void. Everything simply becomes frozen again with the new spatial circumstances caused by the contents of the bubble.

So, the door remains open, the atmospheric molecules remain in place, and your friend is now stuck in the door until time begins again.

There are a thousand problems when it comes to playing with time in fiction. In your case, you're trying to rationalize how inertia, energy, gravity, etc. can continue in the case of T=0. Are you setting a rule that suggests that all those energy states, etc, are somehow preserved? An object in motion remains in motion unless acted upon by another force... which is a problem in spades when you start goofing around the the moments between moments. The door was closed to begin with, meaning it's "at rest." It's motionless once opened and still "at rest," thus preserving conservation of momentum kinda. The door actually is in motion due to the planet revolving and orbiting, the sun moving, the galaxy moving....

So you're up to setting another rule, and the rule I'm proposing is that it doesn't matter. Atoms return to the void caused by a passing bubble, but when that bubble fizzles out, everything remains as-is because there's no longer a void to fill. The contents of the bubble become part of the stationary no-time picture. No consequences, no pain, no death, just one momentarily confused professor who, when universal time restarts, blinks for a few moments and then breathes out, "nuts...."

• I'd prefer it not, but it either works or it doesn't, +1. Commented Oct 7, 2023 at 20:48
• I like this. Things return to their original positions "after a few moments", but that requires time. Without a time field there is no time, so everything stays where it is. Commented Oct 8, 2023 at 9:51
• Inertia and that kind of thing still exists for time-stopped things when meeting an object with time. Otherwise the moment they step out of a bubble the person would instantly start floating and fly into whatever direction through walls, ceilings, floors, planets until it meets another time bubble or they run out. I want to resolve some things by having things at lightspeed be timeless as well, so gravity of a time-stopped planet still pulls you down and if you shine a torch you can still see in the timeless world. And this does matter since its a rule I made, I want to resolve it. Commented Oct 8, 2023 at 11:12
• I think this is also a bit of a science stickler answer, but the question isn't tagged with any of the science tags. The OP wants internal consistency.
– user458
Commented Oct 8, 2023 at 15:31
• @Demigan OK. You need to edit your post to include all those facts. We can't read your mind. The more selective your "time stop" the more the consequence happens "because." The problem is that many forms of magnetism exists because things move through an electric field. You just removed the rationale for the movement. You could rationalize gravity... but light? Of course you can have what you want, but there comes a time where your goals can only be met by an arbitrary rule you invent. They do what you want because you want them to.
– JBH
Commented Oct 8, 2023 at 21:36

The simplest and most logical solution is for anything moved by a person in a time suit to simply stay put wherever the person in the time suit moved it to, or wherever it moved to under the influence of the suit's time field. The field would have to be big enough to move things like doors, otherwise the person wearing the suit would be trying to move those things at effectively infinite velocity, which is an impossibility.

Why would the passage of time reverse to move things back to where they were? Air might move back behind the suit because it's a gas, and that's what gases do, but anything solid or liquid in the suit's field would simply act as it normally would.

So, a falling cup would continue to fall when the suit came near it, as would falling rain, while air would move around the suit.

It doesn't make sense for the position of time-frozen objects to be privileged. The principles of relativity allow objects to move at different rates in time and space all the time.

We can think of the universe as a 3D cellular automaton machine. The speed of light is the speed at which adjacent cells respond to the state of a given cell. If the machine was to be stopped, except for certain parts of it, there is no memory that those parts that continue processing would use to restore a previous state.

• Comments have been moved to chat; please do not continue the discussion here. Before posting a comment below this one, please review the purposes of comments. Comments that do not request clarification or suggest improvements usually belong as an answer, on Worldbuilding Meta, or in Worldbuilding Chat. Comments continuing discussion may be removed. Commented Oct 23, 2023 at 23:56

# Same space, different time

Einstein showed an important thing. Time and space are inextricably linked. It is part of a host of complex theories and ideas, but some are stil refreshingly simple. Object A and object B cannot be in the same time at the same place.

