Just to brighten up a winter's Monday morning (for those of us in the Northern hemisphere), another thread on these forums has just reminded me of this light bulb which has been lit for 117 years...there's even a live webcam so that you can check it's still alight
Photographic tungsten lamps used the inverse principle. Increase the voltage (or effect - lamp's filament resistance) by 10%, increases the lumen output and hence light temperature but reduces the lamp's life to about 10% (100 hours reduces to 10 hours). Heat (something to do with the poor thermal cycle of tungsten in the envelope) and thermal shock being contributing factors.
Photographic tungsten lamps used the inverse principle. Increase the voltage (or effect - lamp's filament resistance) by 10%, increases the lumen output and hence light temperature but reduces the lamp's life to about 10% (100 hours reduces to 10 hours). Heat (something to do with the poor thermal cycle of tungsten in the envelope) and thermal shock being contributing factors.
