Physics

I just read a very nice article by Nature's Zeeya Merali, and I thought I would link it from this blog. It discusses in detail several aspects of the sociology of the very large communities of particle physics experiments taking place at CERN.
The CDF Collaboration blessed yesterday afternoon the results of a search for massive Gravitons decaying into pairs of Z bosons. And it is a startling new result!

Usually after a blessing (which is the result of a collaboration-wide presentation when the analysis is given a final scrutiny) the results are not immediately made public: this non-written rule has the purpose of allowing the analysis authors to be the first to present the results at a conference or other public event. But the rule written in the CDF bylaws, on the other hand, say that after a blessing the result is public, so for this time I will stick to the written one, and fair play be darned this time... The chances to announce what might be the first evidence of gravitons is too appealing!
The formulation of a fun physics problem with practical -and pleasant- applications occurred to me yesterday. I am currently spending a week in Madrid with my family, and we have chosen a very nice hotel in the suburbs, sacrificing travel time to the center for comfort. Among other things, the hotel offers a nice pool with several water jets along the sides. These are meant to allow you to swim against the water stream, so that you keep the same position as you push yourself against the stream.

 

Birefringence and the polarized light

1. Definition

We are on. This afternoon just after 1PM the LHC beams have started to produce proton-proton collisions in the heart of the experiments, at the never-before achieved energy of 7 TeV.

It was a long journey to get here -the project is twenty years old- but this is just the start of a new, more exciting one: In the course of the next two years, the Large Hadron Collider will gradually increase its power, allowing the CMS and ATLAS detectors to collect enough data to significantly extend into discovery territory.
So how dangerous is the Large Hadron Collider? How likely is it that when operated at maximum energy the LHC will create a black hole and wipe out earth? Eric Johnson, assistant professor of law at the University of North Dakota and author of the report The Black Hole Case: The Injunction Against The End Of The World, writes in a recent edition of New Scientist:
Scientists have discovered the world's smallest superconductor, a sheet of four pairs of (BETS)2GaCl4 molecules less than one nanometer wide.

Their new Nature Nanotechnology study provides the first evidence that nanoscale molecular superconducting wires can be fabricated, which could be used for nanoscale electronic devices and energy applications.
The "exceptionally simple theory of everything," proposed by physicist Antony Garrett Lisi in 2007 does not hold water, according to a particle physicist and mathematician writing in Communications in Mathematical Physics.

In November of 2007, Lisi published an online paper entitled "An Exceptionally Simple Theory of Everything." The paper centered on the elegant mathematical structure known as E8, which also appears in string theory. First identified in 1887, E8 has 248 dimensions and cannot be seen, or even drawn, in its complete form.
Two and a half months since Erik Verlinde submitted his entropic gravity paper, and all of physics and cosmology has turned into entropy. Well, I am exaggerating a bit, and perhaps more than just a bit. Yet, fact is that within two weeks of Erik's publication a steady stream of 'entropic everything' papers has developed at a rate of close to one paper per day. Gravity, Einstein's equations, cosmic expansion, dark energy, primordial inflation, dark mass: it's all entropic. Chaos rules.