What does a percentage chance of rain really mean?

What's the evidence that vaccines don't cause autism? Can brain oxygen deprivation lead to memory loss? Do babies bond with their dads as much as with their mums? Do parrots socialise like other animals? What does a percentage chance of rain in a weather forecast actually mean? How can we lip-read if we all sound different? Could the floating door in Titanic have supported both Rose and Jack, according to science? Dr Chris Smith and Relebogile Mabotja have the answers. Like this podcast? Please help us by supporting the Naked Scientists (thenakedscientists.com/donate)