Gravity generators?

[Themohawkninja]

I've been wondering lately. Is there any way (fringe science included), aside from centrifuges and small black holes to make some sort of artificial gravity like we see on Battlestars, Star Wars and Star Trek ships, or any other of the 95% of sci-fi ships out there?

[Ravenchant]

Don't know about fringe science, but even the "black hole" method would be unusable for space travel - you would have to lug its mass around. Centripetal force ftw.

[Nuke]

velcro, lots and lots of velcro.

[Themohawkninja]

Don't know about fringe science, but even the "black hole" method would be unusable for space travel - you would have to lug its mass around. Centripetal force ftw.

Actually, there is a propulsion system based around directing the Hawking radiation emitted by a black hole, so black holes aren't completely a bad idea.

[lajoswinkler]

There isn't such thing as fringe science. There is science (with theories and hypotheses) and there is the stuff that's bollocks, like propulsion by unicorn farts, magnet motors, prayers and other woodoo stuff.

"Fringe science" is the term invented by defenders of bollocks ideas to make it sound as it has some kind of solid basis.

The answer to the question is no. We don't have any method of producing gravity, either practical or "possible, but technologically insanely difficult". We have centrifuges which create an illusion of gravity. I know, I know, I cri evrytim.

[Drunkrobot]

We have a long way to go before we can say we have a complete understanding of gravity fields. Finding the Higgs Boson may turn out to be a red-letter day in the manipulation of gravity one day, you never know. If we manage not to kill everyone everywhere over the next century, the human race is about to get insanely powerful.

Rubbing amber with a feather, generating static electricity.

What understanding it made possible.

[Themohawkninja]

There isn't such thing as fringe science. There is science (with theories and hypotheses) and there is the stuff that's bollocks, like propulsion by unicorn farts, magnet motors, prayers and other woodoo stuff.

"Fringe science" is the term invented by defenders of bollocks ideas to make it sound as it has some kind of solid basis.

Fringe science is a real term to describe things that as far as physics is concerned, CAN exist, but we have no idea how to even begin designing such a thing (think Albecuirre drive).

[K^2]

Alcubierre Drive is prediction of core theory. That's not fringe. Some of the ideas on how to build one in foreseeable future can be qualified as fringe, yes.

But yeah. The term fringe is sometimes used seriously, to mean theories still being developed or tested. Ones that are thought to be more likely to be found false than true, but hopefully, with some benefit to understanding why they don't work. Or they can be used to describe various crack-pottery. It all depends on the context.

On the topic, to the first order approximation, the only way to generate a constant gravity field is by having enough "charge" to maintain it. In case of gravity, the charge is mass, which isn't practical. But there are many different ways of generating time-dependent gravity fields. They are equivalent to using either an accelerated ship, with everyone walking on the floor while ship accelerates, or a centrifuge, or any number of related concepts. So you don't have to think about complicated gravity stuff. Understanding of classical non-inertial frames of reference is sufficient.

Gravity is non-linear, however, so there might be some shortcuts there. We haven't found any yet, but that's not to say that they don't exist.

[lajoswinkler]

Fringe science is a real term to describe things that as far as physics is concerned, CAN exist, but we have no idea how to even begin designing such a thing (think Albecuirre drive).

No, that's part of theoretical physics and hypothetical technology.

"Fringe science" is an umbrella term for bollocks ideas where people pick something obviously fake or not scientific and then by cherrypicking they try to make it seem serious. The fact the term has become so annoyingly common that some people take it seriously and then others think there's something valuable in it, oh well. One of the sad things with humanity.

Science is the way of dealing with natural world problems. You either deal with them properly (rational method), or you don't (bollocks, whishful thinking).

[ZetaX]

http://en.wikipedia.org/wiki/Fringe_science versus http://en.wikipedia.org/wiki/Pseudoscience .

[Themohawkninja]

Fringe science is scientific inquiry in an established field of study that departs significantly from mainstream or orthodox theories, and is classified in the "fringes" of a credible mainstream academic discipline.

It is science guys. No point in questioning it.

[Themohawkninja]

with everyone walking on the floor while ship accelerates

I have thought of this before, but you do run into the issues of (A) not being allowed to accelerate much past one g, and ( spacecraft aren't constantly accelerating by their own engines, so the "gravity" would only exist during periods of acceleration.

or a centrifuge

True, but you have to take into account that in space, a spinning motion will spin both the "axis" and the "wheel", so either the whole spacecraft becomes a circle (which may or may not present it's own problems, at least with regards to construction), or you have to counter the torque on the part of the spacecraft that isn't intended to spin.

