Monday, March 30, 2020

Dark Matter and the Dinosaurs - Lisa Randall

   2015; 371 pages.  Full Title: Dark Matter and the Dinosaurs – The Astounding Interconnectedness of the Universe.  New Author? : Yes.  Genres : Paleontology; Astrophysics; Quantum Physics; Science; Non-Fiction.  Overall Rating : 9*/10.

    Dinosaurs!  Everybody, be they child or adult, is fascinated by them.  They dominated the earth for an astounding 165 million years - from 231 million to 66 million years ago - meaning, as one meme has put it, that Tyrannosaurus Rex was closer in time to listening to Justin Bieber than in meeting up with a Stegosaurus.

    Everyone knows that around 66 million years ago, something happened in a flash (which in paleontological terms means a million years or so) and 75% of all life on Earth perished, including all dinosaurs that couldn’t fly or burrow into the ground.  This is called “The Fifth Extinction”.

    But what caused this immense dying-off?  Well, when I was a kid, the prevailing theory was that climate change was the culprit – the inland seas dried up, the Earth was subject to global warming, and the dinosaurs couldn’t cope with the new conditions.

    Then in the 1980s, that hypothesis gave way to the proposition that a giant meteoroid slammed into the Earth and wreaked cataclysmic destruction.  That theory gained traction when an appropriately sized and appropriately timed impact crater was found off the Yucatan coast in Mexico.

    Lisa Randall now adds a new twist to that scenario in the form of the inscrutable essence called “dark matter”.  It can’t be seen, touched, felt, or measured, yet it penetrates and permeates everything in the universe without have any effect, save for a faint gravitational influence.

    Well that’s all fine and dandy, but what sort of evidence can she produce to support such a wild and wacky theory?  Let’s read Dark Matter and the Dinosaurs and find out.

What’s To Like...
    The central hypothesis of Dark Matter and the Dinosaurs is given in its introduction: the Solar System periodically passes through the midpoint of the galactic plane, wherein lurks a dense disk of dark matter.  The gravitational pull from that disk is strong enough to dislodge a flurry of comets from something called the Oort cloud, sending them into random new orbits, one of which impacted the Earth, wiping out the dinosaurs, and allowing mammals, then eventually homo sapiens, to flourish and dominate.

   The book is divided into three parts.  Chapters 1-5 covers the birth of the Universe itself, from a microsecond after the Big Bang through the time when galaxies and individual stars are created.  Chapters 6-15 focuses on the emergence of our Solar System, with special attention on comets and asteroids.  Chapters 16-21 then shows how Dark Matter could affect all of this, plus how scientists might detect and confirm its influence.

    The book is a cosmological delight.  If you’re interested in, but have never understood the whole concept of Dark Matter (that's me!) , this book will bring you enlightenment.  Moreover, I was impressed by the attention paid to the Kuiper belt and the Oort cloud, both parts of the Solar System that most people have never heard of.  And I was surprised to learn that the Universe, the Milky Way, and our own Solar System are all pretty much “flat”, and why this is so.

    I enjoyed meeting Fritz Zwicky, who first proposed the existence of Dark Matter, and Fred Whipple (not the guy who squeezes the Charmin), who first called comets “dirty snowballs”.  I also learned why meteor craters, both on the Earth and the Moon are almost perfectly round, when you’d think they’d be off-center since whatever caused them is coming in at an angle.

    I laughed at some of the acronyms in the book.  There are “Squids” (Superconducting Quantum Interfering Devices), “Machos” (Massive Compact Halo Objects), “Wimps” (Weakly Interfering Massive Particles), and the mind-boggling “Edelweiss” (Expérience Pour Détecter les Wimps en Site Souterrain).  It was kewl to see Arizona’s Meteor Crater get some ink, ditto for my alma mater Arizona State University, and weird to see Chelyabinsk mentioned, since this is the second book I’ve read this year that featured it.

Kewlest New Word ...
Putative (adj.) : generally considered or reputed to be true.
Others: Conflated (v.).

    The Milky Way galaxy is in a group of galaxies known as the Local Group, which is a gravitationally bound system of galaxies whose density is higher than average.  The Milky Way and the Andromeda galaxy, also known as M31, dominate the group’s mass, but dozens of smaller galaxies belong to the group too – mostly satellites of the two bigger ones.  The gravitational binding force of the Local Group prevents the Milky Way and Andromeda from receding from each other with the Hubble expansion.  Their paths are actually converging and in about four billion years they will collide and merge.  (loc. 1441)

    In the early 1950s, Stanley Miller and Harold Urey at the University of Chicago did a famous experiment in which they heated a flask of water that was enclosed by a container filled with methane, ammonia, and hydrogen.  Their goal was to mimic the primordial ocean in the early atmosphere.  An electrical discharge acting on the water vapor played the role of lightning in their artificially created “atmosphere”.  Miller and Urey successfully produced amino acids with their simple apparatus, demonstrating that the production of amino acids in solar and extra-solar environments is actually no so surprising.  (loc. 3720)

Kindle Details…
    Dark Matter and the Dinosaurs is presently discounted at Amazon, going for the awesome price of only $1.99.  Lisa Randall has four other science e-books available, ranging in price from $7.49 to $9.99.

“All science is either physics or stamp collecting.” (Lord Rutherford)  (loc. 3927 )
    For me, Dark Matter and the Dinosaurs was a fascinating book, but reading Lisa Randall’s technical justifications for her hypothesis can be brain-numbing, particularly the sections involving Quantum Physics.  Trying to comprehend the various “darks”: Dark Matter, Black Holes, Dark Energy, Anti-Dark Matter, Partially Interacting Dark Matter, Double-Disk Dark Matter, and Dark Disk Gravity, was also quite the challenge.  Many nights, after 15-30 minutes of reading this book, I was ready to switch to reading something more relaxing.

    I don’t think this is in any way a fault on the author's part.  Lisa Randall is proposing something radically new here, and her readers are going to range from a.) other astrophysicists, b.) other scientists (like me), and c.) people without a technical background.  If she solely caters to any one of those groups, the other two will be sorely disappointed.  Her astrophysicists colleagues will be particularly nitpicky when looking for holes in her analysis.  You can’t please everybody, but she does a good job in trying.

    Overall I found Dark Matter and the Dinosaurs to be a challenging, fascinating, and enlightening read.  In addition to learning a ton of stuff about Dark Matter, I was especially delighted by the attention given to the Oort cloud and the Kuiper Belt.  Yes, I got lost a lot in the quantum physics chapters.  But a little bit of mental calisthenics is good for the gray matter.

    9 Stars.  We’ll close with a brain teaser.  Suppose scientists detect a huge “Near Earth Object”, still weeks away, but headed for a crash landing on Earth.  What is our best strategy to deal with it:
    a.) try to blow it up,
    b.) try to deflect it by pushing it sideways, or
    c.) something else?
    Answer in the comments.

1 comment:

Hamilcar Barca said...

Answer: Give it a shove. Blowing it up just gives you a lot of chunks of rock hurtling the same direction. Trying to push it sideways requires too big of a counterforce. But increasing (or decreasing) its speed so that it arrives earlier (or later) by a mere seven minutes – the time it takes the Earth to move a distance of its radius – can turn a collision into an exciting but harmless flyby.