artificial gravity in the near future without rotation...

[Mr Orange]

hi all

so i've written a story set in the near future (30-50 years) and with the story as its currently written, i need gravity on my spaceship!

i don't want a big rotating wheel so was wondering if there are any other possible source of artificial gravity that could concievably be used that near in the future...

is it possible that gravitomagnetism is going to be viable by then?? i was thinking i could make a cursory mention of the "gravmag drive".

the other option is to ignore it completely. it's not really hard scifi but i've tried to make everything else justifiable (although i do also have cryostasis cells...)

cheers

Mr O

 

[Bowler1]

Gravity, such a minor detail. Ignored by Captain Kirk and any Trekie worth their salt. But if it makes you feel any better writers like I Banks put gravity into their spaceships and it never harmed any of his sales. Me, I'm putting gravity into my advanced alien ships, but only spin and rotation into my human spaceships. I like to mix it up and be different.

 

[Mr Orange]

i was going to ignore it bowler but it's niggling me...

thinking about it, i definitely need gravity otherwise (amongst other things) there's going to be an unfortunate mashed potato incident...

my main concern is how close it is to now... there's not going to be a lot of time to invent something fantastical..

 

[Overread]

Well go back 50 years and the idea of having, say 1000 books on something the side of your finger was impossible. Heck there are a load of old fantasy and scifi stories about the years we are just moving into and all the amazing technology we should have. Space 1999 suggests we'd have an Earth gravity moonbase (it also suggests that we'd lose the moon to huge nuclear explosion).

So long as you write it well people will accept it - most likely treating it as an alternate reality type affair. It's also important to realise that whilst you generally have to get the basics right most people are not going to know or even understand the hard science and in a story its not really "needed".

 

[Alexander Lesnoy]

Don't forget linear acceleration. Oh, and a high density mass core. But that would require far more fuel to accelerate.

 

[nubins]

You could.. i suppose layer their suits with magnetic material and have a magnetic field powerful enough to draw people down towards it with the force of 1g. Im not sure what health effect that might have though.

It isnt inconceivable that we will understand gravity to an extent of having a workable system. Anti gravity propulsion has been a theory for ages and im sure ive read lots of mutterings about advances in this field.. theoretical i suspect. You coul dmake it brand new, testing it on the journey.. prone to failure maybe.

 

[Ursa major]

thinking about it, i definitely need gravity otherwise (amongst other things) there's going to be an unfortunate mashed potato incident....

They're not eating Smash...?



I don't have an answer to your problem - not that I recall a novel where the artificial gravity is explained (unless it's simulated by rotation, or on ships accelerating close to 1g) - so perhaps you should just have it without explanation. If your PoV character knows how it works, s/he'd only bother explaining it if someone asks about it; they wouldn't spend much time thinking about it unless they were responsible for its operation. If your PoV character doesn't know how it works, you would only need an explanation if s/he asked someone about it who did know.

 

[chrispenycate]

Well, apart from an experiment a few years back involving rotating superconductors, I can't think of anything that will be ready in time to modify/generate gravity. Don't forget either that anything that generates or in any way modulates gravity will be adopted as a space drive; my asteroid miners are stripping old fashioned reaction drives (largely ion) out of their vessels (or leaving them in place for emergency use) and installing gravionic drives everywhere, it's just so much more payload efficient.

It is possible that the supposed Higgs boson will give some clues into gravity manipulation, but I see that rather further into the future (at least practical engineering solutions. Equations could pop up quite rapidly).

So, with nothing that doesn't exist theoretically now, what can I offer you? Null gee cooking (as in my critique http://www.sffchronicles.co.uk/forum/540907-orbital-cuisine.html), where the ingredients are restrained by Newton's laws of motion rather than his falling apple, continuous acceleration, (if your drive is continuously giving a tenth of a gravity thrust the mashed potatoes will show some discipline, even if whipping cream demands caution) or using some other force to do the job of attracting things.

If you plated your decks with magnetised ferroceramics, and everybody ingested microparticles of ferroceramic, the magnetic field would hold them in place. Tools, souvenirs, clothes would all have to be carefully chosen so their magnetic permeability was about equivalent to their mass, liquids would be a problem, as ferroceramic is biologically neutral it would be excreted continuously, meaning no flying faeces (unless deliberately) and, if you had closed system life support, you'd have to reclaim the stuff with an electromagnet and reinject into foodstuffs; potatoes aren't going to incorporate it while growing.

OK, not a perfect solution, but it beats plating panels with neutronium (especially for acceleration rates).

 

[nightdreamer]

Podkletnov effect. I saw it work in Yellow Springs, Ohio. http://arxiv.org/pdf/1108.3488v1.pdf

 

[chrispenycate]

Podkletnov effect. I saw it work in Yellow Springs, Ohio. http://arxiv.org/pdf/1108.3488v1.pdf

That's it, thank you. Half a percent of gravity doesn't seem much, but it's a foot in the door. Still, having gravity that goes away when you get a power cut doesn't seem too good an idea.

 

[Parson]

Some years ago I remember reading a SF novel where gravity was generated because of a new theory of gravity (The author made it up, but at least one scientist said that it was consistent with the observable data. (Of the time, I'd imagine.)) Anyway the theory was that every piece of matter gave off a gravity wave? particle? (my memory could be going here) and that the more massive the object the more of this wave was being cast off and the greater gravitic attraction there was. They were able to manipulate gravity by generating these waves/particles.

