The Infinite Cosmos —— Questions from the frontiers of cosmology

As a general rule, I enjoy reading books about what is currently happening in physics. I enjoy them because I studied physics in school and taught it for many years. Not only am I trying to keep current myself, but I am also looking for things that will help my students understand physics a little better. Unfortunately, though Dr. Silk is clearly up on what is happening, he doesn't communicate it very well. This is not a book I would pass on to my students. When it comes right down to it, this is a very hard book to read. I'm reasonably well-versed in the subjects Dr. Silk is discussing and yet I found his prose unnecessarily dense and filled with numerical data that only superficially helps him make his points. Brilliant and knowledgeable he might be, but Dr. Silk has a real problem communicating his ideas in an appealing way. Certainly, unless you have a physics background and facility with a mathematical argument, I would stay away from this book. That is too bad because the subjects Dr. Silk puts before us are inherently fascinating--black holes, the fate of the universe, et.al.--and he knows his stuff. Additionally, the proliferation of books on the subject show there is an interest out there. Dr. Silk's effort, however, will not likely help many people along the path to understanding unless they are already most of the way there.

This book seems to be a merge-sort/cut-paste of other books by the same author and by others, too. Not as complete as his own "Big Bang" title, wordy, with tints of unconvincing poetical observations that add little to the presentation. OK, it contains sections on dark matter and dark energy etc., but, sorry, the word that keeps coming to my mind is "unconvincing." For high-school neophytes, although the lingo gets pretty technical at some places. Not even close to Silk's much more interesting " The Big Bang " (3rd ed.). P.S. (10/2011): Today I came across a review of this book in the American Journal of Physics, vol. 75, nr. 1, p. 95-96 (Jan. 2007) by Allan Walstad (University of Pittsburgh at Johnstown). No surprise he did not like the book too...

Booooring !

Joseph Silk, a leading cosmologist, gives his latest take on the scientific quest to comprehend our universe, its origins, and where it is going. I've read Silk's book on the Big Bang (which can be considered a companion volume) and he is able to explain scientific cosmology in fairly understandable terms. Unfortunately given the scales of time and space involved, many of which are far removed from our ordinary experience, the heavy use of arcane physical concepts and mathematical ideas far from ordinary life are inevitable. Yet, the conclusion Silk offers is our universe is probably infinite. Interestingly, Silk dabbles in the possible theological and philosophical conclusions of an infinite universe, ranging from the possibility there are infinite numbers of parallell Earths and selves, to the possibility our universe is only one possible universe out of an infinite set of universes, most of which are inhospitable to life. Silk is aware of the limits of speculation (he is deeply knowledgeable about Astronomy) and gives a surprisingly positive estimate of philosophy and what it might offer science, and what science might offer to philosophy. The book is quite enjoyable, though due to its expense, more worth borrowing than buying.

When it comes to cosmology, you need your information fresh, spot on accurate, and as inspired as possible I came to SILK's book, having read about everything on Cosmology I could easily find. I found SILK's book overall inconsistant and confusing. It wasnt what he was revealing, because nearly all of it has been in recent books. Silk needed a better editor to take the time to structure this book, and commision some original diagrams to make some of the information more accessable. Good illustrations can take a very complicated "left brain" type explanation, and visualize it for us "right brain" types. A major problem with this book is that the writer doesnt seem to have a grip on WHO his audience is. IS it NASA research scientists? High school students? At one point he talks about Megaparsecs, kiloparsecs, and gigaparsecs. Now, this book as NO GLOSSERY OF TERMS. He could just as easily given distances in light years. Instead of using the most obvious terms, he obfuscates his writing, and loses his audience. Other times, he repeats explanations of the most fundamental terms. On page 26, he explains that HADRONS are BARYONs and LEPTONS. BUT, this gets explained again on page 118, when the terms of Baryonic matter gets another going over. Even on page 164, he defines baryonic matter again, and then once more tackles dark matter. If he had a chapter, that started with the basics of particle physics, and worked its way step by step into the concept of dark matter, that would have been so much clearer. This writing problem is throughout the book. On page 113, he says that stars become brighter by burning hydrogen into helium. The next sentence, he writes, "They (the stars) become brighter as their fossil fuel is gradually exhausted..". When I read that, i realized this guy was either making inside jokes with his terminology, or his editor didnt understand what was being written. FOSSIL FUELS MAKE THE STARS BURN? I saw this type of writing in many places. He says that distant galaxies produce most of their energy at infrared wavelengths. So, does he mean the energy is OBSERVED at infrared wavelengths (because of redshift), or it's produced that way? I was confused there again. (I'm sure SILK knows what he's talking about, but as a writer, his job is to make ME know what he's talking about.) The worse problem, is that the conceptual unfoldment of the book is not logical. Advanced explanations and terms get thrown sometimes in the front, at other times in the back of the book. If you had never read a book about cosmology before, you would really be lost here. In the end of these cosmology books, is where all the intellectual goodies are usually placed.....TIME TRAVEL, ALIEN LIFE FORMS, BEFORE THE BIG BANG, UNIVERSAL TOPOLOGY, and... GOD AND CONSCOUSNESS? When he started to write about God, conscousness, and how poets and theologicans are afraid of an infinite universe, i had to scratch my head. If i want theology, I'll read a theologian, and if I want poetry, i'll read a poet. When i want science, i read scientists. I have no idea why Silk was pontificating on some subjects, outside of his discipline. The oddest part of this book, is right in the title. The whole book, the writer claims that the universe is "INFINITE". Sometimes, when he speculates on the topology of the universe, Silk states the universe might be bounded, but infinite. (this is the topological part of the book, which is very obtuse. Others have commented about this as well.) A recent popular science writer, required a whole book on topology and cosmology, to explain how a hypertorus might be the shape of the universe, thereby allowing us to see multiple images of our own galaxy. But, Silk devotes less than 3 pages on the topic, and expects himself to be understood. And he isnt. So, he finally gets to the payoff, after talking about the time machines, time travel paradoxes, and the fate of the universe. After this whole book, about the INFINITE universe, he says, (pg.191) "We do not know if the universe is finite or infinite." WHAT? Why not just say that in the first chapter, and forget the circumlocutions? Anyway, there are some great ideas in the book. I'm not discrediting that. I am not sure what part of this book was Silk's original research, but popular science writers need not be scientists themselves. (By the way, there is only 4 or 5 footnotes for the whole book, so Silk isnt telling where he gets his information. And, if you think it might be in the bibliography, well, that's missing too.) I'm sure that SILK is a great scientist. It is his attitude and ability as a popular SCIENCE WRITER, that i have problems with. Difficult ideas and terms are sometimes glossed over, sometimes conflicting facts and oddball terms are introduced without explanations, and sometimes, the point you spend pages trying to prove, is tossed aside, as being without proof. I took a long time to read this, even tho almost all the material in the book, I've read before. Maybe the concept of the book was not fully thought out, or Silk didnt get enough feedback from his editor, before he published. THE INFINITE COSMOS is simutaneously both too basic and repetitive, and too advanced for the scope of a science book for the general reader. I was disappointed overall. I guess I'll stick to Kip Thorne, Hawkings, and Brian Greene.

