Blogger’s Note: Last week I made a nomenclature mistake when explaining the many-worlds interpretation. I referred to the alternate realities as universes while the correct scientific term is histories. I regret the error and have changed the nomenclature for this blog post.
As I explained last week, every decision leads to the creation of infinite new histories and a move to one of these new histories. This quantum physical theory leads to a very interesting philosophical question, namely what determines which history we move into. In other words, what determines the future? What determines our reality? If every history is as valid as ours, why am I in this one? In fact, why am I? These are big questions, right at the intersection of science and philosophy. The answer, I think, is one of the most beautiful and awe-inspiring things in all of reality.
To understand what determines the selection of a history, we first need to have a bit more of an understanding of the process of history selection. Imagine your consciousness as a train moving forward along the tracks of time. The speed of the train can change—that’s special relativity—but the train must always move forward. It cannot stop, and it cannot go backwards. Every now and then along the tracks, there’s a junction where the track splits. Unlike normal train junctions where there are two or three possible tracks branching from a junction, these junctions have infinite tracks stretching out from them. Each track is another history, another reality, another version of the universe. Each one is just as real as any other, each one just as valid, each track an equally likely path. When somewhere in the universe a decision is made, our train of consciousness moves on to one of these tracks. But what determines which track we go on?
The answer is one of the strangest, most beautiful, most sensational, most powerful things in the universe: stochasticity. Random chance. The one true randomness in the universe is the selection of a history. But wait, if each history is equally likely, why does the most likely scenario tend to happen more often? Why don’t smashed plates randomly move back together? Why does entropy generally increase? Why, as Steven Hawking snarkily questioned, are we not in a history where Belize has won every gold medal in every Olympic Games? The answer is that each history is not unique, and there are more of some histories than others.
But wait, you say. If there are infinite histories, how could there be more of one than another? Infinity over anything is still infinity. The answer is that some infinities are larger than other infinities. This isn’t just a John Green quote—this is a mathematic fact. Infinities are assigned a “cardinality”, signified by ℵ (the greek letter aleph). If this hurts your head or leaves you feeling confused, don’t worry. When this idea was first proposed by Georg Cantor in the 19th century, Henri Poincaré, one of the greatest mathematicians to ever live, was so frustrated by it he referred to it as a “grave disease” infecting mathematics. However, Poincaré was wrong—later proofs have proven Cantor right. Heading back to the histories, the more likely a scenario, the more histories that include that scenario.
That means that everything in the universe is a product of probability, nothing more. You, me, the trees, the grass, the flowers, the Andromeda Galaxy, the Sun, Hawaii, EVERYTHING has arisen by sheer luck. These probabilistic histories drive evolution forward—better adaptations lead to increased chances of survival, so well-adapted species exist in more histories than poorly adapted species.
This, for some people, leads to an existential crisis. If we exist sheerly by chance, a simple quirk of the quantum, what is the meaning of life? Does this mean we don’t have a purpose? If we don’t have a purpose, why should anyone ever be good? As these people see it, the stochasticity of the universe is a slippery slope to moral bankruptcy.
Shockingly, I disagree with them. Firstly, there is no “meaning of life”—life is what you make it. But we do have a purpose. Our purpose is to promote our species, promote our genetic line, ensure that we are remembered in the DNA of future histories, for children do not enter into this world a tabula rasa. Children enter into this world full of knowledge written in every cell of their tiny bodies. In every strand of DNA is written the story of humanity; wars, truces, miracles, tragedies, loves, loathings, acts of valor and acts of cowardice, the history of your ancestors is engrained in the very essence of what makes you you. Each one of us is a marvel of evolution and a walking representation of the fortitude of our species. Humanity comes from a line of survivors; at every roll of the dice our number came up and we were included in history. The universe selected us and left out the dinosaurs, the neanderthals, the dodo, and the trilobite. Perhaps the human experience is best conveyed in the opening lines of one of my favorite books, Unweaving the Rainbow:
The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively outnumbers the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here. We privileged few, who won the lottery of birth against all odds, how dare we whine at our inevitable return to that prior state from which the vast majority have never stirred?
-Richard Dawkings, Unweaving the Rainbow
The chance to be selected for this reality over the infinite others, so many of them more qualified than we, THAT is the human experience. Just think it over. Out of all the noise, you were born. Your mother fell in love with your father. Your grandmothers fell in love with your grandfathers. Your great grandmothers fell in love with your great grandfathers. Just think about it—only 3 generations back and we’re already talking about 14 people, 14 places where the wrong number may have come up. But out of the noise, out of the infinite possibility, came you and I. In a very real way, we are the chosen. That’s the meaning of my life anyways. So feel secure in the luck we’ve had in the universal lottery, and remember to wonder infinitely about the infinite wonder that is life.