Will an anti-gravity device ever be created? What would it involve?

[Urwumpe]

No..... I think that if you want to prove an experiment manipulates gravity, its probably a good idea to isolate it from possible "contamination" from electromagnetic effects.

and how do you shield magnetism?

 

[JamesG]

Does the name "Faraday" ring any bells?

 

[Urwumpe]

Does the name "Faraday" ring any bells?

No. Never heard of him. Did he play in Star Trek?

(Joke aside: Faradays cage shields electricity, not magnetism, but the principles are closely related: http://en.wikipedia.org/wiki/Mu-metal)

 

[JamesG]

I wasn't refering to Faraday cages so much as his work on magnetic sheilding.

 

[Urwumpe]

I wasn't refering to Faraday cages so much as his work on magnetic sheilding.

Does not work against static magnetic fields like the one of Earth. Faradays shielding is against RF fields.

 

[Linguofreak]

Now, if there were an object with negative mass, it would automatically travel faster than light. A "mass inverter" would allow a starship to fly faster than light by changing its mass to the equivalent negative value. Or is this mere sci-fi gibberish?

Close. It would actually need to have an imaginary mass.

 

[JamesG]

Does not work against static magnetic fields like the one of Earth. Faradays shielding is against RF fields.

Faraday did more than build cages.

 

[Urwumpe]

Faraday did more than build cages.

He sure did. But not much more in the field of electromagnetic shielding.

 

[george7378]

I think quantum mechanics suggests that gravity may be caused by exchange of particles of some type. Maybe if we know the spin of the gravity particle, it is possible to eliminate it somehow or other. I don't know much about spin though - only that if you rotate a spin 1/2 particle once it looks different, but twice and it looks the same. It's all in Stephen Hawking's book.

Special Relativity says that to travel at the speed of light, an object would have an infinite mass and would require an infinite amount of energy to get to that speed too, so I doubt that faster than light travel will ever be possible.

 

[T.Neo]

so I doubt that faster than light travel will ever be possible.

That's proper FTL. It's a different matter for apparent FTL, which achieves ftl-like travel times by "working around" relativity.

As with antigravity, I certainly won't rule anything out, but I also won't believe it until someone presents a working model (or equation).

 

[Dig Gil]

"Dark Matter" The new answer to everything we don't know...

Like God.

(...) we would see the effects of it (stuff being pushed away instead of attracted).

The galaxies being pushed away from each other for example?

 

[tblaxland]

I don't believe in anti-gravity...but maybe it is possible to create a controlled distortion of space or interaction between gravity and magnetism. The first experiments about it are pretty surprising, since there seems to be something happening that is magnitudes above the measurement accuracy.

It is an interesting experiment but I have not heard any updates on it for a while. Hopefully some results will come from the Gravity Probe B data this year that could be used to compare with this ESA experiment.

 

[JamesG]

Like God.

Perhaps. Does not say much about the "scientificness" of the idea.

The galaxies being pushed away from each other for example?

Heh. Yeah intertia and gravitational interactions couldn't possibly explain that. Besides we witness enough galactic collisons to know that isn't the case.

 

[tblaxland]

Heh. Yeah intertia and gravitational interactions couldn't possibly explain that. Besides we witness enough galactic collisons to know that isn't the case.

Accelerating expansion of the universe does not imply galactic collisions won't occur, or even be rare. Gravity can easily dominate cosmic acceleration depending on scale, just electromagnetic forces can dominate gravity depending on scale.

 

[atuhalpa]

Gravity can only attract. It is a property of matter that is immutable. The "warping" of space/time manifests as an attractive "force". Space/time can not be "warped" to repulse. That would violate basic physical constants.

 

[tblaxland]

The "warping" of space/time manifests as an attractive "force". Space/time can not be "warped" to repulse.

The experiment Urwumpe linked to earlier seems to indicate otherwise. Regardless, I fail to see a physical or logical reason why space/time could not be warped. How to do it is another question...

That would violate basic physical constants.

The mathematical behaviour of an object with negative mass is entirely consistent as far as I can tell. What physical constants did you have in mind?

 

[JamesG]

The experiment Urwumpe linked to earlier seems to indicate otherwise.

Eh? Seemed more like it produced an apparent fluctuation in the gravitational force affecting the accelerometers. There is a big difference between lessening or even changing the vector of a gravitational field and actually reversing it.

 

[Urwumpe]

Eh? Seemed more like it produced an apparent fluctuation in the gravitational force affecting the accelerometers. There is a big difference between lessening or even changing the vector of a gravitational field and actually reversing it.

The key thing is not the magnitude, but the fact that the measured force is one million times higher as predicted by general relativity. Of course it is a tiny force, but it is much higher as the current standard model of gravity predicts. And much higher as measurement errors.

Also, if it is a separate force, like claimed, there is no difference between lessening the resulting force or changing the vector of the resulting force, as the sum of gravity, the force(tm) and all else.

 

[Linguofreak]

We have pretty good control over the electromagnetic spectrum and it can be done with quite crude materials. It would be wonderful to find the gravitational equivalent of wrapping wire around a nail, or alternating current across wires of certain lengths.

Well, part of the problem is that we do have alot of ideas about weird and wonderful things that can be done with gravity, but gravity is very weak. Manipulating it in ways that are any fun generally requires a lot more mass and energy than all of humanity has available to it at the moment.

Also, none of the ways we know of that we could manipulate gravity if we had the resources really comes close to classical sci-fi "antigravity". Even if such manipulation actually is possible, it would probably require too much mass to be useful in the ways it is typically shown in sci-fi.

Now we don't seem to have any gravitational magnetite that acts differently from any other matter, so that clue isn't there.

No, we don't. We have some theories about types of matter that might exist and have non-typical interactions with gravity, and what kinds of things we could build with such matter, but no evidence that such matter actually exists.

But there are some weird anomalies we account for by using dark matter halos.

Dark matter isn't really that special. All it is is stuff that interacts with gravity normally so that we can see its gravitational effects on other matter, but isn't very bright, so that we can't see it itself. Some of it probably consists of matter of types we know about (dim stars and brown dwarves, etc, on the one hand, neutrinos on the other), but certain properties of these types of matter limit how much of the total amount of dark matter they can make up. The majority of it is probably made up of certain types of unknown particles that interact only via gravity. They still, however, interact with gravity in an entirely normal way.

 

[RisingFury]

Isn't it because all mass attracts each other? At least by Newton's theory.

Yes... but why? What's the thing that makes things attract? What is mass?

So to make anti-gravity put an earth sized planet over your head... and then you would be weightless... right before you get squished:rofl:

Well, you'd have to be between these two planets... or else the gravity from the closer one would be stronger



Oh... and when you're dealing with all these mathematical models that *might* make things work, just remember:
There's a mathematical model of a geocentric universe that explains the apperent retrograde motion of planets on the sky and explains the phases of Venus... that doesn't mean we live ina geocentric universe.

And for the love of Probe, please don't call these models "theories"! A theory actually needs some evidence...

---------- Post added at 11:19 PM ---------- Previous post was at 07:59 PM ----------

Meh. That they had to use a superconductor to achieve the results makes me think its purely an electromagnetic phenomenon (ie the latent magnetic field influencing the accellerometers or some such).

Yea, and the physicists working on the experiment so freakin' retarded they haven't though of that themselves!