Electrical engineering seems like a hard subject for people of any age to sit through if they don't have a natural interest in it. However, it might grab wide attention if, for instance, Johnny Knoxville from MTV's "Jackass" opened a lecture or educational video on how the frequency of an electric current can cause pain by biting down on a live wire.
Mehdi Sadaghdar, host of the YouTube channel ElectroBOOM -- its goal: to "find the craziness in engineering" -- does something pretty close to that with his latest video that explores how frequency contributes to the pain that electricity can produce by running a current through his own tongue.
That's right, I said "his own tongue." If such a thing sounds like it would make you too squeamish to watch, maybe this video of a basket filled with puppies is more your speed.
Sadaghdar runs around 4 volts of electricity through his tongue and slowly increases the frequency, or the rate at which the alternating current changes direction across the wire per second, to see just how painful it can get. Along the way, he plots the level of pain by raising his hand as the pain increases.
Frequency creates pain by causing the muscles to move back and forth. Eventually, the pain starts to feel more like intense cramping when the frequency reaches a level where the muscles can't keep up with the vibrations.
Sadaghdar, an electrical engineer based in Vancouver, wrote on his website that when he hit the 22Hz mark, the lights in his vision started flickering because the electricity reached far enough into his head to make either his eyes or eye muscles vibrate. I'll bet Bill Nye the Science Guy never did anything like that for science.
In the video, posted Monday, Sadaghdar seems to be on the verge of tears by the time he pushes the frequency past the 2.2kHz mark. However, as the frequency continues to climb well past that point, his pain begins to subside and become more tolerable. While Sadaghdar doesn't have a solid explanation for this, he has several theories. It's possible, for example, that the nerves and muscles in his body simply stop responding to the frequency, or that the electric current moves to the surface, a process known as the "skin effect."
Sadaghdar didn't just do this for a cheap laugh. He also reviewed the video and created a chart plotting the level of pain he felt at the corresponding frequencies. He wrote that he hopes scientists may be able to use the data he obtained to help make some kind of medical breakthrough, though he doesn't specify what kind.
Well, if there are any psychologists out there conducting a study to see how far people are willing to go to get more YouTube hits, Sadaghdar's video alone should supply them with more than enough data.