How double glasses window reflect ?

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SUMMARY

The discussion centers on the phenomenon of reflection observed in double glass windows of trains, particularly when the train is underground. Users confirm that glass reflects a portion of light while transmitting some, leading to visible reflections when external light is minimal. The presence of bright external light, such as at a station, diminishes the visibility of these reflections due to the overwhelming intensity of outside light. The double glass design serves to maintain temperature control within the train, further influencing the reflection characteristics.

PREREQUISITES
  • Understanding of basic optics principles, including reflection and transmission of light.
  • Familiarity with double glazing concepts and their applications in thermal insulation.
  • Knowledge of the Fresnel equations related to light behavior at interfaces.
  • Basic experience with light intensity and its effects on visibility.
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  • Research the Fresnel equations to understand light reflection and transmission in detail.
  • Explore the principles of double glazing and its thermal efficiency in architectural applications.
  • Investigate the impact of light intensity on visibility and perception in different environments.
  • Study the behavior of light in various mediums, including glass, to deepen understanding of optical phenomena.
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Students of physics, optical engineers, and anyone interested in the practical applications of optics in everyday environments, such as train design and architecture.

vkash
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Today when i was traveling in train(from my study center to home) i found a common but unexplained thing that is a little reflection can be seen on Glass window of train when it is underground or there is any wall behind the windows BUT when there is no window(ex when it is in station there is a lot of light) then i can't see any kind of reflection in window (or very very little reflection). I had read very little on Optics like Lens maker formula etc. I try to explain this during my 30 minute journey but i can't so i want to know it's answer from you why there is reflection in glass window.why this glass window was reflecting when it was underground. This glass window was double(one plate of glass after other as i see) i think because they(manufacturer of train) do this to don't make it hot due to sun in summer/ keep train cool with it's AC.One thing i also want to say that there a lot of lights inside train as a source of light for reflection.

How I explain it.[/color]
first explanation::-> This reflection happen due to reflection backward wall. Limitation wall did not reflect.
second explanation ::-> Double glass window of train reflect light rays every time but i can see them only at that time when there is any obstacle that does not overcome the intensity of light of reflected rays by glass window in case of stations there is light entering inside train which overcome the intensity of reflected light by glass window but when it is underground no light enter externally so i can see reflection of persons inside train. this idea has recently came in mind is it correct? Or there is any other explanation for this?

there is no double glass window in my house or nearby to experiment so you tell me.
 
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vkash said:
Today when i was traveling in train(from my study center to home) i found a common but unexplained thing that is a little reflection can be seen on Glass window of train when it is underground or there is any wall behind the windows BUT when there is no window(ex when it is in station there is a lot of light) then i can't see any kind of reflection in window (or very very little reflection). I had read very little on Optics like Lens maker formula etc. I try to explain this during my 30 minute journey but i can't so i want to know it's answer from you why there is reflection in glass window.why this glass window was reflecting when it was underground. This glass window was double(one plate of glass after other as i see) i think because they(manufacturer of train) do this to don't make it hot due to sun in summer/ keep train cool with it's AC.One thing i also want to say that there a lot of lights inside train as a source of light for reflection.

How I explain it.[/color]
first explanation::-> This reflection happen due to reflection backward wall. Limitation wall did not reflect.
second explanation ::-> Double glass window of train reflect light rays every time but i can see them only at that time when there is any obstacle that does not overcome the intensity of light of reflected rays by glass window in case of stations there is light entering inside train which overcome the intensity of reflected light by glass window but when it is underground no light enter externally so i can see reflection of persons inside train. this idea has recently came in mind is it correct? Or there is any other explanation for this?

there is no double glass window in my house or nearby to experiment so you tell me.
It looks like you have the right idea. Glass will always reflect part of the light that strikes it and will always transmit some of that incident light.

If there is no light coming from outside the train, the only light you will see from the window will be light from inside reflected back to you. If there is a lot of light outside, the light coming from the window will consist mostly of outside light transmitted through the window with a relatively small amount of light reflected back from the inside, so the reflected light will be hard to distinguish.

AM
 
Andrew Mason said:
It looks like you have the right idea. Glass will always reflect part of the light that strikes it and will always transmit some of that incident light.

If there is no light coming from outside the train, the only light you will see from the window will be light from inside reflected back to you. If there is a lot of light outside, the light coming from the window will consist mostly of outside light transmitted through the window with a relatively small amount of light reflected back from the inside, so the reflected light will be hard to distinguish.

AM

:smile:Thanks Andrew.:smile:

I was excepting that there will many replies for this question but Here is only 1.:zzz:
I need more replies to confirm it 100% so please post your opinion guys!.:approve:
 

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