Depending on your point of view (or how drunk you are), tapping another person's beer bottle so that it overflows is either incredibly obnoxious or a funny prank. But only recently have physicists explained exactly why that motion causes the beer to foam so rapidly.
Let's say someone has gotten a little sassy at your family's holiday gathering. Or maybe it's New Year's, and not everyone is getting in the spirit. Here's how to break a beer bottle so it turns into a weapon — using science!
Cavitation happens when movement in water makes it erupt into bubbles. But there's also something called supercavitation, and it might make zooming through the sea a great deal faster.
Just when you think you've seen all the gorgeous helices in the world, here comes another one. This one trails behind propellers underwater. What causes this helical structure to form? And why is it a problem?