Book Review: Dark Matter and the Dinosaurs

Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe, by Lisa Randall

If I have this right, this is what this book proposes:

Dark matter, which we know is out there but cannot see, includes some particles that interact, however weakly, with each other. They also might interact with particles included in regular matter. (These particles are called weakly interacting massive particles, or WIMPs. And you think scientists don't have a sense of humor.)

Assuming these dark matter particles interact with regular matter particles, the interactions are really, really small. So small they cannot be measured except on a galactic scale, and even then, only with precise equipment studied by people who know what they are looking for and what they are doing.

Further assuming these particles interact, they could possibly form a small, flat, dark matter disk in the center of the Milky Way. This disk, which remains theoretical, could then interact, however weakly, with our solar system as it revolves through and around the Milky Way. Over a period of years -- again we are talking large scale, so it's over millions of years -- the dark matter disk causes a wobble in the Oort Cloud, which circles around the outer edge of our solar system. That wobble may knock material out of its orbit, pushing it into the sun's gravitational pull, where it heads toward the earth.

Theoretically, this should happen every 30 million to 35 million years or so -- let's put it approximately at every 33 million years. It could be happening now.

Which means that sometime around, say, 66 million years ago, that dark-matter-caused wobble sent some Oort Cloud matter hurtling toward the sun, and such matter struck earth, causing the Cretaceous–Paleogene extinction event, which snuffed out the life of 75 percent of the earth's plants and animals, including -- you guessed it -- the dinosaurs.

Or, to put it in haiku form:

WIMPs in dark matter

Thin disk in Milky Way, then:
Dino extinction

See how all this is connected? At least, it is in theory. And this is what Dr. Randall explains in her well-written and intriguing book. And she explains the science far, far better than I do.

If this kind of stuff interests you, and you want to know more, go out and buy the book.