What If the Moon Didn't Exist? - Neil F. Comins

The book is a series of what-ifs related to changing one aspect of the cosmos around the earth, then discussing its impacts on the planet and life on earth. So Chapter 1 is about there not being a Moon, Chapter 6 is about a star (other than the sun) exploding near enough to Earth to have some noticeable effect.

A lot of the interest for me is in Comins' discussion of aspects of cosmology I didn't really understand. When he talks about what might happen if the Sun were more massive than it is, he goes into a discussion of how stellar fusion works, and how the energy emitted by the said fusion in the core loses energy as it makes its way to the surface. Or how when iron fuses it absorbs photons rather than releasing them. Some of the information is stuff I remember reading when I was really into astronomy at a much younger age, but fleshed out more fully.

The parts of each chapter discussing how the evolution of life on earth might be affected are a little less interesting because Comins limits himself somewhat to discussing mostly how living organisms we have might be impacted or selected against. He acknowledges that you could potentially have practically anything evolve, but wanted to keep things from getting too far afield. But I can't shake the notion that an Earth without a Moon would have life on it after 4.5 billion years that looks very little like anything we'd recognize. I might be entirely wrong about that, but it's a notion I couldn't shake.

Comins does have a verbose writing style. Everything feels like he could get to the point faster than he does. He's trying to make sure there's no mistake about what point he's making, by trying to be very precise in his terminology. The end effect is his sentences are overstuffed and awkward. In the paragraph below, does he really need either of the uses of "intrinsically" in that sentence for you to understand it?

'Two effects from the passing star would be particularly important to consider: its radiation and its gravitation. As with the supernova in Chapter 6, too much radiation from the interloper could sterilize the earth's surface. Too much gravitational force from the star would pull the earth out of the region around the sun where life could be sustained. Both of these disasters would occur if an intrinsically low-mass star passed close to the earth of if an intrinsically massive star passed at an even greater distance. What we want for this chapter is a star that will take us through the gates of hell but that won't close them behind us.'