Impossibility by John D. Barrow

barrowjd-impossibilityThe subtitle of this book is what really attracted me to it: “The Limits of Science and the Science of Limits”. As a philosopher, I’m fascinated by the idea that there are not only things we don’t know, but things we can’t know. Some scientists are searching for a theory of everything – a set of equations that will account for everything in the Universe. I don’t believe such a thing is possible for us, because it’s not possible for, say, a goldfish. Mankind is just another branch on the evotionary tree, subject to much the same limitations of perception and cognition. I read this book as an attempt to get some additional clarity on this issue.

The content of the book is diverse and deep, covering many areas, from language to mathematics to cosmology, and more. There’s a great deal packed into 250 pages. The most memorable section, for me personally, was a discussion on how complexity occurs on a particular fractal level of the Universe (terrestrial life), not at the extremes of the very large (stars and galaxies) or the very small (atoms and sub-atomic particles). The human brain is the most complex structure in the known Universe, and this gives us reason to speculate that the very function of the Universe could be to bring about the likes of us. We tend to assume that size equals importance, and the images from the Hubble Space Telescope certainly make us feel very unimportant. But what if complexity equals importance?

The book also contains a fascinating discussion on how the speed of light restricts us from ever getting a complete view of the Universe. When we look into deep space, we see it as it was billions of years ago, not as it is today, because it takes so long for light to reach us. And we can’t see the more distant parts of space at all, because the light emitted by very distant stars hasn’t yet had time to reach Earth at all. This puts us in a fishbowl of sorts and it causes us to make assumptions about what is beyond our knowledge. Since we are able to identify inflexible laws of nature in the part of the Universe that we can see, we assume that these laws apply across the entire Universe. But we simply don’t know, and furthermore, we can’t know.

Some of the content of the book was beyond me, particularly the more mathematical parts. Also, some of the content struck me as irrelevant to anything of practical value, such as a section on time travel paradoxes. If anything, this illustrated the importance of philosophy alongside science. It’s very easy to think of time as something physically real, but the only place that time exists, in the sense of a recording of events, is inside brains. Hence, no time travel paradoxes are possible, because there is no time. There is only an ever-changing now. Any discussion of time travel involves a misperception of time as a literal thing making a literal recording of the cosmos as it moves. This material in the book was a waste of time – no pun intended. The book culminated in a discussion of hidden problems in the voting process, which was a bit flat for an ending.

Overall, I felt this was an important book for me to read. The author has a very rational mind and a broad range of knowledge.