Recently, I have been pondering the implications of a civilization being able to control gravity in shape they see fit. One of the more amusing uses of such a technology I've heard was that they would be able to dilate time to store food by slowing down, or even 'freezing' time in a 'fridge' to our perspective. I then began thinking of potential uses of such a technology for other application's (first was aging wine for hundreds of years in just a second by reversing the dilation effect, the next was sped up military training as one second in real time could be a few months or more in dilated time which would be excellent for training a large army quickly etc.).

I then came to the question of if the such a civilization could externalize such a field, how would it affect infantry combat? Well, if this technology was applied to the infantry, the first major thing that would happen would that each side try to have time dilation that affected there soldiers more than the enemy's. This would lead both sides to stretching the dilation to such an extent, that the world for both combatants would, for all intents and purposes, be still, even if in reality it's just that time is so dilated that is appears that way.

This leaves an interesting conundrum for any solider wanting to engage the enemy with projectile/energy weapons as when the bullet/laser/plasma/whatever leaves the dilation field, then it returns to the universes time reference and 'freezes' in place. Now, you wouldn't want to make contact with it, but it is kind of hard to shoot anything if your shot stops midair a few meters ahead of you.

So what does this mean? It means that in order for a solider to engage the enemy, he/she would need to get in close quarters. Now, one could use a gun at such ranges, but perhaps due to armor or surprise, they are unable to use a gun effectively, thus melee weapons of all kinds would be preferred, depending on the specifics of melee combat. Perhaps guns would be still desired, with gun blades, axes and spears being developed. This could be taken any direction a worldbuilder would desire.

However, does this make any sense? Does the base concept of "freezing" time to such an extent that melee weapons would be used actually hold up under scrutiny? If not, then why?

EDIT: Looking at the questions so far, I realized that I should have clarified that the earlier mention's of gravity manipulation was simply the explanation of how I thought of the concept, not how it works.

In short, the time dilation is not achieved through artificial gravity, but some sci fi technology that we do not know of.

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    $\begingroup$ If time dilation is a side effect of increased gravity, what happens to the gravity itself? Gravity manipulation is among well-respected superpowers, and such superhero would have reduced his/her enemies into degenerate matter before time dilation effects become significant. $\endgroup$
    – Alexander
    Jan 4 at 0:02
  • $\begingroup$ when superman throws a punch at you so fast you can see his fist blue shifted for a fraction of a second before the "double flash" vaporize all evident and alibi ;D $\endgroup$
    – user6760
    Jan 4 at 2:58
  • $\begingroup$ If the soldier has such weapons it's reasonable to assume the enemy has them also. They can counter what you do. $\endgroup$ Jan 4 at 3:18
  • $\begingroup$ Still, I'm wondering : Can the soldiers of opposing sides perceive each other, or in general things outside their time field? That can shape a lot the way you take on a battle, ranged and/or melee, as much as that graviton thing you told us to not care ^^. $\endgroup$
    – Tortliena
    Jan 4 at 16:14
  • $\begingroup$ Does the dilation of time affect the physical environment? Like if time stands still and I try to pick up a ROADROLLER, could I still pick it up? How heavy would that ROADROLLER be, since if time stand still, there is no gravitational pull to the ROADROLLER and it should weight 0 kg. If that is the case, then you can just be like Dio and Jotaro in Jojo's Bizzare Advanture and use The World and Star Platinum to do fist-to-fist punch: ORAORAORARORA.... $\endgroup$
    – Faito Dayo
    Jan 5 at 7:24

4 Answers 4


It doesn't because if you use the formulas for gravitational time dilation to compute what it would take to slow time down by merely 90%, it would require a gravity field whose escape velocity (β_e) is 99.5% of lightspeed. Even the ferocious gravity of common neutron stars is estimated to result in an escape velocity of around 1/3 to 1/2 lightspeed. Nothing made of matter will withstand that level of gravity.

Aside from that, some of the descriptions in the question have the effect backwards. Applying the intense gravity field does not result in "sped up military training" since it can only slow things down relative to a zero-g environment. One would have to apply the gravity field to the entire universe, excluding only the target, to get an effect like a speed up of an activity by the target. Similarly, an army would not want "time dilation that affected there soldiers more than the enemy's", they want to have the gravity on the enemy soldiers to slow them down and make it easy for their fellow soldiers to kill the enemy before they can react.

