Why is it harder to lift a wet glass from a table than a dry glass?


Some of the most interesting elements of science are when it tries to explain everyday phenomena. This article looks at the above question that was researched by scientists at Uppsala University.

When you have a layer of liquid between two surfaces, new adhesive forces are created due to hydrogen bonds and/or van der Waals forces and these have to be disrupted in order to lift the glass. By measuring the force required to separate two quartz glass plates that had different concentrations of water and alcohol between them, they determined that it is easier to lift the glass off the table when the layer consists of hard liquor (40% alcohol) than when it is water.

The paper’s authors have a whimsical conclusion about the implications of the finding: “Hence, intoxicated persons may be tempted to drink, e.g., whiskey rather than water as it requires only half the effort to pick up the glass. The impact of this finding on alcohol consumption patterns falls beyond the scope of this work, however.”

Who says that science is not useful?

Comments

  1. machintelligence says

    Because of surface tension, couldn’t there also be a partial vacuum formed under the glass?
    It certainly works with a wet suction cup.

  2. dmcclean says

    Unless you are drinking enough to spill I would think that not much alcohol makes it to the outside of the glass and that the liquid there is primarily condensation. But maybe your lower lip spills more than I think. Or, keeping the tongue in the same cheek, maybe they are drinking that really expensive superfluid whiskey.

  3. Corvus illustris says

    Mrs Corva did not receive kindly my suggestion that there was something particularly Svensk about being interested in the connection between the alcohol content of the liquid and the ease of lifting the glass.

  4. Corvus illustris says

    Ya, I would have thought that atmospheric pressure might play a role here and that they should have tried things in a (partial) vacuum just to make sure.

  5. F [is for failure to emerge] says

    Well, no, just think of all the alcohol condensing out of the air on the outside of a cooler drinking vessel. 😉

  6. Matt G says

    Absolutely! I know this first hand. I had my wet-on-the-outside tea mug on a glass coaster. I picked up the mug, walked a few steps, and crash! No more glass coaster!

  7. evilDoug says

    from the linked article:

    … a 10% MeOH solution between them

    Not the best of libations, what with the formic acid and formaldehyde metabolic products – makes the expression “blind, falling-down drunk” ring with more truth than usual.

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