Reviews

This was a different model of dark matter than I have ever heard before. The author and her colleagues propose a model where a small amount of dark matter is self-interactive. Dark matter is not known to interact with ordinary matter except through gravity. Dark matter is believed to form a halo around the galaxy like an invisible bubble. In this model, the self-interactive dark matter would form a dense thin disk through the center of the galaxy. The density of this disk would be sufficient that the up and down oscillations of the solar system through the galactic disk could cause perturbations of objects in the Oort cloud disrupting their orbits which are only loosely held in place by the solar gravity. These perturbed objects have a periodicity of around 32 million years which also seems to correspond with a number of Impact events and possible extinctions. I loved the painstaking explanations the author included and the connections she made to the universe, the development of life, and the effects of technology on our world. Her conclusion pointed out that a comet crashing to Earth was not our most pending issue. She cautions against using our new technology to plunder the resources of our planet and says that we may be the ones responsible for the next extinction event.

dinodaw's review against another edition

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challenging informative reflective slow-paced

3.5

jdm9970's review against another edition

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5.0

This book is a lot. It starts with cosmology and the Big Bang, goes into particle physics to explain what dark matter is, touches on theories of the origin of life, finally gets to the fossil record and what that tells us about mass extinction events, goes into some concepts of probability theory and statistical significance, then describes large scale features of the Milky Way and our solar system’s traversal through it.

All of this is used to illustrate her idea (which she is very careful to describe as speculative and a “thought experiment”) that there is a disc of dark matter, much thinner than the distribution of normal matter, through the central plane of the galaxy, and that the spike in gravity caused by this disc is responsible for knocking objects out of the orbit of the Oort cloud at the edge of the solar system every 30-35 million years and sending big spikes in the number colliding with Earth, causing mass extinction events including the death of the dinosaurs.

Randall is very clear, though out the work, that some ideas are not established yet and should not be taken as factual, but she does heavily reference other academic work on the variety of fields involved. As a nonexpert I am unable to verify all of the background material, but provided there are no glaring omissions or misrepresentations I believe she makes a compelling case for her theory.

Overall this book is densely packed with a lot of science and will take some thought to follow, but the frame of her “dark matter killed the dinosaurs” hypothesis allows the book to flow reasonably well.

dycaaand's review against another edition

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challenging informative tense slow-paced

4.0

Idenya menarik: beberapa dekade lalu, ada penemuan bukti-bukti yang mendukung teori kepunahan massal dinosaurus oleh hantaman komet. Nah, tapi ada spekulasi di bagian faktor yang berkontribusi terhadap terbentuknya komet tersebut in the first place, yaitu karena pengaruh dark matter.
Buku ini cukup sulit dibaca. Butuh waktu untuk mencerna detail yang disampaikan oleh penulis bagi audiens umum.

estheria's review against another edition

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4.0

Only criticism is that at the end she doesn't circle back around and connect her theory with other observations that would support or deny it. She just finally, finally, after chapters upon chapters of already knowing what the theory will be, puts forth her numbers and ends it. Otherwise this book is a refreshing science read. Some rehashing of physics, but none of it excessive or simplistic. Also she randomly throws shade at politicos throughout the book via analogy, which is both awkward and entertaining.

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