The Best Argument Against the Quantum Multiverse

Recommended Pre-Reading:
The Quantum Multiverse

Some time ago, I argued in favor of the Many-Worlds interpretation of quantum physics, explaining how I had misunderstood it before, and why I changed my mind. I recommend reading that post for the full story, but the short version is, the Many-Worlds interpretation (or more accurately, the Universal Wave Function interpretation) is the straightforward interpretation of quantum physics, explaining the weird paradoxes without adding any extra assumptions to the theory. All other interpretations require adding something; either a collapse condition, where a measurement causes the wave function to immediately change shape all at once, ignoring the speed of light, or some kind of hidden variables we can’t measure. The Many-Worlds interpretation says the wave function described by the Schrodinger equation is correct, and that is all. Everything else, the multiple universes and such, are deduced from that single statement.

However, there is one thing that bugs me, one loose end Many-Worlds doesn’t explain. That is why today, I am going to continue the Best Arguments Against series, and put forth my best argument against the quantum multiverse.

Most people who argue against Many-Worlds don’t understand it. Some dismiss it out of hand as too weird. Others get Occam’s Razor backward and think Many-Worlds has branching universes as a postulate, rather than a deduction. These are not good arguments.

The best argument has to do with probabilities. If we look only at the math, it makes sense that the wave function can split into two worlds, one with an amplitude three times stronger than the other. Think of a pile of sand. Someone splits it into two, one of which is three times bigger than the other. Where there was one pile, there are now two of differing heights. That’s an apt analogy for the splitting of universes, and it’s quite easy to visualize. Nothing confusing or difficult to believe there.

However, when we do an experiment, the outcome with the higher amplitude has a 90% chance of happening, and the outcome with the lower amplitude has a 10% chance of happening. If the universe splits into two equally real branches, as Many-Worlds claims, where does this probability come from? Many-Worlds says there will be two universes, each of which will have an equally real version of us. Thus, before the experiment, it would be natural to think there would be a 50% chance of finding ourselves in each universe after the measurement. But it’s not; it’s 90-10. This is a contradiction, and a currently unresolved paradox in the Many-Worlds theory.

This is important, because we rely on quantum probabilities all the time. The nuclear fusion that powers the sun and gives the Earth energy uses quantum probability. The half-lives of unstable elements, used in various technologies and geological dating methods, rely on quantum probability. And most conspicuous of all, quantum computers work by minimizing the quantum probabilities of the wrong answers and maximizing the quantum probability of the right answer. If there were simply one universe for each possible outcome, our intuition says none of these should work!

There is one way to resolve this conceptually. Suppose instead of two worlds, there are a large number of them, and 90% of them go in the direction of higher amplitude, and 10% of them go in the direction of lower amplitude. Those 90% are completely identical to each other, as are the 10%. This would square off the probabilities. Instead of there being two of you, one in the low amplitude world and one in the high amplitude world, there would be many of you, split between the worlds 90-10.

However, this takes away the straightforward purity of Many-Worlds. The math does not say there will be lots of identical universes, it says there will only be one for each possibility. Resolving this conflict by proposing large numbers of identical universes adds extra fluff to the theory, taking away its advantage over the other interpretations!

This could mean Many-Worlds is the wrong interpretation of quantum physics. Or it could be that we just don’t understand quantum probability yet, and we will find a satisfactory resolution to the paradox. Many-Worlds is still the tidiest interpretation so far, since it explains all the other phenomena of quantum physics, like entanglement and the measurement problem, so neatly. For now, I still rank it as the most plausible, leaving the door open for something else to come in and explain it all.

I don’t like the quantum multiverse. I want there to be only one course of history. It feels cheap if everything that is physically possible happens in one timeline or another. But, as mentioned at the beginning of the post, the fact that it is weird is not valid evidence. I hope Many-Worlds is wrong, but as a truth seeker, I cannot let that hope influence what I believe. The truth is the truth, whatever it turns out to be. Maybe there are a near-infinite number of universes splitting off from one another every moment, or maybe there is just this one. All we can do is follow the logic and evidence where it leads us.

What is God?

I grew up in a Christian home in rural United States, believing, as most people in that culture do, in the existence of God the person. This person called God had his own subjective conscious viewpoint. He had the ability to cause anything to happen merely by willing it to be so, including both temporary suspension of the laws of physics, and the creation of the entire Universe. This God was thought to be real and literal. In other words, I believed in a physical God, also known as a “personal God” or “literal God.”

