twist and turn like a dancer in flight.

It happens when a droplet lands

on a water-repellent surface with a special pattern.

These acrobatic leaps were recorded

by Chinese scientists investigating new ways

to manipulate water.

To understand what they did, let’s step back

and see what Isaac Newton had to say

about bouncing objects.

According to Newton, when an object hits a solid surface,

some of the energy of the impact

is translated into a rebound.

Think of a ball hitting concrete.

If the ball travels straight down with no spin,

it should bounce straight up again.

And it’s the same with a water droplet

on a water-repellent surface.

Theoretically, the droplet should bounce straight up —

no fancy stuff.

But the researchers created a pattern

of adhesive material on the surface that water sticks to.

The water in contact with the sticky patches

recoils more slowly than the water

touching the repellent surface,

and that makes the droplets spin.

Change the pattern of the adhesive,

and you change the shape of the dancing droplet.

The researchers made swirls and half-moons

and dotted circles, each of which

caused the water to behave differently, sometimes even

bouncing sideways.

Scientists also showed how the energy of the droplets

could be harvested.

They set up a magnetically suspended surface.

As the droplet landed on the surface and rebounded,

it pushed down the plate and caused it to spin.

It’s a new kind of hydropower.

And at their peak, those droplets

are spinning at a whopping 7,300 revolutions per minute.

So apart from creating a water droplet ballet,

scientists have also found a new way to harvest energy.

And their work might help in designing

self-cleaning airplane wings.

For now, it’s enough to have the pleasure of watching

the leaps and pirouettes of those dancing drops.