Why is View Through Glass Window Not Dimmed?

[physicsss]

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...

 

[Mk]

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.

 

[ZapperZ]

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.

 

[fargoth]

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

$$R=(\frac{n_1-n_0}{n_1+n_0})^2$$

but this is just the classical vies of things, (its pretty accurate, but feyman got it better)

 

[pallidin]

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.

 

[Claude Bile]

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.

 

[Manchot]

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...

 

[bomba923]

Why would we want glass to transmit UV?
Don't we want to protect ourselves from UV radiation? (it may cause sunburn! )

 

[Mk]

The Wikipedia article for what Zz was referring to: http://en.wikipedia.org/wiki/Fused_silica

 

[ZapperZ]

Why would we want glass to transmit UV?
Don't we want to protect ourselves from UV radiation? (it may cause sunburn! )

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.

 

[DaveC426913]

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.