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The Quest To Crystallize Time - Previously Considered Impossible, Researchers Create Time Crystals (nature.com)
New submitter omaha393 writes: Researchers have addressed a perplexing issue in physics: the existence of time crystals. Time crystals, previously only hypothetical in nature, are structures that oscillate without any external energy supplied. The idea of time crystals set off a massive feud among physicists, arguing that such a state of matter could not exist. As leading time crystal proponent Frank Wilczek describes it: "conceptually, it is a clock that ticks forever without being wound." With the paper published in Nature Wednesday, researchers showed their method of production and the unusual nature of time crystals, which owe their oscillation properties to never achieving a state of equilibrium. From a report on Phys.org: Ordinary crystals such as diamonds, quartz or ice are made up of molecules that spontaneously arrange into orderly three-dimensional patterns. The sodium and chlorine atoms in a crystal of salt, for example, are spaced at regular intervals, forming a hexagonal lattice. In time crystals, however, atoms are arranged in patterns not only in space, but also in time. In addition to containing a pattern that repeats in space, time crystals contain a pattern that repeats over time. One way this could happen is that the atoms in the crystal move at a certain rate. Were a time crystal of ice to exist, all of the water molecules would vibrate at an identical frequency. What is more, the molecules would do this without any input from the outside world. [...] Shivaji Sondhi, a Princeton professor of physics said that the work addresses some of the most fundamental questions about the nature of matter. "It was thought that if a system doesn't settle down and come to equilibrium, you couldn't really say that it is in a phase. It is a big deal when you can give a definition of a phase of matter when the matter is not in equilibrium," he said.
...Physics...you crazy!
"Give someone a program, frustrate them for a day... Teach someone to program, frustrate them for a lifetime."
I read the linked article (which is a summary of the real report). It's not my field.
How is what they describe anything other than just a stable oscillator? It consumes energy, since to run it requires regular (although perhaps not periodic?) pulses of light.
How is this different from a macroscopic tuned circuit that also resists changes in driving force, and oscillates at a stable frequency? Because it's made with a handful of atoms instead of gazoober electrons streaming around a circuit? I'm (not intentionally) being snarky -- I'm curious because by the article the physicists are peeing all over themselves in excitement, so I'm guessing they think there's something to this that I don't see.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
Shouldn't this violate the Law of Conservation of Energy? Or is this literally the achievement of what would have normally been thought of as an asymptote to infinity, where no energy can be extracted from this closed system and it's perpetuating on merely perfect conservation of the energy that was introduced into the system when it was established?
Do not look into laser with remaining eye.
It's easy to get confused when dealing with wibbly wobbly timey wimey stuff.
My sci-fi novel, Ghost Thief, is now available from Amazon.com.
This is nothing new. Thiotimoline was discovered in 1948. It has the property of "endochronicity": when it is mixed with water, it starts dissolving before it makes contact with water. This is because one of its carbon bonds projects slightly into the future, while another projects slightly into the past. There have been several papers on this substance published in the Journal of the American Chronochemical Society.
The Quest To Crystallize Time - Previously Considered Impossible... ...a massive feud among physicists...
The combination of this kind of nonsense with big, glossy pictures does a huge disservice to science. On the one hand, it puts those of us who actually have even a basic knowledge about physics, off our lunch, because it is so, I don't know, either disingenious or perhaps written by idiots who don't understand what they are talking about. And on the other hand, it gives the more naive readers the impression that science is something remote and inaccessible; something that is out of this world and certainly out of ordinary people's league; IOW it discourages those who are interested, but not yet experienced enough from believing they could ever be clever enough to do science. I think it is shameful.
Instead of reading this kind of crap, we should encourage people to take part in things like citizen science; real science and research are things that ordinary people can do, and have done in the past, producing important, real results.
Hexagonal lattice in NaCl?! NaCl forms a cubic lattice!
Yes I'm a crystallographer!
A cube looks like a hexagon, looking down the long diagonal.
The NaCl structure is two interpenetrating FCC lattices of A and X, offset by {1/4, 0, 0} relative to the NaCl cubic unit cell (but by {1/2, 0, 0} relatively between the FCC sub-cells. In space-group symmetry notation, it is F m 3-bar m, in terms of its fundamental (that is most-basically-expressible, reduced unit cell).
In the same manner that an FCC atomic arrangement could be expressed as having a hexagonal unit cell, with it not being the fundamental cell, but instead a multiple formula-unit cell – a supercell – one could do the same with NaCl. I've not had my coffee, but intuitively a supercell double-sized this one could similarly be used to define the crystal structure of NaCl. Not optimal, but possible. Look in the front-matter section of your Space-Groups tome to look up the matrix conversion to transform the atomic positions from one fundamental lattice-type to another.
Put more simply, while HEXAGONAL is ABABAB stacking, FCC is ABCABC stacking of close-packed layers of atoms.
Yes, I am also a crystallographer.