I started the blog on Bowler Hat Science to cover the writing I do at other sites, but to simplify matters, I’m going to move all that content over to my primary blog Galileo’s Pendulum. (This post has more on my reasoning for doing so, as well as a great song.) So, this is the last blog post here, though obviously the main part of the site — my portfolios and other professional information — will live on.
If dark energy will be the same in billions of years as it seems to be today, the future will be dark and empty, as galaxies continue to move apart from each other at ever-faster rates. If dark energy comes and goes, though, maybe the rate of expansion will slow down again. All of this is a long time from now—trillions of years after the death of the Sun—but we might see hints about it today. We hope to see signs of what is to come by looking at how dark energy behaves now, and how it has acted in the past. Similarly, if dark energy is stronger in some parts of the cosmos, then certain pockets of the Universe would grow faster than in others. That also has implications for how the future cosmos looks. [Read more…]
Today, researchers with the LHCb experiment at CERN announced the confirmation of a weird object that first appeared in detectors in 2008. This object is made up of four quarks, where other particles are made of two or three quarks (or zero, in the case of electrons, neutrinos, and the like). But what sort of beast is this? As is often the case, more work is needed before we can say for ccertain.
With that much data, physicists were able to determine the composition of the Z(4430)–: it consists of a charm quark, a charm anti-quark, a down quark, and an up antiquark. The “4430” part of the name indicates its mass: 4,430 million electron-volts, which a little more than four times the mass of a proton (938 million electron volts). The combination of quarks gives the Z(4430)– a negative electric charge, hence the “-” in the label. The particle is highly unstable, so none of them are expected to be seen in nature. [Read more…]
Beyond size, another challenge is Chariklo’s location between Saturn and Uranus. It orbits in a long ellipse, ranging from 13 to nearly 19 times farther from the Sun than Earth. This position, along with its composition of rock and ice, marks Chariklo as a “centaur.” Just like mythological centaurs are half human and half horse, astronomical centaurs combine features of asteroids and comets. (Centaurs would grow comet-like tails if they fell closer toward the Sun.) Tens of thousands of centaurs may lurk among the giant planets, though most of those are much smaller than Chariklo, the largest known centaur. [Read more…]
However, a completely analogous version of SUSY could exist in certain exotic superconductors. This is not built out of elementary particles, but out of interactions between electrons and atoms, giving rise to a set of particle-like quantum excitations known as quasiparticles.
The new paper discussed the idea of emergent SUSY-like behavior in topological superconductors. In these systems (described in more detail in the sidebar story), the interior of the material conducts electricity without resistance, but the outside is an ordinary conductor. The authors argued that experimentally observed magnetic behavior on the conducting surface could be interpreted super symmetrically. It also exhibits a breaking of SUSY due to the fundamental difference in interior and surface behavior of the system.
In this view, the magnetic excitations (acting like bosons) on the surface are SUSY partners with the topological superconductor quasiparticles, which are fermions. [read more…]