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British Scientists Reverse Casimir Effect
An anonymous reader writes "The Telegraph reports that Scientists at the University of St. Andrews have developed a technique to cause the Casimir effect to repel instead of attract. This discovery could lead to near frictionless machines or in theory even levitation."
Isn't it "repel" rather than "repeal"?
Left shift 1 for e-mail...
Gasp, that means we will have to repel one of the laws of seance.
How says science cannot be uplifting.... literally.
This could be put to immediate use in the USA, where much bad legislation needs to be repealed and they need to attract fewer blockheads to a career in politics.
Rich And Stupid is not so bad as Working For Rich And Stupid.
It can revoke laws?
I'm not a big fan of knitwear at the best of times.
At the bottom of the
I have a feeling that this breakthrough will eventually lead to the development of giant flying mecha.
You heard it hear first, on slashdot.
Soon we can do away with stupid things like elevators..
The moral of the story is: "Always remember to mount a scratch monkey."
It's "repel" as in "the body odor of submitter repels women worldwide", as opposed (heh) to repeal, which means, "to remove or reverse a law".
What happens if all the molecules in your body suddenly repels eachother?
(write-line *coolsig*)
i RTFA, but didn't see any explanation or examples. im baffled how this works.. any insight?
FOXTROT UNIFORM CHARLIE KILO
Comment removed based on user account deletion
Or they'll vaporize the universe with this contraption. I suppose somebody's out there looking to make a weapon out of the thing.
What?
when they can figure out how to build those artificial gravity doohickeys used on the USS Enterprise and other spaceships.
So was it only me that heard Sir Alec Guinness read that line out?
You moved your mouse. Please restart Windows for changes to take effect.
The discovery is not to be belittled, but both the article and the poster somehow forget to mention that the "levitation" which is talked about is on the order of nanometers (check the Wikipedia article on the Casimir effect). Far from the kinds of stuff you see stage magicians do.
"Goodness me, how unlike the FBI to abuse the trust of the American public." -- The Onion
Now, Leonhardt and Philbin have calculated that the Casimir force between two conducting plates can turn from being attractive to repulsive if a "perfect" lens is sandwiched between them. A perfect lens can focus an image with a resolution that is not restricted by the wavelength of light. Such a lens could be made from a metamaterial made of artificial structures that are engineered to have negative index of refraction -- which means that the metamaterial bends light in the opposite direction to an ordinary material.
According to the researchers, the negative-index metamaterial is able to modify the zero-point oscillations in the gap between the surfaces, reversing the direction of the Casimir force. Indeed, the researchers believe that this repulsive force is strong enough to levitate an aluminium mirror that is 500nm thick, causing it to hover above a perfect lens placed over a conducting plate. Since the Casimir force acts on the length scale of nanomachines, manipulating it could be important for future applications of nanotechnology. To summarize, nothing has been built yet. It's possible that it could be built, though you'd have to make a "perfect" lens in the tiny space between the two plates. Unfortunately, every "perfect" lens I've heard of tends to be wavelength-specific and relatively large (compared to the gap the Casimir effect requires). It may be that these are just engineering hurdles, but it may also be physically impossible to pull off.
What is this? a spelling contest or a discussion about a new scientific discovery?
/. is populated purely by obsessive pedants with nothing better to do.
Sheesh. Anybody would think
oh..
the future will finally arrive!
But the ad on the right felt to need to cover up half the text of the article
"dry glue" effect that enables a gecko to walk across a ceiling.
"Spider-pig, Spider-pig,
Does whatever a Spider-pig does."
-- Boycott Shell
My frictionless Slip-n-Slide overlords will kick the asses of your levitating overlords.
but seriously.. will this allow someone to build a slip-n-slide to get between cities?
Nicola Tesla would be proud. This sounds like all the electrical field tuning he did back in the 1800's only on a smaller scale and for different purposes.
Modulating fields like this seems to me to be some sort of thrusting action although they don't come out and say it.
The game.
Quantum levitation by left-handed metamaterials
Ulf Leonhardt and Thomas Philbin
Provisionally scheduled for August 2007
now where is my hover skateboard?
Electronic Liberties must be defended at all costs!
A humorous page about these British scientists' work by St Andrews physics Professor Leonhardt explains their work on Casimir "levitation".
--
make install -not war
1. Invent/discover something cool
2. Tell everyone about it
3. ???? 4. NO Profit
It's sad to say that here in the UK we never learn and have a long and distinguished history of brilliant research followed by total fumbling of the ball and making no money out of the discoveries whatsoever.
