Daily Archives: December 31, 2013

How Do I See the End of 2013?

It is with some degree of sadness that I mark the passing of the incandescent light bulb.

Actually it is for one reason in particular – you could understand, and therefore teach others how a light bulb work. If you run electricity through a high resistance wire, the electric energy becomes heat and light.

You could tell your kids how Thomas Alva Edison knew he needed the resistance, and a vacuum would keep the filament from burning out immediately. How, as he tried different materials for the filament, he said, “I have not failed. I’ve just found 10,000 ways that won’t work.” How Edison then went on to invent many things – how to record sound, motion pictures, medical fluoroscopy and how these inventions spawned whole industries.

How it was this date in 1879 when Edison first demonstrated the light bulb to the public and that one of those basic light bulbs has been glowing almost continuously for 112 years.

How when you add a second electrode to an incandescent light bulb and you have a diode rectifier; add a third, making a triode that can amplify an electric signal – an important step leading to the proliferation of radio and eventually television.

What a great teaching tool!


Can you clearly explain how an energy efficient compact fluorescent bulb works? How about an LEDs (light emitting diode)?

Didn’t think so – me either.