Water is sticky. It seems pretty easy to shake it off your hands, but to small things, it’s like glue. So if you have a straw or tube that’s big, morning seems to happen, but as you make it smaller and smaller, you start seeing water stick to the walls above it. It’s enough to pull it up a little against gravity, but water is pretty heavy. As you make the tube even smaller, though, the amount and weight of water goes down faster than the area of tube within reach of the water, and it gets pulled up more and more
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Molecular attraction between water and the substance (adhesion) is stronger than gravity.
Water is sticky. It seems pretty easy to shake it off your hands, but to small things, it’s like glue. So if you have a straw or tube that’s big, morning seems to happen, but as you make it smaller and smaller, you start seeing water stick to the walls above it. It’s enough to pull it up a little against gravity, but water is pretty heavy. As you make the tube even smaller, though, the amount and weight of water goes down faster than the area of tube within reach of the water, and it gets pulled up more and more