Lisa Randall: Dark Matter and the Dinosaurs
Dark matter is already known to be everywhere. But in her new book, Dark Matter and the Dinosaurs, Harvard cosmologist Lisa Randall proposes that this mysterious substance also played a role in the demise of the dinosaurs on Earth.
Although dark matter—which accounts for 85 percent of the universe—is always assumed to be ‘dark’, Randall says that it would be better described as transparent. Matter that is truly ‘dark’ would, in fact, absorb light. Dark matter doesn’t interact with light at all—or people, for that matter—although it does interact with gravity.
“People are trying to devise very clever ways to look for very subtle, small effects, but so far as we know, the dark matter is not interacting with us a whole lot,” said Randall in an interview on On Being. “It’s interacting via gravity, but gravity is actually a very weak force at a fundamental level. That’s why you need large amounts of dark matter to observe its effects.”
There is a lot of evidence suggesting that dark matter is spread out in the galaxy, forming a diffuse spherical halo. However, Randall and her colleagues propose that some of the dark matter might radiate energy and cool down in the same way as ordinary matter. This would allow it to concentrate along the mid-plane of the galaxy.
This concentrated area of dark matter would have consequences that could be observed. It would also affect our solar system as it orbits the galaxy with a slight up and down wobble to its movement. As the solar system passes through the area of denser dark matter, the gravitational effect would be strong enough to dislodge comets from the spherical Oort Cloud that surrounds the solar system.
Read rest of article at: http://scienceandnonduality.com/lisa-randall-dark-matter-and-the-dinosaurs/#sthash.i59tA3N7.dpuf