Slashdot Mirror
Amherst Researchers Create Magnetic Monopoles
An anonymous reader writes "Nearly 85 years after pioneering theoretical physicist Paul Dirac predicted the possibility of their existence, an international collaboration led by Amherst College Physics Professor David S. Hall '91 and Aalto University (Finland) Academy Research Fellow Mikko Möttönen has created, identified and photographed synthetic magnetic monopoles in Hall's laboratory on the Amherst campus. The groundbreaking accomplishment paves the way for the detection of the particles in nature, which would be a revolutionary development comparable to the discovery of the electron." That's quite a step beyond detecting monopoles; the
Nature abstract is online, but the full paper is paywalled.
But how many slashdot stories about fusion reactors, methanol fuel cells, or flying cars has actually been more than investor fleecing vaporware?
.. and can certainly help in the fight against the Ur-Quan!
A government is a body of people notably ungoverned - AC
"The secrets of magnetism"
Requires Superstring Theory, Silksteel Alloys
Leads to Nanominiaturization, Unified Field Theory
Enables: Terraform Mag Tube
someone wasn't playing a trick on them and was turning the electric can opener on and off in the other room?
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
they haven't really found a magnetic monopole. They've created a long skinny solenoid with ends that are far enough apart that they look like independent monopoles.
Great physics, terrible summary.
You could run an electric utility, four railroads, and get out of jail free if this can be produced to scale.
Gently reply
Not the theory put forth by Paul Dirac 85 years ago.... but, otherwise, yes - this is essentially a different source of magnetism from that created by moving electrons.
Except that as far as I understand it, those classical equations are unaffected. It's a quantum-scale effect.
A successful API design takes a mixture of software design and pedagogy.
That's some misunderstanding of what a scientific theory is, right there. A theory must have predictive power - it must be useful for something, that is. Electromagnetic theory, so far, is extremely successful precisely because it works where we need it to work. The monopole demonstration doesn't change it one iota - neither your computer nor your electric plant have stopped working overnight.
It doesn't matter in practice that it doesn't work everywhere, and there's no need to rewrite anything and there's no contradiction. We know that the classical theory of electromagnetism, well, applies to classical scale phenomena, under certain conditions. No scientist in their sane mind would insist that this effect contradicts the classical theory. It's simply outside of the classical theory's scope, just as relativistic effects are outside of the realm of classical mechanics.
The real problem is with extremely widespread, naive understanding of what a scientific theory is and that there are limits to applicability of any scientific theory of nature. The phrase "law of nature" is perhaps the biggest romanticism-imbued snafu there ever was in popularization of science.
A successful API design takes a mixture of software design and pedagogy.
Theory (due to Paul Dirac's work combining quantum mechanics and relativity in the first half of the 20th Century) had been predicting monopoles for a long time. Yeah, the simplified version that you were quoting from didn't predict monopoles, but the full version did. If the submitters of the paper have found one of these rare beasts in the lab, that's a very interesting confirmation.
The real question is whether the result can be reproduced by different experimenters in a different lab. (Since it's lab-scale work, that ought to be possible.) If so, watch out for some really interesting new areas of physics to be opened up.
"Little does he know, but there is no 'I' in 'Idiot'!"
These are pseudoparticles. They're like magnetic monopoles in almost all ways, but they arise from the collective motion of other particles rather than actually existing in and of themselves (think about having an electron hole, versus having an actual positron). The breakthrough is that they've made the first pseudoparticle in a quantum mechanical regime that allows it to behave consistently with the real particle.
No kidding!!! What do you say at this point?
Also, would this allow for the development of an over unity, energy from nothing generation machine.
The answer to that question is always, always no. Except when it's still no, in which case it is no. No.
In conclusion, no.
(no sig)
They actually coaxed a BEC into "simulating" a magnetic monopole. http://www.nature.com/news/qua...
No kidding!!! What do you say at this point?
Meaning, that if they have a south monopole somewhere in their "extremely cold gas", someplace else within the same gas has a north monopole. Then just consider the line linking both to be the magnet.
Call us back when they can separate them by splitting the "extremely cold gas" into 2 containers, in such a way that one container has the south pole, and the other the north pole, and both can be moved arbitrarily far from each other.
