Here's how it works:
* Sunlight: Sunlight contains all colors of the rainbow.
* Water Molecules: Water molecules are small and absorb some colors of light more than others. They absorb longer wavelengths (red, orange, yellow) more effectively, while allowing shorter wavelengths (blue and green) to pass through.
* Scattering: When sunlight enters water, the blue and green light gets scattered in all directions by the water molecules. This scattering is more pronounced for blue light.
* Our Eyes: Our eyes are more sensitive to blue light, so we perceive the scattered light as blue.
Why glacial streams and lakes are especially blue:
* Purity: Glacial water is generally very pure and lacks sediment and other particles that can absorb light and make the water appear cloudy or brown.
* Depth: Deeper water absorbs more of the longer wavelengths, leaving mostly blue light to scatter back to our eyes.
While the blue color is primarily due to Rayleigh scattering, there can be other contributing factors like the presence of dissolved minerals or particles in the water, which can also influence the color.
