Customer Reviews

The Nine Numbers of the Cosmos

5 star:		(1)
4 star:		(3)
3 star:		(1)
2 star:		(0)
1 star:		(0)

 

 

Cosmology is in upheaval. In January, 2004 the AAAS journal Science selected the confirmation of dark energy as the scientific breakthrough of 2003. The universe is only 4 percent ordinary matter (galaxies and interstellar dust). Dark energy and exotic matter make up the other 96 percent. The universe is a strange place.

It is great to be an astronomer, or astrophysicist, or cosmologist in heady times like this. But for an author such times are difficult; a book can become outdated in less time than it takes to write it.

In 1999 Michael Rowan-Robinson, Head of the Astrophysics Group at Imperial College, discussed nine numbers that play a critical role in our description of the universe. Just four years later, with our new understanding of dark energy, this well-written, detailed look at observational astronomy and cosmology needs substantial revision.

We now say the age of the universe is 13.7 billion years plus or minus a few hundred thousand. Just a year ago our best estimate was 10 to 14 billion years. The rate of expansion of the universe is now pinned down at 71 kilometers per second per megaparsec, 10 percent higher than the value in Rowan-Robinson's text (but within his stated margin of error). And how does one now measure the density of the universe?

Should you read this text today? Probably not, even though it does provide a good snapshot of our understanding at the end of the twentieth century. I suggest investing your efforts in the most current literature available.

Possibly Rowan-Robinson will create an updated addition. I hope so.

Nine Numbers is similar to the later work by Martin Rees ("Just Six Numbers") in its approach to a popular work on cosmology. Rowan-Robinson looks at nine cosmological numbers that are so crucial to our understanding that if altered but little would make our existence impossible.

While the work is dated (1999), those aspects are primarily cosmetic (exact value of constants, exact age of the universe, etc.) The key concepts are mostly applicable today, to the best of my knowledge. Those concepts that are radically different in 2006 are still so cutting edge that we can't be confident about them anyway. While we can only hope that the author updates Nine Numbers, it would be a shame to reject this fine book because it doesn't cover Dark Energy, the latest kinks in String Theory or the Holographic Universe.

Rowan-Robinson is unique among cosmology writers in that he does not eschew a bit of technical dirty-work. Readers should be comfortable with graphs, charts, trends, logarithms, and orders of magnitude. At the same time, the work is not so technical that most readers couldn't grasp it.

Especially refreshing is the author's excellent writing -- very fluid, yet direct and unflambuoyant. Nine Numbers is an unassuming work that offers a rich trove of insight. If you are looking for another cosmology book to read at a bargain price, consider this one.

There's a beguiling simplicity to this attractive primer on cosmology. Professor Rowan-Robinson uses mostly plain English in describing what is currently known, and he keeps it short. But make no mistake about it: this is a complex and technical book on a difficult subject. It requires study. I have read it twice, and could profit from additional readings, but, as I like to say, life is short, and I'll have to be satisfied with what I have thus far garnered.

One of my pet peeves about books on cosmology is the constant rehashing of ancient conceptions of how and why the universe came into being, along with mistaken ideas from the early days of astronomy, anything, it sometimes seems, to pad out the requisite three hundred pages or so. Consequently I was pleased not to encounter any tales of turtles holding up the world or any retracing of the Ptolemaic model before the author gets to the current state of affairs (although he does give some brief history as he goes along).

The nine numbers serve as an organizing device through which a picture of modern cosmology is revealed, or as the author puts it in the Prologue, "a peg on which to hang different aspects of our knowledge." Incidentally, the Prologue, "Que sais-je," is particularly well written and candid and valuable for what it reveals about what Rowan-Robinson's knowledge. The first number is the amount of baryonic matter in the universe, as revealed in Chapter 1 entitled, "We exist." Chapter 2 is "We are not in a special place," revealed by the considerable extent to which the universe is isotropic and homogeneous. The third number is the Hubble constant, the fourth, the age of the universe, the fifth, the temperature of the background radiation, etc. I'll leave it to the reader to discover the other numbers. What I want to focus on are Professor Rowan-Robinson's speculations on extraterrestrial life from Chapter 1.

