Q: Recently, I’ve noticed my hot water heater making an unusual noise that I’ve never heard before, and I’m not sure if it’s serious. Why is mywater heater noisy, and should I be worried about it? A: ...

Scientists at MIT have directly captured signs of “second sound” in a superfluid for the first time. This bizarre phenomenon occurs when heat moves like sound waves through an unusual state of matter.

A science video maker in China couldn’t find a good explanation for why hot and cold water sound different, so he did his own research and published it. By Sam Kean Most people are quite good at ...