[bonyetty]

What is gravity (and no not the movie) and does anyone have a picture of some? My understanding is that we have a good understanding of is effects but I don't think we will be able to make or harvest it till we at least know what it is.

[3_bit]

Drunkrobot provides a very good point: Static electrically-induced attraction could allow artificial gravity to an extent. This does sound highly impractical, as you'd need to insulate all devices to ensure that when you touch the main computer console you don't destroy everything. I think that if we could generate massive amounts of static electricity, and some clothing that is attracted to it (It's not so bad, we can all wear jumpsuits similar to those worn by modern-day astronauts). I think the lack of gravity acting on cargo would be a nice thing, making it easy to move, among other things. But I am still in favor of centrifugal force.

Most "aliens" fly rapidly-rotating saucers, so I guess we can actually take a hint from fictional science (something that's happened a lot, actually) and make ships with artificial gravity in mind, and thus saucer-shaped. Launching them, though, would be an issue.

[ANWRocketMan]

Before I start please note that I have a VERY limited understanding of physics, chemistry etc. and I don't know where to go to get accurate information(I don't trust all those documentaries etc. on youtube and TV channels, not to mention they aren't very informative).

So, consider the discovery of the Higgs Boson. Would there not be some conceivable way of either a. creating Higgs particles or b. concentrating them by some other means that actual matter to in effect create a gravitational field?

And considering that the gravitaional acceleration increases the close you get to it, it could(?) be possible to create a small-ish gravitational field with close to 1G of acceleration without the mass as say the entire Earth.

[CalculusWarrior]

Before I start please note that I have a VERY limited understanding of physics, chemistry etc. and I don't know where to go to get accurate information(I don't trust all those documentaries etc. on youtube and TV channels, not to mention they aren't very informative).

So, consider the discovery of the Higgs Boson. Would there not be some conceivable way of either a. creating Higgs particles or b. concentrating them by some other means that actual matter to in effect create a gravitational field?

And considering that the gravitaional acceleration increases the close you get to it, it could(?) be possible to create a small-ish gravitational field with close to 1G of acceleration without the mass as say the entire Earth.

The Higgs field (consisting of Higgs bosons) is theorized to be the mechanism which allows objects to have mass (think of it as a pool full of syrup which us beings made of matter wade through, being weighed down by the mass it gives us); I suppose one could 'create a large Higgs field' in one location, providing an Earth-type gravitational pull concentrated into a small area.

This method does have several problems though, the first being that it might not be even possible to concentrate a Higgs field (or it might not even exist!) and doing so would take a great deal of energy. Secondly, you run into the same problem of the black hole suggestion a few posts ago, now instead of your starship which weighs a few hundred tonnes (or whatever mass you want to make it really) you now have a starship which weighs roughly 6*(10^21) tonnes. Unlike the black hole method, this one does not have a potential engine built in (there was in fact an entire thread on harnessing a black hole for a starship propulsion system).

[Roastduck]

The Higgs field (consisting of Higgs bosons) is theorized to be the mechanism which allows objects to have mass (think of it as a pool full of syrup which us beings made of matter wade through, being weighed down by the mass it gives us); I suppose one could 'create a large Higgs field' in one location, providing an Earth-type gravitational pull concentrated into a small area.

The way I understand the theory, I don't think you can create a Higgs field. The Higgs field just exists, and Higgs bosons are vibrations in the Higgs field, just like electrons are simply vibrations in the electron field. What is more accurate would be to say that we could learn how to manipulate the Higgs field so that, for example, a ship has less mass.

[Seret]

Compared to our ability to manipulate other forces like electromagnetism, or ability to manipulate gravity is laughably primitive. We're essentially at caveman level.

[Skyler4856]

Ship large enough to generate its own gravitational field. XD

[Themohawkninja]

Ship large enough to generate its own gravitational field. XD

That wouldn't work, because (A) a non-spherical ship would have significant variations in the gravitational field, and ( gravity works on objects on the surface of objects, because all the mass is below the object. Unless you are on the surface of the ship, the mass would be both on top and below you, so you would either need an object far heavier than the Earth, or everyone would have to live on the surface of the ship.

