# How would artificial gravity be achieved in space?

I am wondering, what mechanism would be needed to generate gravity on a space ship in interstellar space, like we see it on Star Trek or Star Wars? What is the most realistic hypothetical way what would be achieved?

• This seems pretty world building related to me, not sure I understand the close vote... Commented Jun 22, 2015 at 17:24
• @James Agreed. Op didn't use the hard science or even the science based tags, and did ask for theoretical ideas. I vote leave it open. It could have some fun answers Commented Jun 22, 2015 at 17:28
• @James The close vote isn't about this not being worldbuilding-related, but idea generation. (Note: I wasn't the one who placed the vote.) Commented Jun 22, 2015 at 17:28
• I don't think it's idea generation any more than a good 50% of questions in this site. Commented Jun 22, 2015 at 17:31
• @HDE226868 exactly. Figuring out the plausible science behind something, while it technically is asking for ideas is answerable. I think 'bad' idea generation questions are those that ask for plot points. Questions like this one are more I don't know the science what could work with these limitations and should definitely be on topic. Commented Jun 22, 2015 at 17:47

Most realistic way is centripetal force, which is the rotating wheel that you see on space stations and ships in movies.
Linear acceleration also works, but requires you to maintain constant thrust.

Sci-fi ways to do it...

If you had room temperature super conductors, you could use super conducting magnets to produce diamagnetic fields. They have levitated a mouse that way. It would require a very strong magnetic field, and it is unknown what prolonged effects that would have on living organisms. (You can do it without room temperature super conductors, but it would be easier).

Gravitomagnetism might work, but that's kind of out there. Currently they've only generated 100 millionths of a g. With the right breakthroughs that could be improved...

string theory predicts that gravity and electromagnetism unify in hidden dimensions, so artificial is probably possible with the right knowledge.

Really, unless you want to go with the rotating ring or linear acceleration, you're going to have to hand wave a lot of stuff, so it's probably better to just say "It works" and not explain how, unless it's super important. Just like they do in Star Trek and Star Wars.

Silly Edit: One thing that we know works is mass. So if you were to weave fine neutronium filaments into the carpet, then the resulting mass could have enough gravity pull you down toward the floor...

Edit 2: So a less silly edit. I was thinking about it some more, and I remembered another possibility: The Graviton. It's a theoretical particle, but if they discover it, it will unite quantum theory with gravity. So let's say at some point in the near future that the Graviton is discovered*, and then someone figures out how to generate them to create a (directed) gravitational field. This would also work for tractor beams, which could be a focused graviton laser, and repulsor fields to get an "Anti-Gravity" effect. Graviton drives could be used to take off from planets and for in-system propulsion by attracting or repulsing the planet's/sun's gravity.

* Maybe using the first space particle accelerator, which rings Jupiter and uses the planets power to operate. It had to be a space based accelerator because earth's gravity pushes all generated gravitons away before they can be seen.

• @IvayloV Thanks! It's usually a good idea to not pick the first good answer, as it discourages others from contributing other ideas. Someone may come up with something really fun. Commented Jun 22, 2015 at 17:27
• I like the neutronium weave carpet idea. It'd be interesting to explore this some more. For example, if the carpet has such a huge mass, it would tend to collapse in on itself: very quickly bunching up into a ball. So, i guess you'd need some very powerful glue to attach it to the floor. Also, you'd presumably want it only on the very lowest deck, otherwise you'd be getting pulled up by the one(s) on the floor(s) above you too. Commented Jun 23, 2015 at 15:11
• It just occurred to me that neutronium weave carpets would probably really screw your spaceship's fuel efficiency. Commented Jun 23, 2015 at 15:21
• @MaxWilliams Yeah, that's why it's a silly edit. I have absolutely no idea how much neutronium it would take to make up enough mass to pull you down toward the ground, and it would probably be a bit like moving a small asteroid around. Maybe if the threads were fine enough (mono-molecular?) then the gravitational pull could be localized and not mass to much... Commented Jun 23, 2015 at 17:38
• A neutronium carpet that on average gives you 1G would give how much gravity to your feet? Even if you could walk, falling down to the higher gravity would be really dangerous. And quantum theory and relativity are apparently fundamentally incompatible formalisms, finding the graviton would not help, you'd still have to rewrite at least one of the theories. Commented Jun 23, 2015 at 18:31

It sounds a bit mad - but I'm actually sure I got this idea from a film/series that I can't remember - basically you pair the magnetized floor/boots idea with a power harness which actively pulls you towards your boots, kind of like a puppet in reverse.

It lets you everything else gravity-free - like sleeping in a sleeping bag glued to the wall and drinks that float through the air - while keeping everyone firmly on their feet during normal operations.

Now that I think about it, the idea might have been used in the Defying Gravity (2009) series, how's that for irony.

