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Sound is a wave that we perceive with our ears. It makes our favorite music, and it keeps us out of danger, but it's so much more than that! Hey everybody! Thanks for checking out Dnews today. I'm Trace. Now listen up! Sound is extremely powerful. It's made of invisible waves of energy passing through substances -- ground, water, air -- particle to particle. The human ear can perceive these waves as long as their frequencies are between 20Hz and 20,000Hz. Anything above or below that, we can't hear but they're still there because these waves contains energy. And with enough ding, you can make these waves do some incredible things. Outside of medical technology, like ultrasound, one of the most commonly known ways to make sound do something is by breaking a glass. This works only when the sound wave is at the exact same frequency as the object you're shooting at. If you gently flick a wine glass with your fingernail, you will hear its frequency. Match that tone and turn the volume up! Way way up! To like a eleven! And that glass will probably break. Also within the range of hearing is sound levitation. This is way cooler than breaking stuff if you ask me. Sound levitation has been around for years, but until recently, we couldn't do much with the stuff once it was levitated. It just hung there in the air. Thanks to advances at a Swiss University called ETH Zurich, we can not only levitate stuff, but we can move it around, adjusting floating fluids. This works by using the energy in the sound waves. In this apparatus, the energy waves reflect back and forth so quickly, they form what's called a standing wave or a specific point where the energy from the sound can hold an object in mid-air. Think it like these silly executive desk toys. The ball in the middle, that's the standing wave. The thing that they just figured out is how to move the stuff once it's levitated. Now they can use this system to manipulate liquids combining and separating them, all without touching them with human hands, which is immediately applicable to drug manufacturers. That's kinda cool. These energy waves can do a lot of other stuff too. The LRAD, or long-range acoustical devices, is a weapon that shoots sound. It's like a sonic death ray, but without the death part. It can produce so much sound that you feel physical pain. Like 160 decibels. That's loud. Think NASA rocket launch. But it won't kill you. It just really hurts. Like a sonic hurt ray. If you combine some those technologies, sound can produce really strange effects. In the 1950s, NASA the US Navy built a device the produces ultra low frequencies or ultrasonic sound. If you pointed it at a person and set it to 19Hz, people would have vision problems and get spots and stuff because 19Hz is the resonant frequency of the human eyeball. Kinda like that wine glass example we talked about. If you turn the volume up, people actually would have trouble breathing because the low frequencies were impacting the lungs like energy waves. And if you shot through the ground, your skeleton would vibrate causing nausea and joint pain. So which of these sound inventions is your favorite? The levitating ones for drug manufacturing, ultrasound or maybe one of the ones that are used for EVIL? Share your thoughts with us and we'll see you next time on Dnews.