Your people in a time bubble will probably have two times. One is the time inside the larger bubbles, the other is the stasis. That would mean the people losing power would become stuck at the time bubbles time and place. They've already lived past the stasis time. The door from the example would shut, which isn't a problem. The door shuts into it's own time and the same space, while the person is frozen in the same space, but a different time.

A simple example. If you see a closed door, you cannot occupy the same space at that time. If you open it and stand in the doorway, you are in the same space as the door was, but at a different time. Thus things can occupy the same space, as long as they do so at a different time.

## You are now an object outside of the time-flow of your suit.

Therefore, you will return to the position that you were in before it first affected you. Presumably, that wasn't inside of a door or any other time-frozen object, so on that count, you're in the clear.

Of course, that's not to say that automatically retracing all your past steps for who knows how many hours or days will necessarily be a pleasant experience for you. If you were incautious, your path might be blocked, or you might be revived in a dangerous area - or you might get stuck in a place where nobody knows where you are, until they happen to stumble across you. Cautious explorers will try to minimize this risk by setting up base camps with independent time-generators and periodically visiting them to make sure they don't get stuck anywhere unusual. Those without the time or resources for that will have to hope they get lucky.

• Though the start of the answer was what I was thinking, it'll be a death sentence for everyone. Unless it's the first expedition, they have eaten and drunk for extra nutrition and repairing/splitting cells. Much of the other stuff was expelled long ago. A large part of their internal stuff will end up somewhere else than they are. They will have no energy, missing (parts of) cells, blood, oxygen... they will be dead before they even unfreeze time. Commented Oct 7, 2023 at 11:58
• Most of the people will be part of the group that never got time frozen in the first place. Where would they go? To them time never stopped, they have no time frozen condition to return too. For people unfrozen, if that is inside a time bubble then they would just return to a place where time flows which might itself be occupied by an object which also adds a lot of weird shenanigans. I don’t know if this one can work as a solution. Commented Oct 7, 2023 at 12:30
• @Demigan For people who were in sheltered areas when the time freeze began, that is their "return" position - it's where they were when they went from "natural" time that the rest of the universe runs on to "artificial" time, after all. As for people whose return position is covered in a time bubble, I would assume that as they pass through the wall of that bubble, they become unfrozen again so it's not a big deal. Commented Oct 7, 2023 at 22:42

Taking the second part of KeizerHarm’s answer and running with it…

## Think four-dimensionally.

Think of moving through time as just another direction. Your characters move things in that direction, against a gravity-like force that wants to pull them back (and does so once they’re no longer “holding” it).

This means it’s not quite true that the time bubble doesn’t extend beyond the suit. Otherwise, your suited travellers wouldn’t be able to interact with things outside their suits at all. Any time there’s a concept of change, of “before and after”, hey look, that’s time.

So the suit leaks time, so to speak. But the suit’s effect on its surroundings isn’t “sticky”. Characters can temporarily manipulate matter, moving it through four dimensions. They can grab a box and move it up, left, back, and later. But once it’s outside of the liminal timefield surrounding the suit, it falls back into place through all four dimensions: down, right, forward, and earlier. It moves exactly in reverse to go back where it was.

Now, what does this mean for your out-of-time traveller? I see two possibilities:

1. They’re time-diving. The bubble lets them dive earlier, but once it’s out of power, they “float” back to later. They stay stuck in the same space as the closed door, but not at the same time. They are instead stuck at a moment in the closed door’s future. They neither see nor feel the door move back into place, because they’re frozen in a moment where it’s still open.
2. They’re an obstacle. An object doesn’t necessarily exactly retrace its path exactly to where-and-when it was. It actually moves through the least-energy path until it reaches equilibrium. If something resists its movement, it might come to rest slightly out of position in any of the four dimensions. And your stuck traveller is now jammed in between the moment the door was closed and the one when it was slightly ajar, holding the door to the left and ahead of its closed position.

Option #1 is, in fact, time travel, and raises all the attendant difficulties of multiple time travellers heading to the same moment and trying to manipulate it differently. You also have the issue of which time another, still-energised time-diver would see when they come by. Do they see the closed door’s moment, or the drifting diver’s moment?

