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Philosophy, sociology and religion

Philosophy, sociology and religion

Science pushed to the limit

01 Jul 1998

Impossibility
John Barrow
1998 Oxford University Press 292pp £18.99/$27.50hb

What are the limits of science? Will the pursuit of knowledge lead to a never-ending source of intellectual (and perhaps even monetary) riches? Or are scientists misleading the public on this score, in an attempt to gain even greater support, power and influence? It seems that we physicists are more and more frequently being forced to tear ourselves away from our calculations and experiments to address questions such as these, often posed by sceptical citizens and politicians. In Impossibility, John Barrow strides confidently into these murky waters.

The book takes on these questions from a wide range of perspectives. Barrow explores the philosophers’ contributions, illustrating how the philosophical climate of an epoch can make or break opportunities to advance human knowledge. The natural limitations of the human mind are examined, and speculations about the impact of biological evolution on the form of these limitations are produced. The limits provided by technology, and by the laws of physics themselves (such as the finite speed of light, cosmic singularity theorems and the second law of thermodynamics) are explored, as are the deep mathematical and logical limitations suggested by the likes of “Gödel’s theorem”, which proves that there are limits to the completeness of logical systems. Throughout the book many sociological aspects are touched on. For example, Barrow asks what sort of people are drawn to a pessimistic view of the future of science, and likewise, what type of person is inclined to passionate defence of its future prospects? What personal satisfaction does each of these groups possibly find in their own respective viewpoints?

I have to confess that I was a difficult reader for this particular book. Having the good fortune to be a participant in the ongoing “golden age of cosmology”, where every few months sees yet more significant advances, means that sitting back and contemplating the limits of science seems at best a very odd diversion. This is even more the case when I find the author – also a cosmologist – reassuring me that when some future super-advanced life forms transfer their minds to computers, the gap in experience they would “necessarily” endure would probably not bother them. A chance to contribute to some of the great successes of current science is simply a much more compelling activity. In the end, I suspect we will only really learn about the limits of science by being as ambitious as possible and seeing what happens, not by stepping back and analysing the prospects ahead of time.

Of course, in many ways my impatience is quite self-indulgent. If we cannot give a responsible account of our activities, and convince others there is real progress being made, the opportunities to continue our work will greatly diminish. And, closer to home, the issue of what questions can ultimately be addressed by science is a crucial one in the field of cosmology. At the moment, cosmologists have the luxury of focusing on a set of concrete, tractable questions relating to the formation of galaxies and the large-scale features of the universe. Still, it is not yet clear how effective we will be in bringing other interesting cosmological questions into the domain of solid science. I found Barrow’s thoughtful treatment of this issue one of the many strong points of this book.

Impossibility should be accessible to a very wide readership. Anyone with an interest in the subject matter should be able to read and enjoy this book. For the most part, it reads more like an informal conversation in the coffee room (or pub) rather than a tightly argued case for a particular point of view. This can be a bit distracting at times, but the style is actually very well suited to the subject matter. The limits of human knowledge is by no means a closed subject, and Barrow’s survey of the many different ideas and perspectives that have been expressed on the subject comes across as much more honest than a single-minded defence of a particular view could ever be.

The second half of the book is more technically oriented and does contain some carefully argued points. In the process, the reader is given excellent exposure to several interesting aspects of modern research, including “inflationary cosmology” and time travel in general relativity. I was particularly impressed with Barrow’s discussion of the relationship between “Gödel’s theorem” and possible limits on our understanding of the physical world.

Probably the most provocative aspect of the book for me was the fact that Barrow’s fascination with the “anthropic cosmological principle” gets plenty of play. The idea, roughly, is that many aspects of the universe must be as they are so that living creatures can emerge. My objection is that our understanding of what makes a “living thing” and what role that understanding might play in cosmology is much too poorly understood to allow useful results to be obtained.

In the concluding chapter, Barrow comments on the type of scientist whose knee-jerk reaction to the idea that some things might be unachievable or unimaginable is to see it as “an affront to the spirit of human inquiry: raising the white flag to the forces of ignorance”. I certainly count myself as a scientist of that type. In the end I liked Impossibility a great deal because Barrow has managed to take on this difficult subject with his spirit of human inquiry robustly intact. My recommendation to readers is: read the book. It will help you discuss the future of science in a thoughtful and effective way, you will enjoy many thought-provoking science discussions of fundamental interest to a physicist, and it will be fun. But then, please, indulge yourself in the passionate pursuit of your own research. It is only through that process that we will truly discover what is really possible.

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