We’ve been waiting seemingly for years for the Mac to get gesture recognition. Accessories like the Leap Motion have tantalized us with the possibility of aftermarket solutions, while secret Apple patents have hinted at future Macs with Kinect-like possibilities. Heck, Apple even purchased the company that designed the Kinect’s technology back in 2013, yet we’ve still seen nothing.
Turns out we might not need to wait for Apple to release special hardware for a gesture-controlled Mac. By making use of a very simple phenomenon in physics, Apple could actually enable gesture control in the Mac, iPhone and iPad … no hardware required.
There’s no suggestion that Apple is working on this, but if you go to this webpage designed by Swedish computer scientist Daniel Rapp, you can actually perform a number of different commands just by waving your hands in front of your browser, from scrolling a web page to playing a virtual theremin.
How does it work? Thanks to a physics principle called the Doppler effect. The webpage causes your speaker to emit an inaudible, high-frequency tone. When you move your hands, the sound wave reflects off them and shifts their frequency, which is in turn heard by your microphone and translated into a gesture.
Microsoft actually experimented with this tech back in 2012, so the big tech companies are definitely interested in it:
It’s not ideal, but it works. The issue, of course, is if your speakers are playing other music, or there’s a lot of other noise in the room, your computer can get confused. But it’s a cheap, easy way to enable gesture recognition on any hardware with speakers and a microphone, which is pretty much everything.
Would Apple ever use the Doppler effect to drive gestures on the Mac? For the above reasons, I doubt it. I suspect if we ever see a Kinect-like Apple device in the wild, it’ll use PrimeSense technology. But it’s cool to play around with, and think about what could be.