Let's examine this exciting theory, which is not the same as the parallel universe theory, which is widely used in popular culture, and which claims that new universes are formed during observations.

The multiverse model is a quantum universe interpretation expanded by Sean Carroll, proposed for the first time by physicist Hugh Everett as an alternative to the well-known Copenhagen interpretation of quantum physics, and not yet experimentally testable in nature. Of course, like any theoretical model, it cannot go beyond scientific speculation.

this model defines the universe as a changing set of numbers, known as the wave function, that develops according to a single equation. According to the multiverse model, the universe is constantly branching into new branches to produce multiple versions of ourselves. To date, physicist Sean Carroll thinks that multiple universes are the simplest possible explanation for quantum mechanics.

According to the explanation of this model, which Carroll sees as an interpretation of reality, he describes reality as a vector in the space of hilbert. that is, the technical way of saying that reality is defined by a single quantum mechanical wave function. We see tables, chairs and people and planets that move through space-time. He says that things like quantum mechanics, tables and chairs don't exist. there is only what we call wave function. that is, our classic definition of the world is a higher level of approximate way of talking about the wave function. why do people and planets seem to have tables and chairs? there is no consensus among physicists on this subject.

quantum mechanics says that an electron can overlap all possible positions. there is no such thing as the position of the electron. but when you observe the electron, you see it in one place. this is the main mystery of quantum mechanics. is different from seeing the description when no one is looking.

The multiverse model also says: why don't we just look at the observer as our own quantum mechanical system?

we were also made of quantum mechanical particles. So what happens when you search for the electron that is the observer? the electron starts by overlapping many possible places. When you look at it, you become a combined system of you and the electron in superposition. Hugh Everett's brilliant idea was to say that different parts of superposition really exist. they're just in separate, non-interacting worlds.

we know that our observable universe looks the same as billions of light years away from here. There is a disruption to how far we can look, so it can be infinitely large. if the universe is infinitely large and looks the same everywhere, it guarantees endless copies of something exactly like us. so where are these worlds?

there is no question of where they are. some things have no location. where is our universe? the universe is not something that has a place. Where is fraternity, where is the number five. worlds exist only at the same time as ours.

the quantum system is not just composed of observer and quantum particles

the environment is also part of this system. therefore, the situation of the cat in your room and the situation of the cat in your room in another universe are not independent from each other. each of them consists of a large and singular situation. this overlaps with the feeling that the universe itself is singular. because everything that interacts physically with each other is connected by entanglement at the quantum level. Since the environment is also a part of the system; the observer also becomes entangled with the environment.

that is, the objects we call "closer" to each other are the "more entangled" objects. By doing this, it is possible to see that gravity, or even the universe itself, can be created from this "entanglement space". The distance between objects is actually a quantum entanglement between different parts of the wave function.

Using this interpretation it is possible to combine the theory of relativity and quantum theory.

When you poke different parts of a quantum mechanical infrastructure that you set up this way, you can get extremely interesting products. To do this, physicists change the quantum entanglement by adding energy on this quantum basis, thereby changing the geometry resulting from this wave function. This is how it is possible to produce gravity entirely from quantum mechanics.

This unique perspective developed by Carroll opposes the idea that gravity is a force / structure that already exists and precedes the quantum structure. this means that somewhere einstein's general theory of relativity cannot be used to explain the texture and structure of the universe.

the Copenhagen interpretation claims that one of the universes "disappeared" as a result of observation; This is the so-called "function crash". The multiverse interpretation claims that new universes were formed during observations. this is called decoherence.

So where does the possibility stand in the interpretation of the multi-worlds?

I take the translated interpretation of sean carroll in the evolution tree below:

"The answer to this question comes from the idea of self-locating or indexical uncertainty. To understand this, imagine a situation like this: you are about to measure a quantum system and therefore the wave function is branching out so that different worlds are formed (two for convenience. It would be pointless to ask the question, "Which world will I be on after the measurement?"

here if both people knew the wave function of the universe, there is still something they wouldn't know. it is in which branch (world) of the wave function they are. Inevitably, a certain period will pass after the branching begins. however, observers will not know where they stand in the wave function before they learn what results are obtained in their branches. This is self-locating uncertainty and was first used by the physicist lev vaidman in the quantum context.

