Click-and-frame-drag

August 15, 2006 9:20 PM

An experiment recently performed by the AET RaDAL group shows that the gravitomagnetic field produced by a rapidly-spinning superconductor can cause a 1.117 times increase over the Earth's gravity. Gravitomagnetism, a phenomenon predicted by General Relativity, is a poorly understood but promising topic in modern physics. Speculation about harnessing the bizarre, space-warping and gravity-altering effects of gravitomagnetism has already begun. Reactionless space propulsion [PDF] is the most apparent use (previously discussed), with the potential applications far-reaching and nearly inconcievable. The earlier experiment by the European Space Agency involving another rapidly-spinning superconductor earlier this year found a massive increase in strength over the predicted values, but still miniscule by our standards. Things could become very interesting if the results from this latest experiment pan out.
posted by nervestaple (47 comments total)

From my meager understanding of gravitomagnetism, it's best to use an analogy between gravity and electromagnetism. An electric charge and a gravitational mass can be seen as analogous. A planet is "charged" with gravity - and just like an electric charge, has field lines radially emanating from the center (Of course, electric field lines can point either inwards or outwards, while gravitational field lines always point inwards). The link between electricity and magnetism involves moving charges. Just as a moving charge generates a magnetic field, a rotating mass generates a gravitomagnetic field. The Gravity Probe B satellite was designed to measure the gravitomagnetic field generated by Earth's rotation. Earth's field is obviously too weak to occur undetected except by sensitive equipment, so I'm unsure how the rotating superconductors enter the situation.
posted by nervestaple at 9:20 PM on August 15, 2006

If we spin it the other way can I get a hovercraft finally?
posted by MiltonRandKalman at 9:34 PM on August 15, 2006

This is an oversimplistic question then, but I'll ask it anyway.

If masses are 'charged' with gravity, does it follow that we could take a mass and remove it's gravitic charge (theoretically)?
posted by Kickstart70 at 9:34 PM on August 15, 2006

Errm... I seem to remember a post on Metafilter some time ago, about this kind of thing - a rotating semiconducter with reduced gravity detected above it - and the cynic squad around this place tore it to shreds and proclaimed it junk science. Does anyone remember what I'm talking about? Is this something different?
posted by Jimbob at 9:34 PM on August 15, 2006

The experiments are not predicted by general relativity, and many scientists don't believe it's possible, and in fact believe it so much that many thought previous Russian experiments were fraudulent. This type of thing has been on par with cold fusion for a while, although I've never really heard of any experiments disproving it.
posted by delmoi at 9:35 PM on August 15, 2006

Oh yeah,also these experiments show the opposite effect of what was claimed in the past.
posted by delmoi at 9:36 PM on August 15, 2006

We're all gonna die as a result of this, ain't we? I'm not ready to plummet off the earth and suffocate in space.
posted by Sailor Martin at 9:36 PM on August 15, 2006

Oh, here's a related thread. Looks like nothing too much was debunked in that thread. I'm sure I saw people calling Yevgeny Podkletnov crazy around this place somewhere...
posted by Jimbob at 9:38 PM on August 15, 2006

Also, this link is to a PR website for some led-into-gold huckster.

Weak.
posted by delmoi at 9:38 PM on August 15, 2006

Screw the hovercraft, I want my interplanetary galactic Flying Saucer ! ! ! Whoo-Hooo ! ! ! Naked blue space hotties here we come ! ! !
posted by mk1gti at 9:40 PM on August 15, 2006

This story reeks of bogosity. It states that the increased acceleration was measured with video camera. I did study physics back in college, and nobody ever did measurements with a video camera. They aren't designed for measurement and are very imprecise. Also, its on a site called PRWeb, not the sort of place you expect to see serious scientific results published.
posted by Osmanthus at 9:43 PM on August 15, 2006

Mythbusters masures with a video camera all the time!

