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.
The large black bear in this video was observed ambling around a Monrovia, California neighborhood last Friday morning. The bear walked through residential lawns, driveways and rested in a nearby alley.
How does an owl’s tail help it fly? To better see the role of the tail in raptor aerodynamics, researchers at the UK’s Royal Veterinary College recorded birds of prey flying through clouds of tiny helium bubbles. According to the science journal Nature, analyzing the swirling motion of the bubbles enabled the scientists to discover […]
Thirty years ago today, the Voyager 1 spaceprobe had completed its ncounters with the outer planets and was careening out of our solar system. The time came to shut off the probes’ cameras to preserve power and memory for the other onboard scientific instruments. But before engineers flipped the switch, one last photo opportunity was […]
While mobile devices are all but essential and the center of so many individual universes these days, find one person who loves their wireless plan with that type of passion. Check around. We’ll wait… Didn’t find anybody, did you? That’s because most wireless plans are designed for the convenience of the provider and will nickel-and-dime […]
In the early days of the web, everyone wanted a .com domain for their site. As a result, all the good ones got snapped up. But .com no longer has the cachet it once did. In fact, many new businesses and individuals are opting for other top-level domain extensions. One of the most memorable is […]
As you shiver your way through February, you’re probably thinking about paying your heating bill. But in just a few short months, the summer sun is going to come calling — and the fear of pulling that energy bill out of your mailbox will start becoming very, very real. Air conditioning accounts for about an […]