Physicist Max Tegmark says the mathematical formulas create physical reality

Book Reviewed: Our Mathematical Universe: My Quest for the Ultimate Nature of Reality, by Max Tegmark

At some time in our lives, we all are mesmerized about the secrets of life and the universe. What is the nature of physical laws that govern our existence, and what is physical reality? Physics tries to answer these questions in terms of the laws of physics operating on matter (or energy) in spacetime. MIT Professor Max Tegmark, a well-respected theoretical physicist, says that only mathematical formulas are real; they create physical reality and all else including the laws of physics are an illusion. According to his theory, there are billions of parallel universes (multiverse) which have four levels of existence. Three of them have been proposed by other physicists, and Max Tegmark suggests a fourth level which he calls a mathematical universe.

The first level of multiverse is an infinite space, and our space is only 13.72 billion years old (starting with the Big Bang.) In an infinite space scenario, billions of parallel universes are possible (which share the same space as ours). The second level is created by the application of physics equations on this universe, after the big bang. At level three, the parallel universes exist in an abstract mathematical structure called Hilbert space, which can have infinite spatial dimensions. Each universe is real, but exists in different dimensions of this Hilbert space. The fourth level which is entirely due to the author, which he calls an external reality. This theory proposes that there is a reality out there that is independent of us or our physics; this is created by mathematics. Essentially a mathematical structure is a universe by itself, says the author. This is not entirely a new idea since physicist Galileo said that the nature of reality is written in the language of mathematics.

The ideas of the author are interesting but physicists are not racing to buy his theory. Einstein spent much of his life thinking that there is such a thing as physical reality out there, but he was thinking in terms of unifying the laws of quantum physics with the laws of classical physics. The author goes beyond this frame of spacetime by considering all possible universes out there.

The book does not involve any mathematical equations or "hard" physics, but assumes knowledge of undergraduate level physics to fully appreciate the subject matter.