In this week's io9 show, we delve into the science of ghosts — and the results may haunt you. We talk to author Mary Roach (Spook) about the environmental factors that could explain ghost sightings. We discuss why so many io9 readers think ghosts might exist. And we show how you can create a real-life ghost haunting, using the experiment of Pepper's Ghost.

Explore the secrets of the ghost world, with io9: We Come From The Future.

You can catch more episodes of the io9 Show on YouTube or Revision3. We're also on iTunes! Tune in every Friday for more startling revelations from the world to come!