I will answer to the frequently asked questions on the many-worlds interpretation.
I would like to assume that this world is the paper of two-dimensional. We can put a lot of worlds of paper in the three-dimensional world. Thus, if one dimension increases, the places will increase enormously. There is time as such a dimension.
I think the world of a different time is a kind of the many-worlds. We usually think that the world at the same time is one of the many-worlds. However, the world after 10 minutes is one of the worlds that is contained in the many-worlds.
Since we feel it is possible to measure the time in the same manner as the distance, we feel that the time exists in the same manner as the distance. However, I do not think that the time exists in the same manner as the distance. I think that many worlds of a different time exist actually. We feel the passage of time for the transition between the worlds of a different time.
We feel that the time lasts forever if the universe continues to expand forever. However, I think we cannot measure the time without an entropy enhancement. The phenomenon of the passage of time does not exist in the world of the maximum entropy in the distant future. Though the transition between the worlds around of the world of the maximum entropy occurs, we do not feel the passage of time. The direction of the arrow of time is clear during the entropy increasing. However, it is not clear in the world of the maximum entropy.
Some people think that the number of the world is infinite. I think the number of the world is finite. If we can shift the position of an electron in the infinity small distance, the number of the worlds is infinite because the world of the different position of the electron is a different world.
I think the minimum distance and the minimum time exist. The number of the worlds is finite because we cannot shift the position of an electron for the infinity small distance.
Some people think that the energy increases on the branch of the world. The worlds of many-worlds are same as the worlds of different worlds. We usually do not add energy of a different time in order to confirm the energy conservation law. Therefore, we do not need to sum energy of different worlds in order to confirm the energy conservation law.
A lot people do not think that we can observe the other world. In the future, I believe that we can observe the other world. I guess that the wave function is actually non-linear. We might be able to observe the other world by using the nonlinearity.
The function of non-linear Einstein equation expresses the wave of space. I guess the wave function represents the wave of the new space we do not know yet. The wave function might be non-linear because both of functions represent the wave of space.
I think the path integral and the many-worlds interpretation are closely related. The problem is that there is no way to choose a unique basis. The state of each world depends on the basis. If we do not choose a unique basis, it is impossible to determine the state of each world uniquely
I think we can choose the unique basis. We can choose the position of elementary particles for basis. Though we do not have a method to choose the unique basis for a spin, I guess that we are able to choose the position of the inner space of the spin for basis.