Do you recall that old joke about NASA spending millions to come up with a pen that would write in the zero gravity of space, while the Soviets used a pencil? That's what I thought of when Zach Wheeler suggested using lasers to protect us from rainfall because "an umbrella is boring." A laser would be so much cooler! It's the kind of stupid idea nine-year-olds come up with, yet so many of us revert to our nine-year-old selves in our free time. But no question is stupid when you love to geek out on math and science, so Randall Munroe tackled this one in his "What If?" series (previously at Neatorama).
The opening sequence addresses the stupidity of the idea, but then Munroe explains exactly what would be involved in zapping every raindrop with a laser before it falls on your head. While we should stick to umbrellas for the time being, the explanation of this difficult, dangerous, and expensive theoretical idea is pretty cool indeed. -via Damn Interesting