[email:http://www.metacafe.com/watch/726251/turn_a_pencil_into_a_light/]http://www.metacafe.com/watch/726251/turn_a_pencil_into_a_light/[/email]

saw this on the net! (this is 1st attempt at a link) turn a pencil into a light

'turn a pencil, some wire and a car battery into a light..'

Looks like another great MacGyverism. Thanks

learn something new every day. Awesome trick.

This is essentially what came to be called the "incandescent light bulb". Edison found out you got a longer-lasting light by encasing the filament in an air-tight glass bulb, which slowed the rate of oxydation (burning out). A wire composed of tungsten and carbon was also found to be superior to carbon and clay (a pencil lead).

I would be very reluctant to use it as shown in the video.

Frank2135

Hah! I remember doing this back in my high school physics class with mechanical pencil lead and smaller power supplies. We even impaled some Gummy Bears onto the lead before we lit some of them up. (Yes, this was actually a teacher approved experiment!) BTW, burning pencil lead stinks pretty bad. Keep away from nose, and anything flammable.

We tried this recently. It didn't work. The graphite kept exploding in a shower of white-hot shards. Wear eye protection if you're going to mess with this trick .

Years ago a relative who was a mechanic in his fathers shop had a battery explode in his face. He knew what to do and didn't suffer any damage but the memory stays with me. I would never try anything like this unless all other options were exhausted and it was a Dire Emergency.

I was cringing when Les Stroud used fuel from the plane and sparks from a battery to start a fire in winter on one episode. I would keep a flashlight and a 12v auto light in my car or use light from my cell phone or anything else I could think of, before I decided to resort to something like this. But as a Very Last Resort light or fire starter, maybe.....

My uncle did that when when starter solenoid failed on 1950's Ford tractor and he went to use jumper cables from the battery to the starter and forgot it was positive ground. Dad came flying across the field thinking someone had gotten shot or something.
If your really that desperate for a light then it would make more sense to me to yank a dome light or something out and use it.
I wonder if the graphite would make a good fire starter though.

Heck, you're in a car. Couldn't you just pull out a tail light bulb or interior light bulb and do it easier and safer? Seems like an answer to a non existant problem.

Thats exactly what I was meaning. Those bulbs can get hot which is why I suggested pulling the whole dome light housing so you have something to hold on to.

If you want to get fancy the GM/Chevy trucks from 88-98 had a roll up light under the hood, you open the hood and pull it out and it sticks on the fender via magnet. Then when your done changing your tire you turn a little crank to wind it back up. Its a popular part that a lot of people buy and hook up in newer years and other vehicles.

Exactly. If I'm in a car with a functional battery, a mess of wire and a slew of light bulbs...why am I looking for a pencil?

And not be be completely dense but...assuming the battery works but none of the interior/exterior lights do, how the heck am I gonna see well enought to split my pencil, strip my stereo wire, and hook up my little gizmo?

Guess I'd better take a flashlight.

Frank2135

Thanks for the post Frostbite. Interesting tidbit. Kind of thing that would really impress some younger kids. I will file it away in my..hope I never need this file.

I found only one problem with the video...what self-respecting person doesn't have a length of wire just laying around in the car?

Jumper-cables..