Thursday, December 31, 2015

Book review: “Beyond the Galaxy” by Ethan Siegel

Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe
By Ethan Siegel
World Scientific Publishing Co (December 9, 2015)

Ethan Siegel’s book is an introduction to modern cosmology that delivers all the facts without the equations. Like Ethan’s collection “Starts With a Bang,” it is well-explained and accessible for the reader without any prior knowledge in physics. But this access doesn’t come without effort. This isn’t a book for the strolling pedestrian who likes being dazzled by the wonders of modern science, it’s a book for the inquirer who wants to turn around everything behind the display-window of science news.

“Beyond the Galaxy” tells the history of the universe and the basics of the relevant measurement techniques. It explains the big bang theory and inflation, the formation of matter in the early universe, dark matter, dark energy, and briefly mentions the multiverse. Siegel elaborates on the cosmic microwave background and what we have learned from it, baryon acoustic oscillations, and supernovae redshift. For the most part, the book sticks closely with well-established physics and stays away from speculations, except when it comes to the possible explanations for dark matter and dark energy.

Having said what the book contains, let me spell out what it doesn’t contain. This is not a book about astrophysics. You will not find elaborate discussions about all the known astrophysical objects and their physical process. This is also not a book about particle physics. Ethan does not include dark matter direct detection experiments, and while some particle physics necessarily enters the discussion of matter formation, he sticks with the very essentials. It is also not a history book. Though Ethan does a good job giving the reader a sense of the timeline of discoveries, this is clearly not the focus of his interest.

Ethan might not be the most lyrical writer ever, but his explanations are infallibly clear and comprehensible. The book is accompanied by numerous illustrations that are mostly helpful, though some of them contain more information than is explained in the text.

In short, Ethan’s book is the missing link between cosmology textbooks and popular science articles. It will ease your transition if you are attempting one, or, if that is not your intention, it will serve to tie together the patchy knowledge that news articles often leave us with. It is the ideal starting point if you want to get serious about digging into cosmology, or if you are just dissatisfied by the vagueness of much contemporary science writing. It is, in one word, a sciency book.

[Disclaimer: Free review copy, plus I write for Ethan once per month.]


  1. $98 in hardcover seems high to me, although I suppose it is due to having a lot of illustrations which make it expensive to print. $35 would have been an immediate sale, but there are so many worthwhile causes (including this website) which could use $98 that I hesitate. Although I have a niece whom I could give it to as a high-school graduation present in a few months. (I usually go with Simon Singh's "Big Bang" - plus some legal-tender "bookmarks".) Thanks for the review.

  2. Thanks for your interesting reviews! Just out of curiosity: which science books written by women would you recommend? I realized I have a lot of great (semi popular) economics books written by women but no physics books. But they should exist, because at Gresham College there are several nice podcasts by women in "hard science".

  3. Uair,

    Assuming you mean popular science books, this one for example. I also recommend you have a look at Lisa Randall's and Jennifer Oulette's books. Best,


  4. The strapline, "how humans looked beyond the galaxy and found the whole universe" should be perfectly fine, yet quite involuntarily one is left with feelings of non-specific daftness anxiety. Like maybe they fell down a manhole and thought it was the whole universe.

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  6. Sorry, HTML typos. Here's another try:

    "$98 in hardcover seems high to me, although I suppose it is due to having a lot of illustrations which make it expensive to print."

    I review (mostly cosmology) books from time to time and find that there is little correlation between price and number of (colour) illustrations. For example, this coffee-table book has high-quality colour illustrations on most of its 321 pages but is priced at only $50.

  7. "Trespassing on Einstein's Lawn", by Amanda Gefter

    I just finished reading this book (hardcover, $23 on Amazon Prime), due to the recommendation here.

    It is an amazing book: the detailed history of how Ms. Gefter went about gathering ideas and pondering them to arrive at a personal understanding of how her universe works, over decades of time, having started with that goal at the age of about 15; and despite having avoided math and physics courses in school. As a work of fiction I would have found it unbelievable. I myself have evolved a similar (but not identical) paradigm, but would be unable to give such an accurate, chronological, well-sourced, well-written history of its development, full of amusing anecdotes.

    One point which I would like to argue with Ms. Gefter is her constant use of "observer" and "observations" to define reference frames. No doubt this is conventional usage by the wise, but I would prefer "interacter" and "interactions". As a compromise, I would be willing to settle for "measurer" and "measurement" as less anthropomorphic/dualistic substitutes. The use of "observer" smacks of dualism to me. Many of the wise people she cites, such as John Wheeler, seem to favor some mild sort of dualism, so I could be wrong to oppose it. I will not say no evidence could convince me of its existence, but I will say convincing evidence would annoy me considerably.

    Here is an experiment which might convince me: run the double-slit experiment twice, with a detector in each slit, whose detection or lack of detection is recorded automatically in a computer file without being seen by a human "observer" during the experiment runs. Then erase the file for run 1 without looking at it and look at the file for run 2, and (only) then look at the photographic plates from the runs. I claim both plates will show no interference pattern. If run 1 one does show an interference pattern and run 2 does not, I will start to believe in dualism. (I once asked at Dr. Sean Carroll's blog if such an experiment has ever been done, but received no reply.)

    Of course one of the points of Ms. Gefter's interesting book is that no two "observers" are compelled (by physics) to agree totally about the nature of their universes, so I hope she would not be offended by my slight disagreement. Anyway, I give her book five stars. Thanks for the recommendation.


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