There was worry that some birds might be migrating north south by some measurement of the magnetic field. There's only one species of bird in the universe, two in New Yorker. It's the pigeon. I think we would be okay in Manhattan. We'd be like, this is great. This is totally cool. Is there a way to kill the rats? So there was a genuine concern until we dug up the geologist, dug up the history of the magneticField on Earth,. You know how you do that? You look at volcanic deposits. And before it solidifies, it'll align to the magnetic field of the day. The iron particles that can be launched out of volcanoes will