Back then, if you had asked me if I thought God was physical, I would have said no, God is spiritual. If you had asked me what I meant by that, I would have said physical reality is made of one type of substance, and spiritual reality is made of another type of substance. However, that is a false dichotomy. After all, the part of physical reality my present and past selves agree about is made of multiple types of substances. There are particles, fields, and space-time, and maybe a few things we do not know about yet. However, the reason we group them under the umbrella term, “physical” is because the way in which they exist is the same. The God I believed in was not made of space-time, particles, or fields, but he was thought to exist in the same way. That is why I call this kind of God a physical God.

I viewed God as the answer to questions like, “why does the Universe exist?” and, “why do we exist?” The Earth was the way it was because God made it that way, with human beings in mind. Everything that happened, everything I did, was measured against what God wanted, and how it fit into his grand plan. However, after about 20 years of living like this, I started seeing things that did not add up with this view. I learned how ideas of God and gods appeared in cultures and developed over time, and I saw how my God was the same as any other in this regard. I saw sick people get prayed over. Some of them were healed, and some were not. I had ideas pop into my head about the future. Some of them came true, and some did not. Eventually I came to realize that things can happen by chance, that if there are a million opportunities for things with a one-in-a-million probability to happen in a day, we should expect to see one-in-a-million things happen every day.

As we learn and grow, our mental pictures expand, filling in more of the jigsaw puzzle of knowledge. Sometimes we replace ideas with new ones, which may or may not be more correct, but other times we come to see a larger view of the picture, one which encompasses the views we had before. We come to see those views more clearly, why we held them, and how they fit or don’t fit with the rest of reality.

One fateful day, I was hit with the realization that the Universe and everything in it behaves as it would without a physical God. I looked up evidence for the existence of God, which came in two forms. The first was from science, but these were all either conspiracy theories, or of the form, “this seems like too much of a coincidence, therefore God is responsible.” For instance, I have heard the argument that since the conditions in the Universe make life extremely unlikely, God must have created the Earth for us. These arguments don't stand up to probability, nor do they meet their burden of proof. The second form of evidence for God was in philosophical arguments, like the Ontological Argument, the Teleological Argument, the Cosmological Argument, and the Argument from Morality. However, all of these either have extraordinary claims in their premises without justification, such as “it is possible for a Maximally Great Being to exist,” or their conclusions do not follow from the premises. Ultimately, I had to admit that I could find no evidence that the physical God I had believed in for my entire life actually existed.

For a while, I felt bitter toward the culture I had been raised in and the people who had taught me what I perceived to be nothing but lies. I faced existential and epistemological crises. This period did not last long, but it was rough. It is no wonder people get defensive and afraid whenever someone says something that even hints at a conflict with their worldview.

This was a turning point in my life. From then on, I started studying all different fields of science and philosophy. I wanted to understand the world and humanity as broadly and in depth as possible. In my quest, I have come across many public intellectuals with deep and important things to say. Among them was the psychology professor Jordan Peterson, who introduced me to the concept of Jungian archetypes, the models of behavior built into the human unconscious that manifest in fictional characters.

With perfect timing, in one of those one-in-a-million events that I mentioned earlier, Jordan Peterson started a series of public lectures, which he posted to YouTube, about the significance of the Biblical stories from the perspective of evolutionary psychology. Instead of taking them as literal historical events, like I had for my entire life, he treated them as a window into the depths of the human mind, as stories passed down for hundreds of generations, undergoing a kind of natural selection so that only the most meaningful and resonant parts remained, the rest lost to memory. Freed from the blinders of literalism, the Biblical stories exploded with meaning like I never imagined.

My thoughts turned back to consider once again the idea of God. Of course, a physical God was out of the question; the more I learned of science and philosophy, the more solidly that coffin was nailed shut. However, things I had heard believers say before, but had made no sense to me, started to come back. The idea that morality could not exist without a god. The idea that everyone worships something, whether they profess to or not. And for the first time in my life, it all started to make sense. God is not a person, not in the physical sense. God is an archetype.

Archetypes are the embodiments of human behavior patters. We see ourselves in fictional and mythological characters, and in forces of nature. This is where the gods of Ancient Greece and other pantheons come from. Capital-G God is the archetypal embodiment of all of the best qualities of human nature. This is why religious people take “God is good” as a truism, and why they say that without God, morality does not exist.

Atheists sometimes point to the things God does in the Bible which are obviously evil, and say, “God is not good.” But those instances are a product of the limitations of human knowledge at the time they were written. Archetypes are not made-up, they are discovered and studied. Since Biblical times, humanity has gone through revolutions of moral philosophy, so our understanding of the best of human nature, God, has matured. It is only natural that parts of the ancient views of God will appear barbaric to us. They were trying to understand, and, not having the philosophical knowledge of millennia to draw upon, got some of it wrong.