I want a list of atrocities done in your name - Recoil
The thelegraph is supposed to be one of the more serious british dailies. So heaven help us all if this is what they pass off as a science story.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
I did not know this guy => http://en.wikipedia.org/wiki/Casimir_(dinosaur) had a physics degree.
This wasn't enough for me, so I wandered over to Wikipedia:
The only changes to the Wikipedia article lately have been a link to this article, which is sort of meta. Wikipedia linking to an article plagiarizing from, of all places, Wikipedia. Cute, but also a little sad.
Against stupidity the Gods themselves contend in vain.
I am a physicist, but these subjects are often beyond me. Still, let me try a short explanation. This seems, to me, rather an important discovery.
The Casimir effect happens when you get two surfaces very nearly touching. Virtual particles emerge on the other side of the surfaces and force them together. Virtual particles being, well, virtual -- very short-lived and low-energy -- this effect only occurs when the surfaces are very, very close to one another.
What's intriguing about the Casimir effect is that it is extracting work from the zero point energy of the universe, the base energy field of empty space. (Yes, even a total vacuum contains virtual particles, and thus some energy.) It is not immediately obvious how to make this useful, however, if the only way to tap into the zero point energy is to destructively sandwich two expensive materials together.
Reversing the Casimir effect is brilliant. By placing a perfect lens between the two materials, the virtual particles create a repulsive force. This could, as stated, create a levitation effect by preventing the surfaces from ever touching. 'Levitation' is a strong word, though. It'll 'levitate' a nanometer or so above the other surface, which is only good for reducing the friction between them to zero. So 'frictionless surfaces' is probably the keyword we should be using here.
I'm intrigued because it would seem to be easier to generate power from the zero point energy with a repulsive effect than an attractive one. So this could also be the first step toward a zero point energy generator -- free energy. What will they think of next...
Genocide Man -- Life is funny. Death is funnier. Mass murder can be hilarious.
Given the distance over which the force operates, it doesn't sound like you can use this to levitate large items. Surface roughness is measured in micro-meters and the force operates over nano-meters. http://en.wikipedia.org/wiki/Roughness
A standard solution for a 'frictionless bearing' is an air bearing. http://en.wikipedia.org/wiki/Air_bearing
The utility of this work seems limited to very small things.
"It's a tarp!" -- Dyslexic Admiral Ackbar
"...all-pervasive energy fields in the intervening space between the objects..."
a.k.a. "the Force"
Light cup, beer drink, thin so chain, neck turtle fat, man I won't say it again
Finally, I can retrofit the Prius and get it to fly. And screw you guys that want to retrofit your Hummers.
I say we enact a law that will only allow environmentally friendly vehicles to fly. Do it now before Hummers are grandfathered.
Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong fix.
Given that the Casimir effect actually produces enough force (well, pressure) at tens of nanometres distances between the two plates, that'll be some really tiny giant mecha
A polar bear is a cartesian bear after a coordinate transform.
Is this reverse engineering from Megatron or from one of those cigars??
it's been done... http://en.wikipedia.org/wiki/Iron_Man
I've already patented using this technology on skateboard decks, and no, Back to the Future doesn't count as prior art! I didn't get the idea from there at all!
which is totally what she said
I don't know, I think that Deloreans would definitely need an exemption from that law.
Nothing for 6-digit uids?
I hereby theorize that cramming peanuts into your arsehole will cause levitation.
There, now that I've officially theorized this, I can say, "In theory, cramming peanuts into your arsehole will cause levitation." and it's perfectly true.
I want a hoverboard!!
Seconded. And a Delorean should be the prototype, complete with a Mr Fusion on the back
Check out my sysadmin blog!
FTA: "The force is due to neither electrical charge or gravity, for example, but the fluctuations in all-pervasive energy fields in the intervening empty space between the objects and is one reason atoms stick together, also explaining a "dry glue" effect that enables a gecko to walk across a ceiling." ... and now that scientists have figured out how to reverse the Casimir effect, this will soon enable geckos to walk on the floor.
Visit http://ringbreak.dnd.utwente.nl/~mrjb/growingbettersoftware to download your free copy of the book
always thinking of ways to wage peace with their technology.. not one mention of frictionless bullets.
meh
As millions of geeks try this out on members of the opposite sex.
I don't know the meaning of the word 'don't' - J
like RADAR and Jet motors, but then Parliament voted to keep it all British, once you'd finished helping us make it.
