However, if one assumes in physics, as do many physicists, that the world is not mathematical, then doesn't it mean that conservation of energy laws would become violated for every branching of wavefunction collapses? — Shawn
Sean Carroll explains this by saying that the energy splits too. Each world takes with it half the energy of the parent world, so that conservation of energy is preserved. — fishfry
This confronts a pretty pernicious issue as to what or which kind of wavefunction collapses cause this to occur along with the extent of the parent universe splitting to what localized or even global effect(s)? — Shawn
My understanding is that MWI avoids wavefunction collapse. The wavefunction doesn't collapse; rather, everything happens. — fishfry
This scrutiny forced the question that Everett’s thesis had somewhat skated over. If all the possible outcomes of a quantum measurement have a real existence, where are they, and why do we see (or think we see) only one? This is where the many worlds come in. DeWitt argued that the alternative outcomes of the measurement must exist in a parallel reality: another world. You measure the path of an electron, and in this world it seems to go this way, but in another world it went that way.
That requires a parallel, identical apparatus for the electron to traverse. More, it requires a parallel you to observe it — for only through the act of measurement does the superposition of states seem to “collapse.” Once begun, this process of duplication seems to have no end: you have to erect an entire parallel universe around that one electron, identical in all respects except where the electron went. You avoid the complication of wave function collapse, but at the expense of making another universe. The theory doesn’t exactly predict the other universe in the way that scientific theories usually make predictions. It’s just a deduction from the hypothesis that the other electron path is real too. — Philip Ball
This kind of hap hazardous growth of the entire universe would be in only some mathematical abstraction, no? Otherwise some physicist with an axe to grind would claim something about Occam's Razor. — Shawn
Once we have granted that any physical theory is essentially only a model for the world of experience we must renounce all hope of finding anything like the correct theory ... simply because the totality of experience is never accessible to us. — Hugh Everett
Sabine Hossenfelder is of the opinion that the popularity of MWI and other multiverse ideas are due to the majority of physicists being Platonists. — Marchesk
At its root, the new idea holds that the common conception of “reality” is too limited. By expanding the definition of reality, the quantum’s mysteries disappear. In particular, “real” should not be restricted to “actual” objects or events in spacetime. Reality ought also be assigned to certain possibilities, or “potential” realities, that have not yet become “actual.” These potential realities do not exist in spacetime, but nevertheless are “ontological” — that is, real components of existence.
“This new ontological picture requires that we expand our concept of ‘what is real’ to include an extraspatiotemporal domain of quantum possibility,” write Ruth Kastner, Stuart Kauffman and Michael Epperson.
Observations of a “pure” quantum state, containing many possibilities, turns one of those possibilities [described by the wave function] into an actual one. And the new actual event constrains the list of future possibilities, without any need for physical causation. “We simply allow that actual events can instantaneously and acausally affect what is next possible … which, in turn, influences what can next become actual, and so on,” Kastner and colleagues write.
Measurement, they say, is simply a real physical process that transforms quantum potentia into elements of res extensa — actual, real stuff in the ordinary sense. Space and time, or spacetime, is something that “emerges from a quantum substratum,” as actual stuff crystalizes out “of a more fluid domain of possibles.” Spacetime, therefore, is not all there is to reality.
Like I asked in another thread - what problem does it solve? If the many worlds intepretation is the solution, what is the problem? — Wayfarer
Multiverse theory is the same as unicorn theory — Philosophim
However, if one assumes in physics, as do many physicists, that the world is not mathematical, then doesn't it mean that conservation of energy laws would become violated for every branching of wavefunction collapses? — Shawn
Could well be. But for purposes of this discussion, please note that multiverse theory and the many-worlds interpretation are two entirely different speculative theories. — fishfry
Mind explaining how? — Philosophim
Sean Carroll explains this by saying that the energy splits too. Each world takes with it half the energy of the parent world, so that conservation of energy is preserved. Of course that means that if the total energy of the universe is finite, at some point there's not enough energy to split into any more worlds. I'd like to ask Sean Carroll that. I'm sure he's thought about it. — fishfry
The multiverse theory says that the universe consists of "bubble universes" that branch off and are causally independent of each other. Entirely different theory. Nothing to do with quantum branching. It's a cosmological theory.
https://en.wikipedia.org/wiki/Multiverse — fishfry
MWI is a level 3 classification scheme of multiverse theory.... — Philosophim
MWI is a unicorn theory — Philosophim
MWI is a unicorn theory
— Philosophim
I think it's all nonsense on stilts, but who am I? — Wayfarer
If you read the wiki article you linked, you'll see that MWI is a level 3 classification scheme of multiverse theory. I was correct then. — Philosophim
You seem to have side stepped the larger issue I made however. — Philosophim
In the end, MWI is a unicorn theory. Do you have an answer for this? — Philosophim
All multiverse theories fail at their core, because they are pure speculation without evidence. — Philosophim
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