Halloween is just around the corner, and people are surely trying to find ways to offer the spookiest pranks for their kids and adult friends or relatives just in time for the season.
While motion-activated setups have been used time and again to offer that unforgettable scare, there are different ways to make that Halloween truly nerve-wracking and terrifying. Why not scare the wits out of kids and friends with this chilling "script writing" with ultrasound?
People may view this as otherworldly, but actually it's nothing more than plain science, with a good dose of innovation.
'Ghost Writer' Uses Ultrasonic Transducers for That Ultimate Scare
Thanks to innovator and YouTuber Dan Beaven, everyone can now make that ultimate scare with a variation on ultrasonic levitation projects people have already witnessed through the years, Gizmodo reported. As Beaven witnessed in awe how styrofoam bits levitate through standing waves produced by carefully phased arrays of ultrasonic transducers, he took that concept to a new "ghostly" level.
Still a prototype, Beaven's setup--as seen in his viral YouTube video--shows a 256-transducer matrix suspended on a dark surface. Baking powder is scattered over the writing surface instead of dust, which could be easily dislocated as sound waves reflect on a hard surface.
This array could be controlled to make it seem that an unseen hand is screeching and tracing a design, in this case a pentagram, in the baking powder. Surely, this effect is quite convincing!
It really is downright spooky--something that should leave witnesses speechless and floored. No apparent writing tool is seen making the baking powder move, and other visible indicators since the sound waves are inaudible and invisible.
The bad news is: it's not available in any retail stores or Halloween shops yet. Actually, it has a long way to go before anyone could make jump-scare prank out of this. But, certainly, the proof-of-concept is astounding. Nonetheless, as everyone waits for an actual product to reach shelves, this can be documented as a technique that could allow other applications to move forth, such as sonic tweezers that could lift objects using sound.
'Ghostly' Trick Not New, Used to 'Levitate' Small Objects Without Contact
Actually, moving small items through sound or lasers is not new, yet specific limitations have hindered its progress over the years. Beaven's approach utilizes an array of hemispherical ultrasound transducers, which are speakers that generate sounds beyond the range of human hearing.
Controlling the amplitude and phase of each transducer, acoustic traps form and this could even put a three-millimeter polystyrene ball without any contact, making it appear as levitating. It can also make a small foam bead float in mid-air as this magical effect has surprised many with the practical application seen in Beaven's setup.
Before Halloween strikes, Beaven plans to expand the setup to utilize side-by-side transducer arrays to produce a larger surface for a "ghost" to write messages, allowing creepier, shocking words or statements to appear.