  • $\begingroup$ Agree, the ability to create massive gravitational gradients would be a very potent weapon on its own, the time dilation is irrelevant. (Not original, unfortunately, various SF works have included gravity-based weapons.) If the OP wants to have time dilation effects used by infantry, the pseudo-science explanation should not be gravity control. $\endgroup$ Jan 4 at 1:04

For there to be two opposing sides with the tech someone would need to steal it from whatever side invented it, and then have a battle sort of like you describe.

There's no tactical reason to slow down time unless you're setting "sleeper" traps, have the last survivors of a war trying to outlast their enemies, or something like that. For battle you'd only want to speed up so you can outperform your enemy.

Speeding up like that has its own set of problems.

For a short battle where one side wanted to destroy or capture the other, it works. The time wielders would speed themselves up so that their opponents couldn't see them, probably go set off explosives to kill everyone or put everyone in restraints or something, and then restore themselves to "regular" time.

The amount of time they age while sped up would be maybe a few hours or if it's a giant army maybe a few days. They've essentially shortened their life in "real" time by however long that interval was.

If BOTH sides are trying to out-speed each other it gets dicey. Now instead of a short amount of time spent at hyperspeed you have a protracted battle with no way to predict an end-date. Trench warfare like WW1 or something like the invasion of Germany in WW2 that took years in real life might take very little "real" time but when it's over everyone who survived went in at age 18 but came out decades later.

There's also the issue of how one supplies an army at hyperspeed. They'll still need to eat and drink, but they'll deplete the local food, water, and vegetation and they'd still be subject to real world time, unless you also speed that up. Something like food could maybe be grown at hyperspeed, but water is a finite resource that could get consumed very quickly.

Then you have to consider that if both sides have the same level of tech and/or there is a cap on how fast the tech can speed you up, there's no point in using it at all. You're just aging yourself faster than your universe for no gain.

If one side can go faster than the other, the battle takes no "real" time but from a practical standpoint the defenders could force the attackers to allow a lot of "real" time to pass as described above by forcing the use of this tool. It would probably be a pretty effective albeit costly deterrent.

Armies could also use the tech to construct rapid fortifications, train, make vehicles, etc. Again... an arms race here would be difficult to maintain unless you literally had parallel societies running at different speeds. Again though, they'd need to share the same natural resources and the same water table.

There's an original Star Trek episode (Wink of an Eye) that deals with this. The Enterprise encounters a race of people who are accelerated and are effectively powerless to stop them until Kirk and Spock accelerate themselves.

Once the crisis has been resolves, Spock stays accelerated so he can repair the ship at hyperspeed.


This leaves an interesting conundrum for any solider wanting to engage the enemy with projectile/energy weapons as when the bullet/laser/plasma/whatever leaves the dilation field, then it returns to the universes time reference and 'freezes' in place. Now, you wouldn't want to make contact with it, but it is kind of hard to shoot anything if your shot stops midair a few meters ahead of you.

Have a think about this for the moment. If I shoot a laser at the enemy, and it "freezes" into normal time somewhere between me and them, they can't possibly see it, because the photons won't have reached them yet.

This means that as they advance forwards, they'll eventually have their timey-wimey bubbles intersect my laser beam, which will promptly frazzle them.

All sorts of problems apply to various other kinds of weapon, too, but this seems like a good starting point of how you've introduced a vast amount of complexity into your setting but haven't noticed it yet. Can you even see out of a timey-wimey bubble? Would a super-slow time bubble work like an energy shield? If I walk up a slow-to-fast time gradient, would the temporally-faster bits of me at the front tear away from the slower bits at the back? Can I use this approach to render weapons harmless by controlling the rate at which energy is expended in my local time bubble? What just happened to conservation of energy? The more I think about it, the weirder the whole thing gets.

It means that in order for a solider to engage the enemy, he/she would need to get in close quarters

Why not just attach one of your time-wranglers to an explosive warhead, slap a rocket on the back and shoot it at the idiots who've bought knives to a godtech fight?

More generally, taking some phenomenally powerful technology and trying to work out how it would benefit stoneage methods of combat is probably a silly thing to do, especially as it isn't even clear that you could walk up to someone and hit them. Combat with time-wranglers would likely be radically different from anything we've seen in the past. The sort of society that could wield these things seems likely to be vastly more sophisticated than our own, and you have to wonder why they'd be hitting each other with sticks instead of either spreading out across space without the hassle of generation ships, or inducing stars to nova to smite their enemies, or maybe both...

