system
Given the following post, respond as if you're commenting on Reddit:
human
When water soaks upward into a paper towel dipped into a glass, where does the potential energy gained come from?

Or is the water even gaining gravitational potential energy at all?
gpt
Water is gaining gravitational potential - it's higher up the paper towel. However, what you observe is more a _trading_ of potential energies - electromagnetic interaction between water and the fibres is a type of potential energy as well: electrical potential.