Time crystals, a theoretical phase of matter proposed in 2012, can now be reliably created and measured, thanks to researchers at UC Berkeley. Above: a great primer on time crystals.
The discovery built on the work of several teams of researchers:
Time crystals repeat in time because they are kicked periodically, sort of like tapping Jell-O repeatedly to get it to jiggle, Yao said. The big breakthrough, he argues, is less that these particular crystals repeat in time than that they are the first of a large class of new materials that are intrinsically out of equilibrium, unable to settle down to the motionless equilibrium of, for example, a diamond or ruby.
“This is a new phase of matter, period, but it is also really cool because it is one of the first examples of non-equilibrium matter,” Yao said. “For the last half-century, we have been exploring equilibrium matter, like metals and insulators. We are just now starting to explore a whole new landscape of non-equilibrium matter.”
Maybe the next step is the development of these time crystals:
• Scientists unveil new form of matter: time crystals (UC Berkeley via EurekAlert) Read the rest
Don Komarechka captures astonishing photographs of snowflakes. His book Sky Crystals is a survey of snowflake science, a monograph of his macrophotography masterpieces, and a tutorial on the techniques. At Petapixel, Komarechka explains the surprising pop of color sometimes seen through the lens when he's shooting a snowflake:
As a snowflake grows it often creates a cavity or bubble inside of it where the inner side of the crystal grows slower than the top and bottom edge. This forces the layers of ice on either side of the bubble to be incredibly thin, so much so that light will interfere with itself.
Some light will reflect off the surface of the snowflake, but some will also enter the ice (slowing down due to the density of ice compared to air) and reflect off the inner ice/air boundary back towards the camera. If the ice is thin enough, the distance between the two rays of light is close enough to force them to interfere with each-other now that they are out of sync. Some wavelengths get amplified and others get reduced, resulting in a distinctive color emerging based on the thickness of the ice.
"How I Capture Vibrant Colors Inside Snowflakes" (PetaPixel)
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Filipino student Hillary Diane Andales won a $250,000 scholarship from the Breakthrough Junior Challenge for this entertaining and easy-to-understand explainer on relativity and the equivalence of reference frames. Read the rest
If you've ever observed "wine legs," the rivulets that form when you swirl wine in a glass, you've seen the Marangoni effect. Watch how scientists are using this effect to create tiny motors that emit no pollutants. Read the rest
Laser Maze is a super-fun electronic board game that challenges players to arrange angled mirrors to route a laser beam from an emitter to a sensor, avoiding obstacles; in The Quantum Game, you undertake the same fundamental task, but with a virtual laser that only emits one photon, and virtual beam-splitters, absorbtive polarizers, quarter-wave plates, polarizing beam splitters, Faraday rotators, and other exotic apparatus.
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Numberpile looks at an interesting phenomenon using a common Japanese toy: a small paper balloon that can be crushed and re-inflated. What's the science behind it? Read the rest
The Simulation Hypothesis holds that alien races (or future versions of humanity) will eventually get the computing power and programming techniques to simulate the whole universe and that when they do, they will probably do so millions of times, meaning that most universes are simulations, and thus the odds that this universe is not a simulation are vanishingly small.
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The always-excellent maker of animated explainer videos, Kurzgesagt – In a Nutshell just released a new video that explains what black holes are, explains what information is, and then goes into the way that black holes are the cause of something called "The Information Paradox." The takeaway: we all might be stretched on a flat screen, just imagining that we are in three dimensions. Read the rest
As relaxing, amusing and intriguing as any other: "an impressive Rube Goldberg machine with a 4-minute course. The beads move in a chain reaction divided into several more complex steps, including the one with a whiteboard that turns to release new balls positioned on the back side." Read the rest
Physics Toys is a website (and Instagram account) of kinetic curiosities. Check out all the cool double pendulums, which exhibit chaotic behavior that put fidget spinners to shame. Here's a neat statuette of an alchemist who have a levitating magnetic cube between his hands.
The Alchemist: cast from diamagnetic Bismuth, a neodymium cube magnet levitates trapped between the hands of the ancient scholar. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the cube shaped magnet supplies the field. Diamagnetic fields are pretty weak though so a cylindrical neodymium magnet hangs above the figure and is adjusted to help lift the cube magnet against gravity. Trapped in equilibrium by these magnetic fields, the slightest air currents can send the cube magnet dancing. Although alchemists never succeeded in transmuting lead to gold, in 1981 physicists used the particle accelerator at Berkeley to shoot Carbon nuclei at thin foils of Bismuth- the resulting collisions did produced a tiny amount of Gold atoms! So modern nuclear physics, applied to the element Bismuth, finally accomplished the aspirations of the alchemists.
