Physics

"Since two fermions cannot turn into three fermions, the experimental observation of three-jet events in e+e- annihilation, first accomplished by the TASSO collaboration in June 1979 and confirmed by the other collaborations at PETRA two months later, implies the discovery of a new particle. Similar to the quarks, this new particle hadronizes into a jet, and therefore cannot be a color singlet. These three-jet events are most naturally explained by a hard noncollinear bremsstrahlung . [...] Thus the 1979 discovery of the second gauge particle, the gluon, occurred more than fifty years after that of the photon. This particle is also the first [...] gauge particle with self-interactions.
Is energy conserved? "Of course it is!" anyone with just a rudimentary knowledge of physics will answer. A more pertinent answer would be: "if you can't show me a working perpetual motion machine, shut up and stop wasting my time!" 

The conservation of energy is an insight that stood the test of time. It was Julius von Mayer who first worded it in its clearest form: "Energy can be neither created nor destroyed". That was nearly 170 years ago. 

So why question energy conservation?

The interesting thing about physics is that the deeper you dig, the more you are forced to doubt existing principles. Dig deep into the universe, allow gravity to become a dominant feature, and the conservation of energy becomes much less obvious. 
Quite in advance with respect to the stated goals of its 2010 collider program, the Large Hadron Collider has produced yesterday night the instantaneous luminosity of 10^32 cm^-2 s^-1 in the core of the ATLAS and CMS detectors. This is great news for all of us: at such a collision rate, on average one top quark pair is produced every minute, and one 120 GeV Higgs boson (if the thing exists) every 10 minutes makes its apparition there! (Calculations are in this recent post).
On October 13th 1985 the Tevatron collider started operations, producing the first man-made proton-antiproton collisions at 1.6 TeV center-of-mass energy in the core of the CDF detector. 25 years have passed. It is frankly unbelievable that the machine is still operating today, and with it CDF, which was back then the only game in town (D0 came later).

I find it even more unbelievable if you consider that much of the technology, the magnets, the devices that produced the collisions and the ones that recorded them are still those of 25 years back. 25 years are like a two glaciations time span for particle physics standards.
Today (and the next time in this series on duality), I explain the most interesting insight that I have gotten from string theory about black holes.
Two days ago I wrote here about the projected reach of Higgs boson searches of the Tevatron experiments, discussing what can be seen by CDF and D0 if they combine their analyses results, after improving them as is today thought possible to do. The reach was shown as a function of the integrated luminosity, which allows one to infer what can be done if the Tevatron stops running in 2011 or, as is being proposed, it continues for a few more years.
Last Tuesday I presented new precise Tevatron results on top quark physics at the "LHC Days" conference in Split. The top-quark measurements that CDF and DZERO have produced with their multi-inverse-femtobarn datasets of proton-antiproton collisions are very precise, and they surpass pre-Run-II expectations: suffices to say that the top-quark mass is now estimated with a 0.61% uncertainty, over twice smaller than promised. So it was nice to display these results to an audience mainly composed of LHC colleagues. I received several questions and the interest in my talk was clear.
Sorry, cosmic acceleration, this was not your year.   The Nobel Prize in Physics 2010 was awarded jointly to Andre Geim and Konstantin Novoselov "for groundbreaking experiments regarding the two-dimensional material graphene".

Without question ultrathin carbon is here to stay and a lot of terrific work is done with it every month.  Bendable computer screens and ultralight materials could all result from graphene research.
I am spending a few pleasant days in Split for the conference "LHC Days". I will be representing the D0 and CDF collaborations here in a talk on top physics at the Tevatron; in the meantime, I am pleased to witness that talks are of high quality. This morning the most interesting to listen to (at least to me) was the one by Guido Altarelli, a distinguished theorist from the University of Roma III. Altarelli has given crucial contributions to the advancement of our understanding of Quantum Chromo-Dynamics in the seventies, and it is always a pleasure to listen to him (a previous report of a talk he gave in Perugia two years ago is here).
No, the following does not belong into the humor section, because I know of people who made a career with the method described below. This is serious! This is another article in my series on the usual cheating in science.

POP-science culture (POP = publish or perish = popular) ensures that only publications count in academia. Successful grant applications also count, but the grant you get only if you have many publications. And “friends” count, which you get with coauthoring and publications. And all that impacts science – no conspiracy theory necessary here. This is science today: