Physics

Tomorrow's commercial refrigeration systems, such as those in supermarkets, could be cooled by carbon dioxide instead of hydrofluorocarbons.

Hydrofluorocarbons are a greenhouse gas that is nearly 4,000 times more potent than CO2 and a future with less of them could be important because millions of pounds of HFCs leak into the environment every year, said Brian Fricke, a researcher in Oak Ridge National Laboratory's Building Equipment Research Group.

To address the problem, Fricke and colleagues are experimenting with CO2 and other refrigerants, including a hydrofluoroolefin called R1234yf.


As I reported a couple of times in the course of the last three months, the ATLAS experiment (one of the two all-purpose experiments at the CERN Large Hadron Collider) has launched a challenge to data analyzers around the world. The task is to correctly classify as many Higgs boson decays to tau lepton pairs as possible, separating them from all competing backgrounds. Those of you who are not familiar with the search of the Higgs boson may wonder what the above means, so here is a crash course on that topic.

Crash course on the Higgs and its decays to tau leptons

As a quantum state collapses from a quantum superposition to a classical state or a different superposition, it will follow a path known as a quantum trajectory. For each start and end state there is an optimal or "most likely" path, but it is not as easy to predict the path or track it experimentally as a straight-line between two points would be in our everyday, classical world.


UPDATE III is a rather important one.  There is a group at Cambridge which does some similar work to mine.  Great minds think alike, I guess. I have posted and revised a few times a paper on my new hypothesis for a theory of gravity which unifies Quantum Mechanics and General Relativity.  Whenever someone writes "I have posted and revised a few times a paper on my new hypothesis for a theory of gravity which unifies Quantum Mechanics and General Relativity."  The crank alarms should be flashing red alert, but I assure you all Einstein was quite right, but then so was Feynman and those who followed him.  

First some background on Quantum Gravity research:

In a different blogHenry Brown made the following statement:

Everybody seems to be talking about the Kardashian index (call it K) these days. It is a rather useless number that you compute as a ratio between the number of twitter followers you have and the number of citations that your papers got.

Here is a quote from its inventor Neil Hall:

“I am concerned that phenomena similar to that of Kim Kardashian may also exist in the scientific community,” wrote Hall. “I think it is possible that there are individuals who are famous for being famous (or, to put it in science jargon, renowned for being renowned). We are all aware that certain people are seemingly invited as keynote speakers, not because of their contributions to the published literature but because of who they are.”
The other day I wrote a post reporting of the lowered expectations of SUSY enthusiasts, who now apparently look forward to seeing 2-sigma effects in the next Run data of the CMS and ATLAS collaborations. That would keep their hope going, apparently.

I would have no problem letting them wait for late 2015, when the first inverse femtobarns of 13 TeV collisions will have been given a look at. But another thing happened today which made me change my mind - a colleague noted in the comments thread of that article that the LHC experiments appear to not publish their 2- and 3-sigma excesses when they see them, waiting for more data that "wipes out" the fluctuation. This is a strong (and probably unsupported) claim!
In the world we commonly perceive around us, it takes only a slight disturbance for a pencil standing on its tip to fall in one direction or another, but in the quantum world it is possible in principle for particles of a system to fall both left and right at the same time.

Differentiating this “and” state – the quantum entanglement of particles – from the classical “or” is an experimental challenge. Scientists have now devised a  quantum metrology method that enables entanglement verification for states of large atomic systems.
This morning at the ICNFP 2014 conference in Kolympari (Crete) the floor was taken by Abdelhak Djouadi, who gave a very nice overview of the theoretical implications of the Higgs boson discovery, especially exploring the status of Supersymmetry models.

Djouadi explained how even if the average mass of sparticles is being pushed up in surviving models of Supersymmetry -both because of the negative result of direct searches and because of the effect of hardwiring in the theoretical models the knowledge of a "heavy" lightest scalar particle, which sits at 125 GeV- there is reason to be optimistic. He explained that for stop quarks, it is the geometric mean of their masses that has to be high, but the lightest one may be laying well below the TeV.

One of the baffling electronic properties of the iron-based high-temperature superconductor barium iron nickel arsenide is that, at sufficiently low temperatures, it becomes a better conductor of electricity in some directions than in others.

The odd behavior, which has been documented in a number of materials, occurs at temperatures slightly higher than those needed to bring about magnetism; magnetism is believed to be essential for the origin of high-temperature superconductivity. A new study in Science Express offers the first evidence that the directionally dependent behavior arises from inherent physical properties of the material rather than from extraneous impurities, as had been previously suggested.