Posts Tagged ‘Physics’
Time crystals– crystals that break both spacial and temporal symmetry– were first predicted by Nobel laureate Frank Wilczek in 2012… and were widely deemed amusing, but impossible (e.g., here). Now researchers have created time crystals for the first time and say they could one day be used as quantum memories… and might help reconcile Quantum Mechanics with the Theory of Relativity.
As we ponder Einstein’s insistence that time is an illusion, we might send well-structured birthday greetings to Pierre-Gilles de Gennes; he was born on this date in 1932. A French physicist, he was awarded the 1991 Nobel Prize for Physics for “discovering that methods developed for studying order phenomena in simple systems can be generalized to more complex forms of matter, in particular to liquid crystals and polymers.” He described mathematically how, for example, magnetic dipoles, long molecules or molecule chains can under certain conditions form ordered states, and what happens when they pass from an ordered to a disordered state. Such changes of order occur when, for example, a heated magnet changes from a state in which all the small atomic magnets are lined up in parallel to a disordered state in which the magnets are randomly oriented. Later, he was concerned with the physical chemistry of adhesion.
“in this case there were three determinate states the cat could be in: these being Alive, Dead, and Bloody Furious”*…
Of all the bizarre facets of quantum theory, few seem stranger than those captured by Erwin Schrödinger’s famous fable about the cat that is neither alive nor dead. It describes a cat locked inside a windowless box, along with some radioactive material. If the radioactive material happens to decay, then a device releases a hammer, which smashes a vial of poison, which kills the cat. If no radioactivity is detected, the cat lives. Schrödinger dreamt up this gruesome scenario to mock what he considered a ludicrous feature of quantum theory. According to proponents of the theory, before anyone opened the box to check on the cat, the cat was neither alive nor dead; it existed in a strange, quintessentially quantum state of alive-and-dead.
Today, in our LOLcats-saturated world, Schrödinger’s strange little tale is often played for laughs, with a tone more zany than somber. It has also become the standard bearer for a host of quandaries in philosophy and physics. In Schrödinger’s own time, Niels Bohr and Werner Heisenberg proclaimed that hybrid states like the one the cat was supposed to be in were a fundamental feature of nature. Others, like Einstein, insisted that nature must choose: alive or dead, but not both.
Although Schrödinger’s cat flourishes as a meme to this day, discussions tend to overlook one key dimension of the fable: the environment in which Schrödinger conceived it in the first place. It’s no coincidence that, in the face of a looming World War, genocide, and the dismantling of German intellectual life, Schrödinger’s thoughts turned to poison, death, and destruction. Schrödinger’s cat, then, should remind us of more than the beguiling strangeness of quantum mechanics. It also reminds us that scientists are, like the rest of us, humans who feel—and fear…
More of this sad story at “How Einstein and Schrödinger Conspired to Kill a Cat.”
* Terry Patchett
As we refrain from lifting the box’s lid, we might spare a thought for Charles Babbage; he died on this date in 1871. A mathematician, philosopher, inventor and mechanical engineer, Babbage is best remembered for originating the concept of a programmable computer. Anxious to eliminate inaccuracies in mathematical tables. By 1822, he built small calculating machine able to compute squares (1822). He then produced prototypes of portions of a larger Difference Engine. (Georg and Edvard Schuetz later constructed the first working devices to the same design which were successful in limited applications.) In 1833 he began his programmable Analytical Machine (AKA, the Analytical Engine), the forerunner of modern computers, with coding help from Ada Lovelace, who created an algorithm for the Analytical Machine to calculate a sequence of Bernoulli numbers— for which she is remembered as the first computer programmer.
Babbage’s other inventions include the cowcatcher, the dynamometer, the standard railroad gauge, uniform postal rates, occulting lights for lighthouses, Greenwich time signals, and the heliograph opthalmoscope. He was also passionate about cyphers and lock-picking.
“There is not a discovery in science, however revolutionary, however sparkling with insight, that does not arise out of what went before”*…
Analysis of an ancient codebreaking tablet has revealed that Babylonian astronomers had calculated the movements of Jupiter using an early form of geometric calculus some 1,400 years before we thought the technique was invented by the Europeans.
This means that these ancient Mesopotamian astronomers had not only figured out how to predict Jupiter’s paths more than 1,000 years before the first telescopes existed, but they were using mathematical techniques that would form the foundations of modern calculus as we now know it…
Look more closely at the foundations of modern calculus at “This ancient Babylonian map of Jupiter just changed history as we know it.” And read the Science article reporting the findings here.
* Isaac Asimov
As we calculate the differential, we might send radiant birthday greetings to James Alfred Van Allen; he was born on this date in 1914. A space scientist who learned to miniaturize electronics during World War II, he was instrumental in establishing the field of magnetospheric research in space, and led the scientific community for the inclusion of scientific research instruments on space satellites. The Van Allen radiation belts were named after him, following their discovery by his Geiger–Müller tube instruments in 1958 on the Explorer 1, Explorer 3, and Pioneer 3 satellites during the International Geophysical Year.
Science has a habit of asking stupid questions. Stupid, that is, by the standards of common sense. But time and time again we have found that common sense is a poor guide to what really goes on in the world.
So if your response to the question “Why does time always go forwards, not backwards?” is that this is a daft thing to ask, just be patient…
In our experience the past is the past and the future is the future, but sometimes the two can cross over; and while the past seems set in stone, some scientists believe that the future can change it: “The quantum origin of time.”
* William Faulkner,
As we head down the rabbit hole, we might spare a thought for Jules Henri Poincaré; he died on this date in 1912. A mathematician, theoretical physicist, engineer, and a philosopher of science, Poincaré is considered the “last Universalist” in math– the last mathematician to excel in all fields of the discipline as it existed during his lifetime.
