Physics

2010 has just started with the best auspices to bring us exciting new science, and there comes a pledge to forecast what will happen in 2020. Oh, well - rest is not what I became a scientist for. Making non-trivial predictions today for how will basic research be in subnuclear physics ten years down the line is highly non-trivial. For exactly the opposite reason that it is equally hard in several other fields of research. Usually, in basic research long-term forecasts are complicated by the rapidity of the evolution of the field: one sits on the steeply rising slope of a curve describing our…

Our universe expands, and this expansion is accelerating. Current consensus is to attribute this acceleration to a mysterious form of energy: dark energy. This dark energy density is very tiny and therefore only notable at cosmic length scales. When expressed in natural units, the cosmic dark energy density has a value of 10-123. This tiny value presents a big mystery. Straightforward estimates for the dark energy density based on quantum field theoretical considerations result in values (again in natural units) close to unity. So, the measured dark energy density is smaller than this by a…

The success of today's particle physics experiments relies to a surprisingly large extent on a seldom told functionality of the giant apparata that detect the faint echoes of subatomic particles hitting or punching through their sensitive regions: the capability of triggering. All hadron collider experiments, such as those run by the CDF and DZERO collaborations at the Fermilab Tevatron, or the ATLAS and CMS collaborations at the CERN Large Hadron Collider, are endowed with complex, state-of-the-art, outstandingly designed, and precisely crafted systems which are generically called "triggers…

"One way of thinking about the confinement problem was suggested by e+ e- annihilation into hadrons. Initially, the virtual photon dissociates into a quark and an antiquark that move with almost the speed of light back-to-back. Feynman had argued that additional pairs would be produced in the region between them, along the line separating the initially produced . The new pairs and original would rearrange and become a bunch of outgoing mesons [...]. Feynman's theory of the process was very simple. He would put his hands in front of his face, almost touching. Then he would quickly…

"The threat is much stronger than its execution" Aaron Nimzovich (complaining to the arbiter of a chess match that his opponent had put a cigar in his mouth, after the arbiter had pointed out that the cigar was unlit).

The CDF Collaboration has recently produced a new analysis of proton-antiproton collisions at the now second-world-best collision energy of 1.96 TeV. They searched for very rare decays of the B mesons, particles composed of, would you guess, a b-quark and a lighter partner orbiting around each other. The B meson is a very fancy particle: its featured b-quark cannot be found in ordinary matter and is only produced in energetic particle collisions. However, the eight-years-worth of data collected by the Tevatron experiments contain billions of them by now. The CDF and DZERO experiments are thus…

This article is about physics but it fits under random thoughts also. My writing here on Scientific Blogging is self-educational, about what I am wondering and learning about. Today, it's multiverse theory. On Digital Journal I reported on the article featured on the January 2010 issue of Scientific American Magazine, "Looking for Life in the Multiverse," by Alejandro Jenkins, postdoctoral associate in theoretical high-energy physics at The Florida State University, and his colleague Gilad Perez, a theorist at the Weizmann Institute of Science in Israel, that juxtaposes the anthropic…

    Fundamental Theoretical Physics contains sequences of theories, each of which is explained by previous ones by rules of the classical logic. For example, optics is absorbed by the theory of electromagnetism, classical mechanics - by the special theory of relativity and quantum theory, the theory of electromagnetism and weak interactions - by the theory of electroweak interactions of Sheldon Glashow and so on. That means that basic notions and statements of every subsequent theory are more logical than basic notions and axioms of the preceding one.     When…

As if taken by a spell, my joking claim to be on strike in the last post grew to become one of the longest streaks of absence from blogging of the last few months, for a series of irrelevant reasons tightly packed together. In the meantime I have tried to put together an article on a recent very interesting measurement performed by the CDF collaboration: a study of very rare decays of B mesons, which can now not only determine the rate of said decays, but also have a taste at subtle kinematical effects in the distribution of the final states. The distributions are a new key to discriminate…

Brad DeLong picks up on some nonsense in Businessweek: Kevin "Dow 36000" Hassett of the American Enterprise Institute calls for the USAF to bomb both France and Switzerland, hoping to get the scientists in their tunnels before they can destroy the earth: Follow the link to DeLong's site if you want to read the original piece, which trots out Oxford Professors of Philosophy and a University of North Dakota Law Professor to explain why the LHC is going to destroy the world: [T]he collider’s energy could induce a catastrophic event. A brilliant review of the risks associated with the experiment…