My previous supplier has left me high and dry and I can't finish my perpetual motion machine without one of these. Can I get a discount on more than one? Or do I have to buy them one by one to avoid them neutralizing each other?
"Now, I doubt any of you would prefer a rolled up newspaper as a weapon against a dictator or a criminal intruder."
The spinor order parameter corresponding to the Dirac monopole14,17 is generated by an adiabatic spin rotation in response to a time-varying magnetic field, B(r, t). Similar spin rotations have been used to create multiply quantized vortices18 and skyrmion spin textures19. The order parameter Y(r, t)5y(r, t)f(r, t) is the product of a scalar order parameter, y, and a spinor, f~ðfz1,f0,f{1T¼^ jfi, where fm5Æmjfæ represents the mth spinor component along z. The condensate is initially spin-polarized along the z axis, that is, f5(1, 0, 0)T. Following the method introduced in ref. 14, a magnetic field Bðr,t~bqðxx^zy^y{2z^zzBzðt^z is applied, where bq.0 is the strength of a quadrupole field gradient and Bz(t) is a uniform bias field. The magnetic field zero is initially located on the z axis at z~Bzð0=(2bq)?Z, where Z is the axial Thomas–Fermi radius of the condensate. The spin rotation occurs as Bz is reduced, drawing the magnetic field zero into the region occupied by the superfluid.
No. Maxwell's equations are essentially symmetric with respect to electricity and magnetism. Not surprising, since they are really the same thing. The form that you usually learn in school reduces the equations by having magnetic charge = 0 and magnetic current = 0 everywhere, since as far as we know, that's the world we live in. But magnetic monopoles are in no way disruptive to our understanding of how electricity and magnetism work.
So you're saying there's a chance...?
We don't have a state-run media we have a media-run state.
You should be thanking Alan Guth and the Gods of Inflation they didn't find actual monopoles. Those things are terrifying beasts! They eat protons like it's going out of style!
http://www.npl.washington.edu/...
Those people who think they know everything are a great annoyance to those of us who do. (Isaac Asimov)
Well, they created a magnetic monopole but they didn't create a magnetic monopole. :) They created a magnetic field without it's corresponding opposite field (or actually the opposing field was separated by enough physical distance that they behaved independently), but they didn't create or detect the particle which in theory generates that field.
No it doesn't contradict previous theory. The existence of a magnetic monopole would require adding some extra terms in Maxwell's equations: one for magnetic "charge" (the monopole) and one for magnetic "current" (moving monopole) analogous to electric charge and current. (Adjusting Maxwell's equations this way is a popular exercise in advanced undergrad / grad level E&M courses). If your system happened to have a magnetic monopole in it, then you would need to use the equations with the extra terms. You would see some extra effects due to the monopoles, but they would be accounted for. The extra terms would give a nice symmetry to Maxwell's equations, helping to demonstrate that the electric and magnetic field are manifestations of the same phenomena (which isn't clear until you get to special relativity).
But how many slashdot stories about fusion reactors, methanol fuel cells, or flying cars has actually been more than investor fleecing vaporware?
These are not actually Dirac monopoles. These are magnetic quasiparticles that behave in a way that simulates Dirac monopoles.
The Ars Technicha article has the best explanation:
http://arstechnica.com/science...
Emphasis mine:
"Since we can't seem to find one, though, some researchers decided to emulate monopole behavior using an analogous quantum system. They used a Bose-Einstein condensate: a collection of very cold atoms that behaves like a single quantum system."
http://www.geoffreylandis.com
no, that equation still holds with no known exceptions.
summary is wrong, no monopoles were produced, just a formation that in some ways resembles one but is not a magnetic source or sink.
really, the sensationalist nonsense of half of slashdot's headings needs to stop
(magentic north be damned)
Agreed. I far prefer roseate north.
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
Just like Einstein didn't make anything Newton discovered incorrect.
Of course he did. Newton's laws of motion are wrong, but they're still close enough for use in certain scales and applications. The small angle approximation is wrong, but it still lets you do some trig in your head. Truncating a series expansion after just a few orders is wrong, but that's often all you need.