;-D
posted by Kickstart70 at 9:44 PM on August 15, 2006

Oh I'm sorry, experiments have disproven this. The ESA discovered a tiny one part per million amplification, while others were claiming a large decrease. Now some random unknown person put out a press release saying they found a large increase. I'm almost certain it's bullshit.
posted by delmoi at 9:44 PM on August 15, 2006

On preview, I came to post exactly what Osmanthus said. The idea in science is to measure the effect you have come to measure as directly as possible.
posted by lupus_yonderboy at 9:45 PM on August 15, 2006

Yeah, I'll wait for this to come out in Physics Review Letters thanks very much.
posted by Jimbob at 9:47 PM on August 15, 2006

Yeah, the camera gives it away as bullshit, because it means the experimenter doesn't care about measuring the falling time in less than 1/24 or 1/30 of a second increments. Something as simple as a switch activated by the falling object would give actual useful results. So it's bullshit or this guy is smart enough to amplify gravity but not smart enough to use a stopwatch.
posted by TheOnlyCoolTim at 9:48 PM on August 15, 2006

How the G-Force Inverter works: In the words of Tom Swift:

Tom explained that he had constructed a double-walled, peripheral chamber around the one containing Serptilium. He had found that by sending a flow of Cryotol [a catalyst that his Father had invented; it liquefies gases at higher temperatures than normal] through the outer chamber, a propulsive force was produced.

The propulsive force, of course, drives the Monoswift forward on the rail.

Well, of course. Obviously a second-generation application of Repelatron beams...
posted by cenoxo at 9:56 PM on August 15, 2006

Earth's field is obviously too weak to occur undetected except by sensitive equipment, so I'm unsure how the rotating superconductors enter the situation.

It sounds like you're saying that the Earth's gravitational field can't be detected without sophisticated instrumentation, but that can't be right. Can you elaborate?

/me drops things out of window, onto passers-by
posted by IshmaelGraves at 10:00 PM on August 15, 2006

This Marshall Barnes with his STDTS?
posted by tellurian at 10:06 PM on August 15, 2006

IshmaelGraves: I was referring to the frame-dragging effect of Earth's gravitomagnetic field, not Earth's gravitational field.

Looks like I got a little too excited to fact-check the first link. How will I ever recover my now-besmirched internet rep?!
posted by nervestaple at 10:15 PM on August 15, 2006

heh, it's been 10 years since I first learned about Podkletnov.

Best site on the web covering it, back in the day.
posted by Heywood Mogroot at 10:30 PM on August 15, 2006

I guess maybe these days I'm jaded, but it seems that the golden days of stunning technological breakthroughs are over, and I get a sense that we've already discovered everything that's important. And I'm wondering whether nanotechnology will become the aircar of the 21st century. In 2050 I'll be muttering, "Where's the heart repair nanobots they promised me in 2000?" Will there be any new discovery that doesn't revolve around a computer/electronics?
posted by rolypolyman at 10:56 PM on August 15, 2006

Wait, was this effect discovered by Troy Hurtubise?
posted by lumpenprole at 11:40 PM on August 15, 2006

Tellurian said: This Marshall Barnes with his STDTS?

Sounds like Barnes and STDTS has not gone back to the future yet. From the May 17, 2006 24-7 Press Release, Bexley Physics Students Get 1st Peek at Warp Drive Tech:

The main feature was the analysis of a series of experiments of a device called the STDTS. Invented by Marshall in 2001 it has gone through a series of developments and testing, culminating so far with the footage that the students saw where it accelerated an automobile with the specially modulated electromagnetic field it produces. It is the fact that the field seems to be contracting space in front of the vehicle, and expanding out the back, that makes it appear that it is the first functioning warp drive prototype. The physics foundation of this new development is linked to Einstein's unfinished Unified Field Theory of electromagnetism and gravity.

...Marshall explained his invention and how it worked. The STDTS seems to warp or contract space in front of a vehicle while its moving and expand it out the back. If it were applied to a space craft and modified so that it could pulse the field, it would accelerate that craft without any fuel expenditure and it could theoretically do so past the speed of light. Marshall explained how it seems to function as part of Einstein's Unified Field Theory of gravity and electromagnetism.

Ohio's Bexley High School is a real place, and here are some more links to Marshall Barnes, Philadelphia Experiment expert.

Perhaps STDTS really works, but I think I'll stick with Tom on this one.
posted by cenoxo at 11:50 PM on August 15, 2006

There's so many things that could be a problem here it's hard to believe. There's what osmanthus said about video camera accuracy. There's what TheOnlyCoolTim hinted at about the fact that the measurement difference was only a couple of frames.

Then there's the fact that the thing was wrapped in air-cushions, which could shift each time, change size (it's been sitting near all the coolant for the superconductor and has got cold over time) or whatever which would affect the dimensions of the rig.

There's the fact that he's careful to say how he defines when freefall starts, which suggests he's got a bit of an issue letting go of the thing fast enough at the start of the fall.

