How light can vaporize water without the need for heat

Amazing stuff! This is a huge discovery!

"... What the MIT team discovered is that light in the visible spectrum is enough to knock water molecules loose at the surface where it meets air and send them floating away. In other words, while it's true that evaporation has been happening all of these years due to fluctuations in temperature, water has also been turning to vapor from the force of light beams alone.

The scientists have termed the process the "photomolecular effect" after the photoelectric effect that was explained by Einstein in 1905, in which particles of light could free electrons from atoms in the material they strike. ...

“It could help us gain new understanding of how sunlight interacts with cloud, fog, oceans, and other natural water bodies to affect weather and climate," ... "It has significant potential practical applications such as high-performance water desalination driven by solar energy. This research is among the rare group of truly revolutionary discoveries  ...
Because the discovery of light-based evaporation was so striking, the MIT researchers carried out 14 different verification experiments that all supported the finding. During the course of this process using laser light they found that the strongest evaporative effects happened when light that was polarized in a particular way known as transverse magnetic polarization hit the surface of the water at a 45° angle. It was also strongest with green light ..."

"... The new work builds on research reported last year, which described this new “photomolecular effect” but only under very specialized conditions: on the surface of specially prepared hydrogels soaked with water. In the new study, the researchers demonstrate that the hydrogel is not necessary for the process; it occurs at any water surface exposed to light, whether it’s a flat surface like a body of water or a curved surface like a droplet of cloud vapor. ..."

From the significance and abstract:

"Significance

We use 14 different experiments to demonstrate the existence of the photomolecular effect: photons in the visible spectrum cleave off water clusters from air–water interfaces. We use laser to study single air–water interfaces and show polarization, angle of incidence, and wavelength dependent responses, peaking at green where bulk water does not absorb. Raman and infrared absorption spectra and temperature distribution in air show the existence of water clusters under light. We suggest the photomolecular effect provides a mechanism to resolve the long-standing puzzle of larger measured solar absorptance of clouds than theoretical predictions based on bulk water optical constants and demonstrate that visible light can heat up clouds. Our work suggests that photomolecular evaporation is prevalent in nature.

Abstract

Although water is almost transparent to visible light, we demonstrate that the air–water interface interacts strongly with visible light via what we hypothesize as the photomolecular effect. In this effect, transverse-magnetic polarized photons cleave off water clusters from the air–water interface. We use 14 different experiments to demonstrate the existence of this effect and its dependence on the wavelength, incident angle, and polarization of visible light. We further demonstrate that visible light heats up thin fogs, suggesting that this process can impact weather, climate, and the earth’s water cycle and that it provides a mechanism to resolve the long-standing puzzle of larger measured clouds absorption to solar radiation than theory could predict based on bulk water optical constants. Our study suggests that the photomolecular effect should happen widely in nature, from clouds to fogs, ocean to soil surfaces, and plant transpiration and can also lead to applications in energy and clean water."

Think you understand evaporation? Think again, says MIT

How light can vaporize water without the need for heat Surprising “photomolecular effect” discovered by MIT researchers could affect calculations of climate change and may lead to improved desalination and drying processes.

Photomolecular effect: Visible light interaction with air–water interface (no public access)

The team used a lab device that beamed laser light at water to observe the evaporative effects of light