Scattering of light by dust particles

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    Dust Light Particles
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Discussion Overview

The discussion revolves around the phenomenon of light scattering by dust particles, specifically addressing why dust particles are visible when light enters through a small opening but less visible when a larger window is open. The scope includes conceptual exploration of visibility and light scattering effects in different lighting conditions.

Discussion Character

  • Conceptual clarification, Debate/contested

Main Points Raised

  • One participant suggests that dust particles are visible when light comes through a small hole due to the contrast with the dark background.
  • Another participant argues that the visibility of dust particles diminishes when the whole window is open because the bright background makes it difficult to see the small bright dots.
  • A different participant counters that they have observed dust particles scattering light even with an open window, indicating a personal experience that contradicts the previous claim.
  • One participant draws an analogy to the visibility of stars and planets, noting that they are typically seen at night, although some celestial bodies can be visible during the day.

Areas of Agreement / Disagreement

Participants express differing views on the visibility of dust particles in various lighting conditions, indicating that the discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants do not fully explore the conditions under which dust particles are visible, nor do they clarify the assumptions regarding background brightness and its effect on visibility.

Pushoam
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TL;DR
Inside a dark room, when light comes through a hole, we see the dust particles as the particles scatter the light. But, when the whole window is open, we don't see the dust particles scattering the light. Why?
Inside a dark room, when light comes through a hole, we see the dust particles as the particles scatter the light. But, when the whole window is open, we don't see the dust particles scattering the light. Why?
 
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Because when the whole window is available the background is also bright and small bright dots are hard to see against a bright background.
 
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Pushoam said:
when the whole window is open, we don't see the dust particles scattering the light.
I have seen dust particles scattering light many times in a room with an open window.
 
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Its the same reason you can see stars (and planets) only at night, although sometimes one can see Venus and or the Moon in the daylight (to which @Dale alludes above.
 
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Thanks to all.
 
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