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Gravity's Engines
We’ve long understood black holes to be the points at which the universe as we know it comes to an end. Often billions of times more massive than the Sun, they...
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The phrases "perpetual-motion machine"—a concept derided by scientists since the mid-19th century—and "physics Nobel laureate Frank Wilczek" wouldn't seem to belong in the same sentence. But if Wilczek's latest ideas on symmetry and the nature of time are correct, they would suggest the existence of a bona fide perpetual-motion machine— albeit one from which energy could never be extracted. He proposes that matter could form a "time crystal," whose structure would repeat periodically, as with an ordinary crystal, but in time rather than in space. Such a crystal would represent a previously unknown state of matter and might have arisen as the very early universe cooled, losing its primordial symmetries.
Wilczek describes his work in this article and in this one coauthored by Alfred Shapere of the University of Kentucky, that he posted on the physics preprint server, arXiv.org, on February 12.
"The papers themselves are perfectly respectable, undoubtedly correct, and interesting," says cosmologist Sean Carroll of the California Institute of Technology.
Known for his pioneering work in developing quantum chromodynamics, the theory that explains how the particles inside atomic nuclei stick together, Wilczek, a professor at the Massachusetts Institute of Technology, says he got his latest idea two years ago while teaching a course on group theory. That branch of mathematics, which uses matrices to describe the symmetries inherent in families of elementary particles, also describes and classifies the structure of crystals. Materials such as a liquid or a gas in equilibrium, made of uniformly distributed particles, exhibit perfect spatial symmetry—they look the same everywhere and in every direction.
But at very low or minimum energies, most materials can't retain that symmetry, and they crystallize. The regular geometric pattern of a crystal lacks complete spatial symmetry; the structure does not look the same everyplace. Because crystals have less symmetry than before, physicists say they exhibit spontaneous symmetry breaking. Equivalent processes occur in many domains of physics. A type of broken symmetry, which would be indicated by the presence of the Higgs boson now being hunted at the Large Hadron Collider, would explain why subatomic particles have mass.
Wilczek says he started wondering whether the concept of an ordinary three-dimensional crystal could be extended to four dimensions, with the extra dimension that of time. A time crystal would spontaneously break what Wilczek calls "the mother of all symmetries"—the symmetry of time translation, which holds physical laws remains the same regardless of what time it is. A time crystal would change with time but keep coming back to the same form it began with, like a clock whose moving hands periodically return to their original positions.
The difference from an ordinary clock or other periodic process is that a time crystal, as with a spatial crystal, would be a state of minimum possible energy. At first glance, that poses a contradiction. A time crystal by definition must change with time in order to break time translation symmetry. But a system with minimum energy ordinarily can't move. If it could, then additional energy could still be extracted, until the system achieved a true minimum energy, a motionless state.
"At first I thought this was easy, then that it was impossible," Wilczek noted in a recent lecture at Arizona State University at Tempe. "Now I think it's neither easy nor impossible."
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16 Comments
Add CommentIMO every wave is such a time crystal
Reply | Report Abuse | Link to thisThis might help explain the origin of a big bang. You take a universe of nothing. It needs an energy imparted to make it change to something but where do you get that energy, the energy imparted by time. This may even help with looking at Black holes maybe we can rename them time holes since even light apparently stops in a black hole how it's converted back into time. Crazy I know but I like it and it fits some of my theories.
Reply | Report Abuse | Link to thisI remember when I was in 7th grade and first heard about black holes,I thought to myself that a singalarity in the hole was frozen in time and thus having a fixed mass,all other mass of a black hole was frozen at the event horizen.When t=o all wave function ceases and everything else all the way to the bottom is frozen as well.The black hole as whole may be spinning but everything inside is motionless.Kinda like the time crystal mentioned in the article,but alas I was called an moron by the teacher,and my theroy was not to be spoken again.Sorry about the spelling,I no longer have a working spellchecker.
Reply | Report Abuse | Link to thisI remember when I was in 7th grade and first heard about black holes,I thought to myself that a singalarity in the hole was frozen in time and thus having a fixed mass,all other mass of a black hole was frozen at the event horizen.When t=o all wave function ceases and everything else all the way to the bottom is frozen as well.The black hole as whole may be spinning but everything inside is motionless.Kinda like the time crystal mentioned in the article,but alas I was called an moron by the teacher,and my theroy was not to be spoken again.Sorry about the spelling,I no longer have a working spellchecker.
Reply | Report Abuse | Link to thisMatter in motion creates 3D space and past-to-future time. Neither 3D space nor past-to-future time exist without matter in motion.
Reply | Report Abuse | Link to thisNo, we can't get anything for free. Notice where it says that now energy can be extracted from this system without first adding the same amount in. What goes in is the most that can come out. This is not getting anything for free, just keeping what we got for a long time.
