|White light thru yonder prism breaks|
The heart of the new device is a sheet only nanometers thick made of a semiconducting alloy of zinc, cadmium, sulfur, and selenium. The sheet is divided into different segments. When excited with a pulse of light, the segments rich in cadmium and selenium gave off red light; those rich in cadmium and sulfur emitted green light; and those rich in zinc and sulfur glowed blue.
|Elmers has nothing on "Big G"|
We can't repeat the birth of the universe, but we can peer far across the cosmos. And when we do? From Astronomy magazine, see that "Gravitational constant appears universally constant, pulsar study suggests." (Think of pulsars as very distant, very powerful, astronomical metronomes. This particular pulsar co-orbits with a white-dwarf star. If G changed with time, the properties of that co-orbit would change, with effects, in turn, on the observed rate of pulsing.) That pulsar study shows a constant value for G. The binary star involved is >3000 light-years distant, so (a) the radiation being studied was >3000 years on its way to us, and hence (b) G was constant >3000 years ago as well as (when measured in our home Solar System) recently.
|Waves: a matter of gravity|
You may remember the big announcement last year that gravitational waves had been detected. That report has been discredited. (From Nature, "Gravitational waves discovery now officially dead: Combined data from South Pole experiment BICEP2 and Planck probe point to Galactic dust as confounding signal.") If the newly operational Advanced LIGO (Laser Interferometer Gravitational-Wave Observatory) doesn't soon find evidence of such waves ... that will really be worrisome with respect to our understanding of the universe.
And on a much smaller scale, consider (from Ars Technica) that "Experiment confirms that quantum mechanics scoffs at our local reality: The last loopholes for determinism squeezed out in latest work."
|Tearing out his hair?|
What else is super-interesting? Superconductors! Suppose that, to stay free of electrical resistance, a material didn't need to be kept in the deep freeze. How many applications might there be? How much more energy could be used rather than dissipated as waste heat in long power lines?
Perhaps in my lifetime I'll find out. See (from Physicsworld.com), "Hydrogen sulphide is warmest ever superconductor at 203 K." That is, by superconducting standards, balmy: -97 degrees Fahrenheit. Parts of Antarctica are occasionally that cold. Alas, to superconduct at that temperature, the hydrogen sulphide must be under extreme pressure: ~1.5 million atmospheres. That's a condition we don't see anywhere on Earth (and I'm okay with that).
|Graphene: stick-and-ball model|
A 2-D (one-atom-thick) sheet of material is never going to carry a lot of power, but there are other prospective uses:
The researchers who demonstrated last year the role phonons played in the superconductivity of graphite and calcium, Patrick Kirchmann and Shuolong Yang of the SLAC National Accelerator Laboratory, believe this latest work could usher in the fabrication of nanoscale superconducting quantum interference devices and single-electron superconductor quantum dots.
I can't speak for anyone else, but that's enough exciting news to keep my mind spinning ...