Hey, welcome to Why the Kettle Sings. I am Evan Castellano, I taught physics for eleven years, and these days I build museum exhibits, which means my job is still getting people to say huh, I never noticed that. This show is about the things in your house that are secretly doing physics. Naturally we begin with the kettle. Next time you make tea, listen. It hisses, then it roars, then, right before boiling, it goes almost quiet. That silence is my favourite sound in physics and I will explain exactly what the bubbles are doing. I filmed an experiment with a glass pot and a flashlight that you can copy tonight. At the end, a listener from Denver asks why tea on a mountain tastes weak. You are listening on Witspeak Podcasts. Kettle on.