Evaporation, the ubiquitous process of water transforming into vapor, has long been attributed solely to heat. However, groundbreaking research from MIT reveals a previously overlooked factor: light. In a series of meticulous experiments, scientists have demonstrated that light striking the interface between air and water can trigger evaporation independently of heat.

Published in the Proceedings of the National Academy of Sciences, the study by Professor Gang Chen and his team unveils a phenomenon dubbed the “photomolecular effect.” This effect, observed when light interacts with water molecules at the surface, leads to their liberation into the air, challenging the conventional understanding of evaporation.

The implications of this discovery are far-reaching. It sheds light on enigmatic observations related to sunlight’s impact on clouds, potentially revolutionizing climate change predictions. Moreover, it opens doors to innovative applications such as solar-powered desalination and industrial drying processes.

The research builds upon prior work, demonstrating that the photomolecular effect occurs universally on water surfaces exposed to light, irrespective of the surface’s curvature or composition. Through exhaustive experimentation, the team validated the effect’s existence and elucidated its underlying mechanisms.

Key findings include the effect’s dependence on light angle, color, and polarization, with peak efficacy observed at a 45-degree angle and in green light. While the angle and polarization dependencies are explained by the researchers’ proposed physical mechanism, the color dependence remains a subject for further inquiry.

The photomolecular effect’s potential impact extends beyond scientific curiosity. It could resolve longstanding discrepancies in climate science, offering a novel explanation for the observed absorption of sunlight by clouds. Furthermore, it promises to enhance the efficiency of industrial processes reliant on evaporation.

Already, interest from industry stakeholders underscores the practical relevance of this discovery. From evaporating syrup to drying paper, potential applications abound, with solar desalination systems and industrial drying processes poised to benefit initially.

As researchers continue to unravel the complexities of the photomolecular effect, its transformative potential becomes increasingly apparent. With each revelation, our understanding of a seemingly mundane process evolves, paving the way for technological innovations and deeper insights into the natural world.

By Impact Lab