Physics

"1. Interaction with matter changes the neutrino mixing and effective mass splitting in a way that depends on the mass hierarchy. Consequently, results of oscillations and flavor conversion are different for the two hierarchies.
2. Sensitivity to the mass hierarchy appears whenever the matter effect on the 1-3 mixing and mass splitting becomes substantial. This happens in supernovae in large energy range, and in the matter of the Earth.[...] 
4. Multi-megaton scale under ice (water) atmospheric neutrino detectors with low energy threshold (2-3 GeV) may establish mass hierarchy with (3-10)σ confidence level in few years. [...]

  Modern physics is not accidentally relativistic and quantum, or in other words, Einstein-relative as well as Everett-relative (Bell-violating Everett-relativity is the very core of quantum mechanics!). Modern physics becomes ever more relativistic still today, and description relativity has revolutionized fundamental physics (see string theory dualities, Maldacena conjecture, black hole complementarity/holography, and so on). Why? Because we must take the observer’s perspective, and this means the describer’s perspective, ever more into account.

Less than three weeks separate us from the XVI Neutrino Telescopes, a very interesting conference held in Venice every two years. The physics of neutrinos is a very special niche in the realm of particle physics, one not devoid of cunning experimental techniques, brilliant theoretical ideas, and offering possible avenues to discover new physics. Hence I am quite happy to be attending the event, from where I will also be blogging (hopefully with the help of a few students in Padova).(NB this article, as others with neutrinos as a subject for the next month or so, appears also in the conference blog).
On Friday I traveled to Belluno, a town just south of the north-eastern Italian alps, to give a lecture on particle physics to high-school students for the "International Masterclasses". This was the umpteenth time that I gave more or less the same talk in the last decade or so; but it's not my fault, as particle physics has changed very little in the meantime. Yes, we discovered the Higgs boson, and yes, we excluded many possible extensions of the standard model. But the one-line summary remains the same: we continue to seek, but are not quite sure we'll find, a hint of what lies beyond.
Suppose we we tell you everything quantum mechanics can tell you about a quantum particle; what do you really know? Unfortunately, you still cannot predict with certainty the outcome of a simple experiment to measure its state. All quantum mechanics can offer are statistical probabilities for possible results.

This indeterminacy is not a defect, it's a defining feature of its undefined nature. The particle's state is not merely unknown, but truly undefined before it is measured. The act of measurement itself forces the particle to collapse to a definite state.
A preprint article by the IceCube collaboration captured my attention today in the Cornell Arxiv, and even more interesting was the main result of the analysis it reports, which can be shown as a "temperature plot" on an equilateral triangle. We will get to that, but let me first explain what is the experiment, what are the goals, and what it is that was measured.


The BICEP2 telescope at twilight at the South Pole. The supporting data for the inflation of the universe have also gone off into the sunset. Steffen Richter/ Harvard University , CC BY-NC-SA

By Chad Orzel, Associate Professor of Physics at Union College.

I have decided to rescind this proposal.  The swap of time t for space R and visa versa really didn't change anything: a scalar operator was still needed and the single value of time needed three subscripts, not making it look at all like time.  The exact role reversal is too exact.

Don't like the second law of thermodynamics - that heat transfer has limits when trying to do work? Maybe you can just use a different one.

Rather than being an immutable fundamental law, researchers from University College London and the Universities of Gdansk, Singapore, and Delft write in Proceedings of the National Academy of Sciences that they have uncovered additional second laws of thermodynamics which complement the ordinary second law of thermodynamics, they are just not noticeable except on very small scales.