What s inside a lightbulb?

You probably know that an incandescent lightbulb uses a tungsten filament.

What's even cooler is that it's got 20 inches of double-coiled filament -- and tungsten is a brittle mineral that, under normal circumstances, can't bend at all.

How do they hammer out a brittle metal to a super thin ribbon and then coil it up not just once, but then coil up the first coil?

The answer is in this approachable video (above) by University of Illinois engineering professor Bill Hammack, aka "The Engineer Guy," who not only dismantles a lightbulb but also presents animations and other illustrations to show how this thing is manufactured.

This is the first in the third series of videos produced by Hammack, who earlier tackled such fascinating subjects as how an old-school, pre-digital flight recorder works.

"We specifically aimed the last series and this series toward the Wired/Slashdot/Make magazine community," Hammack told me in an email. "While we want it approachable to people who don't have too much scientific background, we always try to put something in there that will surprise the person with more knowledge."