On Sun, Feb 9, 2025 at 4:57 PM Brent Meeker <meekerbr...@gmail.com> wrote:
*>> That's not peculiar for empirical science at all. We can't detect >> virtual particles and we will never be able to, but physicists believe they >> exist because they can explain how the Casimir Effect works and why the >> electron has the magnetic moment that it has. And it's not just in quantum >> mechanics.* > > > *> Virtual particles are just a mathematical tool to form infinite sums in > a consistent way. No physicist believes they exist.* > *I don't believe that's true. Virtual particles have just as much existence as quarks do even though nobody has ever seen a free quark and nobody ever will if the standard model of particle physics is correct, and nobody has ever seen the Higgs Boson and nobody ever will because the Higgs boson has a half-life of only 10⁻²² seconds, but particle physicist believe it's real for the same reason they believe that quarks and virtual particles are real, because of the effects it has on things that we can see; in the Higgs case its effect is the decay particles that we can see because their half-lives are about a trillion times longer than the Higgs.* *>> We don't know if the entire universe is finite or infinite, or if it's >> open or closed, but either way we do know that the entire universe must be >> MUCH larger than the observable universe. * > > > *>So what? * > *If you believe virtual particles do not exist do you also believe that stars that are beyond our observational horizon don't exist and are just a mathematical tool that enables cosmological models that use General Relativity to remain logically consistent? If you do believe that then you disagree with every cosmologist on the planet. * * >> Schrodinger's equation is deterministic so "the atom just happens to >> decay" is an insufficient explanation. * > > > *> But all MWI does is push the insufficiency off to "you just happen to > be in the world where the atom decayed at 3:10pm"* > *MWI doesn't push off anything! If Schrodinger's equation is correct, and that's all that MWI is saying, then somebody must be in the world where the atom decays at 3:10 PM. By the way, strictly speaking Many Worlds is not an interpretation it is a theory that can be proven wrong; right now experiments are underway in an attempt to detect the objective collapse of the quantum wave function, if they find it then the Many Worlds idea is just wrong, it has no wiggle room. * *>> I think at the deepest level every probability is based on ignorance >> because I think Many Worlds is correct and all that Many Worlds is saying >> is that Schrodinger's equation means what it says, and Schrodinger's >> equation is 100% deterministic. If I always knew what world I was in I >> would know if the cat was alive or dead before I opened the box and I >> wouldn't need to resort to probability for anything.* > > > *> I think you think MWI is correct simply because you don't know of any > alternatives. * > *Guilty as charged. I've said more than once that Many Worlds is the least bad explanation for quantum weirdness that I know of, if somebody comes up with something better I'll drop it like a hot potato. * *> A lot of other physicists, like me, think MWI is no better than > Copenhagen. It just pushes the problem off to more obscure questions, like > how does the orthgonality of worlds spread?* *The worlds are orthogonal because they do not interfere with each other and it is spread because of decoherence. Unless extreme measures are taken, such as cooling them down to close to absolute zero, when two particles become entangled very soon environmental noise randomizes the phases between the worlds so that interference effects between them is destroyed. * *A “measurement” results in the branching of the universal state into non-interfering “worlds,” each corresponding to a different outcome. Decoherence causes the branches to become independent, which is why observers in each branch see one definite outcome and why they never see a cat that is half dead half alive, some observers see a cat that is 100% dead and other observers see a cat that is 100% alive. * *> And why isn't Zeh's Darwinian decoherence enough? * *Quantum Darwinism and Many Worlds are compatible, in fact Quantum Darwinism it explains why an observer in one of those worlds experiences classical reality most of the time and only sees quantum weirdness when difficult sophisticated experiments are performed.* *According to Zeh (and later by Zurek) when any two objects interact they have the same quantum state so they could be fully described by the same quantum wave function, this is what entanglement is; it's very difficult to keep those two particles isolated. and when they become entangled with the outside environment that is called "decoherence" and is the point where quantum weirdness disappears.* *In Everett's idea a measurement causes a branching of the universal wave function in the worlds that do not interfere with each other, so each observer in those worlds observes one definite outcome. And no collapse postulate is required * * John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* ncp > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAJPayv0ZH-vWbDO_KgQhBVnqyo6chKnXwwT2emtFLYoeED%2BxCQ%40mail.gmail.com.