I like option #2 better. It raises questions, but ones that I think would be fun (= story-generating) to answer, rather than just difficult. Like, what does it do to your body to be a temporal doorstop? It can be injurious to be in the path of a spatially-moving object, if it makes some parts of your body move to a greater spatial extent than others. Does the door falling earlier apply a force that could potentially move parts of your body to different temporal extents? Can a bone be broken into two moments as well as two pieces?

And how temporally heavy is the door? Gravity pulls some objects (those with greater mass) with more force than others. What about your stasis-force, the one that pulls all things back to the universal frozen moment?

• Marty, you're not thinking 4th dimensionally!
– user458
Commented Oct 8, 2023 at 15:20
• So, it would behave like gravity, but in what way would it actually be like gravity? Gravity is a property of mass, but the moved objects are attracted to nothing. Only a particular point in space. I have trouble imagining the objects moving themselves at all, so instead envision a teleportation. But, you are on to something describing it like gravity, where the energy put into moving it becomes potential energy, which releases when the object falls back.
– user458
Commented Oct 8, 2023 at 16:14
• @fredsbend It behaves like a very simple model of gravity: “what goes up, must come down”. Any other restitution/reactive force would work too, like elasticity. Is it similar to gravity in other ways? No idea. As for teleporting, that gives me more trouble. I see it as the motion playing in reverse as the object “rolls” back down the notional time hill. Commented Oct 9, 2023 at 15:45

First of all, if you may, you may technically call the timeless region as a region of '0-time' which means that it is a region where time rate is 0 instead of being simply timeless. Now I mentioned 'time rate' which could be useful concept if you set a universal or an absolute rate of time relative to which all other speeds of time could be measured. Suppose the absolute rate of time is T. What your antagonists really did is that they somehow set the rate of time in the timeless region (say T') equal to this absolute rate i.e. T'=T which made the rate as 0 in this region.

Your timesuit is but a special system that has its own rate of time (say T"). When you are out there probing in timeless regions wearing this suit, you are already with a difference in the time rate inside and outside. The greater the value of difference T"-T', the better it is.

When you move something wearing the suit, you are making it a temporary part of your system and it adopts a temporary rate of T", the same as you and your timesuit. Now when you release it, it should start to returning back to its rate of T' or T (remember that in timeless region, T'=T). But this return is not haphazard or instantaneous. This is because time is a continuous quantity that flows continuously for all practical purposes (better not to consider the Planck time which is relevant at very extreme conditions). At the moment of release, its rate was T". It will cover a timelength of T"-T before returning back to T which is its default time rate. Also I said previously that the greater the difference, the better. Since it is in the lowest possible rate with respect to your own, the difference T"-T is sufficiently large for things not to kill the people before returning to their original positions.

• If I understand correctly, you use time as a space dimension instead of time dimension so long as there is a difference between T and someone with T’? A time difference that causes objects without time that were moved to be moved back afterwards? Commented Oct 9, 2023 at 19:52
• Yeah. Specifically, difference in 'rate of time'. Commented Oct 10, 2023 at 1:55

# What happened at the precise moment you entered a bubble?

## It all comes down to this question.

What happened to you and everything else that entered a time bubble (or at the moment when time stopped outside, for the first "survivors")?
And btw you may want to know this answer for other things in your story.

When you will get out of the bubble, exactly the opposite will happen.

And the same two eternal possibilities: single timeline or multiple timelines?

1. Single timeline
When you entered the bubble you've disappeared from "frozen time": there's no version of you in frozen time, you only exist in the bubble. This means that matter has traveled from one time to another, thus in place of each bubble there's a huge void, since the entire content of the bubble has disappeared. The current time bubble may be considered to fill this void, but if so, what happens when a person is unfrozen and moves? According to the rules, they simply push the air around them, leaving an effective void in their place in the frozen time, since "nothing" will try to replace the void. So if we make a void by unfreezing someone or something (removing matter), the reverse is to add matter by freezing again. So, at this place, the existing matter will be pushed aside to make room for the new one.

About your door, it will get back in its place, except for the area corresponding to your body (the time bubble of your costume to be precise). The matter at this point will try to get back in place but will be stopped by your body. It's up to you to decide whether :

A) It compacts around you the closest possible, or
B) It deforms the rest of the door as a result (but this case seems to contradict the "reset" rule).

