Those words combined with "a swish and a flick" of her magic wand let Hermione Granger send a feather from her desk top into the airy heights of a Hogwarts classroom. The combination of verbal command and body gesture was enough to energize the magical levitating force to bring about her feather's aerial feats, sans any attached bird.
When dealing with forces as powerful as magic, one must be sure that the power is only invoked when desired. The combination of words and body language provide just such a safety feature, making it difficult to accidentally trigger these forces.
Today, verbal commands and body gestures are being employed to control all types of electronic gadgets, from cell phones to televisions. Two consumer-based technologies are leading this charge in human-machine interactivity: the Apple iPhone's Siri and Microsoft's Kinect interfaces.
Siri is Apples method of letting you control your iPhone 4S using voice commands. There is one physical gesture you have to perform: hold the "Home" key down until Siri activates. Then just tell it what you want it to do. If it doesn't understand the command, it'll ask you questions until it's happy.
Kinect, on the other hand, works primarily with gestures although recent additions have added a limited voice command capability. The physical activity and motions you make towards the system controls what the system does next. While this might be nice for playing with a virtual tiger as a pet, you might ask what good is it in real life? The answer, of course, is everywhere.
As a simple example, let's take "The Lady" doorlock that leads to the Gryffindor dorm in the Harry Potter movies. In the movie, "The Lady" appears as a full-torso apparition on the door when its approached as though to enter (the physical gesture). She then demands a pass phrase to permit entry. The pass phrase is spoken (the verbal component) , and the door opens. Obviously, this is magic at work...or is it?
Let's attach a full-length thin-screen monitor to the back of an electronically latched door. Small camera vision sensors, like those found in any smartphone, detect anyone approaching or standing in front of the door. A computer generated image demands a pass phrase which must be uttered before the door is unlatched and passage granted. Of course, voice recognition software handles that. We could take this design one step further than the movie version and give the vision sensor access to facial recognition features. In this manner only certain people can use the phrase, or each person could have their own unique phrase.
That's just one idea off the top of my head. It's by no means the only idea. If you think you've got an interesting application for this technology, give a shout in the reply area. I'd love to hear it.
"Any sufficiently advanced technology is indistinguishable from magic," Arthur C. Clarke, Profiles of The Future, 1961