Physics

Physicists at the University of Geneva have succeeded in teleporting the quantum state of a photon to a crystal over 25 kilometers of optical fiber. The experiment shatters the previous record of 6 kilometers achieved 10 years ago by the same  team. Passing from light into matter, using teleportation of a photon to a crystal, shows that, in quantum physics, it is not the composition of a particle which is important, but rather its state, since this can exist and persist outside such extreme differences as those which distinguish light from matter. The latest experiments have enabled…

How is this for some exciting news, straight from the same source as “I Let My Computer Use My Brain” three years ago, but much advanced in the ways artificial intelligence (AI) has integrated itself further so that most anybody can now work with it, or better, play with it and do cutting edge research nevertheless (UPDATE: this is now also featured on the Wolfram website):   “Technology belongs to macro-evolution; this includes the inevitable integration with artificial intelligence (AI). There has been much hype and misunderstanding around AI and the concept of evolution, hence, many…

What is dark matter? No one can say because it can't be detected or measured, but in science inference can help and we know that something is making gravity not work properly at the large scale. What we know as matter - stars, planets, us and other organisms - is baryonic matter, but it is only a small fraction of the universe. The rest gets lumped under blanket terms like dark energy and dark matter. Dark matter must be a form of matter the particles of which move slowly in comparison with light and interact weakly with electromagnetic radiation. The cold dark matter hypothesis is a…

Being at CERN for a couple of weeks, I could not refrain from following yesterday's talks in the Main Auditorium, which celebrated the 90th birthday of Herwig Schopper, who directed CERN in the crucial years of the LEP construction. A talk I found most enjoyable was John Ellis'. He gave an overview of the historical context preceding the decision to build LEP, and then a summary of the incredible bounty of knowledge that the machine produced in the 1990s. Ellis noted that arguably the first step toward LEP was a paper written by Burton Richter in 1976, while the Nobel laureate was on…

After four months of frenzy by over 1500 teams, the very successful Higgs Challenge launched by the ATLAS collaboration ended yesterday, and the "private leaderboard" with the final standings has been revealed. You can see the top 20 scorers below. No big surprises, as the winner Gabor Melis has been leading the public leaderboard (which was computed using only 18% of the data) for most of the past three months. If you compare the above data with the public leaderboard below, you however notice some significant differences. Most of all, just yesterday Lubos Motl had for the first time…

I just read with interest the new paper on the arxiv by my INFN-Padova colleague Massimo Passera and collaborators, titled "Limiting Two-Higgs Doublet Models", and I thought I would explain to you here why I consider it very interesting and what are its conclusions. First of all, what are two-higgs doublet models and why you should care about them ? For a start, I assume that you do know that we (i.e. CMS and ATLAS, the two giant experiments at the CERN Large Hadron Collider) have discovered, two years ago, a new particle which we tried very hard for a while not to call "Higgs boson" (the…

The field of physics attracts crackpots. It is impossible to completely avoid them, and after a nasty incident in 1952 with an actually mentally ill individual who was upset no one would listen to his theories concluding electrons don't exist, the American Physical Society decided to give up trying to avoid them. A membership and willingness to pay a fee will guarantee you the opportunity to share your ideas at major APS meetings. This may shock some people outside academia (and this may not be clear to everyone in physics either), but overall it has had reasonable support in the physics…

One year ago I had the pleasure to spend some time with George Zweig during a conference in Crete (ICNFP 2013). He is a wonderful storyteller and a great chap to hung around with, and I had great fun in the after-dinners on the terrace of the Orthodox Academy of Crete overlooking the Aegean sea, drinking raki and chatting about physics and other subjects. Zweig is acknowledged as one of the two men who understood how hadrons were composed of smaller entities in particle-antiparticle pairs or particle triplets: quarks, as Gell-Mann called them, or Aces, as Zweig named them. However, this is…

By pairing two unconventional forms of carbon – one shaped like a soccer ball, the other a tiny diamond – scientists have created a molecule that acts as a rectifier - it conducts electricity in only one direction, which means it could be possible to cheaply shrink computer chip components down to the size of molecules. Many electronic circuits have three basic components: a material that conducts electrons; rectifiers, which commonly take the form of diodes, to steer that flow in a single direction; and transistors to switch the flow on and off. Scientists combined two offbeat ingredients –…

"If you have seen the movie Particle Fever about the discovery of the Higgs boson, you have heard the theorists saying that the only choices today are between Super-symmetry and the Landscape. Don’t believe them. Super-symmetry says that every fermion has a boson partner and vice versa. That potentially introduces a huge number of new arbitrary constants which does not seem like much progress to me. However, in its simpler variants the number of new constants is small and a problem at high energy is solved. But, experiments at the LHC already seem to have ruled out the simplest variants. The…