«The surface area atop a one - liter beaker of water is less than one square meter. (sciencedaily.com)
For example if you split a beaker of water into two halves with a semi permeable membrane and added salt to one side, water would move from the side of the beaker with no salt until the two concentrations of salt water were the same. (science-sparks.com)
They plopped this rod into a beaker of water and hit it with a laser beam from below. (scientificamerican.com)