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Science: Everything explained by PV=nRT, F=ma=Gm(1)•m(2)/r^2

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Self-Own Hall of Fame nomination:

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I... guess?

The basic ingredients to make this time crystal are as follows: The physics equivalent of a fruit fly and something to give it a kick. The fruit fly of physics is the Ising model, a longstanding tool for understanding various physical phenomena -- including phase transitions and magnetism -- which consists of a lattice where each site is occupied by a particle that can be in two states, represented as a spin up or down.

During her graduate school years, Khemani, her doctoral advisor Shivaji Sondhi, then at Princeton University, and Achilleas Lazarides and Roderich Moessner at the Max Planck Institute for Physics of Complex Systems stumbled upon this recipe for making time crystals unintentionally. They were studying non-equilibrium many-body localized systems -- systems where the particles get "stuck" in the state in which they started and can never relax to an equilibrium state. They were interested in exploring phases that might develop in such systems when they are periodically "kicked" by a laser. Not only did they manage to find stable non-equilibrium phases, they found one where the spins of the particles flipped between patterns that repeat in time forever, at a period twice that of the driving period of the laser, thus making a time crystal.

The periodic kick of the laser establishes a specific rhythm to the dynamics. Normally the "dance" of the spins should sync up with this rhythm, but in a time crystal it doesn't. Instead, the spins flip between two states, completing a cycle only after being kicked by the laser twice. This means that the system's "time translation symmetry" is broken. Symmetries play a fundamental role in physics, and they are often broken -- explaining the origins of regular crystals, magnets and many other phenomena; however, time translation symmetry stands out because unlike other symmetries, it can't be broken in equilibrium. The periodic kick is a loophole that makes time crystals possible.

The doubling of the oscillation period is unusual, but not unprecedented. And long-lived oscillations are also very common in the quantum dynamics of few-particle systems. What makes a time crystal unique is that it's a system of millions of things that are showing this kind of concerted behavior without any energy coming in or leaking out.

"It's a completely robust phase of matter, where you're not fine-tuning parameters or states but your system is still quantum," said Sondhi, professor of physics at Oxford and co-author of the paper. "There's no feed of energy, there's no drain of energy, and it keeps going forever and it involves many strongly interacting particles."
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Having seen some other explanation of that, I'm glad there are some very smart computer scientists out there. I can't understand what that would be used for, but they can.
 
That is one of the worst uses of an analogy I have ever read. They don't describe at all why they selected the fruit fly and why you would want to give it a kick. Then completely abandon the analogy after word #3 of sentence #2.


A better analogy, I think, would be: Imagine an olympic judge. Someone dives into a pool and they hold up a 10 or 0. Usually it's dependent on performance of the athlete. But physicists have found the quantum equivalent of a typical bribe paid to an olympic judge. WHen you want to get a 10, you kick them some money and you get a 10. It repeats the 10 after the second payment you give it.

Or better yet:

Same judge, but this time they're blind. You whisper "Russia" in his ear and he holds up a 10. THe unfortunate part is, you need to say "Not Russia" or he'll keep holding up a 10 in perpetuity. So you say "Not Russia" and he's going to hold up a 0. When you say "Russia" again, you get a 10.
 
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dxmnkd316 said:
That is one of the worst uses of an analogy I have ever read. They don't describe at all why they selected the fruit fly and why you would want to give it a kick. Then completely abandon the analogy after word #3 of sentence #2.


A better analogy, I think, would be: Imagine an olympic judge. Someone dives into a pool and they hold up a 10 or 0. Usually it's dependent on performance of the athlete. But physicists have found the quantum equivalent of a typical bribe paid to an olympic judge. WHen you want to get a 10, you kick them some money and you get a 10. It repeats the 10 after the second payment you give it.

Or better yet:

Same judge, but this time they're blind. You whisper "Russia" in his ear and he holds up a 10. THe unfortunate part is, you need to say "Not Russia" or he'll keep holding up a 10 in perpetuity. So you say "Not Russia" and he's going to hold up a 0. When you say "Russia" again, you get a 10.
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How about just explaining the science, and letting a person figure it out? That's what seeker did in it's video. I kind of figured out what was going on, but get really lost in how it can be used. It's roughly a no power switch for a very short time for this experiment, but should end up being an almost zero power switch.

It's the way the structure can be used in application where I get lost- where there's a randomness in quantum computers that is used for memory and/or logic. Randomness in a system where being known is important is a mystery to me.
 
The thing I had a problem with was later in the article when it said "if this sounds like perpetual motion" because the first time I read it I screamed, no, it doesn't, because you have to keep turning the damn laser on and off!

Science Daily is kind of like that joke about the New York Post: it's like being told the news by a random guy who watched the news.
 
I don't know where, but someone once said, when it comes to betting on whether Einstein was right, take Einstein. I think it was the last time someone had a breakthrough that would have upended one of his theories. Turned out to be a false alarm. Anyways....

Given that we know so little (relatively speaking) about neutrinos, I suppose it could go either way. What a time to be alive.


Edit: lol. Back in 2011/2012 researchers announced similar potential findings that neutrinos were observed traveling faster than light.

Always bet on Einstein
 
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dxmnkd316 said:
I don't know where, but someone once said, when it comes to betting on whether Einstein was right, take Einstein. I think it was the last time someone had a breakthrough that would have upended one of his theories. Turned out to be a false alarm. Anyways....

Given that we know so little (relatively speaking) about neutrinos, I suppose it could go either way. What a time to be alive.


Edit: lol. Back in 2011/2012 researchers announced similar potential findings that neutrinos were observed traveling faster than light.

Always bet on Einstein
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My wife was at CERN at the time (2011), working on one of the rings that provided the protons to the OPERA experiment. That whole thing was a fiasco. It basically started out as an internal memo at CERN, asking for help identifying how they had miscalculated the speed. Somehow the memo got leaked to the press, and it blew up into everyone thinking they were claiming something that they never actually said.
 
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