Physics Buzz

As regular readers of the site know, we try to take time each week to answer an interesting or informative question that lands in our "Ask a Physicist" inbox. Part of the reason why we do this is to make sure that we're addressing your urgent questions and wild what-ifs, but it's also to demonstrate the amazing things you can do with physics. It's almost a superpower, a kind of " second sight " that lets us understand things that would otherwise be frustrating puzzles.

Last week, a reader named Nabilah wrote in to ask: Electrons carry charge, but I've been told that electrons in a DC circuit actually move slower than a snail, and in an AC circuit, they don't move at all, just shifting to and fro. Then how does that make a lightbulb light up?