Hosted by Sandra Tsing Loh, The Loh Down on Science is a fun way to get your daily dose of science plus a dash of humor in less than two minutes.
Hosted by Sandra Tsing Loh
Airs Weekdays 2:31, 3:31 and 5:49 a.m.

Between the Drops

Finally! A cure for a rainy day! Or, at least, driving on a rainy day.

This is Sandra Tsing Loh with the Loh Down on Science.

Rain doesn’t make driving hard; light shining off rain makes driving hard. When headlights shine on rain drops, some of the light bounces right back atcha. Making glare.

But researchers at Carnegie Mellon University have developed a "smart headlight" system that can shine around raindrops and snowflakes. Srinivasa Narasimhan, “if you're driving in a thunderstorm, it will seem like it's only drizzling.”

Why? Because not all the raindrops will be lit up, and therefore visible.

Here’s how it works: A camera tracks the motions of raindrops, then applies an algorithm to predict the particles’ location a few milliseconds later. The headlights then deactivate individual rays of light that would otherwise light up the drops in their new location.

When a car is moving slowly, over 70 percent of rain is deilluminated, while turning off only about 5 percent of the light. All in about 13 milliseconds. For highway speeds, the timing would have to be even faster.

As to tuning out your kids’ annoying music selections? Eh, problem for another day.

The Loh Down on Science is produced by LDOS Media Lab, with 89.3 KPCC Pasadena. And made possible by the generous support of the Gordon and Betty Moore Foundation.?