Slashdot Mirror
First Experimental Success of a Superfluid
J writes "Researchers at Rice University have created and observed a state of quantum superfluidity. Cooled to temperatures near absolute zero, fermions overcome their natural tendency to repel one another. These half-spin particles become dominated by the Strong force and couple up in pairs that behave as one particle. Major benefits to matter in a superfluid state include superconductivity, a state where electrons would flow freely with no resistance, thus preserving the most amount of electrical charge during passage and providing the ability to save billions of dollars in 'lost electricity'. Although the conditions set for this experiment are very unlikely to be able to exist outside of a laboratory, we now know that superfluidity is a concept that can exist. Future research in this topic is assumed to be finding a material that exists in a superfluid state at room temperature."
The research, which appears online this week, is slated to appear in an upcoming issue of the journal Science, together with a paper from MIT reporting related results.
The content of both articles is beyond my comprehension of physics, but it looks like they're both aware of each other's work...
How is this different from a Bose-Einstein condensate?
Fermions are the group of particles that include leptons (the family that includes electrons and neutrinos), and hadrons (the family that is composed of quarks--makes up nucleons like protons and neutrons). They follow the Pauli Exclusion principle, which states that no two particles can have the same quantum numbers. This article states that it gets around the Pauli Exclusion principle because the particles "link up" by opposite spins. It doesn't exactly say how that occurs. What particles are we talking about? Electrons, protons, or neutrons, or a composite of particles?
I'm not exactly sure how a Bose-Einstein condensate creates a single quantum state, but is this more of the same?
Major benefits to matter in a superfluid state include superconductivity, a state where electrons would flow freely with no resistance, thus preserving the most amount of electrical charge during passage and providing the ability to save billions of dollars in 'lost electricity'.
That does, of course, depend on finding a way of cooling the conductor to near absolute zero along it's entire length, using less energy than would be lost during transmission on a normal cable. In other words, it's a pretty ridiculous suggestion
Science Daily are a bunch of 'tards who do no fact checking. It was MIT who discovered it, but it wasn't recently.
:)
Wikipedia knows.
My guess is that some discovery occurred, but the reporters who have only the vaguest understanding of science, didn't understand it.
In the spirit of Christmas, I'll forgive the mistake today. As long as they take care of the problem by tomorrow.
Mod me down and I will become more powerful than you can possibly imagine!
Superfluid materials are well-known; the first example, the boson helium-4, was discovered in 1937. The superfluidity of helium-3, a fermion, was shown to be a superfluid in the 1970s.
Superfluidity occurs when particles pair up (half spin-up and half spin-down) to produce a material without viscosity, in a manner analogous to that of the electron Cooper pairs of superconductivity. The novelty here is that superfluidity has been shown to occur in particle populations in which there is an unequal number of spin-up and spin-down particles, and the discovery of a phase change in which "when unpaired spin-up atoms rose above 10 percent of the total sample, the unpaired loners were suddenly expelled, leaving a core of superfluid pairs surrounded by a shell of excess spin-up atoms" (from TFA).
Helium in superfluidic state has been known for a long time, and studied quite extensively. So, superfluidity is not the issue here.
This achievement, it seems to me, is about getting superfluidity in a bunch of fermions (such as electrons, or, in this case, 'fermionic' lithium-6), and that too in a system in which the up-spins are not the same as the 'down-spins'.
Well to the people who said 'Superfluidity is old news' It is true superfluidity has been around for many years (discovered by Pyotr Leonidovich Kapitsa, John F. Allen, and Don Misener in 1937). However the 'study of superfluidity' (also known as Quantum hydrodynamics) is a recent advancement. (and a very important one I might add)
For those wondering about its 'practical uses', Superfluidity not only unleashes possibilities for new technologies dealing with energy and heat transfer (superconductivity), it also brings us another step closer to developing a better means of energy production. (Check out the link below for more details)
For those of you with a background in atomic physics; If some how (using further experimentation in Superfluidity of helium) we can proove the possibility of electrons in quantum states 'lower' than n=1 (i.e. n=1/2, 1/4 etc) the amount of energy we can produce using hydrogen would increase by almost 70% compared to our present technology (greater than the amount produced by nuclear means) This in turn means that the race for nuclear energy going on in the east (russia, iran, cuba, north korea, china, india etc.) would end.
For more information on the possibility and importance of fractional primary quantum numbers click here.
...describing result here.
Randall Mills is a medical doctor and well known crackpot who has been bilking investors out of their money for years now with his "hydrino" theory, which rests on the idea that there are energy states in the atom lower than the ground state (as the above poster mentioned). The only problem is that no such states actually exist as far as all experiments are concerned, except mysteriously Mills' own experiments, which no one has ever reproduced and the details of which he refuses to release. His hydrino theory itself is based on his "Grand Unified Theory of Classical Quantum Mechanics", found in his 1200-page self-published book, which purports to unify electromagnetism, gravity, Newtonian mechanics, general relativity, and quantum theory.
+4 Informative, my ass.
(And to address another point, I cannot think of any "new technologies" in "energy and heat transfer" that have been "unleashed" by superfluidity.)
Fermions are anything with spin (2n+1)/2, whereas bosons are anything with integer spin n. In both cases n is an integer. Atoms can also be fermions if the electron configuration dictates it (electrons are fermions but the electron configuration may cancel out and make the net atom into a boson), For example helium atoms are bosons but silver atoms are fermions. In fact, the original Stern Gerlach (did I spell that right?) experiment was done with silver atoms. About a year ago I saw a presentation where some people in Spain I believe were using BEC to slow light down. They had some pictures of a monoatom which were black dots. I barely remember the presentation though.
History will be kind to me, for I intend to write it - Sir Winston Churchill