Plasma inside a light bulb?

[iScience]

http://i.imgur.com/bLUjP0Q.jpg

is something like this even possible in a light bulb? i thought the interior was supposed to be a vacuum.

 

[D H]

i thought the interior was supposed to be a vacuum.

The thin glass used in a typical incandescent light bulb is not near strong enough to sustain a vacuum. Incandescent bulbs are filled with inert gases to about 70% atmospheric pressure.

 

[meBigGuy]

wow --- cool --- Never saw or thought of that, but now it's obvious.
http://www.rmcybernetics.com/projects/DIY_Devices/homemade_plasma_globe.htm

 

[vk6kro]

The lights at the back of a car include a combined rear light / brake light bulb.

Usually this is replaced when one of the lamp filaments burns out.

This gives you a chance to experiment since you now have a working filament and a disconnected wire which will work as an anode if the filament is supplied with its normal voltage. It will work as a diode if the bulb is under vacuum or as a plasma display if it contains gas.

Local repair shops usually discard such bulbs but would probably save you a few if you ask.

 

[alphy]

Yes, it is possible for plasma to exist inside a light bulb. In fact, plasma is what allows the light bulb to produce light. When electricity is passed through the filament inside the bulb, it heats up and emits energy in the form of light. This process ionizes the gas inside the bulb, creating a plasma state. The plasma then emits the light that we see. The interior of a light bulb is not a complete vacuum, but rather filled with a gas mixture that allows for the formation of plasma.