The point is that you could write something like that. If there were a sudden breakthrough in the understanding of how gravity works, that might also allow for some manipulation as well.

[I don't remember the story well enough to go for a search of it. But perhaps someone reading this post will. One feature that was somewhat unusual beside the gravity bit, was that it was a time manipulation story. A machine that could receive messages from the future was developed and almost immediately they start receiving messages. The result in the story is that you have two abortive endings, because the time mechanics have received a note from the future and have enacted changes that change the future into a better one. A side light was a romance which was ignited in the original trek, never happened in the second, but when time was manipulated a third time, it blooms again. ]

 

[Laeraneth]

If it's a very very large ship, it could conceivably generate a small amount of gravity just by it's own mass. It would have to get VERY big to be useful though.

If the purpose is for long distance travel, the steady acceleration of approx 1G is a viable method for sure and has the advantage of being comparatively simple. Just have a 'tower' type construction, engines at the 'bottom', floors parallel above, steady acceleration 'upwards', et voila! Fake gravity. (Turn it around and decelerate the same way on the second half of the journey to maintain the same effect)

Assuming it has to be some sort of remotely manoeuvrable ship or actively flown... then you'll need to get creative.
I suppose it might be conceivable to have some sort of containment system that could compress a vast mass in a small space, effectively making the ship it's own little fake planetary 'core' for it's gravity source and presumably doubling as it's power source. That gravity should work in exactly the same way as any planet would work.
Of course, you then need to maintain the power to keep everything contained. Speaking as someone who's not Stephen Hawking, I would imagine the power needed to contain such a force would have to be equal to the power it would generate, but... ignoring/working around that is what the fiction part of science is for

A power cut however would be deadly to say the least!

Though... if you work on the assumption that (somehow) it generates more power than it takes to keep contained, it might be impossible TO cut the power to it, assuming the generators of whatever contains it are powered by what they contain, it could be made independent from the rest of the ship. Thus the only way to 'cut' it's power would be to damage it directly.

 

[Ursa major]

Having a huge mass - enough to produced usable gravity - would also produce an enormous requirement for power to move the ship. (Just imagine the power required to move something with the gravitational pull of the Earth about.)

 

[chrispenycate]

Having a huge mass - enough to produced usable gravity - would also produce an enormous requirement for power to move the ship. (Just imagine the power required to move something with the gravitational pull of the Earth about.)

But gravitational attraction is kMm over d squared If we can reduce d, the distance between the attracting bodies by a significant amount, we can reduce the mass required. If, instead of the force coming from the distance of the centre of the Earth it was at a few centimetres, we would require several orders of magnitude less mass. So, a few megatons of neutronium plated onto the living space floor could easily generate one gee for the soles of the feet, although you might be noticeably light headed. And, while that doesn't help your acceleration rates much (nought to sixty in two days, fourteen hours, seven minutes and six seconds is so disappointing for a spacecraft; Jeremy Clarkeson would be so disappointed. Still, that's the sort of rates ion drives are offering).

 

[Ursa major]

That's why I didn't say, "Just imagine the power required to move something with the mass of the Earth about", but instead said, "(Just imagine the power required to move something with the gravitational pull of the Earth about.)"

And yes, that's what ion drives are offering, for moving a few tonnes of spacecraft. But that isn't for manned flights, as far as I can tell. I would expect, in the absence of something akin to suspended animation (where gravity may not be an issue, as it might not be for short trips), far higher rates of acceleration (and deceleration) would be required for manned missions.

 

[Mr Orange]

cheers for all the responses guys it certainly has made for interesting reading... the superconductor/gravitomagnetism thing could work, as could, thinking about, linear acceleration.

 

[tinkerdan]

It would seem that the best way would be to leave it unexplained as though everyone knows it works and doesn't try to dwell on how. Then the focus could be on how and if it is like the gravity everyone is familiar with or if it has properties that leave people light-head as mentioned.

It could be somehow related to an accelerator and superconductor but the properties might differ a lot from real gravity and unless better means of accelerating things are achieved it could be costly in creating that extra mass just to drive the pseudo-gravitation.

Perhaps down the road-that would be the starry road-we will understand black holes and singularities. Most specifically single singularity or maybe point singularities. There might be an answer in there that will allow us to mask the mass when the ship needs to move.

Then we could turn the gravity on and off or put it on a rheostat that varies the strength. Just stay away from ring singularities,which might generate wormholes. And Conical ones might not be quite as stable to work with.

 

[jastius]

what if there was a liquid core? then a vortex of magnetized nano particles could be cycloned and the resultant forces would act as a gravitational field. they could use the water as a power generator /oxygenator/ power storage and computer memory. the ships brain. and lungs and heart. all in one.

 

[Mr Orange]

right so here's what i've done...

i've tweaked the story so there's casual mention to the ship "still being in acceleration phase" at the time the events take place, and i have changed it so they travel throught the ship on vertical infrastructure rather than horizontal (i.e. lifts and ladders instead of walkways), as you go from back to front. i think this covers me for gravity from linear acceleration.

cheers everyone

 

[Parson]

Sounds perfect to me.