The Case of the Missing Neutrinos

Some readers with a more thorough scientific background may find the information here a little too general, but I wish I had read this book before I had tackled more complex volumes--they wouldn't have been such hard going!
June 16, 2002

As a collection of essays written over the past 20 years, some are not surprisingly out of date, but not badly so. Gribbin has gone to the trouble to arrange the essays in a related fashion, and so the book reads almost as a continuous volume, with each essay flowing nicely to the next.

I was starting to feel as though Gribbin had nothing new left to tell me, but he obviously has plenty of good insights and interesting information still up his sleeve. Definitely one of his better books.
September 21, 2000

The title describes the case of the missing neutrinos - referring, of course, to the fact that the flux of solar neutrinos found in experiments is only about 1/3 the flux predicted by the standard solar model, under the assumption of zero neutrino mass. The book, though, discusses lots, lots more than just the missing neutrino problem. This is a collection of short essays on issues of primary interest to physics - the hot topics of the day. The book is a joy to read - I bought it for the trip from Portland to Newark, and read it in just a few hours.

Chapter 1 consists of speculation regarding the likelihood of intelligent life elsewhere in the universe, and how likely it is that any such extraterrestrial civilizations might count with, say, base eight instead of base 10. It's interesting to compare Gribbin's assumptions and prejudices regarding the existence of extraterrestrial civilizations in light of Ward's recent book, "Rare Earth." The idea of intelligent extraterrestrial life is also extended in chapter 2, which also includes a very brief and simplistic discussion of the history of life on earth.

Chapter 3 reviews the evidence for the Milankovitch cycles, which are associated with ice ages on earth. The chapter predicts that the next ice age is imminent, but does not include speculation about how the current dumping of carbon dioxide and other "green house gases" might affect its onset. If you enjoy chapter 3, you'll also want to read "Ice Ages," by John Imbrie and Katherine Palmer Imbrie. You may also want to read "Is the temperature rising," by S. George Philander.

Chapter 4 is a real gem. It's called, "How Darwin Discovered Relativity." It's an historical recantation of how biologists discovered, through their study of the earth and evolution, that the earth is many thousands of millions of years old. However, at the time there was no known way to keep the sun shinning for that long. It drove everyone nuts, and resulted in some pretty interesting ideas - all classical, about how to provide earth with heat and life long enough for species to evolve the way they have. Eventually, of course, physicists discovered the energy released in atomic fusion, and that solved the problem. It's a great little chapter that illustrates how progress in one branch of science can stimulate progress in other branches.

Chapter 5 finally gets down to the book's title by introducing the fact that the sun does not seem to be emitting the flux of neutrinos that the standard solar model says it should. Gribbin introduces several possibilities, including the notion that neutrinos could have finite mass (in which case they can oscillate from one type to another) and the idea that solar cycles may result in the temperature dropping within the sun's core (blinking on and off) and thus modulating the flux of neutrinos. Gribbin develops these concepts over several chapters (5, 6, and 7), and includes some fine information about the history of measurements of the sun's diameter, and the solar cycles that result in the size and luminosity of the sun oscillating over time.

Chapter 8 is a fine summary of what happens in a super nova. Again, this is all very qualitative, and many details are omitted, but Gribbin does a nice job of presenting the salient issues involved in super novae and also gives some nice historical information and context. Chapter 8, for example, illustrates super novae by describing SN 1987A. If super novae interest you, check out "The Supernova Story" by Laurence A. Marschall.

Chapter 9 is another one that I truly enjoyed. This chapter is mostly an historical accounting of the discovery of pulsars by Jocelyn Bell. It also includes some of the historical highlights of Thomas Gold's explanation of pulsars as rotating neutron stars.

The rest of the book deals mostly with cosmology. Chapter 10 talks about galaxy formation, chapter 11 is an historical account of how Eddington verified the general theory of relativity by measuring the gravitational bending of starlight. Chapter 12 is about the early predictions of dark stars based on analysis done within the framework of Newton's theory of gravitation, and the interesting idea that black holes were really invented (discovered?) hundreds of years ago, long before the observational evidence for their existence came about.

Chapter 13 touches on some pretty controversial stuff about white holes and Narlikar's theory of the steady-state universe. Chapter 14 is called "Time and the Universe." It's really about the second law of thermodynamics, and attempts to use that, along with ideas in quantum mechanics, to explain time's arrow. Chapter 15 is a quick summary of white dwarfs, neutron stars, black holes, and wormholes, and why empty space does not weigh billions of tons per cubic centimeter. The book ends with a chapter on particle physics and a final chapter on inflation.

As I said, I read this book on a trip to New Jersey. While I was there I visited the horn antenna used by Arno Penzias and Bob Wilson when they inadvertently stumbled across the microwave background radiation that confirmed the "big bang" theory of the origin of the universe. It seemed a fitting end to the journey Gribbin took me on with his book.
April 14, 2000

Gribbin does no better with the case of the missing neutrinos. Four billion neutrinos per square centimeter per second are said to pass through the detector tank of cleaning fluid buried in a South Dakota gold mine. Only eight of the calculated 25 neutrinos have been detected per month. Two thirds of the little devils are still missing in action. Perhaps a Sci-fi reader can fill in this blank. As an aside, Gribbin reports that a Russian team has implied that a neutrino does in fact have mass, as much as 25 electron Volts, which would, if so, at least account for the missing mass of the Universe, hunted vigorously for decades, no small feat. Happy hunting.
March 31, 2000