Shame!
Does anybody know how great this force is? I mean, say with one-meter-square plates, each suspended above each other, how much force would be required to push the two plates together? If the answer is two pounds (er, kilograms) then that's one thing, but if it's thousand hogsheads, that's a whole nother thing entirely.
Seems like you could build a nano/macro motor out of both the regular casmir and the anit-casmir materials. Somehow I smell perpetual motion in there somewhere.
The Casimir effect is very wierd indeed. If you take two metal plates and put them close together in a vacuum they will attract one another VERY weakly. The effect is caused by fluctuations in the electric charge of the vacuum. Think of it a little like sea level. On average if you measure sea level lots of times you wil get "0" for the height but if you measure it just once the height you get will depend on the tide and the size of any waves. The same is true for a vacuum. Look at a particular volume of space and measure the electric charge. On average you will get zero but for a particular moment in time it may be non-zero.
Ok so far but how do we get an attractive force? Well it turns out that charge must be conserved so if one region of space has a small positive charge at one instant a neighbouring area must have a small negative charge (in quantum terms we say that we pair produce and virtual electron-positron pair) thuse we have a dipole. Now remember the two conductors? Well the one nearest the positive charge will have the electrons in the conductor attracted to it and being a conductor they will move towards it giving the conductor a net negative charge. The opposite will happen in the conductor nearest the negative charged area of space.
So now we have, instantaneously, a conductor with a negative charge and one with a positive charge...so they attract one another. this is the Casimir effect. If you stop to think about it is is VERY strange because it means that two metal plates in vacuum, with no externally applied fields will attract...so you have to ask yourself what exactly is doing the work i.e. where is the energy coming from to move these plates?
I'm not a condensed matter guy so I must admit I don't quite understand why this effect is so important to them. I understood that in molecules it was known as Van der Waal forces and due to periodic dipoles occuring in molecules in much the same way it does ina vacuum. Only, because there is a real electric field, the effect is much larger. So if there are any condensed matter people out there perhaps they would like to explain why it is Casimir and not Van der Waals that is important? or is it just because they have the same origin the name Van Der Waals has been dropped?
Sorry, sorry.
Maybe this article is discussing a new way of creating a repulsive Casimir force, but a closely related force, known as the Van der Waals force is repulsive for certain combinations of materials. For instance, polystyrene next to a gold surface in water has a repulsive Van der Waals force(See Visser).
http://en.wikipedia.org/wiki/Van_der_Waals_force
Visser, J. "On Hamaker constants: A comparison between Hamaker constants and Lifshitz-van der Waals constants" Advances in Colloid and Interface Science 3(4), 331-361
Would you stop with all this talk of thrusting action please? My parents my walk into my basement/room.
I hold very few opinions. I hold information based on observation and fact. If you wish to disagree, please use facts.
This is all very interesting, but does it at all help us understand how scientists were able to use the Casimir Effect to send "Bunny #15" into the future?
http://www.youtube.com/watch?v=RJaU211gdg8
Are they some special bunch of scientists that they deserved to be addressed as "Scientists"?
According to TFA, the same team announced, last week, some breakthrough with an invisibility cloak. This week they make another spectacular claim regarding levitation (granted on a very small scale). Either this team is having an incredible run and some serious intellectual luck or they are totally full of shit. Given the history of such claims, my money is on the latter.
Maybe next week they will announce they have discovered cold fusion.
I hate to be such a skeptic but these claims seem to lack truthiness according to my gut. Your gut may differ. Either way, I'd take these claims with a very fine grain of salt.
We will finally have Casimir sweaters that will repel lint and pet hair instead of attract it!
Slashdot readers have had the ability to repel instead of attract for years!
Web hosting that doesn't suck!Dreamhost
The Casimir force occurs because the zero point energy of the vacuum is quantized. If you hold two plates close together they tend to align on quantized boundaries. It may be attractive, or it may be repulsive, but either way the plates align on quantized boundaries. I thought this was common knowledge?
A friend of mine is getting his PhD in physics from Stanford this year. Whenever he comes back to town, we'll always go for a run and he'll try to explain a little of what he's been learning and doing lately. I first heard about 'quantum vacuum' and the Casimir effect almost two weeks ago.
http://www.newscientist.com/article/dn12429-three- ways-to-levitate-a-magic-carpet.html/
I recall an argument between Drexler and Smalley in which the "fat fingers" and "sticky fingers" problems mean that molecular assemblers are impossible. My impression is that the Van der Waals force drives the sticky fingers problem in which a nanobot's finger will stick to an atom it is trying to manipulate. That seems to be quite an overreaching statement anyway, but considering that the "fat fingers" problem is on shaky ground according to Drexler, and now we have the possibility of nanoscale repulsion, it seems that the sticky fingers argument is also on shaky ground.