The creator of the statue, Ernie McElhannon, is selling it for $299 on Etsy.
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The Alchemist: cast from diamagnetic Bismuth, a neodymium cube magnet levitates trapped between the hands of the ancient scholar. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the cube shaped magnet supplies the field. Diamagnetic fields are pretty weak though so a cylindrical neodymium magnet hangs above the figure and is adjusted to help lift the cube magnet against gravity.
Chinese researchers demonstrated quantum entanglement at a record distance, between a satellite and ground stations 1,200 kilometers apart. When objects are quantum entangled, their quantum states are linked. Measuring the state of one affects the state of the other. It's weird shit. So weird that Einstein called it "spooky action at a distance."
The experiment by physicists at Shanghai's University of Science and Technology of China could eventually lead to highly-secure communications technologies in space and back on Earth.
"I'm personally convinced that the internet of the future will be based on these quantum principles," says Anton Zeilinger, a physicist at the Austrian Academy of Sciences in Vienna who was not involved in the experiment.
"China’s quantum satellite achieves ‘spooky action’ at record distance" (Science)
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Here's a good video that describes the laws of thermodynamics in an intuitive way, and why perpetual motion machines won't work. Read the rest
Now and then I stumble upon a book that completely blows my mind. The latest of such lucky encounters has been with Seven Brief Lessons in Physics by Carlo Rovelli.
Carlo Rovelli is an Italian theoretical physicist with a solid, international academic career, presently teaching at the University of Aix-Marseille in France. In 2013 he was among the sophisticated minds who were asked the famous Edge.com annual question. The question that year was "What *should* we be worried about?" His reply: "I worry that free imagination is overvalued, and I think this carries risks."
Published in 2014, Seven Brief Lessons in Physics has been an immediate smash hit. In less than 80 pages, Rovelli takes the reader on a friendly trip from the far edges of the cosmos to the edges of the quantum world, addressing some of the hottest ideas revolutionizing our present understanding of the world. And he does so with unassuming innocence, and his enchanting prose makes complex subjects a piece of cake.
In one of his most rhapsodic fragments Rovelli writes:
"There are absolute masterpieces which move us intensely, Mozart’s Requiem; the Odyssey; the Sistine Chapel; King Lear. To fully appreciate their brilliance may require a long apprenticeship, but the reward is sheer beauty."
To this list of timeless masterpieces of human ingenuity, Rovelli appends Einstein's celebrated theory of general relativity, which he calls "the most beautiful of all theories".
Now, here's the deal: modern physics is an unbelievably complex, impenetrable and obscure "thing," well beyond the comprehension of any layperson, however well-read. Read the rest
Wired's Rhett Allain built a rig with a laser and light sensor to study fidget spinner physics and determine how long it will spin based on the starting angular velocity. Allain's article will make a great teachable moment for my kids, as in I'll ask them to read it and explain it to me. From Wired:
If I know the starting angular speed and I assume a final angular speed of zero radians per second, I can calculate the spin time:
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All I need is the angular acceleration—assuming it remains constant as the spinner slows. I could calculate the angular acceleration based on the change in angular velocity, but this isn’t so simple to measure. The spinner moves too quickly to get a good video of its motion, so I will use a laser in a rig I built to measure the change in the angular velocity.
Basically, the laser shines down onto a light sensor. As the spinner spins, it occasionally blocks the sensor, interrupting the laser. By measuring the values from the light sensor, I determine the spin rate. But this creates a couple of problems. First, the light change rate and the rotation rate differ because the three “lobes” in the spinner create multiple openings during each rotation. Second, the spinner will spin for a significant amount of time such that it would be difficult to analyze it all at once...
Now for the fun trick. Instead of looking at a giant plot of light vs. time (the full data is over 2 minutes), I will plot the Fourier transform of this data.
To demonstrate the Magnus effect, YouTuber PeterSripol grabbed a couple of KFC buckets and tricked out an RC plane. The resulting trial and error is mostly the latter. Read the rest
As AI improves, the mystery of consciousness interests more programmers and physicists. Read the rest