Note that in scenario A, if one day the stopped time resumes, there will be violent implosions at each "emptied" location and explosions at each "filled" location as physics takes over. You'll probably die, being at the center of an explosion. In B, you'll probably be alive, but trapped in the door to the nearest atom.

2. Multiple timelines (dimensions, realities or whatever...)
When time stopped, the bubbles copied their contents into a new timeline, and (following the rules) pushed out everything in their location in the frozen timeline. Just as you do when moving through frozen time. So there's a copy of you around your original bubble, waiting for it to disappear, trying to return to its original place. If you rescue someone, the original version will be pushed out, getting back in place when that person's "bubbled copy" moves.

Here too, there are several possibilities when your bubble stops :
A) You just disappear from this timeline as your bubble cease to exist. Like if you pop a soap bubble.
B) Your version from the 2nd timeline will also disappear (like in A), and a new (3rd timeline) version of you is made in frozen time, but this time you'll fuse with the door. Literally. Some atoms will fuse together (or even worse, I don't think we know what happens when two atoms are "superimposed"). At best, you and the door will merge, or have a hole, I'm not a physicist so I don't really know what could happen, but we can all imagine that it wouldn't be good. Obviously this copy of you will not survive if time resumes.

Either way, the Original you is still floating around a bubble.

It all probably depends on how you define "stop time" in a way which permits "time bubbles," which definitively demonstrate that time is not, in fact stopped.

One approach would be to define time as being "stopped" when the rate of change is zero for all things (we call it the "derivative," in calculus terms). Not that time doesn't "run" so much as you don't really need it because nothing is changing. This relaxes the requirements a bit and gives you wiggle room. In particular, now the requirement is simply that the universe has no kinetic energy

The next thing to introduce would be "what is a time bubble anyways?" That could be explained by introducing a Lagrangian mechanics term, "on shell" and "off shell." These terms are used in quantum mechanics, giving it a level of believability, although my use here will fall short of their exacting use, so don't expect it to check out on physics.SE

The "shell" describes a region of phase space where energy is conserved. On shell trajectories through time honor conservation of energy. Off shell do not. In classical Lagrangian mechanics, this is used to model constraints using a concept of "virtual work.". A constraint can be modeled as a force that just happens to do zero work on-shell, but has off-shell properties that make the math easy.

In quantum mechanics, it gets weirder. The math of QM works out such that every now and then a pair of particles spawns I to being (taking us off shell). The statistical nature of QM permits these particles to exist for a short time before vanishing.

I won't say these virtual particles perfectly describe your time bubbles, but their awfully nice prior art. They're something that sure appears to violate the laws of physics for a short time (at least they violate a simplified version of the laws). You can probably steal a lot from them.

One thing that you get to steal is that they DO get to interact. So perhaps your time bubbles are small pockets that have gone off shell, and are doing their best to defy the will of the universe to stay that way. On shell, the universe has 0 kinetic energy, from in time, but off shell, tiny pockets thrive.

This could explain why things move back into place after a while. If your interactions weren't strong enough, the object naturally slips back to its on shell state when you leave.

And it gives you a potential mechanism for what happens when your power starts to run out. Objects begin to move back to their on shell positions, probably starting with the objects that are further away. These objects would still be off shell, having my not fully returned to their on shell state, so they interact with "normal physics" instead of "frozen physics."

Which means your doorway question answers itself. As your power falters, objects return to their on shell state. This may move your body in the same way a car striking you can move your body. It may hurt. It may be fatal. Or it just might sting a bit, depending on what you moved and how far you moved it. If your on shell state, when the batteries fully give out, has a door through your skull, that's it. No rescue is to be had. But if all the door did was send you flying, they might be able to rescue you, bringing you off shell again, and catching you.

Again, it's not really how these mathematical concepts work, but it's close enough that you should be able to steal from the real physics to invent your fictional physics.

## Matter can only return to its original position while not being observed.

The reason a timeless person does not perceive the passage of time or process any external stimuli is because that all happens in the mind. They don’t see you waving your hand in front of their face because new photons aren’t hitting their retinas and there's no electrical activity in their visual cortex; The same can be said for all of their senses. You might say they're stuck perpetually experiencing the exact moment time stopped for them.

