Multiverse theory -- Why don't strange things happen here sometimes?

[rolnor]

TL;DR Summary

Why is our universe always so "normal"??

If I have a brittle piece of rock and hit it with a hammer, can a round ball split of in some universe, verses in our universe a piece with rugged ends always form? If so, why do we always, in our universe seem to get "expected" results? Why dont strange things happen here sometimes? Why is our universe so "normal" if there is always a chance of strange things happening? Edit: There is no "our universe", its the universe I am experiencing I mean.

 

[PeterDonis]

This seems to be a question about the MWI, since that is the only QM interpretation in which a kind of "multiverse" appears (multiple branches of the wave function that don't interfere with each other). Is that what you want to discuss?

 

[hutchphd]

Strange things do happen here sometimes. What would be the signature of an "appropriately strange" event?

 

[rolnor]

This seems to be a question about the MWI, since that is the only QM interpretation in which a kind of "multiverse" appears (multiple branches of the wave function that don't interfere with each other). Is that what you want to discuss?

Yes. Thanx

 

[rolnor]

Strange things do happen here sometimes. What would be the signature of an "appropriately strange" event?

But the world we experience mostly seems to follow logic? The same logic year by year? If this is not true, what examples do you have where it does not follow logic? If someone is born without arms, this is due to DNA-damage, not quantum processes?

 

[DennisN]

But the world we experience mostly seems to follow logic?

Hmm, I'd say that "logic" can sometimes be in the eyes of the beholder. E.g. some may see relativity (just an example off the top of my hat) as illogical, while others may see it as logical.

The same logic year by year? If this is not true, what examples do you have where it does not follow logic?

I'd say there are a number of things in quantum mechanics that could by some be viewed as illogical, e.g. that fundamental (edit addition: individual) quantum processes are/seem to be completely random.

 

[rolnor]

Yes, but the outcome of these quantum events does not give rise to "strange things" on earth? Our universe should also "take strange ways" just as the "other" universes that are fantasised about? If my skin turned green in five years time, this would be "strange", science would have a hard time to explain this and there are no such reports in history that this has happened? really nothing in history seems to completely defy logic, maybe the building of the pyramids is hard to explain, but that is one of the few things that really deffy logic, at least according to some people?

 

[Motore]

If my skin turned green in five years time, this would be "strange", science would have a hard time to explain this and there are no such reports in history that this has happened?

It's not hard to explain: https://en.wikipedia.org/wiki/Hypochromic_anemia

really nothing in history seems to completely defy logic,

Nothing defies the laws of physics, that is the only relevant thing to focus on.
Logic is an ambiguous term.

maybe the building of the pyramids is hard to explain, but that is one of the few things that really deffy logic, at least according to some people?

Well we have a pretty standard explanation for the pyramids, not that fascinating.
Yes you can always find people who have a hard time grasping even basic stuff. The imporant thing is just not the generelize one's own lack of knowledge to everyone else.

 

[rolnor]

It's not hard to explain: https://en.wikipedia.org/wiki/Hypochromic_anemia

Nothing defies the laws of physics, that is the only relevant thing to focus on.
Logic is an ambiguous term.Well we have a pretty standard explanation for the pyramids, not that fascinating.
Yes you can always find people who have a hard time grasping even basic stuff. The imporant thing is just not the generelize one's own lack of knowledge to everyone else.

I do not generalize, mere say that the building of the pyramids are under debate.

 

[rolnor]

I do not generalize, mere say that the building of the pyramids are under debate.

And "we" whos are that?

 

[rolnor]

I do not generalize, mere say that the building of the pyramids are under debate.

Maybe my example with green skin is not the best, lets say blue skin instead.

 

[Motore]

I do not generalize, mere say that the building of the pyramids are under debate.

Well the details of the construction are under debate, but otherwise:

Most of the construction hypotheses are based on the belief that huge stones were carved from quarries with copper chisels, and these blocks were then dragged and lifted into position. Disagreements chiefly concern the methods used to move and place the stones.

https://en.wikipedia.org/wiki/Egyptian_pyramid_construction_techniques

Maybe my example with green skin is not the best, lets say blue skin instead.

Sure: https://en.wikipedia.org/wiki/Argyria

 

[rolnor]

To move 80ton granit beams up the slope of Ceops, thats not a small thing...

 

[Motore]

To move 80ton granit beams up the slope of Ceops, thats not a small thing...

https://en.wikipedia.org/wiki/Egyptian_pyramid_construction_techniques#Ramps

 

[rolnor]

https://en.wikipedia.org/wiki/Egyptian_pyramid_construction_techniques#Ramps

"Some researchers suggest" This is from your reference, the wiki. Its under debate, its not proven anything. And I am not discussing this anymore, its not relevant to the topic. OK?

 

[rolnor]

"Some researchers suggest" This is from your reference, the wiki. Its under debate, its not proven anything. And I am not discussing this anymore, its not relevant to the topic. OK?
View attachment 330614

I am just asking the forum a question, I am not claiming that I am right in anyway. I just want to understand the MVT better

 

[Motore]

Sure the details are not agreed upon, but the method is. And if there is not enough evidence to determine those details that is a matter of evidence not logic. I don't see what your point is and we already veered way off topic now. Their constructon does not in any way defy logic or physical laws.

 

[Motore]

The MWI says that if you have a wavefunction and perform a measurement, let's say you measure the spin of the particle to be up, than you are on the branch (world) of the wavefunction where the spin is measured to be up. Another version of you that measured spin down is on the other branch (world). Everything still works acording to the physical laws, so this is a limitation. Nothing can happen in any world (branch) that could defy the laws of physics.

 

[rolnor]

Thats good, that means that "anything" is not possible, this is often statet in popular science. It greatly reduces what can happen then. Thanx! I was right, popular science, again, is BS.

