“at a microscopic level, this and this happens, and the equation shows that on larger scales it becomes less visible...”
then I misunderstood what it says. But I don’t think many world says that things become less visible, I think it says that they become inaccessible. That’s a level at which concepts like “existence” don’t make sense. Calling it “many-worlds” seems like a misnomer, in that case, because those words seem to imply that there are many worlds, which implies existence.
Less visible, less accessible, the same thing. In physics, seeing something or touching something is an interaction of particles. (If two spaceships can see each other, they can shoot lasers at each other.)
Yes, “many worlds” is misleading, because it makes us think that there is one set of particles, and another set of particles… but it means that there is one configuration of a set of particles, and another configuration of the same set of particles. Many worlds in not like many planets, but more like many possible futures. It is not possible to travel to a parallel universe, because all your particles are already there, they are just entangled in a different configuration, along with the rest of the universe. It’s almost like saying that a set of equations has two possible solutions, but you can’t mix a part of one solution with a part of another solution.
This analogy is also imprecise (all analogies fail somewhere), because one “world” is not one specific configuration of particles, but more like a set of very similar configurations (having particles in similar places with similar speeds). This set can split—if a particle is flying near another particle, in one part of the set the particles hit, in other part they miss each other, and the futures of these configurations are no longer similar.
The quantum experiments show us that these “worlds” interact, and the interaction is greater if the worlds are more similar (if all their particles have the same position and speed, except for a very few particles). Then probabilities increase and decrease in a ways we would not expect in classical physics, but now we have the equations which describe this. And these equations say that the greater the difference between two “worlds”, the smaller the interaction between them. So if you have a difference greater than 10^10 particles (which is less than a number of particles in one cell, e.g. a neuron), the interaction is almost zero; we are unable to measure it. Therefore in a world A we say: “we can’t measure the world B anymore, so it does not exist; speaking of its existence wouldn’t make sense”, while in a world B we say: “we can’t measure the world A anymore, so it does not exist; speaking of its existence wouldn’t make sense”. Practically speaking, we are right in both worlds; they are separated beyond reach.
In addition to this, the collapse hypothesis says that when the interaction is almost zero, in some unspecified moment the interaction becomes exactly zero (as opposed to staying ever decreasing but non-zero forever, as the equations say). This hypothesis is absolutely unnecessary, it does not predict any experimental outcome, it only serves as a justification for saying (in a world A) that the world B now really really really does not exist… that our seeing of the world A is more than mere saying “in a world A we are in a world A, just like in a world B we are in a world B, and the interaction between these worlds is zero for all practical purposes”… that even a hypothetical non-physical observer outside of our universe would have to agree with us that yes, the world A is real, and the world B is not, because at the moment the interaction dropped to zero, some metaphysical property of the world B was removed, but it wasn’t removed from the world A.
If many worlds is only:
then I misunderstood what it says. But I don’t think many world says that things become less visible, I think it says that they become inaccessible. That’s a level at which concepts like “existence” don’t make sense. Calling it “many-worlds” seems like a misnomer, in that case, because those words seem to imply that there are many worlds, which implies existence.
Less visible, less accessible, the same thing. In physics, seeing something or touching something is an interaction of particles. (If two spaceships can see each other, they can shoot lasers at each other.)
Yes, “many worlds” is misleading, because it makes us think that there is one set of particles, and another set of particles… but it means that there is one configuration of a set of particles, and another configuration of the same set of particles. Many worlds in not like many planets, but more like many possible futures. It is not possible to travel to a parallel universe, because all your particles are already there, they are just entangled in a different configuration, along with the rest of the universe. It’s almost like saying that a set of equations has two possible solutions, but you can’t mix a part of one solution with a part of another solution.
This analogy is also imprecise (all analogies fail somewhere), because one “world” is not one specific configuration of particles, but more like a set of very similar configurations (having particles in similar places with similar speeds). This set can split—if a particle is flying near another particle, in one part of the set the particles hit, in other part they miss each other, and the futures of these configurations are no longer similar.
The quantum experiments show us that these “worlds” interact, and the interaction is greater if the worlds are more similar (if all their particles have the same position and speed, except for a very few particles). Then probabilities increase and decrease in a ways we would not expect in classical physics, but now we have the equations which describe this. And these equations say that the greater the difference between two “worlds”, the smaller the interaction between them. So if you have a difference greater than 10^10 particles (which is less than a number of particles in one cell, e.g. a neuron), the interaction is almost zero; we are unable to measure it. Therefore in a world A we say: “we can’t measure the world B anymore, so it does not exist; speaking of its existence wouldn’t make sense”, while in a world B we say: “we can’t measure the world A anymore, so it does not exist; speaking of its existence wouldn’t make sense”. Practically speaking, we are right in both worlds; they are separated beyond reach.
In addition to this, the collapse hypothesis says that when the interaction is almost zero, in some unspecified moment the interaction becomes exactly zero (as opposed to staying ever decreasing but non-zero forever, as the equations say). This hypothesis is absolutely unnecessary, it does not predict any experimental outcome, it only serves as a justification for saying (in a world A) that the world B now really really really does not exist… that our seeing of the world A is more than mere saying “in a world A we are in a world A, just like in a world B we are in a world B, and the interaction between these worlds is zero for all practical purposes”… that even a hypothetical non-physical observer outside of our universe would have to agree with us that yes, the world A is real, and the world B is not, because at the moment the interaction dropped to zero, some metaphysical property of the world B was removed, but it wasn’t removed from the world A.