Why are the sea and lakes blue ? Poll

[nihil]

Nothing has a color, it's the absorption of the light spectrum (or non absorption in the case of refraction) so black reflects all the spectrum, white, none.

The instances of color other than blue in Son of a beach's photos are a function of the quality of light hitting the scene, which is always a function of the cloud cover and the atmosphere in general. An overcast day renders colours grey because the clouds have defused the light and all the colours are bouncing off of each other. It's also a function of how much saturation was applied to the digital raw information of the picture.

Um ahh. Someones rewriting the laws of physics. Move over Max Karl.

ho ho, it was just a reversal (black absorbs, white reflects, duh).

[geoskid]

I much prefer the 'muddied waters' of philosophical thought and creative thinking(like religions, fascinating stuff).

Hehe - Yep, Philosophy, the 'discipline' where anything is possible. The following is kind of fitting

From here : http://consc.net/misc/proofs.html

Goodman - " Zabludowski has insinuated that my thesis that p is false, on the basis of alleged counterexamples. But these so-called ' counterexamples' depend on construing my thesis that p in a way that it was obviously not intended - for I intended my thesis to have no counterexamples. Therefore p."

And so, yeah.. water can be whatever colour you feel it is.

Man, I love science.

[Nuts]

Yeah right, waters blue cause ham sandwiches taste good

[Lindsay]

Water is a clear liquid. In large volumes it reflects the colour of the sky, although matter suspended in it can also affect the colour.

[corvus]

Because my eyes are blue
corvus

[hikingoz]

Harold Gatty describes the difference between green and blue waters in his book "Nature is your Guide".

From memory it relates to the amount of organic material in the water which is influenced by salinity and water temperature. He also mentions that in isolated cases sediment from inland watercourses can cause the ocean to turn different colors.

Apparently there are places where blue and green waters can be seen side by side as currents converge.

[Rob A]

Water is a clear liquid....

Mmmm... nup. Theres links to the science back a page.

...there are places where blue and green waters can be seen side by side as currents converge.

And yellow (horizontal) from the thermoclines.

But the real reason ... ... because the whales have nearly all gone.

[Rob A]

[Son of a Beach]

Here's a follow up question about the river near where I live - the dirty old Tamar River...

The water in the river is brown, but the river is blue. Why is it so?

A a little more explanation...

I so a lot of sailing in the river (and sometimes swimming - when the sailing didn't go as well as planned) and therefore I spend a lot of time up close and personal with the water either on it or in it. I can be very certain that the colour of the water in the river is most definitely brown and not blue. I know that pure water may well be blue, but this water is definitely not pure and has a constant suspension of fine silt. It only takes a very little bit of water to flow over the top of my white sailboard, or to be in front of my submerged hand or foot, to see just how brown it really is.

And yet when I'm viewing the water from a distance (even with the sun behind me?!? ) it appears blue (on a clear-sky day).

If this is not due primarily to reflection of the sky, then I'd be very interested to know why the water is brown, but the river is blue.

[Hallu]

You lost your train of thought, it's going nowhere. No one is refuting the fact that the reflection of the sky can make the surface of any body of water appear blue, I'm just refuting that, as you said, "reflection accounts for the vast majority of colour in the vast majority of cases." I've shown you pictures of blue rivers/lakes on overcast days, I could show you a ton more. Of course, they're not as blue as on a clear sky day, but that's not because there's no sky reflection, that's because there is simply less light going into the water and being scattered by water molecules... hence it's less blue.

[Son of a Beach]

--- POST CONTENT DELETED IN THE INTEREST OF AVOIDING GOING AROUND IN CIRCLES YET AGAIN ---

You don't seem to appreciate most of what I'm writing, so I've deleted the content that I had written in this post. It would probably have just irritated you like the earlier posts appear to have done and that has never been the intention. Its clearly going nowhere, anyhow, so I'll simply leave the last paragraph as it originally was below...

I reckon that the reflection of the sky, from most land-based viewing angles, is a far more dominant factor in making most sea/lakes look blue. You clearly do not. No big deal though. We're allowed to disagree.

[north-north-west]

All that tannin-stained water in the SW isn't blue. Each pool on Tarn Shelf is a different colour - yellows, browns, grey, greens, blues . . .