Our Mathematical Universe by Max Tegmark, Alfred A. Knopf, New York, 2014
At the outset, let me say that I’m not a physicist, although I did major in physics briefly in college. Nevertheless, I’ve had a lifelong interest in physics and, when I learned about theoretical physicist Max Tegmark’s book, Our Mathematical Universe, I figured I ought to read it. Also, it had become a reading project for my wife’s book club, so to keep up with her, I thought I’d better have a look. What I found in Tegmark’s rather long opus was a mix of conventional and speculative physics that left me scratching my head and wondering how such an obviously brilliant thinker could wander so far afield of what, at least to me, appeared reasonable.
Tegmark’s thesis is that we live within a nested set of individually complex universes, each of which he calls a “multiverse” because each contains an infinite number of like, “parallel” universes. He identifies four basic types of universes, stratified as Level 1 through level 4. In his classification, we live in the most basic of the levels, the level 1 multiverse, which more or less consists of the universe that we observe. His level 2 multiverse is one which we cannot perceive because it exists at a distance so great from us that light from it has not yet reached us and, because of his theory of how space is created, may never reach us. Things get weirder at level 3, the quantum level multiverse, and weirdest of all at level 4, where Tegmark’s assertion is that things become purely mathematical, although he pretty much seems to believe that everything is mathematical in the sense that his multiverses all consist at their essence of mathematical relationships.
He takes just under 400 pages to make all of his arguments, as well as to offer his views on life, the future of mankind, and, well, just about everything else you can imagine. Thus, you will understand that in this brief review, I won’t be able to recite and critique all of his arguments and, frankly, some of them I don’t understand, anyway. Let me say, however, that I’m pretty much OK with his level 1 and 2 multiverses, and even with his level 3 multiverse at the quantum level. Where he loses me, and credibility in general, however, is in his attempt to scale quantum behavior from the subatomic/atomic level to the macro scale of our daily existence. I have no problems understanding, or at least following the argument that, say, one cannot know both the position and momentum vector of an electron around an atomic nucleus and, therefore, it must be described in probabilistic terms with the practical result that we view it as a probability sphere around the nucleus. From this, the Heisenberg uncertainty description of observational imprecision, and the work of Schrodinger (his famous equation), Tegmark then extrapolates to the preposterous notion that for every move we make there is an opposite move that occurs in (or creates?) an alternative, parallel universe within our level 1 multiverse but which we cannot and never will perceive. The justification for this extrapolation is never convincingly made, an unfortunate fact given the non-intuitive nature of the assertion.
Tegmark goes on further to look at issues of space-time, and suggests that there is no unidirectional linear streaming of time but only a whole entity of space-time in which everything that has existed or will exist is present. In this view, what we perceive as the flow of time is simply our existence at sequential sections through this four dimensional continuum.
The fact that Tegmark believes his math strongly supports these views does not make them valid. As a theoretical physicist, his ideas do not come from physical experimentation, the actual testing of hypotheses, most of which cannot currently be tested, in any case. Flights of fancy aren’t necessarily gong to be validated, and Tegmark’s extrapolations at the third level and his theoretical fourth level are at least controversial, of not completely wacko.
Finally, Tegmark uses the last part of his book to dive headfirst into a lengthy discussion of perception, current nuclear age morality, and future of the universe. He spends an awful lot of time on the obvious, namely, that what we perceive as reality is merely our brain’s creation in response to the input of our senses and powers of interpretation. Duh. Perception is relative and potentially imprecise. I believe we learned this in high school, and my own retinal disease more than confirms my own distorted, highly subjective sense of reality.
There’s more in the book than I’ve described. For example, his discussion of the probability of other intelligent life in our level 1 niche is interesting but, in the end, his main thesis, that we live in universe of universes that we cannot perceive, and that these universes are at their essence mathematical entities, leaves me a bit bewildered. It’s fairly easy to throw out ideas about things no one can test (not the definition of the scientific method!), and his insistence that the mathematical relationships do not define reality but actually constitute it, require a stretch of imagination – or a degree of brilliance – well beyond me. The book is fascinating, but I’d take a lot of what Tegmark proposes with more than a grain of salt. At least, so says this non-physicist.
Recommendation: Read it if you’re a physics junkie and up for a fascinating slog.