<embed src="http://www.metacafe.com/fplayer/726251/turn_a_pencil_into_a_light.swf" wmode="transparent" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" height="345" width="400"> Turn A PENCIL Into A LIGHT ! - video powered by Metacafe
That's great in case of emergency! Thanks for sharing! Hmmm... I wonder how strong the battery has to be to make this work?
75% of the people today would do much better making sure once every 6 months they have a charged flashlight in thier car with an extra set of batteries . It's a neet thing to know but since you're burning the pencil "lead" how many people would burn themselves trying it ? Or worse blow up the car battery .
I was thinking "science experiment" and wondering if the same effect could be achieved with a smaller battery.
Yes, it could, but. The demo was done with a 12 volt car battery. I would not expect a (say 9 volt) to glow as brightly, and being MUCH smaller, the glow wouldn't last as long. The key element is the ability of the pencil "lead" to conduct the amperage. A couple things stand out in the vid, one of which is that it is pretty high hazard from burning or igniting something, not to mention burned fingers. I don't know what the resistance of pencil lead is, but looks like it might be low enough to behave nearly like a dead short, dunno how long any given battery might last in that service. All that said, it could be a life saver somewhere along the line. (NB, it might be also used to start a fire in a pinch.)
Knew a similar trick from a youth mis spent enouph to associate with folks spending a lot of it locked up figureing out how to light smokes with no lighter in jail. They would strip the wood back on a pencil leaving the lead then short it in a light outlet and ignite the eraser then use it to light a smoke.