I have always assumed that the planet earth was destroyed in the computer wars as it was so dependent on computers that gave rise to the mentats. Must be my own imagination as I can't see our planet make the transformation to a non- computer-age ever again.
Great video. It reminds me of the epic scale of the Dune universe. There must be thousands of planets with thousands of years of history scattered in the known universe for humanity to have forgotten where their race came form.