According to some, the functioning of the Universe in which we exist can be explained through a limited number of laws. So far, scientists have discovered quite a lot of these laws, which is why mankind now has a firmer grip on its future. Unfortunately, when talking about quantum mechanics, a lot of those rules are not applicable and a new kind of physics is required, one that comes with a plethora of new paradigms. Among the things which have eluded physicists for decades is reconciling general relativity with quantum mechanics.
One of the most famous mysteries in this field of science is the double slit experiment. If you’re unaware of it, you have two choices (pun intended): you either stop reading now, or you see this explanatory video^, because the rest of the article will often refer to this phenomenon. The video is 10 minutes long and it is very well explained, but it’s not the kind of stuff that goes well with interruptions.
Influencing the outcome of an experiment just by observing it leads to interesting implications regarding the nature of reality, free will and consciousness, although this is a gray area where debate is difficult because it inevitably turns into pseudo-science. However, bouncing ideas freely can sometimes bring sparks of enlightenment, so let’s take that risk.
I will argue that there is a connection between free will and behaviors observed in quantum mechanics, and I will offer my explanation of why the double slit experiment yields such results. I will start with a hypothesis which is well known in physics: the multiverse^ (also known as parallel universes). This is closely related with one of the possible interpretations of the experiment: the “many worlds interpretation^”, a hypothesis which can reconcile an uncertain, probabilistic universe with a predictable, deterministic one.
Analogies often help in understanding complex systems so let’s imagine the multiverse as an ocean. Every atom in this ocean is one universe, with its own set of rules and distribution of matter. This is a fitting analogy because there are a massive number of atoms in an ocean, making infinity almost imaginable. Whether or not the number of universes in the multiverse is infinite is a separate discussion.
Each universe in this multiverse is predictable down to the very last particle using scientific laws and an initial organization of matter (determined at a moment such as the Big Bang). In such a universe, there can be no concept of “free will” and every single one of our actions can be predicted with ease because it is a result of an electrochemical interaction in our brain. In each of these universes, the double slit experiment exhibits particle behavior – the quantum probability wave is collapsed.
Now imagine that in this ocean that is the multiverse, our consciousness is a shining light which travels through the water, from one atom to the next. The light illuminates a finite number of atoms in the ocean around it (a finite number of universes). These universes are not only very close together, but they are also very alike – they share scientific laws and the constants most of these laws are based on. There is a universe for every single one of our choices, as per the “many worlds interpretation”. The further a universe is from the present location of our consciousness, the more unlikely it is for us to experience it (unless our actions take us there).
My theory is that free will is the attribute of consciousness that chooses in which universe we shall experience the period of time until another decision takes us to the next universe. Free will is how the shining light that is our consciousness moves through the vastness of an ocean of possibilities. With every single one of our actions, we are moving from one universe to the next. So even though each universe is completely predictable, we still have free will because this is a function which resides in the multiverse, a system which is challenging to understand, especially due to computational irreducibility^.
The reason why the double slit experiment behaves the way it does is because when the detector is turned on, we see the deterministic (non-probabilistic) aspect of the multiverse, which is the single universe. The question is why? One answer might be that this is the only way the two separate behaviors can coexist without breaking any fundamental laws; this separation occurs because free will is inherently probabilistic while one single universe (which is what is observed when the detector in the experiment is turned on) is deterministic (completely predictable).
When scientists attempt to closely monitor the behavior of atoms in the experiment, they zoom-in to the particle level, therefore they get the non-probabilistic result simply because that’s what actually happens upon close analysis.
Turning to analogy again, we can compare the two scenarios by imagining watching a movie 3 meters from the screen (a fast succession of frames loaded with pixels) and watching a still frame 1 centimeter from the screen (we can easily analyze every single pixel in this frozen frame). Both of these cases are using the same movie’s content, but the way of perceiving that content is very different.
Physicists trying to come up with a “theory of everything” face an extremely difficult undertaking because current laws are only applicable to our cosmic neighborhood since they rely on all sorts of constants which have no place in the multiverse. Constants are in fact variables with values which are localized to this universe, and they might not even be as constant as we think; minute fluctuations probably occur even across our tiny universe (tiny when compared to the ocean in which it lies).
More explanations for behaviors observed during the famous experiment can be found if we imagine the multiverse as a sort of highly advanced quantum computer. In this case, the phenomenon might simply be the effect of optimized computation. But more on that in the next article^.
Free Will Is Probabilistically Limited
The term “free will” does not mean “unlimited range of decision”; just like the quantum probability wave, our choices are limited. The very first decision any consciousness takes will be contained in a probability cloud determined by the physical properties of the body which hosts that consciousness (genetic heritage) and the electrochemical state of the brain (which starts as organic matter shaped by genetic factors and then influenced by environmental factors during fetal development).
