Your normally talkative 5 and 8 year olds fall silent when you start playing the audio version of Bill Bryson's "A Short History of Nearly Everything." A few minutes later, the 5 year old is arguing with his brother about Pluto being a micro planet while brother is telling him it was a dwarf planet and now isn't... but that he doesn't feel like getting into the whole explanation because "then you will never leave me alone about it."