Study reveals unexpected properties of light

Water evaporation has long been associated with heat, but recent research suggests that light may also play a role in this process. While it is well-known that heat causes water molecules to become more active, allowing some of them to escape as vapor, scientists have discovered that light, especially green light, can accelerate evaporation even further. This is reported by SSP.

Previous understanding relied on heat as the main driver of evaporation. However, experiments conducted by mechanical engineer Gang Chen and his team at the Massachusetts Institute of Technology revealed that individual particles of light, called photons, can actually break bonds between water molecules. This breakthrough finding releases clusters of water molecules into the air, leading to faster evaporation rates.

The researchers conducted their experiments by shining different colors of light onto water contained in a hydrogel. They found that different light wavelengths caused the water to evaporate at varying speeds, with green light being the most effective. This distinction suggests that the color of light is indeed a crucial factor in the evaporation process.

Janet A.W. Elliott, a thermodynamicist from the University of Alberta, explains that the researchers' hypothesis is supported by the fact that light, rather than heat alone, drives the evaporation. Their results showed that using a heater instead of light did not trigger the same phenomenon. Moreover, their findings also indicated that when light drives evaporation, water molecules escape in clusters rather than individually. This cluster evaporation subsequently cools the vapor as the clusters break into individual water molecules.

While there are still unanswered questions about the specifics of how photons break the bonds between water molecules, the discovery opens up the possibility of practical applications. Chen optimistically suggests that this effect could potentially be harnessed to develop more efficient methods of converting saltwater into freshwater.

Researchers note that this light-induced evaporation effect may occur more frequently in nature, particularly in environments where water interfaces with the air. While everyday puddles do not exhibit this effect, water in contact with a substantial amount of air, such as within soil or plants, or in sea foam, could experience accelerated evaporation due to light exposure. The widespread implications of this discovery are intriguing to scientists as they explore its potential applications and continue to unravel the underlying mechanisms.