We find out how pacemakers keep your heart in check, even if you go running after a bus. Plus, we ask how tattoos manage to stay under your skin for so long. Like this podcast? Please help us by <a href="https://www.thenakedscientists.com/donate">supporting the Naked Scientists</a>

Tattoos Forever

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...