WeatherWise

Why Rain Drops Refuse to Be Ridiculous A thoughtful, nerdy, slightly cheeky look at rain Rain feels simple. Water falls. We get wet. End of story. Except it isn’t simple at all. Rain is the outcome of a delicate truce between gravity , surface tension , air resistance , thermodynamics , and chaos — and it works only because raindrops are small enough to survive the trip . Let’s start inside the cloud. Cloud droplets: the illusion of emptiness A cloud looks fluffy, but it’s actually a dense suspension of liquid droplets and ice crystals , typically 10–20 micrometres in diameter . On their own, these droplets fall so slowly they might as well be levitating. Rain requires growth , and growth requires collisions. Turbulence jostles droplets around. Larger ones fall slightly faster, collide with smaller ones, merge, and grow. This runaway process eventually produces drops heavy enough that gravity overcomes updrafts . At that point, the drop is no longer part of the cloud. It’s rain — ...

Why Rain Isn’t the Size of a Bus (and Other Wet Mysteries) For curious early high-school minds If you’ve ever been caught in the rain, you’ve probably noticed something important: Rain falls in drops . Small ones. Sensible ones. Not giant wobbling water monsters that flatten houses and knock pigeons out of the sky. Which raises a very reasonable question: Why aren’t raindrops ten feet wide? Let’s investigate. First: What is a raindrop, really? A raindrop begins its life inside a cloud — which is basically a floating traffic jam of tiny water droplets and ice crystals . These droplets are microscopic . Thousands of them could fit on the head of a pin and still argue about personal space. Cloud droplets bump into each other, stick together, bump again, stick again… and slowly grow. This is called collision and coalescence , which sounds like a sci-fi band but is actually just water playing bumper cars. Eventually, a droplet gets big enough that gravity says, “Alright, you’ve had your f...