Raindrops are tiny lightning bolts, and they’re corroding cars, study finds

[Rzeppa]

From Ars Technica:

The standard explanation for why rain causes corrosion is that water carries dissolved salts and acids to a surface, constant drumming of raindrops abrades whatever protective coating is on it, and oxygen does the rest. Nearly all our tools to prevent this—paints, polymer films, or oxide layers—are built around this idea. But we’ve apparently been missing something important about the rain.


A new study led by Zhongyuan Ni, Rüdiger Berger, and Hans-Jürgen Butt at the Max Planck Institute for Polymer Research in Mainz, Germany, has shown that water drops routinely arrive at a surface carrying an electrical charge large enough to punch through an insulating coating. Not scratch it. Not slowly dissolve it. Electrically blow a hole in it, the way a spark jumps a gap.

Here's the full article

 

[devo]

Remember when acid rain was a concern?

 

[Hulk]

Really interesting stuff. Keep your Cruiser in the garage!

 

[Rzeppa]

My interpretation of the finding are that in order to pick up a charge, the rain drops need to slide across an insulator (like rubbing a balloon on your hair), rather than simply falling straight from the sky. Still, it's certainly something I'd never thought of before reading this.