Physics

"Subatomic particles act in quantum ways—they have a wave-like nature—and so can atoms, and so can whole molecules since they're collections of atoms," Schwab says. "So the question then is: Can you make bigger and bigger objects behave in these weird wave-like ways? Why not? Right now we're just trying to figure out where the boundary of quantum physics is," says Keith Schwab, Professor of Applied Physics at Caltech. 

And that means finding a way to make measurements that go beyond the limits of quantum physics.


I receive much crackpot email. There is a very common misunderstanding often central, one I have not seen a good answer to anywhere. This is partially due to that few who write about physics counter crackpot theories well. Allow me to explain this point with a new personal story before explaining why energy seems quantized, why photons seem to be little packets of energy rather than a concept that describes quantum interactions more or less well.

Very recently, a combination of the precise measurements of the mass of the top quark obtained by the CDF and DZERO experiments at the Fermilab Tevatron collider with those produced by the ATLAS and CMS experiments at the CERN LHC collider has been produced, obtaining a result of 173.34 GeV, which surprised nobody -of course- with a very small total error bar: 0.76 GeV, a mere 760 MeV, not even a proton's mass.
"In the case where the dark matter particle is light (less than 1 GeV) and the interactions is either contact or mediated by light (but not massless) particles, there is parameter phase space that cannot be probed by current underground detectors even with substantially lowered energy thresholds. This region of the parameter space can be probed by shallow site detectors with low energy thresholds. However, since in this case dark matter particles will be very effectively stopped if coming upwards (i.e. below the detector), we argue that a search for a daily modulated dark matter signal is probably the best strategy for probing this part of the parameter space."

Neutron stars are extraordinarily dense stellar bodies created when massive stars collapse. They host the strongest magnetic fields in the universe -- as much as a billion times more powerful than any man-made electromagnet.

But some neutron stars are much more strongly magnetized than others and no one is sure why.

A paper by McGill University physicists Konstantinos Gourgouliatos and Andrew Cumming
in Physical Review Letters  sheds new light on the expected geometry of the magnetic field in neutron stars and could help scientists measure the mass and radius of these unusual stellar bodies, and thereby gain insights into the physics of matter at extreme densities.


This must be the boosted b-jets season... Just a few days ago I discussed here the nice new observation of boosted Z->bb decays pulled off by the ATLAS collaboration using 8-TeV proton-proton collisions recorded in 2012. And today I am pleased to see in the Arxiv a new study by D. Ferreira de Lima, A. Papaefstathiou, and M. Spannowsky on the possibility to measure the pair production of Higgs bosons in their decay to two pairs of b-quark jets.
I was delighted today, as I checked the page of public ATLAS results, to find a very beautiful new result. The signal ATLAS found and just published on the arxiv is not one anybody could doubt to be there: no surprise whatsoever. And yet, it is a difficult one to extract, and one on which I myself have spent several years of my research work on the CDF experiment.

A rare opportunity, likely unique for many readers also in its clarity of how different interests clash, a look behind the curtains of ‘scientific peer review’ as it corrupts science; moreover, revealing sniffs of the stinking swamp that is the established community researching memristors, but the implications are general and can be only more severe with issues where more money than Hewlett Packard’s is involved or hugely powerful political interests like with global warming.

The universe we can see is made up of billions of galaxies, each containing anywhere from hundreds of thousands to hundreds of billions of stars.

Large numbers of galaxies are elliptical in shape, red and mostly made up of old stars. Another (more familiar) type is the spiral, where arms wind out in a blue thin disk from a central red bulge.

On average stars in spiral galaxies tend to be much younger than those in ellipticals.

Now a group of astronomers led by Asa Bluck of the University of Victoria in Canada have found a (relatively) simple relationship between the color of a galaxy and the size of its bulge – the more massive the bulge the redder the galaxy.
Relativity says that spacetime is smooth, and only big things can warp it, in ways that are exactly known. Quantum theory says that the smallest parts of the universe are constantly fluctuating and dramatically uncertain. How can something be both smooth and fluctuating, both exact and uncertain?

How, in other words, can we make a quantum theory of gravity? It's unknown. String theory and loop quantum gravity have tried, but a unified theory has remained out of reach.

Enter – of all things – condensed matter physics.