There's no indication of how the rig is set up to make sure the distances are sufficiently consistent, and there's probably about a dozen other things you could come up with if you could actually see the thing.

Now I don't think in principle there's any reason you couldn't actually detect the effect with a video camera if you had enough runs with sufficient controls, but there's way too many things we don't know about the run to take any real notice of, and the way the whole thing is described just sounds too uncontrolled for something so difficult to detect.
posted by edd at 12:43 AM on August 16, 2006

Don't fret rolypolyman. There's still a great deal left to be discovered.
posted by newscouch at 1:21 AM on August 16, 2006

rolypolyman: the reason you feel that way is because this country no longer does basic research. It's almost all 'applied', that is... they have a specific goal in mind.

It's the seemingly pointless basic research that generates the really stunning, mind-blowing stuff. But it doesn't do it obviously, right up front... it takes years, sometimes decades, for the results to bear fruit. So it doesn't get funded anymore. The Superconducting Supercollider was that kind of project, as an example. And we've mostly tapped out the rich veins of experimental results we'd created in the 50s and 60s. So there aren't many big surprises. If we want big surprises, we have to pay for them.

The US was once a much, much smarter country in many ways.
posted by Malor at 2:03 AM on August 16, 2006 [1 favorite]

The US was once a much, much smarter country in many ways.
posted by Malor at 2:03 AM PST

And now the Internet tubes are to everyone, and we are dum.
posted by rough ashlar at 3:14 AM on August 16, 2006

The difficulties in 'messing about' with gravity were pointed out by HG Wells in The First Men in the Moon. A disk of arcane substance called "Cavorite" lessened, or shielded the effect of gravity above it. The consequence was to immediately blow off the roof of the discoverers house as the air above the disk, now free of gravitational pull, shot upwards to be replaced with air flowing into the gravity shadow.

That's the problem. If anyone claims to have developed (usually with superconductors, the mystic substance de jour) a gravity shield, lens or booster - ask them to explain why this will not allow a stack of perpetual motion machines in the aura or shadow of this wonderful device. Considerations like this make it seem likely that gravity is not like the other forces, not cabable of being generated or modified with our limited and finite amounts of energy.
posted by grahamwell at 3:39 AM on August 16, 2006

the reason you feel that way is because this country no longer does basic research

Maybe the reason he feels that way is because, as technology becomes more complex, it takes longer and longer just to understand the "basics" in order to make the next big leap in understanding (in a particular field). But still, don't fret, rolypolyman. The age of the lone scientist, toiling away at his workbench, slowly laboring towards his eureka moment is not dead yet.
posted by Civil_Disobedient at 3:54 AM on August 16, 2006

ask them to explain why this will not allow a stack of perpetual motion machines in the aura or shadow of this wonderful device.

Another problem I see is in the _directionality_ of the observed paucity of gravity. The original experiment, if I recall, involved a thin, verticle zone of reduced gravity above the spinning superconductor.

But why would it be such a thin, straight, verticle zone? Sure, in theory, the earth may have a "point" centre of gravity that the device is blocking the influence of, but in reality the mass of rocks underneath in all directions, horizontally as well, is what's creating the influence of gravity. If something is stopping gravity, therefore, it should stop it in all directions away from the earth's surface, not just straight up vertically away from the earth's theoretical centre of gravity.
posted by Jimbob at 5:10 AM on August 16, 2006

Every time I read about this topic, I think of James Blish and the Spindizzy^ powered "Cities in Flight" stories from the 1950s.

rolypolyman, be careful or you might be misquoted for 160+ years like Henry L. Ellsworth, who didn't say "Everything that can be invented has been invented." For the opposite viewpoint, you might check out "The Coming Technological Singularity" by Vernor Vinge.
posted by Enron Hubbard at 5:41 AM on August 16, 2006

Someone get Ming the Merciless on the dial-o-tron. We might be able to revive his career.
posted by Blazecock Pileon at 5:50 AM on August 16, 2006

This makes me think of the Dean Drive that Astounding/Analog magazine pushed for many years.
posted by octothorpe at 6:09 AM on August 16, 2006

Appreciate the optimism. I just hope that there are many new cool things to see before I get old.
posted by rolypolyman at 6:32 AM on August 16, 2006

Kickstart70: If masses are 'charged' with gravity, does it follow that we could take a mass and remove it's gravitic charge (theoretically)?

The source of the electromagnetic field is electric charge (and currents). The source of the gravitational is rest mass (and energy - including the energy of the gravitational field itself, ooh, non-linear).

