Gravity Manipulation: Can It Be Done? Research for Hard SF World

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The discussion centers on the plausibility of gravity manipulation for a hard science fiction setting, with participants expressing skepticism about the feasibility of concepts like artificial gravity and tractor beams. While some mention theoretical ideas, such as using hyper-dense materials or negative energy, most agree that current scientific understanding does not support practical gravity manipulation. The conversation highlights the tension between scientific accuracy and creative storytelling, suggesting that focusing on narrative may be more important than strict adherence to scientific plausibility. Additionally, some participants reference advanced theories like zero-point energy and its potential implications for gravity, but caution against overestimating their validity. Ultimately, the consensus leans towards the idea that while intriguing, gravity manipulation remains largely speculative.
  • #31
actually I have an idea to produce artifical gravity. Fill a container in space full of water, and pump the water whatever direction that someone would intend your "artificial gravity" to be pulling. That would provide quite a natural environment would it not?

Then again, this has nothing to do with the original topic. Just one of those ideas that I come up with every now-and-then.

*edit* after reading the rest of the post about antimatter, and negative mass, I realize how off-topic I am.. for this, I apologize.
 
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  • #32
pervect said:
There are two main possiblities that I see - either the particles of the exotic matter are charged or uncharged. If they are uncharged, then they won't be affected by a magnetic field.

IF they are charged, the particles will curve when they enter the magnetic field - the "magnetic mirror" effect. But, an accelerating charge will radiate away energy. With normal matter, this means that the matter loses speed. With exotic matter, this means the matter gains speed.

So the magnetic bottle won't contain exotic matter, as near as I can tell, because the exotic matter particles will keep radiating away energy until they have so high a velocity and so much momentum the magnetic field can't contain them anymore. I think the instability problems with negative mass are fundamental. Possibly someone with a better grasp on QFT could say more - I believe tachyons have similar stability issues.


That's some weird stuff. Even if it could be contained it still wouldn't support machines in the sky above an Earth sized and massed world would it? Would negative mass thrusters push much more than their own weight?


Since this NM stuff doesn't seem to be working out is there anything else that might work? Some sort of use of the Magnetic, Strong or Weak forces?
 
  • #33
SkepticJ said:
That's some weird stuff. Even if it could be contained it still wouldn't support machines in the sky above an Earth sized and massed world would it? Would negative mass thrusters push much more than their own weight?


Since this NM stuff doesn't seem to be working out is there anything else that might work? Some sort of use of the Magnetic, Strong or Weak forces?

Negative mass wouldn't directly support a city in the sky, but if there were some way to contain or stabilize it, it could reduce the mass of the structure enough to allow it to "float" due to buoyant forces from the displaced air.
 
  • #34
pervect said:
Negative mass wouldn't directly support a city in the sky, but if there were some way to contain or stabilize it, it could reduce the mass of the structure enough to allow it to "float" due to buoyant forces from the displaced air.


If that's all then vacuum sphere balloons made from Higgsinium could be used. Speaking of higgsinium, would a few mountain masses of this along with exmohsium(matter I made up; super dense and has negative mass and inertia close to that of higgsinium's positive) get around this? If matter can't touch exotic matter without doing freaky stuff, and magnetic bottles can't hold it, then how in the universe can one contain it? And I though anti-matter was a pain to deal with. :eek:
 
  • #35
That's a cool link!

I'm afraid I really can't see any way to make negative masses act in a stable manner, but it's always possible I might be missing something.

The instability issues have some interesting and perhaps unfortunate implications for wormholes, which by the articles I've seen naturally tend to have one end acquire a negative mass. So negative mass is not only needed to build wormholes, but is a natural consequence of having them around - just put large quantites of matter through a wormhole, and one end should become more massive, the other less massive, up to and including one end acquiring a negative mass. For instace, see the following link.

http://www.sff.net/people/Geoffrey.Landis/wormholes.htp

Wormholes provide one possible way to create astronomical objects of negative mass, according to theoretical calculations by Matt Visser, professor of physics at Washington University in St. Louis, a co-author of the article. A key element of the theory is the finding that, as matter passes through the wormhole, the "entrance" and "exit" mouths of the hole gain and lose mass.

"According to theory, either end of a wormhole can swallow mass, ejecting it out the other end," said Benford. "But a wormhole mouth in a dense region of matter swallows mass faster than its other end, if that end is in a sparse region. Mass emerging from an end curves space-time oppositely. It's as though the end loses mass, finally reducing to zero mass and then to negative. Gravitationally, that negative end looks like a negative mass, maybe even a large, stable one."