Reply | Report Abuse | Link to thisWith With all due respect, Prof. Wilczek, Prof. Shapere, and the rest of us here, might appreciate that crystals, like all other forms of matter, or mass-energy, consist basically of atoms- which are the true perpetual-motion machines in our universe. The vibrant and ever-breathing atom - even in its ground (unexcited) state - breathes in mass-energy [currently termed a a virtual particle, flitting out of the void (and into the atom)] and breathes out an ethe quantum over the following half-cycle of exhalation [virtual particle flitting (out from the atom and) into the outside void]. And the sooner we realize this most fundamental fact of natuure, the sooner will 'modern physics' emerge from the woods, for the complete unification of physics and the advancement of science. Get the picture in:
Reply | Report Abuse | Link to thishttp://www.sittampalam.net/MassEnergy.htm and
http://www.sittampalam.net/TheSpin.htm
With all due respect, Prof. Wilczek, Prof. Shapere, and the rest of us here, might appreciate that crystals, like all other forms of matter, or mass-energy, consist basically of atoms- which are the true perpetual-motion machines in our universe. The vibrant and ever-breathing atom - even in its ground (unexcited) state - breathes in mass-energy [currently termed a a virtual particle, flitting out of the void (and into the atom)] and breathes out an equal quantum over the following half-cycle of exhalation [virtual particle flitting (out from the atom and) into the outside void]. And the sooner we realize this most fundamental fact of natuure, the sooner will 'modern physics' emerge from the woods, for the complete unification of physics and for the advancement of science. Get the picture in:
Reply | Report Abuse | Link to thishttp://www.sittampalam.net/MassEnergy.htm and
http://www.sittampalam.net/TheSpin.htm
(Please use Internet Explorer if possible.)
Thank you all for your time here. Cheers!
The article prompts two thoughts. First, let's simplify the picture of our universe, without changing its laws of physics. Assume the universe consists of a single hydrogen atom at N degrees K. Overtime, the atom cools, throwing off photons to carry off the vibrational energy -- conserving the energy of the system, and increasing its entropy. Ultimately the atom stops vibrating completely (except for the occasional jolt it might get if one if its photons happens to bumo into it). Thus the energy of the universe is concerved, but the universe itself, is (thereby) a perpetual motion machine (albiet, one from which no energy can be extracted). Interesting to think of what this means for multiverse theories in which universes can interact (colliding branes, et al).
Reply | Report Abuse | Link to thisThought 2 is a quesiton ("Quesiton" was invented as a typo, but I have since defined it as the smallest unit of something you want to know): What accounts for the energy required for the electron to keep spinning around the proton in my hydrogen atom -- or any other atoms, for that matter?
Even though the electron appears to orbit an nucleus, it's not really an orbit like the moon orbiting the Earth. The orbit analog of electrons is a useful first order approximation but falls short of complete fidelity. The orbit of an electron(s) is a probabilistic state bounded within energy "shells" define by the Pauli exclusion principal. If you observed the moon an hour ago, and then again now, you could be very certain of the whereabouts of the moon in the between time. Not so with an electron.
Reply | Report Abuse | Link to thiswhoops - Pauli exclusion principle...not principal.
Reply | Report Abuse | Link to thisUnderstood about the "orbits." My question is about the movement of the electrons, and where the energy comes from that motion. Or are you saying that there is not real motion, as such, just that there is only probability about where the electrons are (so they might as well be moving)... and a degree of interaction potential?
Reply | Report Abuse | Link to thisIs it possible, in considering your 7th grade hypothesis, that; "I no longer have a working spellchecker." Kinda closes the discussion?
Reply | Report Abuse | Link to thisThe Black Hole thing is interesting. But the second clause is disturbing.
Mr. Markcomman, if I may kindly comment here on your above thoughts,the atom is an ever-vibrant entity and, therefore, cannot simply cool itself by breathing (throwing) off photons; the atomic vibration itself is the direct cause of this breathing, which would conserve entropy over a cycle of breathing at steady state. Please note that the the atom cannot ever stop vibrating (which can occur only at the unreachable absolute temperature of zero Kelvin).
Reply | Report Abuse | Link to thisFurther, in this fractal universe of ours, the electron's orbit around the atomic nucleus is but the submicroscopic image of the planetary orbit around the sun (or central star). A quick glimpse of the following, illustrative website should bring to light this great recurring design element in nature.
http://www.sittampalam.net/AntiGravity.htm
Reuuest for any further clarifications is most welcome. Thank you, and Cheers all!
http://toe.tv
Maybe someone should tell Wilczek about real perpetual motion systems, which have been studied in the laboratory for many years, viz. superconductors? There's too much specialisation in physics these days!
Reply | Report Abuse | Link to thisFor completeness, it should be added that in the two superconductor case there is time dependence as well as perpetual motion (the phase difference is a function of time). When you connect the two there is an ac supercurrent which is a reflection of that time dependence. If you do this you'll get dissipation, but that will happen in any periodic system once you try to _observe_ the oscillations.
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