Once free will starts to express itself, it also shapes the physical state of the brain (through the imprinted memories that are gained after each decision) while in the same time moving to the universe which hosts the appropriate state. The body can be seen as a hardware resource while awareness is the volatile software which “inhabits” it.
The more we experience and the more we learn, the brighter our dot of light shines within the ocean that is the multiverse, therefore making available a wider selection of universes through which our consciousness can travel – a logical conclusion to having expanded our knowledge.
There is an obvious connection between our free will limitations and the behavior of the double-slit experiment. We perceive the particles in the experiment as waves because that is exactly how consciousness works: what it needs from perception is a cloud of probabilities from which we, through free will, can pick the next moment-universe.
But making our way through existence based on navigating probability clouds doesn’t sound very much like daily life does it? That’s because the choice process is abstracted somewhere along the way, by our consciousness and/or by the brain itself. We are also probably making choices more often than we realize: most of these decisions might occur in the subconscious, which has long been suspected to operate the hidden levers in our brain.
The double-slit experiment proves that upon close investigation, the current universe is perfectly predictable, down to the last quantum of energy. However, when not investigated at all, the universe explodes into a finite number of possible universes, a fraction of the multiverse. That finite number of possible universes represents all the possible positions of a particle at a given moment, given the particle’s properties. The behavior is replicated at a larger scale of matter organization by our free will, which acts upon a probability cloud made up of all the possible choices a brain can make given its electrochemical state.
Learning & Choice Prediction
The ocean-of-universes analogy also presents us with a beautiful way to describe how free will is governed by certain factors, for example learning. Let’s imagine how learning influences the shining light that is our awareness, traveling through the multiverse.
Learning is directional; if we become better in a certain discipline, the light will extend more in a certain direction; we have more choice in that direction and this increases the chances that we will continue on that path. Cross-disciplinary learning causes our light to shine towards more directions, therefore revealing even more alternative universes that bring new opportunities for us to choose. Humans are versed in dozens of disciplines, most of them learned passively, so the light of our consciousness is an irregular halo.
The ocean analogy is also suited to explain the mechanism of choice. Light cannot travel infinitely through water. The universes immediately close to us are our most likely choices, but as our knowledge expands, we can glimpse alternatives which were unimaginable in the past. At the edge of our “sight”, there will always be murky areas where our light barely shines – these are choices which we are unlikely to make given our experience, but never out of reach.
For example, I’m aware I could smash my keyboard right now, but I will not do it. Smashing my keyboard is in my cloud of probabilities but not a universe I shall go into (my keyboard probably agrees). Of course, there are choices which are completely beyond my imagination and knowledge, which is where the free will limitation lies.
Work In Progress
In a nutshell, free will is the function of the multiverse which chooses the universes which our consciousness experiences. Every single one of our decisions (and its consequences) leaves its mark in the repository of experiences located in our brain, which becomes the starting function of the next probability cloud of choices. Therefore, it’s understandable that making certain choices might completely prevent us from making other choices in the future, since every choice we make modifies the probability cloud.
The brain can be likened to a navigational device, because every day we become conscious, our awareness taps into this reservoir of past information, basing its decisions on it, and lots of these decisions rely on previous events (beings whom we interact with, our place in society, etc.).
Earlier, I mentioned that in a deterministic universe, every action of ours can be predicted. This is because in such a universe, the brain is, after all, a highly advanced but still understandable system: external stimuli are converted into electrical signals which end up physically modifying the nervous system. Therefore if technology would exist to copy an exact snapshot of the brain, we could infer its answer to any external stimulus.
The double slit experiment shows, however, that we do not live in a deterministic universe, but in a probability cloud made up of more universes; even more, every single particle in our brain exhibits that behavior, therefore our brain is anything but understandable: every single neuron is an intricate maze of quantum effects.
What is free will? What is consciousness? Who, or what is tracing this path through the multiverse and who are all the other beings we run into? When we’re having a conversation with somebody, if we switch universe every time we make a decision, then how many versions of that individual will we meet? Many of these questions run into the wall of computational irreducibility: it is difficult to explain something that is external to this universe while we’re part of it.
What we can do, however, is to emit theories which are based on what we know so far. Amusingly perhaps, these theories will eventually form yet another cloud of probability: one made up of our guesses at what lies beyond and underneath.
Rather than classifying this article as pseudo-science, I’d rather file it under hard science fiction^. You can view it as a story of what might be the reason why things behave the way they do, just as you could make up a story that the world is round because that’s how gods like their meatballs. But science-fiction was, after all, the source of many advances in our society.
There is one thing that I have no doubt about: all this is a work in progress. Life is a journey of exploration and enrichment, and I have no doubt that throughout the years, humanity will concoct the most fascinating of theories. I, for one, am enjoying the ride, trying to put in that which I am capable of.
On the question of whether or not the number of universes in the multiverse is infinite or not, you can read this article’s follow-up^, which also offers an explanation regarding the chasm between quantum mechanics and general relativity.