Physics

Thermonuclear fusion can be achieved through a controlled reaction between two light variants of hydrogen, called deuterium and tritium - that sounds simple enough but improving the ignition stage of fusion reaction isn't trivial. Theoretical calculations described in a paper published in EPJ D involve increasing the uniformity of irradiation using high-power laser beams on the external shell of a spherical capsule containing a mix of deuterium and tritium.  Reaching uniformity of irradiation matters. Indeed, if it can be achieved, it rapidly heats up the capsule and makes it…

The president Fernando Ferroni sent today an open, touching message to the personnel of the National Institute of Nuclear Physics, the Italian research organization he directs. The INFN contributed to the discovery of the Higgs boson by participating to the CMS and ATLAS experiments at CERN, providing funding and personnel -administrative staff, technicians, and researchers who are active members of the two big collaborations and who gave critical contributions to the discovery. Particularly significant is the last paragraph in Ferroni's message (I hope he will excuse my rough translation…

Researchers have come one step closer to understanding unstable atomic nuclei. The protons and neutrons inside the atomic nucleus exhibit shell structures in a manner similar to electrons in an atom. For naturally stable nuclei, these nuclear shells fill completely when the number of protons or the number of neutrons is equal to the 'magic' numbers 2, 8, 20, 28, 50, 82 or 126. But not always. For exotic nuclei, 28 is not a magic number of neutrons. Traditional magic numbers, which were once thought to be common for all nuclei, can change in unstable, radioactive nuclei that have a large…

Today I was in the mood of cleaning up some areas of my labyrintic hard drive, after having performed a periodic backup of its contents. I thus came across some pieces of text that had been sitting in a remote folder, waiting to be used for a project now obsolete. I was about to just dump these files in the trash bin, when it occurred to me that this was stuff that had taken me some good time to put together, and maybe there was a better use for it. Indeed, I have a blog ! This blog is in some sense a kind of "trash bin" of my thoughts, which I happily share with whomever is willing to read…

HIGGS AND ENGLERT! Note: this article is being updated in real time as events unfold... Updates are at the bottom. Note in particular the 12.05 update...! --- Everybody is waiting for the announcement of the recipients of the 2013 Nobel Prize in Physics, which will happen at today 11.45AM CET. The prize giving announcement has always been an entertaining moment, but this year many expect that a recognition will be given to the discovery of the Higgs boson. Last year the finding was declared by the CERN experiments on July 4th, making it impossible to award the prize in 2012 (it was too late…

It bugs me a little when 'time' is randomly called a dimension in casual talk. Since just after Einstein's relativity, we've been treated to the mathematical idea that time is its own dimension - though Einstein never said that. The pickle in the ice cream for 19th century physicists was light. Or, to use my other unnecessary metaphor from The Genesis of Supersymmetry, Electromagnetics was the evil Serpent in the mechanical Garden of Eden; Newton and Maxwell did not agree, light did not act as matter should act.  Einstein reconciled them by showing that space and time are relative, and…

Just a small post to mention the recent activity in my Greek blog, where with the help of a very kind Greek student we are offering a selection of articles translated in Greek language. Here are the latest additions: A translation of the guest post by Marek Karliner on doubly-heavy baryons (English version here) Translation of article on the search for a Invisible Higgs in ATLAS (English version here) Translation of article on the measurement of the top quark lifetime (English version here) I hope you can visit the greek version of these posts, if only to show appreciation for this attempt…

Most stories on the so called "accelerator on a chip" either fail to mention or deeply bury an important detail.     This device needs to be primed by a conventional accelerator.   In doing so, they give the wrong impression of what has been developed. First, this is an important advance in accelerator physics and a really cool example of what can be done with the creative use of common scientific apparatus and materials.   It is advances like this that will make next generation high energy physics affordable.    With that out of the way.... THIS IS NOT A…

In 1963, Roy Kerr's hypothesis was of a "clean" black hole model and that remains the dominant paradigm. From theory to reality things may be quite different, black holes may be much "dirtier" than what Kerr believed, the authors write. According to the now-traditional model, black holes are defined by only two quantities: mass and angular momentum (a black hole rotation velocity). Once their progenitor has collapsed (a high mass star, for instance, that at the end of its life cycle implodes inwards) its memory is lost forever. All that is left is a quiescent black hole, with almost no…

A few days ago I posted the results of a poll ran on 50 or so participants to a workshop on the Higgs boson in Madrid. The poll consisted of six questions on the expectations one had on the possibility of new discoveries by present-day accelerators, as well as on the nature of the underlying theory of fundamental interactions, and on the nature of dark matter. The poll results were interesting to me since they showed how the general perceptions of HEP physicists has changed in the last five years, following the startup of the Large Hadron Collider and the observed absence of striking new…