Physics

The Quantum Randi Challenge (QRC), first introduced here, exists in order to stop the spread of pseudo-science by simply teaching quantum mechanics. Here is the official version of the challenge (also published here and partially in Annals of Physics 339: 81-88). [We are still looking for people who can help to turn it into a multiplayer internet app.*]


What is a “Randi-type” challenge?

According to Feynman, the 2-slit experiment with electrons "has in it the heart of quantum mechanics" and "is impossible, absolutely impossible, to explain in any classical way". To begin with, it may not be amiss to inform the never-ending discussion of this experiment with a knowledge of the rules that go into calculating the predicted and observed interference pattern.

The mathematical formalism of quantum mechanics can be built up on the basis of the following rules. Suppose that you want to calculate the probability of a particular outcome of a measurement M2, given the outcome of am earlier measurement M1. Here is what you have to do:
The ATLAS Collaboration, one of the two high-energy physics experiments at the CERN Large Hadron Collider, has just produced updated results of their ongoing search for new heavy particles decaying into lepton pairs. They are now using up to 236 inverse picobarns of 7 TeV collisions, which is seven times more data than previous searches based on 2010 datasets. A seven-fold increase in data size grants a significant increase in sensitivity, so it is worth taking a look at what they see.

Quantum physics has proven that the world cannot be described by local realism. Therefore, Many-Worlds Interpretations (MWI) are now in vogue.

This is already wrong: Everett's is a relative state description, not necessarily a multiple worlds interpretation.

New results from the T2K collaboration have been presented at a KEK Physics Seminar today, and they are really interesting stuff. In a nutshell, six electron neutrino events have been seen by their far detector, illuminated by a pure and intense beam of muon neutrinos. The estimated backgrounds from non-oscillating-neutrino sources are estimated to amount to 1.5+-0.3 events, and the observed counts thus constitute a 2.5-standard-deviation effect, hopefully a first hint of direct detection of nu_mu -> nu_e oscillations.
The LHC has been running very well in the last few weeks, and I can announce, with some anticipation, that the 1-inverse-femtobarn line will be crossed in the next few days. Check it out in the figure below, which shows, together with the delivered luminosity (red line), the one acquired by the CMS experiment (that is, the part acquired with CMS fully operational).

The total bounty available before the next shutdown (end of June) is probably going to amount to 1.3-1.4/fb. Expect exciting new results by ATLAS and CMS for the summer 2011 conferences!
CMS has recently produced an updated search for black hole production in the 7 TeV proton-proton collisions delivered by the LHC. The data sample now consists of 190 inverse picobarns of collisions collected in 2011, and the limits set on black hole production are more stringent.
I got counter snarked. At the end of my blogs, I include what I call a snarky puzzle. If you can follow along with the technical parts of my blogs, a snarky puzzle is  suppose to be a playful but snide problem with a straightforward answer. David Halliday asked a question of his own which I will present after setting up the context.
click or skip this reading of the blog
The British have their Copley medals, the French the CNRS Gold medals, the Germans have Leibniz awards, and the Dutch... they have their Spinoza prizes. Each year three to four Spinoza laureates split a total of ten million euros (14.3 mln US$). In the Netherlands the prize, named after the Dutch philosopher Baruch Spinoza, is often referred to as the 'Dutch Nobel Prize'. No other Dutch science prize comes close, neither in monetary amount nor in prestige. 

Amongst the three winners of this year's Spinoza prize is theoretical physicist Erik Verlinde.* A well-known name for readers of this column.

And here they come. Much awaited (and anticipated), today the DZERO collaboration presents their findings in the search of the same dijet resonance which made it to the New York Times as well as to several physics blogs around the web, and which brought frantic theorists back to the blackboard to try and figure out a model that could allocate the cumbersome new find.