Two short and enjoyable reads this past week. Last night I finished Alone in the Universe. John Gribbin takes the reader through a careful tour–in turn: the galaxy, the sun, the solar system, the Earth, the Cambrian Explosion, and human beings. A series of factors contribute to Dr Gribbin’s take that human beings are the only intelligent life form in the universe. Quite frankly, I agree. But I didn’t need this book to convince me.
The first five chapters deal with astronomy and they are absorbing. Chapters six and seven examine two momentous events: the explosion of life about 530 million years ago and the volcanic resurfacing of Venus around the same time. Dr Gribbin makes the case that the latter was the instigation for the onset of Snowball Earth. His theory is that a moon-sized object hit Venus, caused a worldwide volcanic resurfacing of that planet (the evidence of the resurfacing is not in doubt) but that the debris from that collision may have been enough to tip the entire planet Earth into an ice age. Eventually Earth’s own build-up of carbon dioxide and methane from our own volcanoes thawed the planet. Life bloomed as a result.
The blooming of life–of hard-shelled fossils–in undeniable. Dr Gribbin is going to need more than two pre-Cambrian events to show conclusively there is a connection between them. Earth has teetered on going Big Snowball earlier in its history. It would be interesting to nail down those earlier periods and see if there is a correlation to the infusion of dust into the inner solar system. It would be a darned difficult piece of scientific sleuthing.
Despite the weakness on paleontology, this is a good read. I’m convinced, as I was before, that there is no other life in the universe that matches human intelligence. Most critics of this book seem to latch on to the notion that somewhere out there, there’s somebody else. I would be happy if they found people. But I’m not banking on it.
In a similar vein I also enjoyed Dimitar Sasselov’s The Life of Super-Earths. This volume starts in the 1990′s, and chronicles briefly the discovery of planets outside the solar system, and the gradual fine-tuning of our discovery sieve to the point where we can identify planets larger than Earth, yet smaller than Neptune. Hence the term, super-earth.
Dr Sasselov has had a part in these astronomical discoveries of the past two decades, so that personal touch makes this book a bit more engaging. And like modern astronomers, he draws on many disciplines like cellular biology, geophysics, and chemistry to offer his readers a more complete canvas of this scientific frontier.
We will eventually find Earth-sized planets. They may well harbor life. I think it more likely they will be locales for very interesting chemistry and geology. That is still a good reason to explore them.
To the lay reader, each of these books is engaging and readable. Read them quick, because the rapid pace of science these days may render some of the details incorrect, or at best, incomplete in just a few years.