Can Light Bounce Forever in a Vacuum Bulb?

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Discussion Overview

The discussion revolves around the hypothetical scenario of an elliptical-shaped bulb that reflects light internally and is placed in a vacuum. Participants explore whether light could theoretically bounce indefinitely within this setup and the implications of such a scenario.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions the logic of the original scenario, suggesting that if the bulb is covered, it would not emit light, and that no reflectors are perfect, leading to absorption and dissipation of light.
  • Another participant expresses confusion about the specifics of the scenario, including the significance of the elliptical shape and the implications of being covered, stating that a light bulb requires energy from a voltage source to emit light.
  • A later reply raises the idea of a thought experiment involving a hollow sphere with perfectly reflecting walls, questioning whether light could bounce indefinitely in such a setup.

Areas of Agreement / Disagreement

Participants do not reach a consensus; there are multiple competing views regarding the feasibility of light bouncing indefinitely in the proposed scenario, and several points remain unclear or contested.

Contextual Notes

Participants highlight limitations in the original question, including assumptions about the bulb's shape, the nature of its coverage, and the requirement for an energy source to emit light. The role of the vacuum in this context is also questioned.

Who May Find This Useful

This discussion may be of interest to those exploring theoretical physics, thought experiments related to light behavior, and the principles of reflection and energy conservation in closed systems.

Acemave
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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
 
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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.
 
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.
 
Chandra Prayaga said:
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.
 
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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