Poincaré was a co-discoverer (with Einstein and Lorentz) of the special theory of relativity; he laid the foundations for the fields of topology and chaos theory; and he had a huge impact on cosmogony. His famous “Conjecture” held that if any loop in a given three-dimensional space can be shrunk to a point, the space is equivalent to a sphere; it remained unsolved until Grigori Perelman completed a proof in 2003.
“I used to think information was destroyed in black holes. This was my biggest blunder, or at least my biggest blunder in science”*…
Gravitational waves sent out from a pair of colliding black holes have been converted to sound waves, as heard in this animation. On September 14, 2015, LIGO [the Laser Interferometer Gravitational-wave Observatory] observed gravitational waves from the merger of two black holes, each about 30 times the mass of our sun. The incredibly powerful event, which released 50 times more energy than all the stars in the observable universe, lasted only fractions of a second.
In the first two runs of the animation, the sound-wave frequencies exactly match the frequencies of the gravitational waves. The second two runs of the animation play the sounds again at higher frequencies that better fit the human hearing range. The animation ends by playing the original frequencies again twice.
As the black holes spiral closer and closer in together, the frequency of the gravitational waves increases. Scientists call these sounds “chirps,” because some events that generate gravitation waves would sound like a bird’s chirp.
More background from LIGO:
* Stephen Hawking
As we scan the event horizon, we might send difficult-to-detect birthday greetings to Lawrence Maxwell Krauss; he was born on this date in 1954. A theoretical physicist and cosmologist, Dr. Krauss was among the first to propose the existence of the enigmatic dark energy that makes up most of the mass and energy in the universe. He directs the Origins Project, and has written several books on science for the general public, including Fear of Physics (1993), The Physics of Star Trek (1995), Quantum Man: Richard Feynman’s Life in Science (2011), and A Universe from Nothing (2012).
… imposing old Newtonian Schema thinking on new quantum-scale phenomena has landed us in situations with no good explanations whatsoever. If these phenomena seem inexplicable, we may just be thinking about them in the wrong way. Much better explanations become available if we are willing to take the future into account as well as the past. But Newtonian-style thinking is inherently incapable of such time-neutral explanations. Computer programs run in only one direction, and trying to combine two programs running in opposite directions leads to the paradoxical morass of poorly plotted time-travel movies. In order to treat the future as seriously as we treat the past, we clearly need an alternative to the Newtonian Schema.
And we have one. Most physicists are well aware of a different framework, an alternative where space and time are analyzed in an even-handed manner. This so-called Lagrangian Schema also has old roots and has become an essential tool in every field of fundamental physics. But even physicists who regularly use this approach have resisted the last obvious step: thinking of the Lagrangian Schema not just as a mathematical trick, but as a way to explain the world. Perhaps we haven’t been taking our own theories seriously enough.
The Lagrangian Schema doesn’t just allow future-based explanations. It demands them. By treating the future and the past on the same footing, this framework avoids paradoxes and makes new explanatory opportunities available. And it just might be the viewpoint that physics needs for the next major breakthrough…
More at “To Understand Your Past, Look to Your Future.”
As we disentangle entanglement, we might spare a thought for Bede (or as he is more frequently remembered, Venerable Bede); he died on this date in 735. An English monk, Bede studied and wrote widely on scientific, historical, and theological topics, ranging from music and metrics to exegetical Scripture commentaries. He was an accomplished translator (Pliny the Elder, Virgil, Lucretius, Ovid, Horace, and other classical writers in both Greek and Hebrew). And his Historia ecclesiastica gentis Anglorum (The Ecclesiastical History of the English People) has earned him the title “The Father of English History.” Indeed, it was in this work that Bede established as common practice the use of “BC” and “AD” with dates.
Just when the confirmation of gravity waves seemed conclusively to affirm Einstein’s theory of general relativity…
If you thought regular black holes were about as weird and mysterious as space gets, think again, because for the first time, physicists have successfully simulated what would happen to black holes in a five-dimensional world, and the way they behave could threaten our fundamental understanding of how the Universe works.
The simulation has suggested that if our Universe is made up of five or more dimensions – something that scientists have struggled to confirm or disprove – Einstein’s general theory of relativity, the foundation of modern physics, would be wrong. In other words, five-dimensional black holes would contain gravity so intense, the laws of physics as we know them would fall apart…
“If naked singularities exist, general relativity breaks down,” said one of the team, Saran Tunyasuvunakool. “And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power – it could no longer be considered as a standalone theory to explain the Universe.”
If our Universe only has four dimensions, everything is cool, and ring-shaped black holes and naked singularity are not a thing. But physicists have proposed that our Universe could be made up of as many as 11 dimensions. The problem is that because humans can only perceive three, the only way we can possibly confirm the existence of more dimensions is through high-energy experiments such as the Large Hadron Collider…
* Robert Coover, A Child Again
As we marvel at models, we might send very carefully-crafted birthday greetings to Jacques de Vaucanson; he was born on this date in 1709. A mechanical genius, de Vaucanson invented a number of machine tools still in use (e.g., the slide rest lathe) and created the first automated loom (the inspiration for Jacquard). But he is better remembered as the creator of extraordinary automata. Among his most famous creations: The Flute Player (with hands gloved in skin) and The Tambourine Player, life-sized mechanical figures that played their instruments impressively. But his masterpiece was The Digesting Duck; remarkably complex (it had 400 moving parts in each wing alone), it could flap its wings, drink water, eat grain– and defecate.
Sans…le canard de Vaucanson vous n’auriez rien qui fit ressouvenir de la gloire de la France. (Without…the duck of Vaucanson, you will have nothing to remind you of the glory of France)