my understanding is that
1 it has an unusually good vacuum
2 as it runs the carbon filament slowly evaporates raising its resistance.the higher the resistance the less current it pulls and less evaporation.the evaporation is very even or it would have died long ago.
if you look at the pics the glass is rather dark.
what will do it in is a thin/hot spot .
or a accidental whack of some kind.
Originally posted by Chris M.:
There is a lightbulb that has been burning for 100yrs
http://www.centennialbulb.org/
I assume this longevity to the low current
I know that one well! They even have a BulbCam looking over it all the time.
We have often pondered over why it`s lasted so long. No-one seems to know for sure, and no-one probably will. It`s probably just one of those things- like life- which should just be marvelled at, and not endlessly discussed over why and how. Although we have and we do!
Burn on little bulb
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