What If the Moon Didn't Exist: Voyages to Earths That Might Have Been

Who needs tales of far-off galaxies or intergalactic "federations" after imagining the horrific roar of 300-foot tidal waves occurring daily if our moon was only 70,000 miles away? Comins' book transforms dry facts about our Solar System into haunting, mesmerizing scenes that frame the fragility of our existence in a world almost sublimely unsupportive to life.

Starting from the coalescense of the accretion disk that formed the Earth, and changing the parameters to create a whole new ecosystem for the planet. It details how the Earth would be different if certain events never happened or did happen during the development of the planet. With detailed explanations of processes that occur on the Earth we know today and juxtaposed against an Earth that developed differently. I count this as the best book I have ever read and I have read it multiple times and occasionally I still pick it up and read it from a point I thumbed to and till I can't stay awake any longer.

This book is absolutely fascinating! The scenarios that writer describes are realistic. Yes, its possible that Moon didn't form or that the Sun was much more massive or Earth could have been tilted. Well, now we get to find out what Earth would have been like under any of those conditions and its definately not boring!

In this book, Neil Comins walks a fascinating tightrope between science and science fiction. He presents ten carefully detailed scenarios, in which intriguing astronomical "what ifs" are asked. Each scenario is alloted about 25 or 30 pages, on average. The title scenario, dealing with a posited Earth without a moon, is the longets essay, weighing in at 50 pages.One of my favorite sections is the chapter pondering "what if" the Earth were struck by a black hole. Comins generously approaches this question from two completely distinct vantage points. First, he asks what would happen if we were hit by a stellar mass black hole. Second, he delves into how things might be if we were hit by a primordial black hole, formed at the beginning of the universe, with a mass about the same as that of the moon. Comins also asks great questions about how things might be if a local star went supernova; how the Earth might fare if the Moon's orbit was closer to us; and what Earthly life might be like if the Earth were tilted on it's axis perpendicular to its orbit, like Uranus.This book is really interesting. It isn't exactly science fiction -- just speculation. Comins sticks very close to known science, with no departures at all. When necessary, he includes little essays about Stephen Hawking's theories, etc, to help us understand the sound foundation of his theorizing.If you know any "absent-minded professor" children, or an adult with a bent in this direction, then I recommend the living daylights out of this book... To clarify that -- the highest praise I can give this book is that I wish I discovered it when I was about 10-13 years old. I remember my summer vacations when I was about that age, when my friends would plant me in deep, deep, deep left field during whiffleball games. I had to at least go out in the field, to save face, but I usually wanted to be thinking about science. Whichever team was actually at bat, I was the designated deep-cubed left fielder for the duration of the game. I'd sit there and daydream, and mumble to myself about astronomy or fantasy, until my friends eventually let me know when the game was over. One summer I spent those afternoons thinking about "The Lord of the Rings." Another summer it was Carl Sagan's "Dragons of Eden" (which I also recommend). Another summer it was the science chapters from "The Book of Lists." This book would have been just as fascinating, and would have kept me happily spaced out in dreamland for months. In my book that's high praise. I would also recommend this for science teachers, at any level from elementary school to high school. Two thumbs way up.

While, as a reviewer below noted, this book occasionally suffers from digression, the author's decision to take on subjects rarely talked about in popular terms more than compensates for that minor flaw. While much of what Mr. Comins discusses in this book has been covered in other works, those have been overwhelmingly targeted at people with a strong grasp of astronomy, while Mr. Comins has succeeded in producing a book that novices as well as the more experienced can enjoy.However, the book is not solely limited to astronomical phenomena. It also contains a very enlightening chapter on the feasibility of organisms using forms of electro-magnetic radiation other than visible light for purposes of seeing. Superman's x-ray vision will never seem quite the same once you know that his eyes would have to be ten-thousand times the size of regular human eyes in order to be able to process an image at the same level of resolution.I would also strongly recommend this book to people who like alternate histories, or who enjoy writing "hard" science fiction. I have found it to be a very valuable reference work for my own writing.