Water forms droplets on the surface of a leaf but it spreads and completely wets the skin of a snail. Why does water behave so differently on the two surfaces? In this video, we introduce the fundamental concepts of surface tension, contact angle and the difference between hydrophobic and hydrophilic materials. Also, we illustrate with examples how the physics of wetting helps understand biological features in cells!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The Earth, which once was a messy ball of melted rock, is now teeming with complex living creatures extraordinarily adapted to their ecosystem. But the second law of thermodynamics tells us that systems spontaneously tend towards disorder and structures states, just like milk tends to mix with coffee. Then, where does complexity come from? Watch this quick intro to Complexity to understand how Nature creates complexity!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

Have you ever seen a movie backwards in time? How did you figure out that the time was flowing backwards? This could seem a silly question. But think about it. It strongly depends on the what process the movie was showing! If you see many pieces of broken glass coming together from different directions to build a bottle that moves against gravity, you’ll immediately know that the movie is reversed. You know that because breaking a bottle is a very irreversible process. But how would you know it if the movie shows a pendulum? Or two billiard balls colliding? Or a planet orbiting a star? The way we guess the arrow of time on irreversible processes has to do with the Second Law of Thermodynamics! Watch this quick intro to Irreversibility!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.