School of Rock: The Physics of Waves on Guitar Strings

The rubber band example does indeed have two nodes—they are at the ends of the rubber band where your fingers hold it. We only have half a wavelength in the standing wave, but there is indeed a relationship between the length of the rubber band and the size of the wavelength. Guitar Strings It’s time […]

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How to Measure the Calories in a Candy Bar—With Physics!

This Halloween, when you grab a candy bar, pay attention to the wrapper. In the United States, a “nutrition facts” label has been required for all packaged foods since 1994, giving the serving size and the amount of sugar, protein, fat, and sodium the food contains. But the most interesting bit is the metric for […]

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The Physics of Faraday Cages

This also works the other way: Incoming electromagnetic waves will get canceled by the moving charges in the Faraday cage. Your phone won’t know that it’s getting a text message or call. Let’s focus for a minute on why the cage’s materials are important. A Faraday cage is made from an electrical conductor, metals like […]

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A Novel Type of Neural Network Comes to the Aid of Big Physics

Graham tried tweaking the CNN approach so that the kernel would only be placed on 3-by-3 sections of the image that contain at least one pixel that has nonzero value (and is not just blank). In this way, he succeeded in producing a system that could efficiently identify handwritten Chinese. It won a 2013 competition […]

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The Tiny Physics Behind Immense Cosmic Eruptions

During fleeting fits, the sun occasionally hurls a colossal amount of energy into space. Called solar flares, these eruptions last for mere minutes, and they can trigger catastrophic blackouts and dazzling auroras on Earth. But our leading mathematical theories of how these flares work fail to predict the strength and speed of what we observe. […]

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The Physics of ‘Sniping’ for Gold

There are three forces acting on the debris. First, there’s the downward-pulling gravitational force (Fg) due to the interaction with the Earth. This force depends on both the mass (m) of the object and the gravitational field (g = 9.8 newtons per kilogram on Earth). Next, we have the buoyancy force (Fb). When an object […]

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The Physics of Mandalorian Jetpacks (Hint: They Aren’t Jetpacks)

Let’s say you don’t need to fly quite so far. What about a jet engine? These are the things you mainly see on commercial airliners, but very small jet engines can also be used to make a real-life jetpack. Just like rockets, jet engines produce thrust by shooting mass out the back, which is mostly […]

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The Physics Principle That Inspired Modern AI Art

Sohl-Dickstein used the principles of diffusion to develop an algorithm for generative modeling. The idea is simple: The algorithm first turns complex images in the training data set into simple noise—akin to going from a blob of ink to diffuse light blue water—and then teaches the system how to reverse the process, turning noise into […]

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You Can Use This Silly Game to Do Some Serious Physics

I’m a sucker for interesting online games that don’t have a score or even a goal. In this case, it’s a cartoon space simulator to promote the book What If? 2 by Randall Munroe, the author of the xkcd comics. You can play it by clicking here. (Don’t worry, I’ll wait.) The game works like […]

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A Crucial Particle Physics Computer Program Risks Obsolescence

Recently, I watched a fellow particle physicist talk about a calculation he had pushed to a new height of precision. His tool? A 1980s-era computer program called FORM. Particle physicists use some of the longest equations in all of science. To look for signs of new elementary particles in collisions at the Large Hadron Collider, […]

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How to Use Physics to Tell If That Steph Curry Video Is Real

A few weeks ago, Sports Illustrated tweeted this video of Golden State Warriors point guard Steph Curry that instantly went viral. It shows him taking a shot at the basket—from the far side of the court. The ball goes in. OK, I can believe that. He’s a famously great shooter. But then he turns around […]

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The Physics of Scuba Diving

Another unit is the bar, where 1 bar is equal to 14.5 psi. The value of 1 bar is very close to the pressure of air on Earth. The atmospheric pressure of the air that surrounds you right now is probably 14.5 psi. (Yes, I said “probably” because I don’t want to judge you. Maybe […]

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The Physics of Smashing a Spacecraft Into an Asteroid

There are a couple of things to notice. First, after the collision DART is moving backwards, because it bounced. Since velocity is a vector, that means that it will have a negative momentum in this one-dimensional example. Second, the kinetic energy equation deals with the square of the velocity. This means that even though DART […]

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The Physics of Going Fast—but Not Too Fast—on a Giant Slide

Really, the only difference is that this is a downward-curving path with the center of this circular curve below the slide instead of above. (Once again, the gray C-shape represents the path of the rider on the slide and the circular trajectory of their body, and the dot is the center of the circle.) That […]

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How the Physics of Nothing Underlies Everything

Most of the quantum fields that fill our universe have one, and only one, preferred state, in which they’ll remain for eternity. Most, but not all. True and False Vacuums In the 1970s, physicists came to appreciate the significance of a different class of quantum fields whose values prefer not to be zero, even on […]

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Behold the Weird Physics of Double-Impact Asteroids

When an asteroid strikes a planet, it can pack a powerful punch—as the dinosaurs discovered to their detriment 66 million years ago. But what if two asteroids strike at the same time and in the same location? A first-of-its-kind study published in the journal Icarus investigates this phenomenon on Mars. Looking at the planet, researchers […]

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The Unwritten Laws of Physics for Black Women

She decided to study physics. It was, in a way, good timing—a Black American woman had just become the first of her kind to earn a physics PhD, back in Greene-Johnson’s home state. At Stanford, Greene-Johnson was the only Black student in her major, but that didn’t surprise her. What did was the presence of […]

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A Puzzling Quantum Scenario Appears to Violate a Law of Physics

Remember we’re dealing with the photon’s wave function here. Since the bounce doesn’t constitute a measurement, the wave function doesn’t collapse. Instead, it splits in two: Most of the wave function remains in the box, but the small, rapidly oscillating piece near where the mirror was inserted leaves the box and heads toward the detector. […]

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A Newly Measured Particle Could Break Known Physics

Physicists have found that an elementary particle called the W boson appears to be 0.1 percent too heavy—a tiny discrepancy that could foreshadow a huge shift in fundamental physics. The measurement, reported April 7 in the journal Science, comes from a vintage particle collider at the Fermi National Accelerator Laboratory in Batavia, Illinois, that smashed […]

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