In a Surprising Finding, Light Can Make Water Evaporate Without Heat

David L. Chandler reports via MIT News: Researchers have been baffled by the fact that in recent years the rate at which water evaporating from a sponge material called a hydrogel was higher than the heat or thermal energy that was being received. The excess is significant, doubling or even tripling the theoretical maximum. Researchers at MIT have concluded that light, when used in certain conditions and at the interface of water and air, can cause evaporation even faster than heat. Researchers at MIT have found that light can evaporate water without heat in certain conditions. In fact, it does so even more efficiently than heat.

Researchers say that the phenomenon could play a key role in fog formation and cloud evolution, and it would be crucial to include this into climate models for improved accuracy. It could also play a role in industrial processes, such as the solar-powered desalination process of water. This would allow for alternatives to converting sunlight into heat. Water does not absorb much light, so the new findings are surprising. It is because of this that you can see the surface below through a few feet of clear water. These findings have been published by the journal PNAS.