Posts tagged matter
“Dust is everywhere because its source is everything. Its most remote origins in time and space are the Big Bang, collapsing stars, and the dark line across the center of the Milky Way, which, according to astronomer Donald Brownlee,“is a line of dirt perhaps 65,200 light years across, and 3.832 X 1017 miles long.” Here on earth, dust comes from everything under the sun: minerals, seeds, pollen, insects, molds, lichens, and even bacteria. Its sources also include bone, hair, hide, feather, skin, blood, and excrement. And things of human fabrication, too numerous to mention, also cover the earth and all the atmosphere with dust.”
–Joseph A. Amato. Dust.
Despite being forbidden in equilibrium, spontaneous breaking of time translation symmetry can occur in periodically driven, Floquet systems with discrete time-translation symmetry. The period of the resulting discrete time crystal is quantized to an integer multiple of the drive period, arising from a combination of collective synchronization and many body localization. Here, we consider a simple model for a one-dimensional discrete time crystal which explicitly reveals the rigidity of the emergent oscillations as the drive is varied. We numerically map out its phase diagram and compute the properties of the dynamical phase transition where the time crystal melts into a trivial Floquet insulator. Moreover, we demonstrate that the model can be realized with current experimental technologies and propose a blueprint based upon a one dimensional chain of trapped ions. Using experimental parameters (featuring long-range interactions), we identify the phase boundaries of the ion-time-crystal and propose a measurable signature of the symmetry breaking phase transition.
via http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.030401
Normal crystals have an atomic structure that repeats in space - just like the carbon lattice of a diamond. But, just like a ruby or a diamond, they’re motionless because they’re in equilibrium in their ground state. But time crystals have a structure that repeats in time, not just in space. And it keep oscillating in its ground state. Imagine it like jelly - when you tap it, it repeatedly jiggles. The same thing happens in time crystals, but the big difference here is that the motion occurs without any energy. A time crystal is like constantly oscillating jelly in its natural, ground state, and that’s what makes it a whole new form of matter - non-equilibrium matter. It’s incapable of sitting still.
via http://www.sciencealert.com/scientists-have-just-announced-a-brand-new-form-of-matter-time-crystals
In 1928, the late Francis Wayland Thurston published a scandalous manuscript in purport of warning the world of a global conspiracy of occultists. Among the documents he gathered to support his thesis was the personal account of a sailor by the name of Gustaf Johansen, describing an encounter with an extraordinary island. Johansen`s descriptions of his adventures upon the island are fantastic, and are often considered the most enigmatic (and therefore the highlight) of Thurston`s collection of documents. We contend that all of the credible phenomena which Johansen described may be explained as being the observable consequences of a localized bubble of spacetime curvature. Many of his most incomprehensible statements (involving the geometry of the architecture, and variability of the location of the horizon) can therefore be said to have a unified underlying cause.
http://arxiv.org/abs/1210.8144