Maximum Lean Angle

I can't even touch my toes. Read the rest

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:

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

Constructive Interference is a laser-cut sculpture that demonstrates the "double slit" phenomenon that causes periodic wave patterns. I've posted about the math involved previously.

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Ariel Waldman writes, "Neutrinos are tiny particles spit out by supernovas that were rumored to travel faster than light. Even though we still don't have FTL spaceships (sigh), I share with you why neutrinos are still freaking amazing." Read the rest

Hugh writes, "These amazing animated shorts on physics feature an adorable, 1930's style version of Maxwell's Demon. There are 3 so far -- can't wait to see more!" Read the rest

Steve Mould explains the physics behind the squeak in "squeaky clean." Read the rest

Hyperloop One engineers demonstrate the power of maglev using spinning arrays atop a copper plate. Despite weighing over 100 pounds, the gadget floats and could hold considerably more weight. Read the rest

Do you ever wonder why we need kneecaps?

The demonstration shows how kneecaps provide leverage. I'm happy the Flying Spaghetti Monster built us this way. Read the rest

YouTuber KittyPouncer created this terrific timelapse video of curly icicles extruding from pipes. Here's how it happens: Read the rest

This isn't your usual kinetic pachinko balls-in-a-gravity-maze toy, but a mindbending demonstration of magnets. It starts getting really crazy at about 2m in but one should enjoy the subtle pleasures too. Read the rest

Diguo's Luxury Royal Family Balance Syphon Coffee Maker is an amazingly elaborate coffee siphon, a brewing method dating to the 1830s which is said to produce "a delicate, tea-like cup of coffee," albeit with the caveat that it is "quite persnickety." Read the rest

Volume warning! YouTuber Latheman666 demonstrates how an air compressor with the right nozzle can make all sorts of things float. Looking forward to a "Will It Float?" channel! Read the rest