 

[rolnor]

One thing, does that mean that the big bang "must" be the same in all universes? the laws of physics must be the same? that also limits what is possible, if the start is very similar?

 

[GarberMoisha]

Because the observable world is fully classical. Or even better - fully clasically-equivalent based in quanta. This is why airplanes fly, boats float, ricks fall down, etc. It's just that if you want to explore how it all works down there, there is a limit to what can be known with precision after a certain limit which at presents sits at around 2nm(from processor industry finding). After it, the world starts fighting back turning to quantum mode and the particles become akin to probabilities. This limit on knowledge and what can be inferred about quanta is fundamental and cannot be overcome.
The way nature hides what can be known, suggests that there aren't trillion worlds and that the MWI is likely wrong.

 

[vanhees71]

Yes, but the outcome of these quantum events does not give rise to "strange things" on earth? Our universe should also "take strange ways" just as the "other" universes that are fantasised about? If my skin turned green in five years time, this would be "strange", science would have a hard time to explain this and there are no such reports in history that this has happened? really nothing in history seems to completely defy logic, maybe the building of the pyramids is hard to explain, but that is one of the few things that really deffy logic, at least according to some people?

Well, the outcome of an experiment is often not strange at all. E.g., if you do a Stern-Gerlach experiment, then it's not stranger that the Ag atom is measured to have spin up than it is that it's found to have spin down. It's just prepared in a state before the experiment, where this is indetermined before the measurement is done.

The only thing which I find puzzling with the MWI is, why all of us experience obviously the same "branch of the universe". Also why don't I spontaneously experience a jump to another branch, i.e., I wake up one day and everything is at least slightly changed from yesterday?

 

[vanhees71]

Because the observable world is fully classical. Or even better - fully clasically-equivalent based in quanta. This is why airplanes fly, boats float, ricks fall down, etc. It's just that if you want to explore how it all works down there, there is a limit to what can be known with precision after a certain limit which at presents sits at around 2nm(from processor industry finding). After it, the world starts fighting back turning to quantum mode and the particles become akin to probabilities. This limit on knowledge and what can be inferred about quanta is fundamental and cannot be overcome.
The way nature hides what can be known, suggests that there aren't trillion worlds and that the MWI is likely wrong.

This envokes the quantum-classical cut a la some flavors of the Copenhagen interpretations. This is also highly dissatisfying, because there's not the slightest hint that such a cut really exists in Nature. To the contrary better and better measurements reveal "quantum behavior" at larger and larger macroscopic systems.

 

[GarberMoisha]

This envokes the quantum-classical cut a la some flavors of the Copenhagen interpretations. This is also highly dissatisfying, because there's not the slightest hint that such a cut really exists in Nature. To the contrary better and better measurements reveal "quantum behavior" at larger and larger macroscopic systems.

The microprocessor industry has been dealing with the cut for a decade.

 

[rolnor]

The microprocessor industry has been dealing with the cut for a decade.

Does that mean that the "strange" things" are something seen i the quantum world, not the classical world? There will not be universes where the earth is made of icecream?

 

[GarberMoisha]

Tunneling limits the minimum size of devices used in microelectronics because electrons tunnel readily through insulating layers and transistors that are thinner than about 1 nm
https://semiengineering.com/quantum-effects-at-7-5nm/

 

[vanhees71]

The microprocessor industry has been dealing with the cut for a decade.

Can you explain what you mean by that? Semiconductors are described by QT. You cannot describe them with classical mechanics.

 

[GarberMoisha]

Does that mean that the "strange" things" are something seen i the quantum world, not the classical world? There will not be universes where the earth is made of icecream?

Yes, it suggests that there are likely no such universes

 

[rolnor]

Well, the outcome of an experiment is often not strange at all. E.g., if you do a Stern-Gerlach experiment, then it's not stranger that the Ag atom is measured to have spin up than it is that it's found to have spin down. It's just prepared in a state before the experiment, where this is indetermined before the measurement is done.

The only thing which I find puzzling with the MWI is, why all of us experience obviously the same "branch of the universe". Also why don't I spontaneously experience a jump to another branch, i.e., I wake up one day and everything is at least slightly changed from yesterday?

Yes, thats interesting, our consciousnesses seem to follow the same line of universe. I think this is a indication that there are only one universe. Not a proof, but an indication.

 

[GarberMoisha]

Can you explain what you mean by that? Semiconductors are described by QT. You cannot describe them with classical mechanics.

See post 26

 

[Motore]

The only thing which I find puzzling with the MWI is, why all of us experience obviously the same "branch of the universe".

This branch version of me and this branch version of you experience the same branch, but you cannot interfere with another branch where there is already (in parallel) a different version of me and a different version of you.

The same as the spin up of the Ag atom, cannot suddenly become the spin down.

 

[vanhees71]

Tunneling limits the minimum size of devices used in microelectronics because electrons tunnel readily through insulating layers and transistors that are thinner than about 1 nm
https://semiengineering.com/quantum-effects-at-7-5nm/

That the more underlines the fact that QT is the right way to describe semicondutors, not classical mechanics/electrodynamics.

 

[vanhees71]

This branch version of me and this branch version of you experience the same branch, but you cannot interfere with another branch where there is already (in parallel) a different version of me and a different version of you.

The same as the spin up of the Ag atom, cannot suddenly become the spin down.

An that's just by an additional assumption of the MWI proponents?

 

[GarberMoisha]

That the more underlines the fact that QT is the right way to describe semicondutors, not classical mechanics/electrodynamics.

And that if you can infer the dynamics with precision, nature fights back with the full arsenal of quantum behaviour.

 

[rolnor]

Yes, it suggests that there are likely no such universes

Thanx, I feel better now.