The only reason you can perceive and interact with things in timeless regions is because the time bubble created by the suit allows your brain to process the world around you. Due to quantum something-or-other, any matter within your perception necessarily becomes part of that time bubble, or else everything would be pitch dark and stuck fast. As Monty Wild put it, every hydrogen atom would be like a needle piercing your suit. So you can perceive the world, but it will never advance forward in time; That is, things won’t move unless you move them, and they'll return to where they were only as soon as no one is observing them.

Ok, so you open a door and walk into a dark room. The door won't necessarily snap back the second you cross the threshold because light is still streaming in through the door behind you, bouncing off of things in the room, and reaching your eyes. As long as you don't turn around, those photons will eventually run out. The room will gradually darken, and there will come a point where you turn around and the door is closed.

If, however, your suit loses power halfway through the doorway, then your mind, body, and perception freeze in place. You've created your own timeless frame of reference, technically distinct from but fully integrated into the larger region of frozen time around you. From your perspective there is no reason for the door to go back to being closed because you opened it, then time froze, and your perception of the universe is perpetually in a state where the door must be open.

Eventually someone might come along to power your suit, and if you both walk away from that place, the door will shut again. Until that happens, you and the door will remain inanimate.

As a complete alternative to my first answer, the suits that allow people to move through time-stopped areas do so by creating a bubble of self-contained space-time. Effectively, it works by pushing aside time-stopped space-time, not just matter. It doesn't matter what is in the way, the suit will just push it aside, like a ship moving through the sea, and whatever it is will just move back once the suit has gone, like the water behind a boat... only because time isn't passing, it'll be more like jelly in the wake of a knife.

If the wearer wanted to interact with something, they'd need to expend a little more power to expand their suit's field to cover whatever they wanted to interact with, but usually the suit's field would just affect the suit. The user wouldn't walk around, they'd fly like a space ship, using a thrust effect caused by the field, a little like an alcubierre drive.

If the suit runs out of power, the suit and the person inside it are stuck in time-stopped space as much as any other part of that space-(no)-time, it's no longer a privileged separate space-time. If the suit stops in a solid object, it'll be stuck there in a suit-shaped bubble even if time resumes. If the wearer knew they were running out of power, they'd want to get to an open area where someone could come help them or where they'd be fine when time resumed.

So, the person in the suit wouldn't open the door, they'd just glide through it like a rather substantial ghost, and if they ran out of power in it, they'd just be stuck there, part-way through it, like Wile E. Coyote half-way through running through a solid wall, in the process of leaving a coyote-shaped hole.

• So you are suggesting they also pass through the matter around them?
– user458
Commented Oct 8, 2023 at 16:19
• I feel this answer creates more problems than it answers. If you can phase through objects, why not the floor? How would you be able to push off from anything to do anything? It is the gery definition of ghosts. Things that cannot interact with the world any more. Commented Oct 8, 2023 at 21:42
• @Trioxidane I've edited to show how the suit could interact with things and move around. Commented Oct 9, 2023 at 23:15

Set Theory

This question tickled my 'paradox' buttons.

Let's look at this from a Set Theory perspective. You have the set of all things A that are 'frozen in time', and you have the set of all things B that are in the bubble.

Let us consider that Set A and Set B are mutually exclusive. so that Set B is equivalent to NOT A. If this is not true, then we have Schrödinger's cat which can exist in two places at the same time.

To be in a set, the item must satisfy the conditions for being in the set. It seems from the question that the conditions for being in Set A are that:

1. Time does not exist.
2. Therefore motion does not exist.
3. Therefore everything is in an absolutely static position with respect to everything else.
4. There is an exact 'spot' for everything, and everything is in that 'spot', in perpetuity. That is, something can not both be 'in its spot' and 'not in its spot' because that would of necessity require two instances of time, an inconsistency with the conditions for the set.

The conditions for Set B is that:

1. Time exists.
2. Motion exists.
3. A 'static position' does not exist, as one has to consider the passage of time in order to determine position.
4. There is no 'one spot' that an item must always exist in. The universe of that set is dynamic, and between each instance of time, things change.