With one-meter-square conducting plates in vacuum with meter distance between them plates it is something on the order of magnitude 1^^-30 kg. That is one-billionth of one-billionth of one-billionth gram.
In seriousness, what devices are there that can hold the tolerances necessary for a practical application?
When the people fear their government, there is tyranny; when the government fears the people, there is liberty.
Just a wild idea ... ... Casimir force is short reaching but quite strong in interesting distance, so it should oppose electrical and mechanical force in gap ... ;-)
There was an article some time ago about device using very thin gap between conductors to generate electricity from temperature gradient (asymmetrical tunneling of electrons with different temperature). Main problem was to get conductors close enough and still keep place between them.
But with negative Casimir force it could be easier to manage this
So where is the catch ?
My hummer is environementally friendly, you insensitive, and very jealous, clod!!
Oh - I know - why don't enact a law that will only allow environmentally friendly vehicles to fly, provided that their owners follow a strict vegan diet
** rolls eyes **
I guess if it's something you don't like then it's ok to pass a law banning it, right?
OK, go ahead an mod me a troll now. MOD PARENT FLAMEBAIT.
How long before I can have my flying car?
The contest for ages has been to rescue liberty from the grasp of executive power. -- Daniel Webster
Is it me or are scientists assuming that there are no particles smaller then quarks now? For all we know the effect could be the result of really tiny widgets making ultra-tiny (even for widgets) ropes. Tossing them out and pulling!
-=[ Who Is John Galt? ]=-
So does this mean they've discovered the complete opposite of duct tape, or should there be a midichlorian joke here?
Just because you can mod me down, doesn't mean you're right. Shoes for industry!
first invisibility and now levitation, man these guys are on a roll, next up has to be teleportation...
Big Deal David Blaine has been doing this for years, w/o the need of overpaid scientists.
Reversing the Casmir effect would enable nanobots to "Put down" atoms or molecules which they have "picked up".
If we're moving through a swirl of particles that can put some pressure on plates, how come out of two object traveling at different velocities through space, one of them doesn't experience more drag than the other from these virtual particles?
Play Command HQ online
The universe has three sections: the part between the plates, the part to the left of the left plate, and the part to the right of the right plate. All three parts of the universe are undergoing adiabatic expansion and are thus applying pressure to their boundaries. Generally they have more success at the edges of the universe (near where the CMB appears) than at the surfaces of the plates since it isn't clear that they have anything to push against near the CMB, but the boundary conditions at the surface of a plate are different because of the universe on the other side. The universe in the middle of the plates doesn't do a good job of expanding because even virtual particles have trouble fitting in there (the plates form a high pass filter that attenuates any long wavelength standing waves), so the other two parts of the universe make it contract. Soon the virtual particles in the middle universe have very high energy and apply an imaginary pressure on the plates that counters the imaginary pressure being applied from the two external portions of the universe, and this affects the position of the plates relative to one another. The force can either be attractive or repulsive depending on the electromagnetic characteristics of the plates and their effects on the wave functions of the charged virtual particles inside.
The explanation of the Casimir effect is plagiarized from Wikipedia.
I think that I'd love to see frictionless bearings and hoverboards as much as any slashdotter, but I am afraid that I'm just far too much of a skeptic to buy that a magic lens can produce long-range matter repulsion.
Our greatest enemy is neither a single man, nor is it a nation, it is, as it has always been, our own greed.
tceffE rimisaC?
Didn't Led Zeppelin do a song about this? ...Oh wait, that was Kashmir.
The Hummer already is a grandfather (see H3).
And Mr. Blaine isn't overpaid ?
CAPCHA is 'fraudster' LOL
Great! Now I can keep the damn geckos of my windows, I just need to coat them with negative index of refraction materials.
Indeed. The power of privacy that comes with being an Alternating Commenter can be electrifying but is sometimes a revolting experience. It's sometimes better to take charge and post directly as your user name instead.
