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Posted on 11/16/2011 5:53:30 PM PST by neverdem
Twenty-three-year-old conjecture set to guide future quantum field theories.
When John Cardy proposed a far-reaching principle to constrain all possible theories of quantum particles and fields1, he expected it to be quickly rebutted. But for almost 25 years that hasn’t happened — and it now seems that his theorem may have been quietly proved earlier this year.
If the solution holds, it is likely to guide future attempts to explain physics beyond the current standard model. It will certainly have implications for any previously unknown particles that may be discovered at the Large Hadron Collider (LHC) at CERN, Europe’s particle physics lab near Geneva, Switzerland.
“I’m pleased if the proof turns out to be correct," says Cardy, a theoretical physicist at the University of Oxford, UK. “I’m quite amazed the conjecture I made in 1988 stood up.”
His conjecture is called the a-theorem. It says that the number of ways in which quantum fields can be energetically excited (a) is always greater at high energies than at low energies.
The proposed proof2, from theorists Zohar Komargodski and Adam Schwimmer of the Weizmann Institute of Science in Rehovot, Israel, was put forward in July 2011, and is now gradually gaining acceptance as other theoretical physicists have a chance to check it.
“I think it’s quite likely to be right,” says Nathan Seiberg, a theoretical physicist at the Institute of Advanced Study in Princeton, New Jersey.
Many quantum field theories have yet to be exactly solved, meaning that they cannot be used to produce comprehensive predictions of what particles will do. One example is quantum chromodynamics — the theory of the strong nuclear force that describes the interactions between quarks and gluons. That lack leaves physicists struggling to relate physics at the high-energy, short-distance scale of quarks to the physics at longer-distance,...
(Excerpt) Read more at nature.com ...
Like, *PING*, dudes and dude-ettes.
See if I got that ~ (1) At real low energy levels you have fewer options than you have at real high energy levels.
(2) Corollary 1: At real high energy levels you have more options than you have at real low energy levels.
(3) Corollary 2: At real low energy levels you might have no options, but at real high energy levels you might have many options.
(4) Corollary 3: At real high energy levels you might have many options ~ but not an infinite set of options, which is better than being at real low energy levels with no options at all.
I am sure there are thousands of permutations and combinations. Uh, that's a conjecture. No doubt some teenager is working on that one to see what the limits are.
At the rate this sucker progressed he'll be famous in a couple of hundred years!
Why I ask is it was recently brought up that math seems to have an existence totally separate and apart from "reality" which means purely mathematical proofs can really lead us astray.
Ping me when these taxpayer-supported theorists figure out anti-gravity drive, faster-than-light propulsion, or any other useful advancement.
Oh, like I don't have enough to do at my day job?
I think it’s amazing how physical theoreticians come up with their guesses, often decades in advance of any experiment that could prove them true or false. In the field, I wonder what the guess to hit ratio is? Are there a thousand, a million almost-Einsteins to every Albert Einstein?
It’s an intriguing area of study, whatever else it is, and sometimes theoreticians do anticipate stuff that doesn’t become apparent in the lab for years.
I don’t know about faster than light travel (the G forces would be to kill), but faster than light signaling would be a good start. And earlier this year someone allegedly found that this was happening with a beam of neutrinos. Not all that much faster than light, just a trifle. But the fabled tachyon, a particle which cannot travel any slower than light, might have been seen in the lab.
Milk thistle stops lung cancer in mice
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Too long after heart attack, bone marrow cells lose effect: study The story links a FReebie.
AHA: Cardiac Stem Cells Show Promise in Heart Failure
FReepmail me if you want on or off my health and science ping list.
Simply put: If it quarks lika luck, it musta be a gluon. I believe this theory was originally developed by Chico during a night at the opera.
... and one more time: read John Horgan's book, The End of Science
Perhaps, but for every theoretician who brings forth a new understanding of fundamental physics that leads to a practical and useful advancement, there are hundreds more who do nothing with their lives but poke around with arcane and esoteric formulas, while sucking a living off the taxpayers.
Some, like Stephen Hawking, even become cultural icons, while giving back little of exchangeable value to the world. Pardon if I don't hold most of these people in high esteem.
Seems like Albert Einstein came up with some gnarly stuff without taking a taxpayer dime. Reforming the system wouldn’t kill it. There is some measure of national prestige, however, viewed by high muckety mucks. Kind of like the space and moon shots.
If I recall my history correctly, Einstein wrote his most famous work while he was a postal employee, and yes, his work led to some practical applications.
Reforming the system wouldn’t kill it. There is some measure of national prestige, however, viewed by high muckety mucks. Kind of like the space and moon shots.
Engineers did more to put men on the moon than any physicists did.
Albert Einstein was a Patent Examiner in Bern, Switzerland.
Right you are. Thanks for the correction.
I certainly agree with you if we were to tabulate the diploma fields of NASA for example. But keep in mind that this was not the case when the theoretical foundations of space flight and its machines were being developed in the 1930s though about the 1950s.
Physicists are engineers but the opposite of this does not hold too accurately. That is, an engineer is a physist usually only at a basic level or narrow specialty. Physicists and engineers work within the same universe if you'll pardon the pun but a physicist usually tends to the theoretical whereas the engineer tends to the applied. Chemists also overlap with physicists in the area of thermodynamics and kinetics for examples. To give a specific example, I worked with one physicist that designed the computer chip in my company's process analyzer products that ran at gigahertz speed in the late 1980s plus designed the circuits (electrical engineering), the math algorithms that needed the high speed (mathematics) and wrote the programming (computer science). I am an engineer and my job was to apply the technology so the company could make a profit.
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