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.
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.
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.
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.
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.
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.
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.
"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.
Materials made from nano-particles have long been touted as the future viable solar energy production and better touch screens.
The black box between the present and the future of these wonder-materials is organizing the nanoparticles into orderly arrangements. Nanoparticles of magnetite, the most abundant magnetic material on earth, are found in living organisms from bacteria to birds. Nanocrystals of magnetite self-assemble into fine compass needles in the organism that help it to navigate.
The NSA is not allowed to gather intel on US citizens (at least not without a FISA court order), but there is an obscure Reagan era loophole--Executive Order 12333, or Twelve Triple Three--that allows NSA to scoop up data on millions of Americans and store these data (about 350 billion searchable records—that’s “billion” with a “B”) for up to five years.