What is the point of kissing? Does it have any benefit for us or our progeny? Plus, we ask how much you'd have to fart in order to lift yourself off the ground! Like this podcast? Please help us by <a href="https://www.thenakedscientists.com/donate">supporting the Naked Scientists</a>

How much farting is required for lift-off?

Each week we set out to solve one of the world's weirdest, wackiest, funniest and funkiest scientific puzzles. And along with the answer there's a brand new question to think about for next time...