why the water goes up if I hold a paper towel up but touching it on a plate? What force is pushing/pulling the water against gravity?
In: Physics
It’s called [capillary action](https://en.wikipedia.org/wiki/Capillary_action), and it happens because water molecules are attracted to each other and to other molecules. This is why water forms a [meniscus](https://en.wikipedia.org/wiki/Meniscus_(liquid)) when poured into a glass. In a sufficiently narrow tube or a porous material, these intermolecular forces are strong enough to draw the water up against gravity. This is also what allows trees to transport water from their roots to their leaves.
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