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Relativity Finally Meets Quantum Theory?
prion86 writes "Physisist Fotini Markopoulou Kalamara (try saying that 3 times fast) believes she has found a way to blend relativity with quantum theory. The article can be found on the Scientific American site."
Just like to point out that what she's doing is combining relativistic gravitation with quantum physics to produce the physicist's holy grail - quantum gravity.
Merely mixing relativity and quantum theory has been done for years and years - the form of the strong nuclear force was found by Yukawa to be a solution of the Klein-Gordon equation - which was proposed in 1924. The relativity papers were published in 1905, 1908.
OK, so I haven't actually clarified anything at all, have I?
Physisist Fotini Markopoulou Kalamara (try saying that 3 times fast)...
Try saying "physicist" once, and slowly.
Lisp is the Tengwar of programming languages.
Wow.. you must be really smart to be calling Stephen Hawkings a layman ;)
...can be found in the arXiv database. A search for Fotini gives ten results between 1997 and 2002, most of them published in well-known journals, such as Phys. Rev. D, Nucl. Phys. B etc. Not that I understand any of it, by the way...
Some of the players in loop quantum gravity (LQG) before Kalamara are Abhay Ashtekar, Lee Smolin, Carlo Rovelli, John Baez and Chris Isham. Also, Julian Barbour has written a cute semi-popular book called The End of Time on the subject as has Lee Smolin---Three Roads to Quantum Gravity
Anand Rangarajan anand@cise.ufl.edu
I suspect people haven't yet forgiven him for creating the Daleks.
Why are women always associated with cooking? Maybe she does cook well but that's not the point of the article... so why open and close it with that?
It looks like the cooking analogies CAME FROM THE SCIENTIST HERSELF. Perhaps you should try to convince her to act less stereotypically feminine -- because you say so.
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Correct spelling of "Glass Ceiling": C-H-I-L-D-R-E-N.
Such a mentalistic approach to quantum mechanics is a fairly odd approach to take. For starters, it seems to be much more anthropocentric than we would usually like physics to be, indeed when Wigner first suggested a mentalistic theory of wave function collapse in the 1950s, people thought he had gone mad. The other problem is identifying exactly what kind of mind counts as an observer; does a rabbit observe? Maybe we want something more intelligent than that? How about a chimpanzee? If we start at this point, then we simply ask ourselves, how about if we made the chimpanzee a tiny bit less intelligent, an infinitessimally small amount less. Do we still want to allow him to be an observer? Of course we do. Now, let's repeat the process a near infinite number of times. What do we have? Something much less intelligent being an observer that we didn't initially want to be one. The same argument applies if we start from a human also. We have to define some threshold of intelligence, therefore. But this is hideously arbitrary and not the kind of pattern that we want to see in nature or in our scientific theories. The term observer is difficult to define, and does not, therefore, lend itself to inclusion in a well defined theory of physics. See my post on quantum observers for further complaints.
John Baez is a well-known mathematician/math. physicist who works in, among other things, quantum gravity. He is also very well known for the Usenet column This week's finds in mathematical physics, which is certainly worth a look a t if you're at all interested in these things and have a bit of a mathematics background.
One of the great things about TWFiMP is the writing style: when reading it, one really does get the idea that one understands what's going on. Of course this tends to wear off soon after leaving the computer, but. At any rate, many of the TWFiMP talk about spin networks and quantum gravity, including for example week 43 and week 55. Week 110 talks specificially about Penrose's spin networks. He mentions some of Markopoulou's work in week 99, week 114 and week 133. These might provide a bit of a middle-ground between the very fluffy SciAm article and the hard stuff on arXiv.
Of course there is also Markopoulou's recent expository article, which is a great introduction!
I'd like to see more stories like this on slashdot. It would be nice if we could spend more time contemplating real science and less time bashing microsoft.
I for one spend to much time being bitter at microsoft and not enough doing interesting things.
The EPR 'paradox' isn't a problem at the level of physics. Quantum theory (even non-relativistic) makes very clear predictions about the statistical properties of measurements on spatially separated but correlated particles, and experiments agree. There is no violation of causality. No information propagates faster than the speed of light. Certainly the effect is weird, and it conflicts with some of our naive (i.e. non-quantum) intuitions of how to interpret a physical theory, but there is no logical contradiction and no need to extend or modify the quantum theory to account for experiment.
Wavefunction 'collapse' has some interesting details to be worked out, and some deep matters of interpretation that could use clarification, but it also to date presents no conflicts between experimental results and theoretical predictions. Wavefunctions follow the time-dependent Schrodinger equation, always. It's just when the quantum mechanics extends substantially into macroscopic systems with very large numbers of degrees of freedom, the dynamics of the many-body correlated wavefunction becomes quite complex and our regular intuitions can't keep up very well.
One thing to keep in mind is that wavefunctions do not exist, according to a reasonable definition of exist. The only thing that exists is that which can be measured, that which is physically observable, that which is accessible to an experimental observation. A wavefunction is not physically observable. It is a mathematical tool used to make predictions about experimental results. The simultaneity of collapse of a wavefunction isn't like the simultaneous collapse of say an egg carton. All physical properties related to the process of collapse of an egg carton can be measured by experiment as a function of distance across the carton: density, shear forces, stresses, shape, etc. Not so for a wavefunction.
Curtains for windows?