Why is the Spectrum of Ordinary Light Bulbs Continuous?

[Gavroy]

hi

i was wondering why the spectrum of an ordinary light bulb is continuous. i know that "i think it's thermodynamics" says that some temperature creates a specific continuous radiation, but how is this reconcilable with quantum mechanics and e.g. a sodium gas, that emits only a tiny yellow spectrum? and to which energy transitions does thermodynamics here refer to? where does this energy come from? i mean, if it is the crash of atoms that have such a high speed that electrons jump to higher levels, then this should be discrete transitions too, or where am I wrong?

 

[mathman]

Ordinary light bulbs give off light from a heated wire, which acts like a black body.

 

[jtbell]

Here's a recent post with a brief explanation.

https://www.physicsforums.com/showthread.php?p=3491621#post3491621