ELI5: Explain Like I'm 5

knife-edge effect

Okay kiddo, have you ever played with a seesaw? You know how when you sit at one end and your friend sits at the other, you can rock up and down?

Well, imagine that instead of a seesaw, we have a really sharp knife. If we balance the knife on its edge, it can start to wobble back and forth just like a seesaw.

Now, here's where the special part comes in. When the knife is perfectly balanced on its edge, it looks like it's standing completely still. In fact, it's moving so slowly that our eyes can't really tell that it's wobbling.

But if we give the knife just the tiniest nudge to one side or the other, it will start to wobble faster and faster. This is because of something called the "knife-edge effect."

Basically, when the knife is perfectly balanced, its weight is distributed evenly on either side of its edge. But when we nudge it, that weight shifts slightly to one side or the other. This makes the knife start to tilt more and more, which makes it wobble faster and faster until it falls over.

So, the knife-edge effect is just a fancy way of saying that when we balance something on a very narrow point, it can be very unstable and wobble a lot if we disturb it even a little bit. Cool, huh?