Why is uncontaminated water colorless?
1 Answer
Apr 5, 2018
It's not actually. Strictly speaking it is very pale blue......
Explanation:
You will not perceive it unless you view water through a very very long path length (e.g. through a very long glass tube), but water is in fact a very very pale shade of blue (almost turquoise).
It is caused by certain vibrational modes of the water molecule (stretching of the two O-H bonds, and harmonics caused by this) which leads to weak absorption of visible light in the red region. The remaining wavelengths (which, minus the red light appear blue) are then perceived by the observer.
Not the same situation as "blue oceans" which often can be also caused by simply reflecting the sky......
