Awesome Physics

Drones can be used to capture aerial images or deliver packages, but they can also be weaponized. Mark Rober explores some of the technology being developed to take down dangerous drones. Then, he teamed up with fellow makers to build backyard drone defense tech, including a mega-turret, an electrified stream of liquid, and a powerful vortex cannon.

Science educator Steve Mould shows off a fascinating thing that happens when you ignite lighter fluid in a narrow channel. The flame travels around and around until the fuel is fully burned. He started with a circle and tested various shapes to see how the flames behaved. Along the way, you’ll learn about the concept of an excitable medium.

If you attach different-weight objects to a string and hang them over a bar, the lighter object can prevent the heavier one from hitting the ground when dropped. As this happens, the rope spirals around the bar. Science teacher Bruce Yeany attached LEDs to the objects and captured long-exposure photos of this fascinating looping pendulum action.

Randall Munroe and Henry Reich’s What If? attempts to answer the hypothetical question of what might happen if every living human stood close together, jumped off of the ground, and landed at the same exact time. While the answer to that question is less exciting than you might think, there would be plenty of unintended consequences of such an event.

This electromechanical plaything from Nikola Toy automatically steadies itself and balances on its point. Its curved Reuleaux triangle shape allows it to teeter while sensors, circuitry, and a spinning wheel help hold its position. It also has built-in RGB LED lighting.

A gravity well is a cone-shaped device that pulls marbles or other small balls into its center like a vortex. JBV Creative built a version of a gravity well connected to an elevator, so as spheres drop through its middle, they head back up to the top and start their journey all over again. It’s incredibly satisfying once he drops thousands of steel balls into it.

We’ve heard the phrase “singing sands” but never really knew what it meant. James from Atomic Frontier headed to Australia to explore why some sand makes a squeaking noise when you walk on it. After putting some of the rare squeaky sand beneath a microscope, he explains how sand dune can make a much larger sound under the right conditions.

xkcd’s What If? is back with another hypothetical question. This time, a follower asked: “How long could a nuclear submarine last in orbit?” Along the way, you’ll learn if a sub’s hull could withstand the conditions in space, and more importantly, what might happen to its occupants and nuclear reactor.

If you put a powerful fan on a boat and blew it at its sail, would the boat move? Engineer Mark Rober channels Mr. Wizard with a series of experiments and easy-to-understand explanations of this and six other perplexing physics questions. He also debunks a viral video along the way.

You know those toy cars that move using a flywheel? The car-chopping madmen of Garage 54 took another rusted-out old Lada and fitted it with such a mechanism. They connected its engine and transmission to the flywheel via a differential, pulley, and belts. After giving the car some gas, let it coast to see how far it would go under flywheel power.

Astrophysicists estimate that our universe came into existence roughly 14 billion years ago, and it’s been expanding ever since. Kurzgesagt ponders the question whether the universe is truly infinite if it keeps growing, or if it has an edge somewhere that we just can’t see.

When you heat fluids, they typically produce patterns. Science expert Steve Mould built a special rig that lets us see how these turbulent patterns emerge when applying heat. He tested with a few different liquids and particles to visualize these fascinating flows. Things get really interesting when mixing oil with mica.

Imagine, for a moment, that it was possible to pitch a baseball at 90% of the speed of light. Not only would you easily eliminate the batter, but there would be other major consequences according to this hypothetical physics exploration by the mighty Randall Munroe of xkcd. Weapons makers, don’t get any funny ideas.

Over a decade ago, Destin from Smarter Every Day and his pal John Henry tested the idea that you could light a match with a bullet. Now that he’s got a much better high-speed camera, he and John wanted to revisit the experiment. Once they dialed in the aim, they captured some incredible slow-motion macro footage at speeds up to 380,117 FPS.

Season two of Loki featured one of the nastiest torture devices imaginable. The TVA’s Time Cube shrinks around its subjects until they relent – or die a horrific, squishy death. While Disney+ was relatively tame depicting the prison box’s wrath, Atomic Marvel scratches the itch for more, using a human avatar made up of thousands of tiny particles.

You might not feel it, but the Earth is spinning quite quickly. Depending on your latitude, you could be going more than 1000 MPH. xkcd’s What If? explores what might happen if, all of a sudden, the planet stopped spinning and the atmosphere kept going. Things wouldn’t bode well for living creatures or structures, thanks to the extreme wind and waves.

The Slow Mo Guys, Gav and Dan, stopped by the Colorado School of Mines to observe what happens when you fire two identically shaped charges into each other. Their high-speed cameras captured the 15,000 MPH collision in slow motion for us to enjoy. It was really tough to keep the exposure from blowing out because of the intensity of the fireball.

xkcd’s What If series ponders another viewer-submitted question. With no regard for rules, what would be the fastest way to get a human around a race track 200 times – without killing the driver. After coming up with some creative solutions, it turns out the limiting factor isn’t the vehicle, it’s the person inside of it.

Have you ever wondered how the gravity on different planets might affect your ability to throw a ball? Dr. James O’Donoghue created this infographic that explores how far and high you could toss a ball, assuming no air resistance. Basically, on Mars, Mercury, and Pluto, you could hit a home run without a baseball bat.

Time isn’t as simple as what shows up on your phone’s screen. Erin McCarthy of Mental Floss offers up a number of interesting tidbits about the nature of time, how humans perceive its passage, how space and time relate, and the different ways of measuring time itself.

For today’s physics lesson, kids, we will learn about weight, density, and air resistance. In this very short video, we’ll see one worker’s simple yet effective method of separating red beans from dirt. Sure, a machine might be more efficient, but we appreciate this guy’s low-tech solution.

Contrary to popular belief, one horse is said to produce about 15 horsepower. But that number is disputed because there’s some question about the accuracy of the original measurements. With the help of Motivo, the guys from Donut came up with a new test: connecting a horse to a dynamometer to measure its true pulling power.

Using large syringes, Tom Stanton shows us how the vacuum captured inside can be used to drive gears, a belt, and an axle. The result is a mini dragster that travels an impressive distance compared to the short distance that the syringe’s piston moves.