The Theory of Everything (Review of ‘The Accidental Universe’ by Alan Lightman)

In the first of his essays about the universe, The Accidental Universe, Alan Lightman reflects upon the miniscule probabilities of life emerging within the universe. There are specific parameters that must be met for life to be able to exist – there cannot be too much nor too little dark matter in the universe (because the universe would expand too fast or too slow respectively), there cannot be too much nor too little distance between the prospective planet and its sun, there cannot too much nor too little force within the nucleus of an atom, and so on and so forth.

Some use this probability to prove the existence of God – how can our universe exist? The chances of life emerging in a universe are so infinitesimal, how can there not be a God?  And there are others, Steven Hawking among them, who believe there are an infinite number of universes, combining together in a number of alternate universes, creating something called the multiverse.

While some believe that alternate universes can portray the differences between the two paths forming the fork in the road – in one universe, I could’ve become a ballet dancer, and in another, a world-renowned pianist – physicists believe that each alternate universe has varying fundamental properties. In one universe, there is a slightly larger amount of dark matter (larger than ours) and the universe accelerated so quickly in its early stages that matter couldn’t congregate to form stars. In another universe, the nuclear force is slightly stronger than it is in our universe, and all of the hydrogen atoms in that other infant universe would’ve merged with other hydrogen atoms to make helium, leaving no hydrogen and subsequently eliminating water from the universe completely.

In the theory of the multiverse, our universe just happens to be the one where the amount of dark matter is just right, the nuclear force and the distance between Earth and the sun slides right into the parameters that life can grow within.

If that is the case, Lightman postulates, then search for the theory of everything – the mission of every physicist to describe all of the properties of the universe – is meaningless. The properties of our universe simply are. You are here. I am here. Humans are here in this universe because the properties permit life to exist. This means that our universe is one in an infinite amount of others. According to Lightman, “the basic properties of our universe are accidental and incalculable. In addition, we must believe in the existence of many other universes. But we have no conceivable way of observing these other universes and cannot prove their existence. Thus, to explain what we see in the world and in our mental deductions, we must believe in what we cannot prove,” which Lightman furthers in his third essay, The Spiritual Universe.