A really nice, clean, simple story line. Then you mess it all up. You have introduced the concept of 'things' moving between the two Sets. And herein is the conundrum, the paradox. Things can not be in both sets at the same time. They are mutually exclusive. Unless, of course, you go full-on 'spooky action at a distance', and go all-out quantum mechanics, such that things can exist in two locations at the same moment. Probability theory, where the probability of something being in two places is not zero.

In fact, it seems that the defining rule between being in Set A and being in Set B is that, the universe of Set A is NOT relativistic. There can be no relativistic frames of reference. There is only space, not space/time. The Set B universe is that of our traditional notions of relativity. (Note: Nothing that I can see prevents it being a Quantum Universe, except to the extent that 'quantum probability' somehow implies the existence of the variable 'time'.)

How does a Relativistic Universe interact with a non-Relativistic Universe? Everything in Universe A has to be completely independent of everything in Universe B. It is no longer the same object when it moves from Set A (Universe A) to Set B (Universe B), and in point of fact an item CAN be (of necessity) in both Universes. The sets are mutually exclusive, in every aspect. There is absolutely no connection between something in Set A and something in Set B. Especially a temporal/spatial connection, because spatial/temporal connections are meaningless between relativistic and non-relativistic worlds.

Take that coffee cup transitioning between inside and outside the bubble. The coffee cup transitions into the bubble, the person takes it in hand and keeps it stationary relative to the person's hand and the bubble moves on. As the bubble passes the 'location' (what does 'location' mean in a non-temporal Universe A?) that the coffee cup occupies in the non-relativistic Universe A, the coffee cup ends up being in both Universes at the same ... instant? It will be both inside the bubble, as the bubble moves, and it will be in its non-relativistic 'spot' when the bubble passes that spot. By the conditions of Set A, an item can not both 'be' and 'not be' in its 'spot' in the non-relativistic Universe A. How can that be? Because there is no temporal connection between the coffee cup in the person's hand in Universe B and the coffee cup in the non-temporal non-relativistic Universe A. The two Universes do not exist at the same instant of time.

So what happens when the 'bubble' disintegrates? All elements of the Set B, that is, Universe B, disappear, along with the conditions for inclusion in Set B. All of the elements of Set A (Universe A) 'reassert' themselves in the proper 'spot' as they have always been, and always will be, because there is no time in Universe A. All of the elements that transitioned from Set A to Set B, which may or may not have been in the two Universes coincidentally, simply revert to being in Universe A exclusively.

Or not. Maybe the Universe B does, indeed, continue on, as it seems to me what you are really describing is 'parallel Universes', one relativistic, one non-relativistic, that are overlapping.

Of course, the person in the bubble would be completely unable to see anything outside the bubble. The boundary of the bubble would be completely dark, in every sense of physics. Only when the bubble 'moved' would there be a new wave of photons and radiation 'activated' at the boundary, and only in the direction of travel, but they would only last for a very, very short instant as they traveled through the bubble.

And in true 'Groundhog Day' fashion, if the bubble went through the same area twice, the same things would appear as on the first trip through. Deja Vu over and over and over.

However, continuously expanding the bubble is a different story.

• While I like the set theory, you seem to have the idea that the time bubble extents beyond the suit, which isn’t the case. If I understand correctly you have two outcomes, one where the person running out of time dies (which narratively isn’t supposed to happen), and one where universe B carries on after running out of time? Could you explain that one further? Commented Oct 12, 2023 at 4:54
• My assumption is that there are large stable areas where they have a 'time bubble' and a large community, and the people in suits are venturing out from these areas. The large stable areas do not move, but only expand. Objects that change from one Set to the other remain permanently in their new set. The person who's bubble collapses does not 'die', they just stop being in either set. The only way to accommodate this is for there to be a third set whose elements are not in Set A or Set B. Really, when it comes down to it, you are talking 'multiple universes'. Commented Oct 15, 2023 at 14:29

## Everything Takes Time

Timesuits run on septatimohydrofluoride* (SHTF) and consume it to generate gram-seconds of time. The baseline cost of Delving the Deep is the amount of time you want to have out there -- and making it back to Today -- multiplied by the mass of both you and your suit.

