About us: We own the Wild Birds Unlimited nature shop in East Lansing, Michigan,
a store that provides a wide variety of supplies to help you enjoy the birdwatching hobby.

This blog was created to answer frequently asked questions & to share nature stories and photographs.
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Monday, July 20, 2009

Look out for falling pancakes!

When raindrops leave a cloud several thousands of feet off the ground they are larger than a softball. Scientist originally thought these large drops collided with each other to create smaller drops. Now a study published online July 20, 2009 in Nature Physics produced new evidence to explain how single drops shatter into a wide variety of sizes.

Two scientist from Aix-Marseille University in France, Emmanuel Villermaux and Benjamin Bossa, conducted experiments on isolated water droplets. A high-speed camera captured each contortion of a solitary drop as it fell. Though the drop fell only a few meters, the researchers applied an upward air current to simulate the experience of a raindrop during its long fall from the sky.

The photos reveal a large drop flattening out like a pancake and then collecting air like a parachute until it eventually shatters into many smaller globules.

After creating mathematical equations to describe this shattering, the researchers found that the breakup of individual drops alone was enough to explain the staggering variety of raindrops — no collisions necessary.

Click HERE for video.

Source: http://www.nature.com/nphys/journal/vaop/ncurrent/abs/nphys1340.html
Aix-Marseille Université, IRPHE, 13384 Marseille Cedex 13, France
Institut Universitaire de France, 103 bd Saint Michel, 75005 Paris, France
Correspondence to: Emmanuel Villermaux e-mail:
villermaux@irphe.univ-mrs.fr

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