You can't get rid of it. Do to the non-linearity it is however possible in principle to make a rest-mass-less gravitating object which consists only of gravitational energy. John Wheeler invented the idea.
posted by snoktruix at 6:33 AM on August 16, 2006

Ok, wait, so this stuff is bogus then? God, I hope so. I can't take a confirmation of antigravity and the Ruination of the Spheres all in one day.
posted by Pastabagel at 7:58 AM on August 16, 2006

their effect is "much larger than expected.."

Someones gonna blow up the earth by accident one of these days and the last transmission will be ""much larger than expected.."
posted by stbalbach at 7:58 AM on August 16, 2006

I don't know why you're all finding this so hard to believe. PRWeb is an entirely reliable source of information.
posted by dansdata at 9:59 AM on August 16, 2006

Yeah, the camera gives it away as bullshit, because it means the experimenter doesn't care about measuring the falling time in less than 1/24 or 1/30 of a second increments.

High frame-rate cameras are often used for ballistics and explosives research. In those applications, and this, it makes sense to use a camera when any kind of mechanical probe would interfere, and where laser or accostic probes would be unreliable. But the use of a regular video camera (quote from the article says "12 frames, or nearly 2/3 of a second") does sound amateurish.
posted by Popular Ethics at 10:45 AM on August 16, 2006

Gravitomagnetism is interesting--not just because of sci-fi implications--but interesting for astrophysics and philosophy.

Frame dragging--or the Lense-Thirring Effect is important near black holes or neutron stars. There you have lots of mass rotating very fast--just the conditions you need for gravitomagnetism.

Einstein's General Relativity was originally supposed to support the still-contoversial Mach's Principle, reducing even rotation to a relative effect of the interaction of matter.

Near a black hole or neutron star, the overwhelming mass and rotation "out-votes" the surrounding Universe on determining what "non-rotating" means. So nearby matter finds its standard of rotation pulled along with the rotating mass.

In the Bardeen-Petterson effect the accretion disk of gas swirling onto a neutron star or black hole is forced, by gravitomagnetism, to align itself with the rotation plane. This may have observable effects.

I first became interested in this stuff when I noticed that the math for the Coriolis Effect has a cross-product with the particle's velocity, like magnetic forces. And it turns out that's not an accident--the Coriolis Effect may be thought of as the gravitomagnetic force of the surrounding Universe.
posted by Schmucko at 1:18 PM on August 16, 2006 [1 favorite]

free of gravitational pull, shot upwards

That reminds me of a short SF story I read once, where a scientist who invents anti-gravity murders his hated colleague by staging a demonstration where he gently rolled a billiard ball across a pool table towards a small zone of said properties, making sure in advance that his not-so-observant foe was standing directly west of the setup.
posted by CynicalKnight at 1:23 PM on August 16, 2006

That would be "The Billard Ball" by Asimov. I think an alternate title was "Dirty Pool."
posted by sonofsamiam at 1:37 PM on August 16, 2006

How will I ever recover my now-besmirched internet rep?!

Your name contains the answer: end your one-man drone riot with a session of autonervestapling!
posted by PinkStainlessTail at 1:38 PM on August 16, 2006

Marshall Barnes, Philadelphia Experiment expert.


... and here's our intrepid "Special Civilian Investigator" correcting Stephen Hawking about worm holes and time travel
posted by CynicalKnight at 1:51 PM on August 16, 2006

PST: The Hive will triumph!

At least the world of Alpha Centauri appreciates stuff like the pseudoscientific mumbojumbo that I posted, with their Singularity Inductors and whatnot.
posted by nervestaple at 9:18 PM on August 16, 2006

Gravity sure seems like a more general electromagnetism -- or, conversely, electromagnetism seems like a special case of gravity. I suspect that we will, at some point, gain a similar proficiency in locally controlling gravity as we currently have for electromagnetism. I'm guessing, however, that it will take much more energy to exert a force on a pound of plastic, via gravity, than it takes to exert that same force on iron using electromagnetism. I suspect that anti-grav vehicles will never be feasible -- heck, mag-lev trains only levitate 10mm above the guideway; the energy required to make one float even just a meter above the track would be ridiculous!

But considering all that we've done with electromagnetism (generators, media storage, etc.), I'm curious as to what new techs gravitational manipulation will make possible. (Sorry, no time travel...)

< / truthy>
posted by LordSludge at 6:38 AM on August 17, 2006