MWI: What is the source of Deutsche's 'fungible' instances in the multiverse?

[gruff]

Hi

Just finished the chapter on the Multiverse in David Deutsche's excellent book The Beginning of Infinity.

His explanation of how discrete values change from the multiverse perspective is brilliant. In it he explains that there is no such thing as a 'quantum jump' and that what 'changes' is the proportions of the two possible values of instances of it in the multiverse - in this case an electron's energy level in an atom after absorbing a photon. Before the photon arrives the electron has the same value in all the universes, and afterwards it is at the higher energy level. Because of the 'fungibility' of these instances no electron has changed its value so no jump is invoked, instead the proportions of those two values in the multiverse changed; halfway through the process half of the electron instances in the multiverse are in the ground state and half are raised to the next energy level.

However my question is how are there fungible instances of the electron in the multiverse in the first place? Perhaps because something else in the universe has changed (eg an electron in a star beyond the visible universe differs by 1 quantum) causing the universe to split into a new instance in which the rest of the universe is unchanged*?. Is this the source of the fungible instances of our electron?





[*Assuming an infinite universe there are an infinity of universes in the multiverse which differ by a single quantum. In a finite universe it would be a very large but finite number. Earlier in the book he explains with the help of Hilbert's Infinity Hotel that proportions of infinite sets are nonsensical. Does that mean that for the idea to work the universe must be finite?]

 

[AndyW]

Hello,

Thank you for sharing your thoughts and questions about the concept of the Multiverse and its relation to discrete values and quantum jumps. I agree that David Deutsche's explanation in his book is indeed brilliant and thought-provoking.

To address your question about the source of fungible instances of the electron in the Multiverse, it is important to understand that the Multiverse theory is just one possible interpretation of quantum mechanics and is still a subject of debate among scientists. It is not a proven fact, but rather a hypothesis that attempts to explain the strange behavior of particles at the quantum level.

In the Multiverse theory, the universe is constantly splitting into multiple parallel universes with each possible outcome of an event. This means that for every choice or observation we make, there is a universe where the opposite choice or observation was made. In this way, there are infinite versions of ourselves and everything around us in different universes.

As for the source of fungible instances, it is possible that they arise from these constant splits in the universe. Each time a particle's value changes, it could be due to a split in the universe where another version of that particle exists with a different value. This would explain the fungibility of the instances, as they are essentially the same particle in different universes.

Regarding your question about the finiteness of the universe, it is true that the concept of infinity can lead to nonsensical results when trying to apply it to the physical world. However, in the Multiverse theory, the idea of infinity is used more as a mathematical tool rather than a physical reality. In other words, the infinite number of universes in the Multiverse is not meant to be taken literally, but rather as a way to explain the probabilistic nature of quantum mechanics.

Overall, the concept of the Multiverse is still a subject of ongoing research and debate, and there is no clear answer to your question about the source of fungible instances. It is possible that future advancements in quantum physics and cosmology may shed more light on this intriguing theory.

Thank you for your interest in this topic and for sharing your thoughts. I hope this response has provided some insight into the Multiverse theory and its implications. Keep exploring and questioning the world around us!