(Photo: Screenshot from Abe Davis video, below)
Scientists at MIT revealed a mind-bending new invention this week: using a setup they call a "visual microphone," they were able to reconstruct music and even speech by analyzing the tiny vibrations caused by the sound... on a bag of chips. (No, really.)
Here's how it works.
As you may remember from high school science class, sound is caused by repeating vibrations of air moving in waves. And when those waves strike against an object like a bag of chips or the leaves of a houseplant, they cause that object to vibrate too — although the movements are so small that they're invisible to the naked eye.
The MIT system uses a high-speed camera that captures about 6,000 frames per second (the fastest smartphones top out at 120 fps) to detect these minor fluctuations, and then runs the video through some fancy software to reconstruct the sound. The video below demonstrates the system in action — the most impressive moment might be at the 2:20 mark, where they recover Queen and David Bowie's "Under Pressure" from a video of ordinary earbuds playing the song. And then feed that into Shazam.
They can even use the software with standard smartphone cameras, although the reconstruction you get is much less detailed (you can can just make out a tune, but not what someone's saying).
"We’re scientists, and sometimes we watch these movies, like James Bond, and we think, ‘This is Hollywood theatrics. It’s not possible to do that. This is ridiculous.’ And suddenly, there you have it," Alexei Efros, a professor of electrical engineering at the University of California at Berkeley said in a statement. "This is totally out of some Hollywood thriller. You know that the killer has admitted his guilt because there’s surveillance footage of his potato chip bag vibrating."
If that setup sounds familiar, it could be because that's pretty much what happens in the 2008 conspiracy flick Eagle Eye, when an evil super computer reads the ripples off a glass of water to listen in on a conversation.
It's also not far off from the premise of "The Extractor," a dark comedy of a radio story about an invention that can reconstruct the sounds made by departed loved ones — that are embedded in ordinary pieces of wood all around us.
Via MIT News