Our lives are filled with controls - switches, knobs, buttons - to control all of the devices and machines that we use in our life. Set the temperature on the stove, enter a time for the microwave, get the sink's water at just the right temperature. Turn on your TV, your lights, adjust the volume of your speakers. ...
As I said, we live in a world of controls. And it's been an area of intense study - to the point where there are industrial design handbooks that tell you the exact size for a knob to be, with what type of ridges, so that it's as easy as possible for the human hand to use it.
And it's very important that we've perfected these controls - imagine a nuclear power plan operator accidentally causing a meltdown because a knob didn't work the way he expected!
But, just because they're good now doesn't mean that they can't get better. A lot better. These industrial controls have worked well, because they've been the best we have.
Until now. Watch as a group of hackers, in just a few hours, made it possible to control a light using hand gestures:
It's true that these gestures might be slightly less "intuitive" than just flicking a switch. However, the devices in our lives are becoming increasingly complicated, to the point that our old control methods simply don't work. Imagine trying to design a physical control system for a lightbulb with variable color - you'd need at least three knobs! (For red, green and blue - or hue, saturation and luminance)
And this is where innovation is needed. For all of the amazing new gadgets that are coming out (the Pebble, Lockitron, Lifx, etc), the number of options and inputs under our control is growing exponentially. It's up to us to figure out how to deal with it!