Recent Breakthrough Reveals that Light Itself Contains the Ability to Evaporate Water

By Max Alchin

Have you ever learned a fact about a subject that you thought you understood, that completely changed your perception of it? Well, this happens in the science world too. Just recently scientists have discovered that heat may not be the sole contributing factor to evaporation.
In a recent study by Gang Chen and Yaodong Tu at MIT, they discovered that in certain conditions light can start the process of evaporation more efficiently than heat. They found this by testing different wavelengths of light at the same intensity. Keeping the temperature controlled ensured that any difference in evaporation speeds was solely due to the change in wavelength. This discovery was surprising to scientists because water does not absorb much light at all, meaning that theoretically, light should not have much of an effect.
In an article published by, they state that: “...the excess evaporation was being caused by the light itself —that photons of light were actually knocking bundles of water molecules loose from the water’s surface. This effect would only take place right at the boundary layer between water and air, at the surface of the hydrogel material”.  Furthermore, the team found that green wavelengths are the most effective at evaporating water, however, it is not known why.
Why does this matter? Well, this new method has a surprising amount of real-world applications. For example, a new known factor in evaporation will have a significant impact on the understanding of the way clouds and fog form, which will allow us to make better weather forecasts. It also may play an important role in speeding up the process of industrial desalination – the separation of salt from seawater. It is predicted that three times as much water could be produced with the use of light. It has also been speculated that the process of light breaking down the water molecules could lead to an extremely effective solar cooling system.
While this exciting discovery is not fully understood yet, it is far from an attention-grabbing claim. The study that revealed these results was first gathered in early October of 2023, and since then a variety of different research labs have independently recreated and confirmed it. As of right now, There are multiple potential applications of this effect that have already been confirmed; however with this news still being fairly new, there may be many more innovations in the world of science to come.