Traditionally, the evaporation of water occurs when molecules on the surface of a liquid gain sufficient energy to transform into gaseous form and release water vapor. However, researchers from the Massachusetts Institute of Technology showed that heat is not the only energy source in this process. Instead, they found that light could effectively evaporate water, even exceeding its thermal efficiency.

This discovery was prompted by observations during recent experiments with hydrogels that revealed the discrepancy between the evaporation rate and the added heat. Researchers realize something fundamental is happening in the physics of evaporation not fully understoodThis led them to investigate this age-old phenomenon.

What did the experiments lead to?

Initial experiments showed that light, rather than the heat energy carried by water, was the potential cause of water’s rapid evaporation. What makes this finding particularly intriguing is that water is transparent to visible light, challenging our conventional understanding of this process.

To test this hypothesis, scientists conducted experiments in which a hydrogel sample was exposed to light of different wavelengths and carefully measured the rate of mass loss due to evaporation. The sample was isolated from all external equipment and lamps to prevent heat transfer.

The results of these experiments confirmed that water evaporates at a rate well above the thermal limit and that this rate is affected by the wavelength of light used, with a peak at the wavelength associated with green light. These findings once again emphasize that evaporation does not depend only on heat transfer.

Scientists confirmed their findings

To confirm their results, the researchers repeated the experiment in complete darkness by applying electrical heat to the hydrogel sample. This time, well-known principles of physics worked and the volume of evaporated water fell within the expected thermodynamic limits; this was much smaller than when exposed to light alone.

The study’s authors called this newly discovered phenomenon the “photomolecular effect” and suggested that photons of light could displace clusters of water molecules on the surface of the liquid. If this process occurs naturally, it could have far-reaching consequences for our climate models and potentially impact our understanding of how sunlight affects oceans and cloud cover.

The scientists behind this revolutionary discovery have received a grant to further investigate this phenomenon, with potential practical applications on the horizon. This discovery could pave the way for more energy-efficient desalination systems that outperform existing thermal methods. As our understanding of the effects of light on the evaporation of water continues to improve, it promises to revolutionize various aspects of science and technology.