- #1
- 19,044
- 14,659
I apologize for the fact that this information is 2nd hand but a very intelligent and reliable friend tells me that in “Dark Matter and the Dinosaurs” by Lisa Randall she hypothesizes a disk of dark matter, which she calls “Double-Disk Dark Matter (DDDM)” that is superimposed over the center of the Milky Way galaxy, and which oscillates above/below the plane of the galaxy. The hypothesis is that this oscillation, combined with the orbit of our solar system, and the gravitational pull of the dark matter in the disk, pulls comets out of the Orrt Cloud and sends them towards the Earth every 33 million years. She thinks this may be what happened 66 million years ago when the Chicxulub event pushed the dinosaurs to extinction. Her claim is that all of the current data makes this a viable hypothesis.
I thought that current observations were fairly solid that the shape of the halo is that of a somewhat flattened beach ball (like if you put your foot on one and pressed down some) but she seems to believe, unless I'm misunderstanding, both that it is far more flattened and that it shifts up and down relative to the galactic plane.
Can anyone comment knowledgeably on this?
Thanks,
Paul
8/6 5:45pm correction: Friend got back to me after I asked him to see if she cited evidence for the oscillation and turns out he had misunderstood. She was just talking about the oscillation of the solar system relative to the galactic plane. Sorry about this confusion.
I thought that current observations were fairly solid that the shape of the halo is that of a somewhat flattened beach ball (like if you put your foot on one and pressed down some) but she seems to believe, unless I'm misunderstanding, both that it is far more flattened and that it shifts up and down relative to the galactic plane.
Can anyone comment knowledgeably on this?
Thanks,
Paul
8/6 5:45pm correction: Friend got back to me after I asked him to see if she cited evidence for the oscillation and turns out he had misunderstood. She was just talking about the oscillation of the solar system relative to the galactic plane. Sorry about this confusion.
Last edited: