Ned Simmons wrote:

(...)

I understood the article to say not that the filament is thinned, but
that its surface is modified to increase emissivity.

Chunlei Guo:

"We fired the laser beam right through the glass of the bulb and
altered a small area on the filament. When we lit the bulb, we
could actually see this one patch was clearly brighter than the
rest of the filament."

Sounds to me as if the modification was just redistribution of
filament metal. What would happen when you increase the resistance
of a portion of a filament by thinning it? It dissipates more power
because it's resistance is higher (P=I^2R) It glows more brightly
than the rest of the filament but will cause the bulb to fail much
earlier than it would have without the modification, I think.
Would Occam be pleased with this guess?

I've got a prototype on my desk of some rebuildable lamps I designed
and built a couple years ago for a customer who was doing similar
research. They disassemble easily so new filaments can be mounted, and
have cute plumbing and electrical feedthroughs for thorough purging.
The most surprising part of the project, which I think I've mentioned
here before, was obtaining a small quantity of getter. One of the
ingredients in the getter for incandescent lamps is red phosphorous,
which is apparently strictly controlled these days because it's used
in cooking meth.

That'll be the thing I learned today.

--Winston


--

We now return you to the economic collapse, already in progress.