Circles of Light: Explore the Phenomenon

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Discussion Overview

The discussion revolves around the observation of a rotating laser beam projected onto the inner circumference of a circle with a radius of one light second. Participants explore the implications of different observational frames and the resulting perceptions of intensity and motion.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant proposes that the observer will see a projection of the laser sweeping across the circumference with reduced intensity of 1/(2pi).
  • Another participant emphasizes the distinction between "seeing" and "observing," suggesting that the perspective of the observer significantly affects the interpretation of the phenomenon.
  • A later reply notes that if the observer is in a non-inertial frame, the situation becomes more complex, indicating that the frame of reference alters the observation.
  • Another participant suggests considering the observer's proximity to the inner circumference to further analyze the observation dynamics.

Areas of Agreement / Disagreement

Participants express differing views on how the observation changes based on the frame of reference, indicating that multiple competing perspectives remain without a consensus on the correct interpretation.

Contextual Notes

The discussion highlights the dependence on the observer's frame of reference and the implications of being in an inertial versus non-inertial frame, which remain unresolved.

Who May Find This Useful

This discussion may be of interest to those exploring concepts in optics, relativity, and observational physics, particularly in relation to the effects of motion on perception.

John Richard
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Hello to whoever is kind enough to read this!

A question,

Suppose I place a rotating laser at the centre a circle so that the beam will hit the inner face of the circles circumference.

If the radius of the circle is one light second, then the circumference would be 2pi light seconds. (We can ignore the length of the laser source device)

If I now rotate the laser through 360 degrees in one second.

What will I see on the circles inner circumference?
 
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A projection of the laser sweeping across the circumference with 1/(2pi) original intensity?
 
John Richard said:
What will I see on the circles inner circumference?


I think the correct term is "What will you *observe*?" - there is a difference. But that depends on the point of view... If you observe from rest, #1 has given the aswer. But if you observe from a frame that is rotating with the laser, the problem is more subtle, since then you are not in a inertial frame!
 
Last edited:
That depends on the point of view!

Lets assume as the viewer you are within touching distance of the circles inner circumference
 

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