On Mon, Nov 13, 2017 at 1:24 AM, <[email protected]> wrote: > >>> >> >>> >>> What is your definition of non-realistic? >>> >> >> >> >> Nonrealistic means when something is not being observed it doesn't exist >> in any one definite state. >> >> >> > > > > You have to be careful here. For example, when the Earth-Moon system > formed, it existed in a definite state, but was NOT observed. >
That's just stating as a fact the very thing we're debating. Was the Earth-Moon ever in one definite state? If MWI is right the answer is no, it was always in a huge number of states, every state that was not forbidden by the laws of physics. If Copenhagen is right then Earth-Moon system was in no state at all for billions of years until somebody made a measurement and the fuzziness collapsed into one sharp definite state. Exactly what does and does not constitutes a measurement the Copenhagen people leave as a exercise for the reader. > > > OTOH, when an electron is prepared for a double slit experiment, it is in > a superposition of states; that is, NOT in a definite state. > The MWI can give a pretty good explanation why big things like the Earth-Moon system and a small things like an electron behave so differently, but to my mind Copenhagen is much less successful at doing that. > > You're conflating Multiverse with the MWI. > You can't have the MWI without the Multiverse, and if there is a Multiverse then the MWI explains a lot. There are about 10^80 atoms in the observable universe and obviously there is a finite number of ways 10^80 atoms can be arranged in a sphere with a radius of 13.8 billion light years; so if the entire universe (not to be confused with the observable universe) is infinite then at a very large but still finite distance things must repeat and there is a universe identical to our own, and at another hyper large distance there is a universe identical to ours except that the freckle on my right thumb is on my left thumb instead. And at a even greater distance one second after a John Clark hits send on a message identical to this one all the air molecules in the room he is in go to the other side of the room due to random thermal vibrations and that John Clark suffocates. Bizarre events like that are not impossible just very very unlikely, but if the universe is really infinite then everything that doesn't violate the laws of physics will happen, and the Many World people say that's what the wave function is trying to tell us, everything that can happen will happen. > > where the energy comes from in the MWI cannot be easily dismissed by the > lack of global energy conservation in GR, > Why Not? Energy conservation is not a logical necessity, it was just a empirical fact that we found that seemed to be always true, until it wasn't. Twenty years ago we discovered the universe was accelerating. > > Agreed that "observation" is misleading when there is no consciousness > involved in a quantum experiment. We should speak of detectable changes > recorded by instruments; aka "measurements". > Measurement is an even worse word to use than observation because it implies not only information but meaning, and you can's have meaning without a mind and you can't have a mind without a brain and you can't have a brain without atoms arranged in certain patterns. Many Worlds strips things down to their bare essentials, no need to worry about observation or measurement or information or meaning or consciousness, all that's needed is a change. > > So if David Deutsch takes a right turn at an intersection, there's another > identical David Deutsch in another identical universe who takes a left > turn? I can't disprove it, but why would anyone of sound mind want to > assert it? > Because the bizarre outcome of experiments forces me to conclude the universe is not of sound mind; if I were God I probably would have just stuck with Newton but unfortunately I didn't get the job. I admit the MWI is stark raving mad, but the big question is it crazy enough to be true? Whatever the truth turns out to be you can be certain it will seem nuts to all bipedal hominids that evolved to be good at hunting game on the African Savanna and not good at probing the mysteries of the quantum world. > you can have a detector recording outcomes, and if the detector is designed to determine which-way, the interference will be destroyed. In other words, we can have quantum observations without any conscious "observer". Yes, and that gives more support to many Worlds than Copenhagen. In the MWI when the electron passes the slits the universe splits and if the which way information is retained then there must be a physical difference between the two universes because information is physical, and so they remain split and no interference pattern is seen. However if after the split the which way information is subsequently erased then there is no longer a physical difference between the two and the universes merge back together. But there are still indications the electron went through slot X and a equally strong indications the electron went through slot Y, and so we have a interference pattern. The reason we see this bizarre behavior in a electron but not a baseball is that a electron is just one simple particle and so the difference between the two universes is very small , so it you're very clever you can with delicate experiments get them to merge back together again, but a baseball is made up of about 10^25 particles so the difference between the universes is 10^25 larger, so it would be 10^25 times harder to do the same thing with a baseball. So in the MWI we see splitting far more often than merging, but it does happen, > >> >> Many Worlds just requires a simple change to trigger a split, a change in >> anything, and nothing triggers >> the collapse o >> f >> the wave function >> because the mathematics doesn't even hint at such a thing happening, >> the Copenhagen people just tacked that on. >> > > > > Not exactly true IMO. When the measurement occurs, the probability becomes > unity for the value of the measurement, implying collapse of the > probability density > I know , that's what I'm talking about . T he Copenhagen people tacked on that a measurement (whatever that is) collapses the function to just one thing. But why? The mathematics doesn't say why and the Copenhagen people certainly didn't derive it, they just waved their hands and said that it does. Many World people say the mathematics mean what it says and they don't tack a collapse or anything else onto it that is not inherent to the mathematics itself. > > > Thanks for an interesting discussion. > And thank you, I enjoyed it too. John K Clark -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
