Page Nav


Classic Header




A question about the many-worlds interpretation of quantum physics - is our reality part of the many-worlds?

The many-worlds hypothesis is an interpretation of the quantum theory . According to many-worlds interpretations, the possibilities allow...

The many-worlds hypothesis is an interpretation of the quantum theory. According to many-worlds interpretations, the possibilities allowed by quantum mechanics all appear together in a multi-universe consisting of many independent universes that exist in parallel. According to the many-worlds interpretation, wave nature is persistent in the quantum world, the wave packet never collapses, the wave function never takes a specific value (for example, in a measurement), but all possible outcomes are realized simultaneously, only in different universes.

According to the many-worlds interpretation of quantum mechanics, many worlds exist in parallel, in the same space and time as ours. We are part of a world in which where we perceive the result of the quantum interaction of the world.

The many-worlds hypothesis seems to be a perfect interpretation of the quantum theory. It gives everything but asks nothing directly from us. It gives everything because the many-worlds interpretation seems to be completely in line with the observed reality. There is no need to rewrite the well-developed quantum mechanics that describe reality very accurately. It asks nothing directly from us in return, the infinite multitude of supposed parallel universes have no effect on our experiential reality, they may even exist. The only thing to believe is that these parallel universes are constantly being born and exist. The many-worlds interpretation is a convenient explanation of the mysterious quantum world.

Of course, this interpretation also leaves many questions open. How do the universes, which are constantly being created side by side, separate? How can these universes not interact with each other? And the questions could be listed even more. The general answer to these questions is that we do not know, but perhaps only because of our current ignorance and the lack of our knowledge.

The question also arises as to how we interpret our own universe within the multi-universe. How is it that we feel this universe somehow our own? Somehow, it's like having a distinguished universe, ours. More precisely, I have a universe, which is mine what I perceive, of which I have the experience, of which I have knowledge. Even my universe is constantly changing through quantum interactions, and according to many-worlds interpretations, all quantum possibilities are constantly being realized in the emerging worlds. And I exist in all of them too. None of the emerging universes has a prominent role over the others. Somehow, subjectively, I still feel that there is one that is mine.

The many-worlds interpretation of this problem answers that other self in other worlds feel that the world in which he exists is his. Of course, one can get used to this explanation, which is perfectly logical in the interpretation of the many-worlds, yet it is somehow subjectively disturbing. However, science is not based on subjective judgment, but on objective reality, which may even be the reality of a multitude of universes.

Of course, our reality, the universe that exists for us, is part of the many-worlds. It is one of the infinite numbers of parallel universes. This universe seems special only because of my subjective vision: I exist in this universe. Or I exist in other parallel universes, but they are not, they cannot affect me, they cannot be in contact with me, it is not a problem that the rest of me are me. This my is one of the many self, this one that exists for me because I sense it, another universe is perceived by another self of me.

No matter how perfect the many-worlds theory is, how we may have only subjective feelings against the hypothesis, there is a universe, which still seems special. I am aware of this universe only, of course, that this universe is different from the rest. But of course, this is just a subjective feeling. In reality, in the many-worlds hypothesis, all worlds are equal, all of the universes are the realization of different possible quantum states. Our perceived universe which seems to be real is only one among the other universes. An equal, non-exclusive member of the multitude of universes.

The my-world problem within the many-worlds interpretation of quantum mechanics seems to be only a subjective problem, exists only because of the subjective view.

Yet, by logical thinking, if the many-worlds hypothesis is a correct interpretation of the quantum world and virtually an infinite number of other universes are created and exist in addition to our perceived reality, then it can be seen objectively that the chances of the survival of the perceived reality are infinitely small and more this perceived my-reality exists, the less likely it preserves. If the many-worlds hypothesis is correct, then the existence of the universe that I perceive is objectively not-sustainable, so it must be a special universe. Why?