But it doesn't stop there. Moving things in the Deep takes SHTF too. Every time your timesuit hits even one molecule of (time-frozen) air, it has to expend SHTF just to give it time to move out of your way. (That's why the Delvers stick to the Lanes, long corridors of hard vacuum laboriously carved out for years by vacuuming up the air into canisters and bringing it back to Today.)

The timesuit's AI takes care of microscopic things automatically. But when a Delver runs across anything that's too big (its mass is larger than some quantum gravity timey wimey limit), they have a choice to make. They can charge up their suit's time capacitors with some SHTF and decide how much they want to juice the object. Juicing a half-kilo water bottle with three kilogram-minutes of time will let you move it for six minutes, and at the end of those six minutes, the water bottle will stop and spend the next six minutes rewinding back to where it was, retracing its path exactly.

Hopefully you planned far enough to get out of the way. Getting your guts smashed through by a rewinding rock in the Deep is ... not pretty.

And that's why your timesuit's AI also has a brutal failsafe. It's always scanning the surroundings and updating its estimate of how much mass things have and how much SHTF you'd have left after juicing them. (Light somehow still works normally in the Deep, because it's massless something something.) And if it detects that you're about to spend more SHTF than you can afford (that is, you're going to juice something large enough for long enough that you won't have the reserves to move out of the way), it will spend all its remaining SHTF juicing itself and you. Since you are (presumably) safe at the moment the failsafe triggers, when your extra time runs out, you can be assured of being rewound into safety, albeit frozen in time yourself until someone can come out and rescue you.

*At least, mine do, even if yours don't. It helps so much to be concrete about these things, and it gives a chance to work in both a homage to Asimov and a nod to real world superacid chemistry.

From your description, it sounds like the "stopped time" universe is a static thing that cannot be altered since change is a fundamental property of time, and without time no change can occur. Only by asserting some sort of temporality can you affect anything, and only within the temporal locus of the time field.

So far, so good. Impossible, but still understandable.

They can move objects, damage them, throw them etc but anything not inside the timeflow of the suit will reset itself after a few moments.

And this is where it all break down. This breaks everything, even more-so than the idea of stopping time itself.

What you have here is a static state that cannot be altered outside of the imposed temporal mechanics. and reverts all changes. Not by reversing things - that would require time - but by simply erasing any change. The universe returns to the prior state as soon as your time field dissipates.

Unfortunately your batteries are about to run out and you’ll be frozen in time until someone can power up your suit again.

No. No you won't.

The question:

How do I resolve the consistency problem of objects returning to their position if time runs out, without instantly killing the person by clipping matter through their bodies?

Well, I have some good news and some bad news.

The good news is that there is no consistency problem. You don't have to worry at all about the door materializing in the middle of your body, turning you into some bizarre door-human melange. Because that would be horrific.

The bad news is the reason for that good news: you don't exist anymore. That doorway has a door in it, and there's air and things around it. There is no human body in a time suit with dead batteries. You just got reverted out of existence.

Which sounds like a really good reason to not go out without at least a triply-redundant power supply.

Now that we've seen the worst, let's add some upsides here.

First, you can source an unlimited number of people and resources to help you rebuild, because every time you wrap a time field around something in the outside world and bring it back, reality reverts to how it was before you removed the item... or person. And now you have two of them.

Look out there (with this magic device that lets you see things without any particle interactions at all, because time isn't a thing anymore) on the edge of our time field. That's Sue and Tim, a lovely couple who didn't quite make it into the shelter. Tim is a big strong guy who also happens to have two degree in science. He'll be hella useful for all sorts of things. And his wife Sue, apart from being a genuinely lovely person, is also an engineer and fitness instructor. We might not need much in the way of fitness instruction, but engineers are damned handy right now.

Let's throw a little more power into the field so that it expands to cover them and they can finish running into the shelter. They're going to massively improve our chances of survival. Right, now they're here we need to conserve power, so cut back to minimum again.

Oh.

