Happy St. Patrick’s Day!
This is Sandra Tsing Loh with the Loh Down on Science and a fun bar bet!
David van der Spoel and team at Norway’s Uppsala University wondered: Is it harder to lift a glass off a table wet with water, or alcohol? They measured the work needed to separate two plates of quartz stuck together with varying alcohol/water mixtures.
And? WATER is stickier! The culprit’s surface tension–liquid molecules’ tendency to expose the least amount of their surface to the air. Think how water huddles into drops, or how tiny bugs can skitter across a pond’s surface.
Alcohol lowers surface tension, making it easier to break hydrogen bonds and weaker connections called Van der Waals forces.
No wonder a slightly spilt glass of whiskey’s easier to lift! Captain MORGAN? Captain OBVIOUS!
Reference: van der Spoel, D., Wensink, E. J., & Hoffmann, A. C. (2006). Lifting a wet glass from a table: a microscopic picture. Langmuir : the ACS journal of surfaces and colloids, 22(13), 5666–5672. https://doi.org/10.1021/la053284f