For the explanation of the impossibility, perform a well-known quantum mechanical experiment, a series of quantum mechanical measurements. Suppose I decided to measure the spin of an electron in two orthogonal planes. I pick a plane and do the measurement. The electron was randomly selected, initially I don't know anything about the state of the spin. Because the spin is quantized, there are two possible results of the measurement. Let's call the two possible results UP and DOWN spins. Suppose my measurement finds that the spin of the electron is in the UP state. Since spin is a quantum property, and now I have done a quantum measurement, according to the many-worlds interpretation, the world splits by the measurement creating two worlds, one in which the spin of the electron is in the UP state and another world where the spin is in DOWN state. The series of the predetermined experiment continues to measure the electron spin in both worlds, but now in a plane perpendicular to the previous one. This quantum-mechanical measurement also can have two outputs. Let's call RIGHT and LEFT spins. I do the measurement and find that the spin of the electron is in a RIGHT state. According to the many-worlds interpretation, the world is split again by the measurement, creating two worlds, one in which the spin of the electron is in the RIGHT state and the other is in the LEFT state. With the two measurements, four worlds have been created (let ignore now that events are constantly happening in the worlds and more and more worlds are being created, let's just concentrate on the designated series of measurements and their associated worlds). The pre-planned series of measurements continues to measure the spin of the electron in all four worlds, but now in the same plane as in the first measurement. This quantum-mechanical measurement can have two outputs also, the UP or DOWN spin states. I do the measurement and experience UP or DOWN spin again. I continue the series of measurements and after a while, I look back and evaluate the results of my observations. What am I experiencing? The longer I do the experiment, the more I realize that my world, the world in which I exist, the world that I am experiencing is an unlikely and increasingly unlikely world. Why?

Let's look at my series of measured data. If I make the measurement in reality, the measurement will result in a series of values of UP or DOWN and LEFT or RIGHT in a completely random order. According to the laws of quantum mechanics, this series is fundamentally random, and there will be no any recognizable order in it (except of course the alternatively appearing value pairs). The outcome of this experiment reinforces this theoretical rule. However, there will be a rule that will prevail. I find that the more times I do the experiment, the truer it is that the sum of the DOWN and sum of the UP, as well as RIGHT and LEFT measurements, are getting closer to each other. The more times I do the measurement, the truer it is that the proportion of DOWN, UP, RIGHT, and LEFT in closer and closer to one as all the measurements are made. Or in different words, the sum of the different measurement values is getting closer and closer to each other in the proportion of all the measurements that are made if I make sufficiently enough measurements. Every time I do this series of experiments, I always experience this. The series of measured values will always be different, but the number of measured values will always be closer to each other and the difference between them will become smaller as more and more measurement is made. I always find myself in a mediocre universe. However, the probability that this would be is mathematically close to zero. Why?

It is mathematically obvious that when I do the measurements x times observing the state of the electron spin


different series are possible. These many different worlds are created according to the many-worlds interpretation.

How many of these worlds will be where the result of the measurements shows, so where the series of measurement is such, that I have the same number of measurements with the different measured values? For simplicity, it is sufficient to examine the measurements only on one plane, the conclusion won’t be affected by this simplification. Mathematically it can be seen that on the selected plane - say the plane where the measurement results were DOWN and UP - if I made a total of n measurements then


different series possible where the measured values contain the same number of UP and DOWN values.

(The main conclusion of the reasoning is not influenced by the circumstance that the real measurements do not necessarily provide the same number of UP and DOWN values, so there are more different experimented series of measurements possible. The main point is that the ratio between the difference between the measured values and the total number of measurement is approaching to zero.)

The ratio of the cardinality of the different series that I can measure in practice to that which is theoretically possible as I do more and more measurements is approaching to zero:

Graph of the function

What conclusions can be drawn from the results I get from the measurements I have made? If I make measurements, so when I observe reality, I will always see, practically in one hundred percent, that I am part of, I am existing in an unlikely universe.

What does it mean for me that I always find myself in an unlikely universe? What does it mean for me that this unlikely world is my reality? It means that the many-worlds interpretation - which assumes that there is no specifically distinguished universe among the universes created through quantum interactions - is flawed. Thus, many-worlds interpretation cannot be a suitable interpretation of the quantum world.

Or it might mean that the reasoning and the conclusion drawn of this thread of thoughts are wrong somewhere.

No comments