Dave Bacon explains why he is not a Bohmist. While I doubt it will turn out to be a correct interpretation of quantum mechanics, I think the Bohm interpretation deserves to be better known, since its existence contradicts a certain amount of conventional wisdom on the meaning of quantum mechanics.
I had no idea that David Bohm himself was driven out of the country by McCarthyism.
ArXiv has announced a new numbering scheme for preprints. Instead of yymmnnn, they will now use yymm.nnnn. In a time of dizzying change, arXiv has taken from us one of the few constancies we had. Won’t they think of the children?
From Asymptotia, I just learned about the Antikythera mechanism, an ancient Greek analog computer. Its full capabilities are not yet known, but the device’s thirty interlocking gears simulate the movements of the Sun, Moon, and Earth well-enough to predict eclipses. Not much is known about the history of the mechanism, which uses technology that was not reinvented until the fourteenth century.
In a blow to the physics weblog community, Christine Dantas has closed her weblog, and deleted all of the posts but one. She outlines her reasons on Physics Forum. She had gotten embroiled in the fight over string theory (even in the Brazilian media), and as she put it:
You see, I do not have the right temperament for “living in the blogosphere”…
I am a quiet person, and wish to go back to my quiet life, to my quiet readings and studies.
It’s a fairly tragic development: Christine had been teaching herself various alternate approaches to quantum gravity, and would summarize her readings. It was evolving into a handy guide to the literature. She was also unfailingly polite, an obvious rarity on the internet.
Via the comments at Not Even Wrong.
Bee of Backreaction has an excellent summary of the evidence for the existence of dark matter.
Backreaction has a long post on applications of the AdS/CFT correspondence in heavy ion physics. The topic is interesting because it is a potential experimental prediction derived from string theory. Interestingly, it doesn’t involve string theory as a theory of everything; instead it uses string theory ideas to make calculations about quark-gluon plasma.
Penny Smith has posted a preprint to arXiv, Immortal Smooth Solution of the Three Space Dimensional Navier-Stokes System that, if correct, would solve one of the Clay Institute’s Millenium Problems. Christina Sormani has created detailed summary of Smith’s work on PDEs and Navier-Stokes.
The Navier-Stokes equation is a set of equations that describe fluid flow in Newtonian mechanics. The equations are notoriously difficult to analyze. The existence of smooth solutions for all time (the meaning of â€œimmortalâ€ in the paper title) has long been an open question. One now perhaps closed.
Via Peter Woit.
Update. The paper has been withdrawn. (Via John Baez in the comments.)
I’d like to point out that the 2006 Nobel Prize in Physics was awarded for this diagram:
No word on whether the original diagram included the same caption. More information available from Backreaction. Graphic via XKCD.
I’m back from vacation. With any luck, I’ll even think of something to say. Until that happens, I wanted to link to Peter Woit’s post, Open Access Publishing, which links to this CERN task force report on the subject. I haven’t read the report, but Peter’s description makes it sound pathetically timid. As he characterizes it:
The CERN task force doesnâ€™t seem to me to be providing a viable long-term plan for moving to the kind of open access model they are supporting. It doesnâ€™t address the fundamental problem of keeping a system where physicists hand over the scientific literature to Elsevier, then have to figure out how to buy it back.
The enterprising citizen-journalists affiliated with the Huffington Post have discovered the truth about me: I am a Pluto-hating fiend. First we remove it from the list of planets, next we remove it from the sky altogether…