Transcripts

Ivan Semeniuk:
One of them has to do with just keeping sweat out of the eyes and you can imagine how that would be useful.

Ivan Semeniuk, US Bureau Chief for New Scientist Magazine which has put out the new book, Does Anything Eat Wasps?, says there's probably another more important reason we have eyebrows.

And that is for human expression. Your eyebrows really accentuate what you're trying to express with your face. And we read each other's expressions more easily, especially across distances by being able to watch each other's eyebrows.

Ever wonder why, for example, a liquid like beer, which is brown, has bubbles that are white?

It really has to do with the scattering of light. When you're looking at the bubbles sitting on the head of a glass of beer, the tiny bubbles are acting like curved little mirrors, they're capturing light from all directions. They're scattering that light all around and they're scattering all the different colors around. So, in a sense you're getting all the colors at once from all of those different bubbles.

And why do dogs howl at sirens?

Even though a siren clearly doesn't sound exactly like a howling dog, some part of that siren, perhaps does sound like some part of a dogs howl. Enough for a dog to be triggered into thinking that somewhere nearby is a dog that's trying to signal. And this goes back to dogs hunting in packs, howling at each other to maintain communication.

At somethingyoushouldknow.net I'm Mike Carruthers and that's Something You Should Know.