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

Finding reveals an overlooked way that water can damage surfaces.

The short version

• 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.

What happened

Electrically blow a hole in it, the way a spark jumps a gap. The starting point of the study is a phenomenon called “slide electrification,” which has only been properly quantified in the past few years.

Why it matters

When a water drop slides across an insulating surface like a leaf, a painted wall, a windowpane, or a plastic panel, it strips charge from that surface and leaves an opposing charge behind.

Summary by Nerd News Network. Read the full article at Ars Technica via the links above and below.