'Our Incredible Shrinking Planet' explores the possibility that gravity slowly increases over millennia forcing the Earth to become more massive and crush itself under the pressure. Scientists cannot explain how the dinosaurs managed to attain their huge sizes or how enormous pterodactyls were able to fly in our current gravity, so was it once less? Nor do they have a satisfactory reason for why or how the tectonic plates move and subduct each other inflicting us with tsunamis and earthquakes in the process.