Langmuir GE vaporization studies and tungsten filament burnout

Tom credits Irving Langmuir (GE Research Labs, ~100 years ago, Nobel laureate) with founding surface-vaporization science motivated by tungsten light-bulb filament failure. The "Langmuir" unit (~10⁻⁸ atm·s for one monolayer at unity sticking) anchors the vapor-deposition rate argument.

The first thing you need to know is the Langmuir. There's this guy Irving Langmuir who worked at General Electric Research Labs about a hundred years ago. He was a pretty good scientist — won the Nobel Prize for his study of surfaces. He was interested in surfaces for lots of reasons. He was interested in tungsten light bulbs and how the tungsten vaporized from the surface, because that's how the old tungsten light bulbs burned out. You basically had tungsten vaporizing away from the hot filament, and the filament finally fractured in two — a vaporization, degradation, erosion by vaporization. Langmuir did a lot of fundamental scientific studies on vaporization. We now have a scientific term called the Langmuir, and it works out to about 10 to the minus 8 atmosphere-seconds.