We are surrounded by crystals; a crystal is simply a repeating stacked arrangement of atoms. The Earth is made of them: rocks, metals, semiconductors, minerals like salt and calcium. Noting this natural ubiquity, one physicist decided to look into whether there could be a time analog of these "space" crystals, something he called "time crystals".
So what exactly is a time crystal? Mathematically, instead of a particular arrangement of atoms repeating every nanometer in space, this would be an event that repeats every few nanoseconds in time. A time crystal would be a recurring event, similar to the steady beat of music or the 12 hour spin cycle of a clock's hands
There's just one problem: Time crystals are impossible!
A picture of individual strontium and titanium atoms making up a strontium titanate crystal. This pattern repeats billions of times to make a crystal smaller than a sand grain. (Made by a transmission electron microscope. Source: Wikimedia Commons)
Since the publication in 2012 of theoretical papers addressing time crystals using classical
mechanical methods, this idea by physicist Frank Wilczek (along with collaborator Alfred Shapere) has received much attention from other physicists and from the media.
Time crystals are so outlandish and crazy that the entire concept would have been dismissed, likely not even published, were it not for one thing. Frank Wilczek is a Nobel Prize winner, a man with an enormous reputation in theoretical physics. His reputation has given the idea life despite an enormous, gaping massive problem: Time crystal theory allows for the possibility of perpetual motion.
A realized time crystal would accomplish perpetual motion by breaking the second law of thermodynamics, a sacred and apparently inviolable law of nature. (The law says that all transfers of heat to work involve loss of energy. As a consequence, all mechanical processes lose energy, and no machine can ever be 100% efficient.) If you asked physicists and engineers what single scientific law is the most rock-solid and unlikely to ever be broken, this would probably be it. Many of history's best scientists have voiced strong beliefs
about the truth of the second law and the impossibility of perpetual motion.
If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations -- then so much the worse for Maxwell's equations. If it is found to be contradicted by observation -- well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.
-Sir Arthur Eddington
A theory is the more impressive the greater the simplicity of its premises, the more different kinds of things it relates, and the more extended its area of applicability. Therefore the deep impression that classical thermodynamics made upon me. It is the only physical theory of universal content which I am convinced will never be overthrown, within the framework of applicability of its basic concepts.
Nothing in life is certain except death, taxes and the second law of thermodynamics.
In the face of such strong evidence against it, how much credence should we give the time crystal concept? Is the stellar reputation of a Nobel Laureate scientist enough to justify pursuing the seemingly impossible?
Actually, scientists of this caliber aren't as infallible as you might expect. Extraordinary claims put forth by great minds occasionally turn out to be bizarre, unsubstantiated or just flat-out wrong. Everyone has failures, but when you are famous for brilliant ideas, your claims rightly garner much more consideration before they are dismissed. You get more leeway. There are many examples, though, of famous geniuses who have proposed or supported fantastical and incorrect ideas.
Brian Josephson is a physicist who won the Nobel Prize for theoretical work on superconductors. Graduate students are jealous and awed that he did the computations before he received his PhD. Later in his career, Josephson became notorious for advocating another line of "research": parapsychology
. This field includes extrasensory perception, telepathy, homeopathic medicine and mysticism. Its believers also tend to believe in ghosts, clairvoyance, trying to catch poltergeists on cassette tapes and listening to Led Zeppelin records backwards to ferret out Satanic messages.
Linus Pauling was probably the greatest chemist of the 20th century. He was awarded two Nobel Prizes! Pauling spent much of his time
in the 1970s and 1980s pushing incorrect claims, writing books and undertaking public advocacy for orthomolecular therapy
, in particular, medicinal megadoses of vitamin C to cure everything from cancer to the common cold. (It doesn't work.)
Richard Feynman is the physicist we all hear stories about: the A-bomb safe-cracker, the unparalleled lecturer, the man who worked in topless bars and invented the most precise physics theory ever created. Did you know that he did not believe in daily toothbrushing? According to a fellow genius physicist, Murray Gell-Mann
, he spent much of his time cultivating his renegade image, including refusing to brush or floss his terrible teeth despite being shown medical evidence.
Isaac Newton spent more time working on alchemy and calculating doomsday than working on physics. Nobel Prize-winner William Shockley, one of the small team of Bell Labs physicists who invented the transistor, was a staunch supporter of eugenics.
Bottom line: Nobody is above being wrong sometimes.
Wilczek's idea of time crystals is fascinating, but despite his prestigious affiliations, we should treat it with a massive dose of skepticism. Brilliant scientists make mistakes and support unsound science sometimes. Given that a working time crystal would violate the second law of thermodynamics, this will likely turn out to be one of those times.