Colour of water

I cannot understand what is the colour of water.I was reading an Optics book by Hecht,& suppose that we see coluured bodies due to Dissipative absorption.That is taking up of incident photon,converting a part into thermal energy,and releasing the rest energy as another photon.But, ordinarily we say water colourless.What wavelength is actually emittted?
 

Andrew Mason

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Kolahal Bhattacharya said:
I cannot understand what is the colour of water.I was reading an Optics book by Hecht,& suppose that we see coluured bodies due to Dissipative absorption.That is taking up of incident photon,converting a part into thermal energy,and releasing the rest energy as another photon.But, ordinarily we say water colourless.What wavelength is actually emittted?
Water will reflect light at the surface and from suspended matter within the water. I would think that only a very small portion of the light that passes through the surface of a deep body of water that has no suspended solids will be reflected. So the cleaner and deeper the water, the darker it will look.

AM
 
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re colour of water

Sir,I did not understand what you want to say.I think it will be helpful if you provide with the mechanism in which any (possible) wavelength reaches our eyes.
Thank you.
 

Andrew Mason

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Kolahal Bhattacharya said:
Sir,I did not understand what you want to say.I think it will be helpful if you provide with the mechanism in which any (possible) wavelength reaches our eyes.
Thank you.
The mechanism by which light incident upon a body of water will reach our eyes is reflection.

AM
 
Your logic is understood.Possibly, you have changed something:water will reflect 'light'...
Well,that's fine.But, when you take a glass of drinking water, just look at it, and what colour do you find?It's my question.
If you like, I wish to know the colour of stainless steel,or...
i.e. ordinarily which are said to be colourless.Reflection of course is the mechanism to make us see those objects...but I want to know the wavelength involved.
Please note this
 

Andrew Mason

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Homework Helper
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Kolahal Bhattacharya said:
Your logic is understood.Possibly, you have changed something:water will reflect 'light'...
Well,that's fine.But, when you take a glass of drinking water, just look at it, and what colour do you find?It's my question.
If you like, I wish to know the colour of stainless steel,or...
i.e. ordinarily which are said to be colourless.Reflection of course is the mechanism to make us see those objects...but I want to know the wavelength involved.
Please note this
If water has no particles suspended in it, it is transparent: light passes through it. Light does not reflect off the water molecules. The light that reaches the eye from the water is either reflecting off the surfaces or bottom or sides of the container or it is passing through the water. It is not reflecting off the water molecules. The frequency of the light coming through the water to your eye is not materially affected by passing through pure water. So the frequency is whatever the frequency of the light source is. (Lower frequency em radiation such as microwave - radar is a different matter).

AM
 

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