So... see out there? Where Sue and Tim were standing? Well, when we collapsed our field back down, reality reverted and... did you want another Sue and Tim? More to the point... how useful would it be to have 50 more engineers and scientists around? Oh, and while we're at it, send a few Tims out to the nearby store to grab all the food and batteries they can find. We can always send a Tim for the same goods whenever we run low.

Not only do you have infinite Tims and Sues, you have infinite resources. I mean, sure, it might get a little weird at times with all those copies of people running around. I hope Sue doesn't get jealous of how much attention all those Tims are getting from the other Sues.

Also hope that the old "the same particles touching themselves in a time loop go boom" isn't a thing, otherwise we're going to have to be really careful who drinks from each copy of a bottle of water. At least we don't have to worry about the rubbish piling up.

• Comments have been moved to chat; please do not continue the discussion here. Before posting a comment below this one, please review the purposes of comments. Comments that do not request clarification or suggest improvements usually belong as an answer, on Worldbuilding Meta, or in Worldbuilding Chat. Comments continuing discussion may be removed. Commented Oct 25, 2023 at 20:13

Why would the suit run out of energy? When (as in your example) the suit-wearer displaces the door and stands in the frame, there is tension between the door's new position and the place it wants to be - back where it has to be because timeless objects really shouldn't move (like raising a rock in a gravitational well, it really wants to go back where it was). This tension creates potential energy between the door's new position (the source) and its previous "correct" position (the destination). The suit's capacitors absorb the energy and top themselves up; when they are fully charged and can't absorb any more of the potential energy, that energy exerts itself as a force on the blockage (i.e. the suit and its occupant).

This leads to some interesting side effects such as: while the wearer of the suit is moving, the energy created by displacement of matter (or even vacuum/quantum [yes, another problem you can "solve" by saying "quantum"] states in "empty" space) just causes the matter etc. to return to its "correct" position, no harm done; but when the suit is stationary (and fully-charged), the energy builds up until the suit (with its wearer) is flung into motion along the axis of last movement. The longer you manage to hold position against the force, the more it builds up and the bigger the shove when you can't resist it any more. This can be handy if you need to get somewhere in a hurry but less handy if you are, for example, facing a brick wall.

Expand this to the energy build-up round "stationary" habitats/bubbles and you have to find a way to deal with it - such as keeping the bubbles in constant motion and/or having somewhere they can dump any excess energy they just can't use (into the black hole they're orbiting, maybe).

I don't know if this is a viable idea or not - it's your universe - but it's full of (drum roll) potential.

## Apply a new law of thermodynamics

The problem you're facing is that you aren't applying energy consistently, nor are you applying your time-tech consistently. This means your mathematics is broken. If you want it to be consistent, you need to fix the math. Maybe you need to retcon your story afterwards.

Anything for which time is stopped would, for that moment, no longer have momentum. It would only have position. You are claiming that, when you change something's position, that change in position isn't persistent.

Let's start by defining the interface. If you move a coffee cup, what happens to the coffee inside it? Gravity isn't acting on it, so there's nothing preventing the coffee from resisting the movement by flowing out the top and immediately snapping back.

Maybe your interface is "those parts you are currently applying force to."

Consider the case of opening a door. You grab the handle and twist, driving the mechanism to open the latch. You have to let go of the knob if you're going to pass through the door. Maybe you hold the door open with your other hand to keep it from snapping back, but the mechanism inside the door would snap back immediately. Some parts of the knob mechanism would never move in the first place.

In Terry Pratchett's Diskworld novels, when time was stopped, only those who could generate their own time could move about. This brings up a couple of possibilities. Your timesuit/bubble might need to expend energy to get something to change position, equivalent to the change in relative potential within the object. It might need to apply a 'holding force' to keep things in place.

The snapping back mechanism is more problematic. It implies teleportation. More to the point, it implies that the object was never actually out of that location in the first place. That means that your time bubble is creating an alternative causality line, outside of the normal causality line. That suggests that the time bubble collapsing results in a recombination of quantum states between the two causality lines.

I would expect, at minimum, a nuclear explosion as a whole bunch of subatomic particles try to sort out which atom they belong to. That, however, would take time, so maybe someone outside of time could pull the person or door out of the other.

But THAT brings us back to defining your interface, doesn't it?