Now, you may think that you can take a quick look at the experimental result without any noticeable time of uncertainty. however, in the real world, the wave function quickly branches out in 10-21 seconds or less. this is a much shorter period of time than an electrical signal reaches your brain. therefore, there will always be a certain period of time in which you will not know which branch you are in when you are in a particular branch of the wave function.

self-positioning uncertainty is a type of epistemic uncertainty different from uncertainty that appears in pilot-wave models. You may know what to know about the universe, but there will still be something you doubt about (the subject where you are in it). Although your uncertainty follows ordinary probability rules, it will take a lot of effort to convince yourself that there is a logical way to assign numbers to your belief [to a certain probability that you hold strongly].

Before you begin branching, you can oppose the idea of self-positioning uncertainty, saying that you can make predictions right now. there is, after all, nothing uncertain; you can know exactly how the universe will evolve. however, this information contains an assumption that all future versions of yourself will be uncertain, and these versions must follow the born rule to develop beliefs about the various branches they may be on. In this case, given the frequency of the various consequences conferred by the born rule, it makes sense to act as if you were living in a real stochastic (variable, random) universe. (david deutsch and david wallace put this argument on solid grounds, using the decision theory]. "

final note: the parallel universe theory and the parallel universe theory are not exactly the same thing. multiverse theory is an interpretation of the working principles of quantum physics; It is an alternative to the Copenhagen interpretation. parallel universe theory is the idea that there can be more than one universe cosmologically. parallel universe theory is the result of a multiverse interpretation; sometimes it can even be used synonymously. but when you think of parallel universes, if you dream of physically separate and interactable universes, then you are not exactly considering the interpretation of multiple universes; because there is an event called "dissonance" between the separate universes in the interpretation of the multi-universe, and accordingly, the universes cannot interact with each other after separation. There is another multiverse model, in which there may be another universe within a universe. this is a very different concept. Finally, there is an interpretation of universes that are formed with quantum foam (which may be statistically likely and may occur as quantum tunneling), which is also not related to wave function.

The multiverse model is a quantum universe interpretation expanded by Sean Carroll, proposed for the first time by physicist Hugh Everett as an alternative to the well-known Copenhagen interpretation of quantum physics, and not yet experimentally testable in nature. Of course, like any theoretical model, it cannot go beyond scientific speculation.

this model defines the universe as a changing set of numbers, known as the wave function, that develops according to a single equation. According to the multiverse model, the universe is constantly branching into new branches to produce multiple versions of ourselves. To date, physicist Sean Carroll thinks that multiple universes are the simplest possible explanation for quantum mechanics.

According to the explanation of this model, which Carroll sees as an interpretation of reality, he describes reality as a vector in the space of hilbert. that is, the technical way of saying that reality is defined by a single quantum mechanical wave function. We see tables, chairs and people and planets that move through space-time. He says that things like quantum mechanics, tables and chairs don't exist. there is only what we call wave function. that is, our classic definition of the world is a higher level of approximate way of talking about the wave function. why do people and planets seem to have tables and chairs? there is no consensus among physicists on this subject.

quantum mechanics says that an electron can overlap all possible positions. there is no such thing as the position of the electron. but when you observe the electron, you see it in one place. this is the main mystery of quantum mechanics. is different from seeing the description when no one is looking.

The multiverse model also says: why don't we just look at the observer as our own quantum mechanical system?

we were also made of quantum mechanical particles. So what happens when you search for the electron that is the observer? the electron starts by overlapping many possible places. When you look at it, you become a combined system of you and the electron in superposition. Hugh Everett's brilliant idea was to say that different parts of superposition really exist. they're just in separate, non-interacting worlds.

we know that our observable universe looks the same as billions of light years away from here. There is a disruption to how far we can look, so it can be infinitely large. if the universe is infinitely large and looks the same everywhere, it guarantees endless copies of something exactly like us. so where are these worlds?

there is no question of where they are. some things have no location. where is our universe? the universe is not something that has a place. Where is fraternity, where is the number five. worlds exist only at the same time as ours.

