Do you want to hear the most annoying sound in the world? What about watching the most annoying sound in the world levitate objects? Acoustic levitation takes intense sounds and reflects them back on themselves, producing what's known as a standing wave—a sound wave that seems to kind of vibrate in place, rather than traveling the way a normal wave does.
Ordinary standing waves can be relatively powerful. For example, a standing wave in an air duct can cause dust to collect in a pattern corresponding to the wave's nodes. A standing wave reverberating through a room can cause objects in its path to vibrate. Low-frequency standing waves can also cause people to feel nervous or disoriented -- in some cases, researchers find them in buildings people report to be haunted.
The kind of high-decibel standing waves used in acoustic levitation can actually create pockets of air pressure strong enough that objects inside them can resist the pull of gravity. This particular acoustic levitator was designed by physicist David Deak in 1987, to help NASA mimic the low-gravity environment of the space shuttle, on Earth.
I’ve had quite a few fun afternoons playing with dry ice from making spooky fog in the kitchen to exploding plastic bottles in the yard. But I’ve never had the opportunity to pour hot lava over dry ice. In this video, the lava is 1400 °C and the dry ice is -78C°. So cool! And […]
A Boston University team have developed an acoustic, 3D-printed metamaterial whose topology is such that it reflects 94% of human-audible sound; the researchers' demonstration involves inserting a ring of this stuff in a PVC pipe and blasting a speaker down one end: light and air emerges from the other end, but sound does not.
Got a vision to put on film? The Film & Cinematography Mastery Bundle shows you how to put it there, with classes covering gear, lighting, production – even marketing. Even in this age of indie cinema, filmmaking can seem like an exclusive world for the chosen few. But with the right eye – and the […]
If you’re into tech at all, you should definitely consider unleashing your inner tinkerer on a Raspberry Pi board. If you’re intimidated, don’t be. It’s a statistical probability that people half your age have created cooler things than you can imagine with the versatile kit. Not sure where to start? The Complete Raspberry Pi 3B+ […]
Are you super organized? You’re going to love the Genius Pack G4 and its seemingly limitless, well-placed compartments. Not that organized? You’re still going to love this piece of luggage because it’s so well thought out that it practically does the packing for you. We’ve all tried to stuff a piece of carry-on so full […]