[Seret]

Ship large enough to generate its own gravitational field. XD

Why bother with the ship? Just attach the engines to your home planet.

[Nuke]

True, but you have to take into account that in space, a spinning motion will spin both the "axis" and the "wheel", so either the whole spacecraft becomes a circle (which may or may not present it's own problems, at least with regards to construction), or you have to counter the torque on the part of the spacecraft that isn't intended to spin.

this is an engineering problem, a solvable one.

[Nuke]

Why bother with the ship? Just attach the engines to your home planet.

i thought about attaching arrays of large nuclear water rockets to an ice dwarf, using the ice as fuel. never really considered what the deltav of such a ship would be. would probibly be a feasible interstellar generation ship.

[K^2]

I was thinking about it a bit more. There is an interesting possibility.

To first order, gravity works like electromagnetism. So one can build an electrogravitomagnetic artificial gravity generator. First, you build two giant mass current loops. In practice, they'd probably have to be particle accelerators. The two loops are in the same plane, side by side, almost touching, and mas rotation is in opposite directions. The region of artificial gravity is going to be located between the two loops. The way you generate gravity is by giving the whole thing a bit of a spin around the axis that connects the two loops. That will generate enormous stress on the structure, as the two gyroscopic effects will fight each other, but no net torque, so this will not require any energy to maintain, other than what you need to run particle accelerators.

Why will this generate gravity? Faraday's Law of Induction. Mass current generates gravitomagnetic field. Because that field rotates, the total flux is time-variable, and that's going to induce a gravitational field around the rim of the current loop.

Unfortunately, effect isn't strong. Given some surface density àof the current traveling at some proper-velocity u, the total mass current is J = ÃÂu. That gives us the field strength B = (4ÀG/c²)J. The total flux is going to depend on the area of the loop, Φ = ÀBR². Time derivative for a rotating loop (axis of rotation perpendicular to axis of the loop) is dΦ/dt = ÉΦ. And that induced potential is divided along the perimeter of the loop. So we get g = ÉΦ/(2ÀR). Putting it all together, and taking into account the fact that we have two loops, we get the following overall formula.

g = ÉR (4ÀG/c²) ÃÂu

The biggest problem is the G/c² term. It is equal to 7.425x10^-28 m/kg. Units work out because àis in kg/m². In fact, lets talk about ÃÂ. This is density of the particle stream in accelerator times the thickness of the stream. Later is limited by what we can do with the magnets. Former is very difficult to get to a high value. Let me push it to the limits of imagination and say that we can get the stream almost as dense as air, and we have a 10m gap between magnets. That gives us à= 10kg/m².

Next, lets talk about ̉ۡ. The limiting factor is the same as in centrifuge. Humans don't like going spinning at high rates for very long. For a comfortable experience, the limit is about 2RPM. If we are prepared to venture a bit beyond comfortable, we can do, maybe, 5RPM. That gives us ̉ۡ = 0.52/second.

Finally, the one place where we can make decent impact is u. That's proper velocity and we have a particle accelerator. Woot. LHC launches protons at well over 400GeV. Lets say we can achieve 1TeV per nucleon in our matter beam. Mass of a nucleon is just 1GeV. So we've achieved u = 1,000c.

So if we wish to walk away with an Earth-like acceleration of g = 9.8m/s², using all of the above parameter, we get the loop radius of (drum roll, please) R = 6.69x10¹⁴m = 4,470 AU = 0.07ly.

In other words, a structure with above parameters is not only implausible, but impossible (an internet cookie to whoever figures out why) But if you don't care how much gravity you are generating, so long as you are generating some, and it's not due to the object accelerating with centrifuge, or whatever, you can just get to flywheels spinning in opposite directions next to each other and then start rotating the assembly. Gravity you can generate this way is going to be less than detectable, but it'd be completely artificial.

Can this be improved on? Maybe. You can try increasing both density and the proper velocity. You need about 6 orders of magnitude between the two to make the structure plausible. It would still be a megastructure, though, and centrifuge is much, much easier to build.

[DonLorenzo]

That's very awesome.

Make this toy sized, call it the SpaceTimeTwister and sell it to kids everywhere. Get rich and make a big version and put it in the basement of a skyscraper with a big tesla coil on top for the lightning.

Still don't detect the gravity, but live in your very own (very slightly) warped space.

Yes