the quantum system is not just composed of observer and quantum particles

the environment is also part of this system. therefore, the situation of the cat in your room and the situation of the cat in your room in another universe are not independent from each other. each of them consists of a large and singular situation. this overlaps with the feeling that the universe itself is singular. because everything that interacts physically with each other is connected by entanglement at the quantum level. Since the environment is also a part of the system; the observer also becomes entangled with the environment.

that is, the objects we call "closer" to each other are the "more entangled" objects. By doing this, it is possible to see that gravity, or even the universe itself, can be created from this "entanglement space". The distance between objects is actually a quantum entanglement between different parts of the wave function.

Using this interpretation it is possible to combine the theory of relativity and quantum theory.

When you poke different parts of a quantum mechanical infrastructure that you set up this way, you can get extremely interesting products. To do this, physicists change the quantum entanglement by adding energy on this quantum basis, thereby changing the geometry resulting from this wave function. This is how it is possible to produce gravity entirely from quantum mechanics.

This unique perspective developed by Carroll opposes the idea that gravity is a force / structure that already exists and precedes the quantum structure. this means that somewhere einstein's general theory of relativity cannot be used to explain the texture and structure of the universe.

the Copenhagen interpretation claims that one of the universes "disappeared" as a result of observation; This is the so-called "function crash". The multiverse interpretation claims that new universes were formed during observations. this is called decoherence.

So where does the possibility stand in the interpretation of the multi-worlds?

I take the translated interpretation of sean carroll in the evolution tree below:

"The answer to this question comes from the idea of self-locating or indexical uncertainty. To understand this, imagine a situation like this: you are about to measure a quantum system and therefore the wave function is branching out so that different worlds are formed (two for convenience. It would be pointless to ask the question, "Which world will I be on after the measurement?"

here if both people knew the wave function of the universe, there is still something they wouldn't know. it is in which branch (world) of the wave function they are. Inevitably, a certain period will pass after the branching begins. however, observers will not know where they stand in the wave function before they learn what results are obtained in their branches. This is self-locating uncertainty and was first used by the physicist lev vaidman in the quantum context.

Now, you may think that you can take a quick look at the experimental result without any noticeable time of uncertainty. however, in the real world, the wave function quickly branches out in 10-21 seconds or less. this is a much shorter period of time than an electrical signal reaches your brain. therefore, there will always be a certain period of time in which you will not know which branch you are in when you are in a particular branch of the wave function.

self-positioning uncertainty is a type of epistemic uncertainty different from uncertainty that appears in pilot-wave models. You may know what to know about the universe, but there will still be something you doubt about (the subject where you are in it). Although your uncertainty follows ordinary probability rules, it will take a lot of effort to convince yourself that there is a logical way to assign numbers to your belief [to a certain probability that you hold strongly].

Before you begin branching, you can oppose the idea of self-positioning uncertainty, saying that you can make predictions right now. there is, after all, nothing uncertain; you can know exactly how the universe will evolve. however, this information contains an assumption that all future versions of yourself will be uncertain, and these versions must follow the born rule to develop beliefs about the various branches they may be on. In this case, given the frequency of the various consequences conferred by the born rule, it makes sense to act as if you were living in a real stochastic (variable, random) universe. (david deutsch and david wallace put this argument on solid grounds, using the decision theory]. "

final note: the parallel universe theory and the parallel universe theory are not exactly the same thing. multiverse theory is an interpretation of the working principles of quantum physics; It is an alternative to the Copenhagen interpretation. parallel universe theory is the idea that there can be more than one universe cosmologically. parallel universe theory is the result of a multiverse interpretation; sometimes it can even be used synonymously. but when you think of parallel universes, if you dream of physically separate and interactable universes, then you are not exactly considering the interpretation of multiple universes; because there is an event called "dissonance" between the separate universes in the interpretation of the multi-universe, and accordingly, the universes cannot interact with each other after separation. There is another multiverse model, in which there may be another universe within a universe. this is a very different concept. Finally, there is an interpretation of universes that are formed with quantum foam (which may be statistically likely and may occur as quantum tunneling), which is also not related to wave function.