Is dark matter a dinosaur killer?

摘要

Dark matter might live up to its ominous name. A recent theory about the behaviour of the elusive stuff leads to a scenario in which dark matter could be to blame for killing off dinosaurs. Last year, Lisa Randall at Harvard University and her colleagues suggested that dark matter can clump up into a thin, flat disc in a galaxy's plane. As the solar system orbits the centre of our galaxy, it bobs up and down on a regular cycle, so if the galaxy contains a dark matter disc, we would pass through it every 35 million years.