Particles defy gravity, float upstream

Inspired by tea leaves’ reverse route, physicists demonstrate that water’s surface tension allows unexpected movement

UPSTREAM FLOW  When pouring clean water into a cup filled with tea leaves, some leaves glide upstream into the kettle thanks to differences in the water’s surface tension.

S. Bianchini et al./Proc. Royal Soc. A 2013

This article is only available to Science News subscribers.

Subscribers, enter your e-mail address to access our archives.

Not a subscriber?

Science News is a nonprofit.

Support us by subscribing now.

More Stories from Science News on Physics

From the Nature Index

Paid Content