Some water appears cyan primarily because of how water molecules interact with light, absorbing certain colors while reflecting others.
Water molecules can vibrate in three different modes when they interact with light. This molecular vibration causes the absorption of specific wavelengths from the visible light spectrum.
The Science Behind Water's Color
When sunlight, which contains all the colors of the rainbow, passes through water, the water molecules absorb certain colors more strongly than others.
- Absorption: The reference states that the red, orange, and yellow wavelengths of light are absorbed by water molecules.
- Reflection/Scattering: As a result of this absorption, the remaining light that is reflected or scattered back to our eyes is what we see.
- Visible Color: The remaining light seen is composed of green, cyan, and blue wavelengths.
This process explains why large bodies of water, like the ocean, often appear blue or cyan. The deeper the water, the more light is absorbed, particularly the red end of the spectrum, making the blue and cyan colors more prominent.
Key takeaway: The selective absorption of red, orange, and yellow light by water molecules, leaving the green, cyan, and blue wavelengths visible, is the main reason the ocean's color is cyan.