You can hold down the "B" button for continuous firing.
http://en.wikipedia.org/wiki/Ad_infinitum
"Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on,
While these again have greater still, and greater still, and so on."
http://en.wikipedia.org/wiki/Augustus_De_Morgan
Holy http://en.wikipedia.org/wiki/Holy
Siphonapteric http://en.wikipedia.org/wiki/Flea
Recursion! http://en.wikipedia.org/wiki/Recursion
Batman http://en.wikipedia.org/wiki/Batman
Why the hell did this get modded down? I think this is an insightful point.. he is right.
I used to post AC when doing this, but it's just Slashdot. I don't give a shit about my karma anymore. Mod me down all you want.
If creativity is the field, copyright is the fence.
Real hoverboards don't work on water, dumb ass. :I
I know it's not always true, but most of the time if someone is willing to pay more for something, that is because it's worth more. The reason Capitalism took so long to come about is that lots of people can't tell the difference between fraud and quality, and it wasn't until sophisticated property law that Avarice was more often OK than evil.
The point of the Market is to prioritize. Most research has a good output - but what about the opportunity cost? Nothing is free. The money for this lab might have been spent on a lab to cure malaria, for all we know. Sometimes the government picks things that are better for society that corporations, but that isn't always the case.
Most inventions are made by corporations, as are most goods, because politics doesn't confuse priorities in corporations. Research run by politicians is valuable to lobbyists, research run by Corporations is valuable to anyone who will pay. The latter is slightly more democratic.
Hallelujah. My username is finally getting the credit it deserves.
I hadn't known there were so many idiots in the world until I started using the Internet -Stanislaw Lem
Don't put those spinning type II superconductors away just yet kids.. The Casimir effect is so small it'll never lift my fat ass off the ground.
I remember the Casimir effect was measured using two closely spaced plates, but I thought it was an only-repulsive force, not attractive. Oops, I guess I didn't input that data correctly. Gosh I wish I had known that before. As always, just a reflection away.
But of course this is the natural way to build machines. Use the infinitely-renewable natural birth-force of the universe to keep things that do exist and are dynamically in opposition from crashing into one another. The birth-force of the universe emanates from nothing, but not from something. If there is no local space for the birth-force virtual particles to actualize into something, it shall extinguish and reincorporate as the force to either attract or repel any two objects considered in relation to one another. Is this not the perfection of "Good Fences Make Good Neighbors?" Something like "The Holy Spirit?"
I can't imagine this doesn't take place in thought, as well, and therefore in our personalities, and therefore in society.
I'm trying to imagine how fast a frictionless cylinder could spin in a vacuum. I wonder if this would be possible with data storage devices. Would it affect magnetic or optical storage? Anyone have any idea how hard it is to accomplish this repulsion? (In other words, any idea how soon we might start seeing children's toys based on this discovery?) Anyone know how much effect the Casimir effect has on what we call friction and how much is electromagnetic or otherwise? (In other words, once the Casimir effect is reversed, what else has to be done to alleviate friction? Or is this going to take electromagnetic friction out of the picture entirely?) And levitation aside, will this significantly reduce friction in machines that can be lubricated with oil, or will it simply make them maintenance free, more reliable, and marginally more energy efficient?
Sorry, I have so many questions. I'm really curious about all of this now!
... may the (Casimir) force be with you...
everyone can get reverse casimir effect, I know a guy who observed reverse friction http://www.totalizm.pl/free_energy.htm
I think I'm with the people who are thinking zpe. There should be a way to roll up multiple layers of this and form some sort of continuous quantum oscillator. Sad thing is, non of use will probably live long enough to really see the true impact of this type of technology.
If flat "Jo-blocks" (super flat gage blocks of metal that have been super-finished to laboratory grade tolerances, eg., +/- 1 microinch or so, their contact area is about 3/8" x 1", with thicknesses determined during manufacture) are wrung together, they will be difficult to seperate. A stack of them is assembled from a combination of sizes (in this case, the thicknesses) to yield a very specific stack-height. A stack of them can be held suspended by any of the blocks in the stack without the stacked blocks falling apart if they are wrung together correctly. I always thought this was due to the air literally being squeezed out of the contacting surfaces and the air pressure forcing (read: keeping) the blocks in 'contact'. Is this Casimir Effect related?
If they demonstrated the effect on wood. That would differentiate this from already well known magnetic levitation. Maybe a chess piece or balsa wood glider?
Always going forward, 'cause we can't find reverse.
what causes Teflon to stick to the pan.
Meh, again, because this is slashdot and reading articles from a week ago means you had to have been able to read a week ago.
--same guy that posted GP