Bulb in a vacuum?

  • #1
2
0
,
the question was: if a elliptical shaped bulb , which was covered from outside and internally reflected light in the bulb itself . what would happen if it were placed in a vacuum ? would it emmit light for eternity ?
hope someone would shed some light on the matter ?:) , and explain this to a laymanlike myself? all observation and theories are welcome .

sos
acemave
 

Answers and Replies

  • #2
russ_watters
Mentor
19,949
6,440
Welcome to PF!

I'm not really sure of your logic, but if it is covered, it wouldn't emit anything, would it? Anyway, since no reflectors are truly perfect, it would quickly absorb and dissipate the light.
 
  • #3
Chandra Prayaga
Science Advisor
650
149
Several things are not clear. Why the elliptical shape? What do you mean by covered from outside? With what? Why should it internally reflect light on itself? The last question makes it sound like a contradiction of something, where there should be none. A light bulb will not emit anything unless energy is supplied from a voltage source.
 
  • #4
13,839
11,026
Several things are not clear. Why the elliptical shape? What do you mean by covered from outside? With what? Why should it internally reflect light on itself? The last question makes it sound like a contradiction of something, where there should be none. A light bulb will not emit anything unless energy is supplied from a voltage source.
Plus: How does the placement in a vacuum come into play? It would probably get broken sooner because of its heat.
 
  • #5
bigfooted
Gold Member
596
113
I think this a version of a thought experiment where you have a hollow sphere, with perfectly reflecting walls, and you trap light inside. Will the light be bouncing back and forth from the walls forever? Can you confirm this, Acemace?
 

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