Light question

[Hemichordate]

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I think I saw this question somewhere, but why is it that when you turn off a light bulb, you often see red light before the light goes out?

 

[Baylor2012]

If you are talking about the red glow of the wire it is because when the bulb is on electrons are flowing(from the + to - terminal) through the wire which excites the electrons of the fillament. When you shut it off the residual electrons are falling back down to their regular energy levels and give off that notable glow and also because of the residual heat. Thats my stab at your question.

 

[Omni]

It's from the EK Light and Optics chapter (just did it today)
It's because by turning off the voltage sources, the energy decreases, and hence goes to red and eventually to infrared before completely turning off.