  • $\begingroup$ These are some very good points that were pointed out. Thanks. $\endgroup$
    – Seraphim
    Jan 5 at 2:51

I'll assume a few things :

  • That shots cannot have a time field attached to it, otherwise you probably wouldn't be asking this question.
  • I'll assume that both parties can see their environment outside the time field normally and without offsets, movie-style. You don't seem to care that much about this, so I took the time rule that is the most seen, and the one that -probably- change the less how battlefields work.
  • I guess both parties have access to about the same field power, and given they are able to stop at least bullets, they're quite powerful, in the order of 10 000x faster at minimum.
  • Most importantly, that somehow, opposing parties manage to be always on the same speed automagically. Indeed, if one party activates the timefield 1s before the other, they have basically won as they can do many hours of work against the enemy.

Now, by speeding up time for both parties...

You have invented easily deployable claymore minefields

You're about to set some sort of campment, or you have a strategic point to protect. Instead of going out, putting those big, heavy mines around here, take your machine gun and a few ammo clips. Shoot everywhere around towards the outside. In less than a minute, you've set up a deadly barrier for anyone who dares come towards you.

Indeed, you cannot approach the defensive line without a time field; You'd be seen by the casually looking guard that moves and see 100 times as fast as yourself. Then, if you activate the time field to get to your target fast enough, you'll just "activate" the bullets which were frozen in time, shredding you to death.

The two possible cases of an enemy approaching a defensive line

The two possible cases of an enemy approaching a defensive line on the right, left without timefield and right with it. All the tiny lines are ammo which have been fired.

The only way to manage this out is to come from the side and the back, which will "detonate" the trap without being hit by it. That's also the way you can disarm your minefields safely and without effort (just be cautious no ally's on the wrong side :) ).

You are converting ranged damage bursts into timed ones

Wait, does this count as a sticky trap? Is every stickies its own trap? [...] I get it now! The very idea of a trap is subjective! That's the beauty of manual detonation! It doesn't matter if that these stickies weren't meant for this spy, they're the perfect trap for the flying soldier I was "totally" expecting! Stickies haven't missed until you detonate them.

How it feels to play Demoman in TF2, Lazy Purple

Shooting bullets at no apparent enemies is not only a minefield, it's an actual weapon! That's your enlightment (and game design) time!

Range offers what I like to call "ranged burst damage". If your range exceeds the enemy, you get more shots against them, that's the "ranged burst damage". Now, long weapon range is nullified in your concept, or... Is it?

The reality is, ranged burst damage is converted into timed burst damage! Timed burst damage is the trap's ideal, as long as it has not been set off at the wrong place and wrong time, they cannot "miss". And when they hit, they add all the damage you spent time putting them. Time you couldn't spend on attacking the enemy!

Now, look back at what we learned in the first paragraph : You can "set off" traps by coming from behind the bullets. Do you see where it goes? If you have an huge party in front of you, use the time you can to shoot as many ammo as you can. Then send off a time field carrier to push the bullets forward. When said carrier reach the enemy's rank, all flying bullets will tear through the enemy ranks, for all the time you spent shooting them!

An illustration of what could happen on the battlefield

An "epic" illustration of what could happen on the battlefield

If enemies move away, then first you've won the position they held, and then you still control when the bullets are effectively shot : It's just when you reach another time bubble!

Final answer

Yes, you will get in close-range, but with ranged weapons. That seems silly, but look at it, the extent of where you can harm people is up to the field range. Now, with the above, you actually extend that range as long as you are able to predict the other party's moves. It will be like a big game of chess, where you shoot pawns to checkmate the pieces who are creating them.

  • $\begingroup$ That's...something. Never thought of it this way, but what stopping a flanking mauv-more Dakka, right. $\endgroup$
    – Seraphim
    Jan 5 at 2:53
  • $\begingroup$ @Seraphim That's only the tip of the iceberg of possibilities, as Starfish Prime said. There's so much more that I cannot detail in an answer (for text size and because it is blowing my mind, too :p). You should tread each element with care, time dilation breaks more than physics ^^. $\endgroup$
    – Tortliena
    Jan 5 at 8:33

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