A review by miocenemama
Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe by Lisa Randall

5.0

This was a different model of dark matter than I have ever heard before. The author and her colleagues propose a model where a small amount of dark matter is self-interactive. Dark matter is not known to interact with ordinary matter except through gravity. Dark matter is believed to form a halo around the galaxy like an invisible bubble. In this model, the self-interactive dark matter would form a dense thin disk through the center of the galaxy. The density of this disk would be sufficient that the up and down oscillations of the solar system through the galactic disk could cause perturbations of objects in the Oort cloud disrupting their orbits which are only loosely held in place by the solar gravity. These perturbed objects have a periodicity of around 32 million years which also seems to correspond with a number of Impact events and possible extinctions. I loved the painstaking explanations the author included and the connections she made to the universe, the development of life, and the effects of technology on our world. Her conclusion pointed out that a comet crashing to Earth was not our most pending issue. She cautions against using our new technology to plunder the resources of our planet and says that we may be the ones responsible for the next extinction event.