Watch Think of a Number Season 4 Episode 1 Online

The first of six programmes with Johnny Ball This week Johnny finds out about reproduction, discovering where your heart is and what your voice looks like. Also a machine that looks like us, but doesn't think like us and next generation robots that don't look like us, but think like us. Meanwhile - get around to generating an answer to this one - how many grooves are there on the average long-playing record ?