He begins by expressing his "difficulty...with the idea that advanced technological civilizations like ourselves are common in our Galaxy" (p. 16). I think he has expressed it exactly right here with the words "like ourselves," which I want to emphasize. However on the next page he goes on to present the familiar argument (from Fermi) that a civilization much in advance of ours would have found us by now. He cautions that he doesn't accept the view that "they keep themselves hidden so as not to interfere with our development." Hence the tired conclusion that THEY probably do NOT exist.

The main problem with this argument is that it projects human psychology and desire onto beings of an advanced civilization. They might very well have their reasons for leaving us alone. Additionally, it's not clear that the problem of interstellar travel is as easily solved as some might think, and I'm thinking here of the emotional and psychological difficulties as well as the technical ones. Rowan-Robinson writes that he doesn't accept "any really fundamental limits on colonizing the Galaxy" (p. 17). Even if he is right, would such beings have the desire to colonize? I suspect that their psychology might differ, perhaps startlingly, from our own, and that they may prefer to stay at home.

Rowan-Robinson also considers the case of an advanced civilization, unable to colonize other planets, facing the death of its star. He believes they "would surely put some effort into demonstrating that they had existed. There would be the astronomical equivalent of the pyramids, some kind of beacon signaling forever" ( p. 17). To me, such a vain glorious enterprise is more characteristic of human psychology than anything else, especially that of our pre-technological civilizations. I would add that in advancing it, Rowan-Robinson is guilty of anthropomorphizing the aliens! Surely, one would think, after a billion years or so of development, there would be some advance on this sort of psychology. Perhaps Professor Rowan-Robinson would appreciate being reminded of the lesson of Shelley's poem, "Ozymandias," that "king of kings" whose "shattered visage lies" amid the drifting sands.

Rowan-Robinson concludes the book with a prediction for the year 2100 (repeated from page 64) that the Planck era (10 to the minus 43 seconds after the Big Bang) will remain "shrouded in mystery." He adds, "It would not surprise me if this were still a mystery in the year 3000." There are some helpful diagrams and tables, some black and white photos, a brief glossary, and a name, and a subject index.

Although written in 1999 this book was a clarifying reading. I am not going to say that I understood everything, but despite of that, I was able to grasp the author excitement about what we currently know about the universe and what to expect in the future, whether we conquer the knowledge of these numbers or not --- and the author is optimistic. It is difficult to swallow the bing bang, especially on what happened during the planck time and the succesive exponential expansion of the universe, but that is what physics theorist say was the likely beginning of the Universe, supported by the very well known temperature of the microwave background. One interesting number is the density of the universe because is one of the numbers that cannot be explained only by radio "visible" matter, so that is where dark matter (and dark energy) makes its appereance.

This is an interesting subject indeed, mainly because there are so many facts to learn, and perhaps correct on our actual knowledge, but we are advancing, new projects are in phase of construction, like the Atacama Large Millimeter Array (ALMA) and bigger accelerators will be ready soon. We just have to wait for their results.

Great! A new book for the course I'm teaching on Glorious Accidents. Rowan-Robinson includes photos, plots and data that add a reality note to pretty abstract stuff. He describes complex issues in words that are usually clear and non-technical, but sometimes mathematically oriented. My artistic and non-tech students would have a hard time with about 1/4 of the book, so I suggest limited portions and supplement this book with chapters from others: "Just Six Numbers" by Rees; "The Five Ages of the Universe" by Adams and Laughlin; "The Origins of Life" by Smith; and brief readings from Theilhard and Zen (theology), Hawking (physics) and Mayr (biology). It all makes for a stimulating experience for us all.