Why does water defy gravity and seep upward through a paper towel?

[Anticitizen]

Why will water seep upward, against gravity, through a paper towel that has one end dipped in it? Is it some quirk of surface tension?

 

[mathman]

I wouldn't call it a quirk. It is a very common phenomenom, most important for plants, where water goes from the roots to the rest of the plant, carrying nutrients.

 

[MATLABdude]

To dovetail in on Mathman's response, it's called capillary action, and it's been known since antiquity:
http://en.wikipedia.org/wiki/Capillary_action

 

[junglebeast]

Why will water seep upward, against gravity, through a paper towel that has one end dipped in it? Is it some quirk of surface tension?

Because of osmosis. Here's an explanation:

http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/diffus.html