Joseph Silk is an expert on galaxy formation, structure and clustering. He knows how to read the cosmic microwave background for pointers on these things and for confirmation of the influence of dark matter. Unfortunately, the chapter on these topics is somewhat impenetrable for anyone not already familiar with concepts such as last scattering horizon, angular scales, sonic peaks, Compton scattering and so on. There are not even any diagrams as an aid to comprehension. The general idea is sufficiently discernible to whet the interest; but it is then necessary to get busy with Google because there is no bibliography in this book. Anyway, the earlier chapters contain so many errors that you will probably want to check everything you read by this point. Some mistakes can be put down to unchecked misprints or imprecise language, but others are just plain wrong. Examples: p18 - Earth contains 10^80 atoms (out by a factor of 10^30); p20/29 - Sun orbits galaxy every 200/100 million years (about 225 perhaps?); p36 - baryons include electrons (ouch!); p54 - Cosmic ray protons can have the energy of 1Kg dropped from the Eiffel Tower (out by x60 even for the most energetic particle ever recorded); p57 - a billion solar mass black hole has a radius equal to the diameter of Earth's orbit (out by x50; nearer to Jupiter's orbit); p71 - there are a billion galaxies within 10 billion light years (out by something like x100?). . . The chapter on supernovae combines error with unintelligibility. I wonder if it was dictated but not read. We read that Supernova 1987A (a Type II, core collapse) was lit up by decays of radioactive cobalt, first to nickel, then to iron. A glance at the periodic table shows this order must be wrong, and it is. The general scheme of events for Type I explosions is so muddled as to be harder to fault. No mention is made of mass accretion to a critical threshold as the key standardisation mechanism for Type Ia explosions. It is variously suggested that uniformity is due to a one solar mass limit on burning before core collapse, or to the ejecta consisting predominantly of iron and heavier elements. And yet we were just told that the iron decomposed to neutrons, protons and neutrinos. But hold on, some iron is converted to radioactive nickel, and yet about seven tenths of a solar mass is ejected as iron in a final burst of neutrinos. I read as far as p90 where it said that supernovae had been detected in galaxies "beyond redshift unity, corresponding to a distance of about 10 billion megaparsecs"! I wondered what sort of co-moving coordinates were in mind for the observable universe, and decided to give up and stick with Google rather than read further. Wikipedia is a good source on supernovae. So is The Magic Furnace by Marcus Chown.

Whew! What a great deal of work that was! While I, nor most of the general reading public, are doing our post-doctoral work of cosmological physics, I found this book extremely difficult to plow through. Yes, the author is a brilliant man and, yes, his concepts are far-reaching and highly informative, but, no, he does not relate them very well to those of us without a PhD in Physics. Mr. Silk, my suggestion to you is that you perform the same exercize that Jonathon Swift did before he released any of his writings; give your work to someone who does NOT have the theoretical understandings that you do and if he, too, fails to grasp your meanings, rewrite them such that he (and the rest of us) will. I wish you great success in your profession, for in it lies the horizon for all of our futures. At this stage of our human evolution, few positions are as important and exciting as yours. But, please realize that we all do not speak 'Physicese' and have no means of doing so.

I've been studying what has been happening in Astronomy for about five years now, and this is a very exciting time, with the various improved scopes reaching farther out into the Universe than ever before. It is one thing to see the images, it is quite another to understand even a glimmer of what is going on out there. It is a truism that to get a real understanding of structures and the distances involved, which are the everyday bread and butter of astronomical discussion you need a good grounding in Math and I have to admit that I don't have that, although I'm working on it. Professor Silk does use the complex Mathematics in his prose, but to a lesser and less confusing extent than many of his writing contemporaries. He is understandable, even if you do have to work at it to get the best out of it. It is worth reading twice, and I find myself going back and back to both this and Silk's other remarkable work, "On The Shores Of The Unknown". Highly recommended, and enjoyable. brendan