The Color of Water

Water is the color blue, many people believe that it is clear and that the blue you see is the reflection from the sky. THEY ARE INCORRECT.

An excerpt from a Dartmouth study.

The blue color of water may be easily seen with the naked eye by looking through a long tube filled with purified water. We used a 3 m long by 4 cm diameter length of aluminum tubing with a Plexiglass window epoxied to one end of the tube. Ten or more observers each reported seeing a blue color when they looked through the tube and observed a sunlight-illuminated white paper placed below the vertically-suspended tube (see for yourself in Fig. on the right: H2O- on the left and blue, D2O-on the right and transparent). This observation is in accord with the spectrum of H2O recorded in Fig. 1. For example, from the measured absorbance at 660 nm, the calculated transmission of a 3 m water-filled tube is 44% -- a loss of red intensity that should be perceptible. Light transmitted through the empty cell was white. The large tube volume and a limited budget precluded checking to see if light transmitted through a D2O filled tube was indeed white, as expected.

For more information,

http://www.dartmouth.edu/~etrnsfer/water.htm

http://www.serc.si.edu/labs/phytoplankton/primer/water.jsp

http://en.wikipedia.org/wiki/Color_of_water

http://www.lsbu.ac.uk/water/vibrat.html