Why is View Through Glass Window Not Dimmed?

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In summary: The reason is that every lens surface has a certain amount of reflection.In summary, glass has a refractive index of 1.5 and does not absorb or reflect much light. However, it does cause a slight decrease in light intensity due to air-glass reflection, which is not noticeable to the naked eye. Ordinary glass does absorb light, especially in the UV range, but materials like fused silica are used to allow UV light to pass through. This is necessary for certain experiments, such as those done in ultra-high vacuum. The Newtonian telescope, which uses mirrors instead of lenses, is based on the fact that glass does absorb light and can lead to a decrease in light intensity.
  • #1
physicsss
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If light reflects from all surfaces, why is the view through a glass window not noticeably dimmer than the view with the window open?

Can someone give me som hint? I know glass has a refractive index of 1.5...
 
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  • #2
The glass does not absorb very much light, and does not reflect very much light.

A strawberry absorbs wavelength's other than red. That is why it looks red to you.

A black object absorbs most of the light that comes at it, so it looks black.
 
  • #3
Ordinary glass DOES absorbs light, espeically in the UV range. We pay a lot of money to get quartz and fused silica to let UV light passes through. There's no material that I know off that let's light of all frequency to pass through.

Zz.
 
  • #4
this is fresnel relaction, as you can see the percent of reflection is very small.

[tex]R=(\frac{n_1-n_0}{n_1+n_0})^2[/tex]

but this is just the classical vies of things, (its pretty accurate, but feyman got it better)
 
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  • #5
physicsss said:
If light reflects from all surfaces, why is the view through a glass window not noticeably dimmer than the view with the window open?

Can someone give me som hint? I know glass has a refractive index of 1.5...

It IS dimmer, just not necessarily "noticable" through "human" eyes. I know of no glass(or any substance for that matter) that transmits light with no loss.
 
  • #6
Our eyes are logarithmic detectors - that is, they are capable of measuring light intensities over many orders of magnitude. As such, a 4% change in intensity (typical for air-glass reflection) is not readily apparent to the naked eye, as it would be for a linear detector such as a photodiode.

Claude.
 
  • #7
ZapperZ said:
Ordinary glass DOES absorbs light, espeically in the UV range. We pay a lot of money to get quartz and fused silica to let UV light passes through. There's no material that I know off that let's light of all frequency to pass through.

Zz.

I guess that's why I can't get a tan through the window...:tongue2:
 
  • #8
Why would we want glass to transmit UV?
Don't we want to protect ourselves from UV radiation? (it may cause sunburn! :redface:)
 
  • #10
bomba923 said:
Why would we want glass to transmit UV?
Don't we want to protect ourselves from UV radiation? (it may cause sunburn! :redface:)

I have a laser that is in the UV range. But my experiment is done in ultra-high vacuum. I'll give you ONE guess on why I would need a fused silica window somewhere on my vacuum chamber.

Zz.
 
  • #11
The Newtonian telescope is based on the fact that glass does absorb light.

A Newtonian is different from other types of telescopes in that it uses mirrors rather than lenses. Every lens the light passes through costs you a fraction of precious, precious brightness, which is what astronomy is all about.
 

1. Why is the view through a glass window not dimmed?

The view through a glass window is not dimmed because glass is a transparent material. This means that it allows light to pass through it without scattering or absorbing much of it. As a result, the light passing through the window is not significantly reduced, and the view appears clear and undimmed.

2. Does the thickness of the glass affect the dimming of the view?

Yes, the thickness of the glass can affect the dimming of the view. Thicker glass is more likely to absorb or scatter some of the light passing through it, resulting in a slightly dimmer view compared to thinner glass. However, the difference in dimming between thin and thick glass may be minimal.

3. Can the type of glass used in windows affect the dimming of the view?

Yes, the type of glass used in windows can affect the dimming of the view. For example, frosted or tinted glass may reduce the amount of light passing through it, resulting in a dimmer view. Additionally, mirrored glass may reflect some of the light, making the view appear darker.

4. Is there a difference in dimming between single-pane and double-pane windows?

Yes, there can be a difference in dimming between single-pane and double-pane windows. Double-pane windows have two layers of glass with a layer of air or gas in between. This layer of insulation can reduce the amount of light passing through the window, resulting in a slightly dimmer view compared to single-pane windows.

5. Can dirt or debris on the glass affect the dimming of the view?

Yes, dirt or debris on the glass can affect the dimming of the view. When there is dirt or debris on the glass, it can block some of the light passing through, resulting in a slightly dimmer view. Regular cleaning of windows can help maintain a clear and undimmed view through the glass.

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