# The Many-worlds Interpretation is Hard to Swallow

Me: Hello! I want to talk about the many-worlds interpretation today. I am having a tough time understanding why it could possibly be true.

AI: The many-worlds interpretation is a controversial interpretation of quantum mechanics that suggests the universe splits into multiple parallel universes, each corresponding to a different outcome of a quantum measurement. While it is a valid interpretation, it is still a matter of debate among physicists and philosophers. Many people find it difficult to accept because it violates our everyday intuition and common sense, but it is important to remember that quantum mechanics often defies our classical understanding of reality. Ultimately, whether or not one accepts the many-worlds interpretation is a matter of personal interpretation and perspective.

Me: What is the best argument against many-worlds? I understand it's not falsifiable, and I understand it's not intuitive. But what are the best arguments against it other than that? Is this where Copenhagen comes in?

AI: One argument against the many-worlds interpretation is that it is not able to provide a satisfactory explanation for the probabilistic nature of quantum mechanics. While the many-worlds interpretation can explain the collapse of the wave function as a result of branching into parallel universes, it doesn't explain why the probabilities of certain outcomes occur in the first place. In contrast, the Copenhagen interpretation, which is the most widely accepted interpretation of quantum mechanics, explains this through the concept of wave function collapse and the role of measurement in determining the outcome of a quantum experiment. Another argument against the many-worlds interpretation is that it can be seen as adding unnecessary complexity to our understanding of the world, as it posits the existence of an infinite number of parallel universes. Some physicists and philosophers argue that it is more elegant to have a simpler, more parsimonious theory that can still account for the observed phenomena. However, it is worth noting that the concept of Occam's Razor (which favors simpler theories) is not always applicable in physics, where the most accurate theory is not necessarily the simplest one.

Me: Explain the collapse of the wave function in a way that a non-scientist can understand

AI: The wave function is a mathematical description of a particle in quantum mechanics that gives the probabilities of finding the particle in different states. When a particle is observed, the wave function collapses, meaning that the particle takes on a definite state that can be observed.

One way to understand this is to think of the wave function as a cloud that represents all the possible locations the particle could be in. Before observation, the particle is in a superposition of states, meaning that it exists in all of these possible locations at once. But when we make a measurement, we are essentially "looking" at the particle, which forces it to take on a definite position. This is like shining a flashlight on the cloud, causing it to condense and take on a particular shape.

The collapse of the wave function is a fundamental concept in quantum mechanics that can be difficult to understand, but it is important for explaining the probabilistic nature of quantum mechanics and how measurement affects the behavior of particles.

Me: And this is where schrodinger's cat comes in, eh?

If taking a measurement causes a particle to snap into one reality or another, how do we know there's no measurement before then? Isn't that a measurement in its own right?

AI: Yes, the famous thought experiment of Schrödinger's cat is often used to illustrate the concept of wave function collapse.

In the experiment, a cat is placed in a sealed box with a vial of poison that will be released if a radioactive particle decays. According to quantum mechanics, the particle is in a superposition of states, both decayed and not decayed, until it is observed. Therefore, until the box is opened and the particle is observed, the cat is in a superposition of states, both alive and dead.

The paradox highlights the question of when exactly the wave function collapses and whether an observer is required for this collapse to occur. The many-worlds interpretation would suggest that the wave function collapse occurs when the particle interacts with its environment, even if no conscious observer is present. However, the Copenhagen interpretation holds that a conscious observer is required to cause the collapse of the wave function.

To address your question, even though the exact moment when the wave function collapses is not well understood, it is generally believed that any interaction with the environment can cause the collapse, not just conscious measurement. In the case of Schrödinger's cat, the interaction of the particle with the environment (which includes the cat) would cause the wave function to collapse, even if there is no conscious observer present to witness it.

Me: Superposition is strange

AI: Yes, superposition is one of the most fascinating and counterintuitive aspects of quantum mechanics. In classical physics, objects have definite properties that we can measure, such as position and momentum. However, in quantum mechanics, particles can exist in a superposition of states, meaning that they can simultaneously possess multiple properties at once.

For example, a particle can exist in a superposition of two positions, two energy states, or two spin directions, among other properties. This means that until a measurement is made, the particle does not have a definite position, energy state, or spin direction, but rather exists in a probabilistic cloud of all possible states at once.

While superposition is strange and difficult to understand from a classical perspective, it is a fundamental aspect of quantum mechanics that has been extensively confirmed by experiments. It is also what makes quantum computers potentially more powerful than classical computers, since they can harness the power of superposition to perform multiple calculations at once.

Me: So it sounds like you're saying:

- We have confirmed superposition over and over
- Generally people believe that wave function collapse happens with any environmental contact, not just with a conscious observer
- But if that's true, that's where Copenhagen loses credibility, and where many-worlds asserts itself

So if #1 and #2 are true, that makes many-worlds more likely. Which means there's a version of me somewhere where I am legally married to a toad. Is that true?

AI: Yes, it is generally accepted that superposition exists and that any interaction with the environment can cause the collapse of the wave function, not just conscious measurement.

The Copenhagen interpretation suggests that wave function collapse occurs when a conscious observer makes a measurement, while the many-worlds interpretation suggests that collapse occurs when the particle interacts with its environment, even if there is no conscious observer present.

If the many-worlds interpretation is true, it would imply that all possible outcomes of a quantum experiment actually occur in separate parallel universes, including the outcome where you are legally married to a toad. However, it is important to note that the many-worlds interpretation is still a matter of debate among physicists and philosophers, and is by no means a proven fact. The concept of parallel universes is certainly fascinating, but it is still very much a speculative idea that is difficult to test experimentally.

Me: Thanks dawg

AI: You're welcome! If you have any more questions, feel free to ask!