Physics
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.
IceCube is a very cool experiment in Antarctica (no pun intended), which looks at very energetic neutrinos to understand more of the cosmos. It is composed of "strings" of photomultipliers inserted into km-long holes dug vertically…
How much do you accept science, cat? Robert Couse-Baker, CC BY-SA
By Eric Cavalcanti, University of Sydney
It’s a century-old debate: what is the meaning of the wave function, the central object of quantum mechanics? Is Schrödinger’s cat really dead and alive?
I was recently involved in an experiment conducted by Andrew White’s Quantum Technology Lab at the University of Queensland that has now provided the most significant evidence on that question in years.
And it doesn’t look good for the cat.
To understand the importance of this result, we need to delve into its history. At the root of…
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.
Last March, the BICEP2 collaboration announced that they had used a microwave telescope at the South Pole to detect primordial gravitational waves. These tiny ripples in spacetime would be the first proof of the theory known as “inflation,” an astonishingly rapid expansion of the universe in the instants after the Big Bang.
The result was…
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.
I do continue to investigate the assumption for self-gravitational system whose mass is distributed over distances of light years that the only effect of gravity is like mA (or mV^2/R for a rotating disk). The force of gravity may decide not only how fast things go, but where they go. mA or…
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.
The ordinary second law states that the universe…
After the joint analysis by Planck, BICEP2 and Keck Array has been made public (arXiv:1502.00612) invalidating the March 2014 announcement by BICEP2 (arXiv:1403.3985v1), a Forbes contributor writes « When Science Gets It Wrong: Gravitational Waves ». Obviously, scientific institutions should be more careful before launching or supporting certain kinds of propaganda. But contrary to the OPERA announcement of September 2011 (arXiv:1109.4897v1), where the claimed evidence for a superluminal neutrino was finally found to result from a flaw in the experimental setup, nothing similar has happened…
The sixteenth edition of the internationally known Neutrino Telescopes conference will take place on March 2nd-6th 2015 in the usual venue of Palazzo Franchetti in Venice. This is a conference which gathers from around the world researchers who study neutrino physics and related topics. The field has boomed since the discovery of neutrino oscillations by SuperKamiokande at the end of last century, and the focus is now on precise measurement of the neutrino mixing matrix and on the mass hierarchy of these almost unfathomable particles. Hence the conference is a very good thing to put in…
vongehr |
A common misconception is that all good scientific theory must be based on empirical science and provide ingredients where the theory can be potentially falsified (Karl Popper).
This dogma demands that a hypothesized theory should include something falsifiable, something that could be *possibly observed* and would then refute the theory (here in the words of Lee Smolin).
However, the final theory of everything (ToE) is precisely the theory that is by fundamentally desired definition supposed to take account of and therefore allow all possible observations O. The ToE can therefore by…
James D. Bjorken, also known as "BJ" by colleagues and physicists around the world, has been awarded the prestigious 2015 Wolf prize in Physics together with cosmologist Robert Kirshner. Bjorken deserves a lot of credit for his contribution to subnuclear physics: the official motivation is
"For predicting scaling in deep inelastic scattering, leading to identification of nucleon's pointlike constituents "
"Scaling" is a property of the cross section of subatomic processes involving the collision of an energetic electron with a proton or a neutron. I will explain what this is…
Today I collected in my mailbox the hefty "Review of Particle Physics", the publication of the Particle Data Group which contains a summary of everything we know about subatomic particles. For the first time, the publisher is a Chinese journal: Chinese Physics C. This might be considered a detail, but it is a sign of times: China has been increasing its involvement in fundamental physics research in the last decade, and it may well become the leading country in this business in the future.The book is a 1700 page brick which no human will ever read from cover to cover: the bulk of it is a…