Unfortunately I don't see any way for a negative mass wormhole mouth interacting gravitationally with the rest of the galaxy to avoid the stability issues we've already talked about.
 
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  • #36
Poor Reasoning


Danger said:
Hi, folks;
Think I'll go check out those links. If the guy thinks that Uri Gellar was anything more than a good sleight-of-hand artist, he's for sure nuts. One thing to mention: the expansion of the universe has nothing to do with gravity. It's the space-time itself that's expanding, not the stuff in it. The regions of space that contain the stars and galaxies are moving away from each other uniformly, but the bodies are not separating within them. They remain gravitationally bound. The molecules in a chocolate chip don't move apart just because the chips themselves mutually recede during baking.
I fail to understand the wholesale condemnation of Puthoff because he dealt in some ideas you reject. This is not scientific investigation. As Mark Twain said, "The best way to get a sure thing on a fact is to go and examine it for yourself, and not take anybody's say-so." If you wish to refute Puthoff for his ideas, here is the math and the theory:Zero-Point Fluctuations . I am sorry that it is a PDF file. I hate them, myself. If you wish to know more about what Puthoff is saying, go to More Puthoff .
I am not being a Puthoff proponent here. I am just saying it is ridiculous to condemn wholesale anything based upon false reasoning. Lots of people hold all kinds of ideas, both brilliant and bizarre. Disproving the theory on observation and math is the only route for scientists. Further, there is nothing inherently wrong in any idea being controversial. SR and GR were extremely controversial. They stun the mind even today. It is the controversial we NEED.
I do believe that something on the order of Puthoff's ideas will be proven true.
I cannot concede that ridicule alone, such as is displayed in the links included above, demonstrates anything. As Mark Twain also said, "There is no character, howsoever good and fine, but can be destroyed by ridicule, howsoever poor and witless. Observe the ass, for instance: his
character is about perfect, he is the choicest spirit among all the humbler
animals, yet see what ridicule has brought him to. Instead of feeling
complimented when we are called an ass, we are left in doubt." For all I know, the person who posts the ridicule believes all sorts of ludicrous things. After all, don't we all?
 
  • #37
i think it was in a brian green book i read that said at the initial big bang era there was a moment where matter/energy became so dense that gravity actually became a replusive force? any way to harness that in a 5x5 coffee table cover? that would make a great conversation piece next to my aquarium :)
 
  • #38
Well I found a possible means to hold something against a planet's, star's or other mass' gravity. They're called orbital rings. Check out the idea here--> http://www.paulbirch.net/ Scroll down past the talk of church and ethics and you'll see the links. I've fallen in love with those suprastellar planets; what a neat idea. I'm not going to write a book any longer though. I did find a creative outlet though. Called www.orionsarm.com
 
  • #39
Here is something that I fould on the inter-web last year but have lost it again, it was gravity manipulator that twisted space-time due to frame dragging (an unproven effect postulated by einstien?).
This "Twister device" was a regular large heavy spinning mass that twisted space-time along with it.
This effect would not do anything on its own, but a few of these devices in conjuntion could focus this effect on 2 points outside of the machine, a positive gravity diffence at the front and a negative gratity difference at the back.
This was the only gravity manipulator on the net that I have found that I believe would work.

results of gravity probe B pending.
 
  • #41
Non Physics person here. I saw a youtube video featuring an engineer who had worked in aeronautics. He said he took two magnets and forced them together - north pole to north pole, south to south. He bolted them together with a brass bolt. He found when he dropped the double magnets from atop a tower, the mated magnets dropped slower than another item that he dropped. This was reproducible. Always the same result. Apparently there is an appendage to the gravity formula, with a magnetism element. Best wishes to everyone working on gravity manipulation.
 
  • #42
Can you link to that video, cpacapt?
 
  • #43
hey all

ill admit that I am not among the most knowledgeable on this subject i have previously looked up the topic of gravitational manipulation...

while not a genious in the field of physics i do have a rudimentary understanding of it thanks to the us navy's naval nuclear power training comand... lol

as one person mentioned gravity may very well be a sort of "wave" if you will, if so you need not switch polarity, but to conceiveably change phase by... let's say "180 degrees", that would negate the net force of gravity acting on an object

hope that idea helps
 

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