• Why do you have to have your waist/chest pulled towards your boots? Your feet are stuck in your boots, and your feet are attached to your legs & waist/chest pretty well already... And if it did work, then leaning way over would still have you "pulling" towards your feet, so you wouldn't fall over anyway, same as just having the boots with no harness part Commented Aug 20, 2017 at 3:35
• Originally from The Adventures of Tintin: Explorers on the Moon, but you probably know it from Star Trek VI: The Undiscovered Country Commented Sep 21, 2020 at 23:24
• @Xen2050 pulling everything down towards the boots would at least help keep some strain on the bones and muscles, preventing those from going "oh, I'm not needed? bye!". Magnetized boots solve only one problem that the lack of gravity brings - namely, being unable to stand/walk. They do nothing to help with "my bones are getting brittle and my muscles atrophy because I'm not using them as much as under gravity", and "without gravity pulling down, all my organs are moving upwards!" and "when I cry, the tears just stick to my eyes! My snot isn't moving as my body expects it!" and so on ;) Commented Sep 24, 2020 at 12:21
• Organs, snot, and tears are not a serious issue, no matter if you are standing, lying down, upside-down, or in zero-G. Commented Sep 26, 2020 at 3:26

I am not sure about it. It is rather a theoretical idea of mine. Everyone knows, that mass increases when a spaceship gets more near to the speed of light. Thats from Einsteins relativity theory. At leasts this aspect is always used to explain why it is impossible to reach speed of light: Because your spaceship will show more and more inertia because of increased mass.

https://en.wikipedia.org/wiki/Mass_in_special_relativity#The_relativistic_mass_concept

In the linked wikipedia section about relativistic mass they also denote that nowadays the term "relativistic mass" isn't welcome by some physicists. It is stated that people may thend to believe that increased velocity (or charge) causes a change of internal structure. Which is not the case in my model either. I build my idea upon the fact that a body becomes more and more heavy to accelerate as it reaches speed of light.

The idea is:

Place a solid ring below the mentioned carpet. The ring should rotate almost at the speed of light. First this would stabilize your ship and second the mass rotating at that very high speed would be that heavy that it generates enough gravitational force to act as articificial gravity for your travelers.

I am not sure about this use of relativity. Maybe I am getting it wrong. Is it known whether an object having its outside rotating almost at the speed of light seems to increase it's mass (and thus gravity) from a non-moving observer??

Of course you would have to find a materials which can take the high forces being caused by centripedal force on the disc.

I already tought a lot about this and if this maybe is even the reason why any particles are showing mass at all. Think of a proton having some quarks in it which oscillate at such a high frequency (and speed) that they are "relatively" heavy and cause gravity.

Thus mass would be a result of moving materia (particles).

• Welcome on Worldbuilding.SE. You could improve your answer by adding some references and clarifying your point. As it is, it looks like a discussion more than an answer. Commented Jun 23, 2015 at 19:54
• As far as I have seen worldbuilding Beta is not absolutely about physical facts or at least not about "makeables". I guess placing Neutronium in a carpet is also something which would have to get objected :) Commented Jun 24, 2015 at 12:27
• The major problem in my idea is indeed a proper material. As mankind isn't even able to find a proper material for building a space-lift I guess there isn't really something proper for building a disc withstanding the centripedal forces of the above decribed concept. Commented Jun 24, 2015 at 12:28
• Which leeds to a question of mine: Why isn't anyone building a spacelift or some other form of propulsion. Maybe it is even forbidden to ask such question here? If this is the case just delete the comment. Commented Jun 24, 2015 at 12:31
• One cannot really generalise it, as different questions bring different types of anwsers on WB.SE. It does not have to be "makeable", but it should be "realistic" and argumented and better even, backed up. Except for the "hard-science" tag. Now sentences starting with "Everyone knows..." are usually poor demonstration, and certainly not backed-up. I was merely trying to suggest to improve your answer, which you partially did, to convince OP and members that your answer is worth up-voting. Commented Jun 25, 2015 at 8:45

Let's go completely Terry Pratchet / Hitchiker's Guide!

You attach a huge bladder containing some heavy, but fluid liquid to the underside of your ship and fill it with, say one earth mass of liquid to obtain 1 g of gravity.

However, this ship will, of course be impossible to move, so while accelerating or decelerating you suck the liquid into a pocket universe...

And for some, to us yet unknown physical reason, or perhaps quality of the pocket universe, the content of the pocket universe can be accelerated or decelerated along with the ship, however at much less mass... let's say one kilogram.

Then, when you've reached cruising speed, inflate the bladder and have a dance!

:)

Theoretically, if you can manipulate space and create a curved space within a small area below the floor (gravity well), you should be able to generate gravitational pull within that small area.

Not sure if someone else has already said this but here's my idea-

You have your ship, probably one or two levels. Each level has the same floor, so Bob can be walking on level 1, but to someone viewing on level 2 Bob is walking on the ceiling. How? The floor material is dense enough make a strong enough gravity field to hold humans to it. Going between levels is just walking through a big U to the other level so you end up upside down in relation to the other floor you were on. Your ship, or at least the interior where everyone is, will probably be a disk(but it could be any shape) with rounded edges so you can enter/exit other floors basically anywhere on the perimeter. This will definitely require some hand-waving to work, and I'm 99% sure we can't do this with today's technology.