So why do most people insist on believing, and requiring others to believe, in a physical God rather than an archetypal God? Or from another perspective, what could drive me to speak such heresy? The answer lies in our psychology. We have a natural instinct to search for the meaning in facts, and to take that which is meaningful as factual. Only in the past few hundred years, since the dawn of science, have we begun to learn the difference.

Some would call me an atheist, because I believe there is no physical God. Others would call me a Christian, because I actively try to learn about and model my life around the best and fullest aspects of human nature, which God represents, and because I find value in the philosophy and culture that has come from the Christian tradition. I don’t care about the labels myself. It’s the honest search for truth that matters; after all, that’s in accordance with the nature of God.

Rationality: The Linchpin of Knowledge

What is Knowledge?

Toolbelt of Knowledge: Practices
Skepticism
Listening
Deconstruction
Rationality
Mindfulness
Steel Manning
Common Sense

Most people think they are more rational than average. Think about that for a minute.

All right, what have you concluded? Perhaps that most people are full of themselves. After all, “average” means by definition that half of all people are above it and half of all people are below it. So it is impossible for most people to be above average.

However, this does not automatically lead to the conclusion that most people are full of themselves. There are two leaps in logic that require more information. The first is that we need to know whether these people think being rational is a good thing. If they don’t, then incorrectly believing themselves to be more rational than average is self-debasing rather than self-exalting. I think it is safe to assume almost everyone believes being more rational is a good thing, so that hole is patched up. The second is about numbers. If being wrong about being more rational than average is what makes someone full of themselves, then only up to half of people can be full of themselves in this way. It might be true that most people are full of themselves; I don’t know. But, it is impossible to conclude it from this premise alone.

What we have just done is an exercise in rationality. We all know what rationality is. It’s figuring things out in a smart way. It’s the process of examining ideas and seeing if and how they fit together. It’s like taking apart a radio or a toaster to see how it works, except with ideas instead of technology. Rationality is our distinguishing feature among life on Earth, the one thing we do better than all other animals, and the rest of the Toolbelt of Knowledge is useless without it.

Rationality is a skill. It must be learned, trained, and kept in shape. We can do this by solving puzzles and mental challenges, contemplating philosophical ideas, listening to public intellectuals like Sam Harris and Bret Weinstein, and playing logic-based video games like Phoenix Wright: Ace Attorney.

Like all tools, there are good and bad ways to use rationality. One of the best is to update your mental picture of reality so that it fits better with true reality, at least in the ways that are important to you. For instance, a lot of people’s lifestyle decisions depend on what they believe about their ability to affect the environment. If you don’t believe humankind is responsible for the current trend of global warming, you might buy the cheapest electricity, drive a lot when there are alternative methods of transportation, vote for politicians promising to support coal and oil industries, etc. However, if you spend the time to learn about how the global climate works, properly exercising your skill of rationality, your choices might be different.

The most common abuse of rationality is rationalization, which is when we observe ourselves doing or believing something, and retroactively construct an argument for why it was logical.  It might have made sense if this logical reason was our motivation, but most of the time we get it wrong. We humans are more motivated by instinct than logic, and we fear that admitting this will make us seem irrational and lose us reputation points. However, quite the opposite is true. We all know people who are full of themselves, believing they are the most rational person in the world, but who have obvious blind spots on display for all to see. They cannot understand why nobody sees their genius. After all, they can give logical reasons for everything they do. To avoid the trap they have fallen into, we can take two steps. The first is admitting we are driven by instinct. The second is to listen regularly to people with all kinds of views, and recognize that one can be rational and still come to different conclusions from other rational people.

Another downside of rationality is using it so much that you miss out on the things life has to offer. Rationality has a purpose, and that is to figure things out. If you’re having a conversation with friends, or enjoying a good joke or other bit of entertainment, rationality can get in the way. Remember, the most important thing in life is not to find out what is true all the time, but to do things that are meaningful, and sometimes that means putting rationality on hold.

When you properly apply rationality to your fundamental beliefs about yourself and reality, you never know where it will take you. It might challenge beliefs you hold deeply, and you may have to ask yourself whether you are going to follow the logic, or drop it and stick with your beliefs. Neither choice is wrong on principle; there is a proper time for both. When you are ready to follow where reason leads, you will find yourself in some places that are amazing, some that are devastating, and some that seem too weird to be true. However, as someone who has turned his worldview upside-down several times, I can attest that following rationality into the dark and zany places is worth it one hundred percent.