A Revolution in Thought: Part Two

[The Lone Ranger]

Originally Posted by davidm

Of course you can set up experiments that amplify quantum probabilities to macro scale; this is the idea behind the famous Schroedinger's Cat thought experiment.

True, though a lot of people mis-understand Schroedinger's point. He came up with the thought experiment to illustrate the absurdity of thinking of macroscopic objects as being in indeterminant states. His point was that the cat is not in some in-between, neither-dead-nor-alive state, but simply that it's not possible to know which state (dead or alive) it's in until you open the box.

The cat, being a complex system that's well above the level at which quantum indeterminacy applies, will have definitely caused the "collapse" of the wave function, and so will be in one of the two possible states before the box is opened. It's just that it's not possible for an outside observer to know which one before you open the box.

[davidm]

That's right, Schroedinger definitely intended the experiment as a reductio of the idea that macroscopic systems can be in superposition. But even so, some have interpreted QM as meaning that from the point of view of an observer outside the box, the cat really is in an indeterminate state for that observer, until the observer becomes entangled either with the "live" or "dead" state. Then there is a 1/2 chance of the observer becoming entangled with either live or dead.

And then there is the Many Worlds account, which is that the cat really is both alive and dead, in separate versions of reality. And whoever opens the box also splits off into two versions, one finding a cat alive and the other finding a cat dead.

[davidm]

Just for interest, here is a map of the world that the aforementioned Eratosthenes made:

[Dragar]

Originally Posted by The Lone Ranger

True, though a lot of people mis-understand Schroedinger's point. He came up with the thought experiment to illustrate the absurdity of thinking of macroscopic objects as being in indeterminant states. His point was that the cat is not in some in-between, neither-dead-nor-alive state, but simply that it's not possible to know which state (dead or alive) it's in until you open the box.

The cat, being a complex system that's well above the level at which quantum indeterminacy applies, will have definitely caused the "collapse" of the wave function, and so will be in one of the two possible states before the box is opened. It's just that it's not possible for an outside observer to know which one before you open the box.

I'd disagree, Michael. The equation of quantum mechanics are perfectly correct in describing a cat in a quantum-superposition of states. There's no process by which wave-functions 'collapse' (it's actually completely inconsistent with Schrodinger's equation!), nor do large, complex systems cause any such thing. Browsing wikipedia informs me that we've set up superpositions with objects of ~10 trillion atoms; at what number of atoms should we call this a 'macroscopic' effect?.

Interaction with the environment can lead to a similar thing happening in a smooth sort of way (quantum decoherence), but that's a practical point, not one of principle. And even then, the 'collapse' is not perfect; there's always a smidgen of dead-cat superposed with alive-cat, or vice-versa.

Schrodinger's goal was indeed to point out the absurdity of applying quantum mechancis to macroscopic scales; the correct response is that the absurdity is entirely correct. We don't 'experience' such absurdity because quantum mechanics doesn't predict we will. But that doesn't mean such a thing isn't a correct description of the universe in the language of quantum mechanics.

You should be trying to interpret macroscopic, classical experiences in terms of quantum mechanics, not trying to explain quantum mechancis in terms of macroscopic, classical experiences.

[Dragar]

Originally Posted by The Lone Ranger

"Unpredictable" doesn't necessarily mean "undetermined."

That's true, Michael. However it's quite possible to prove that in the case of quantum mechanics, unpredictable does indeed mean indeterminate - it simply isn't the case that the predictions of quantum mechanics are consistent with an object having a definite position and momentum (for example), not merely that we can never know it.

Subject to no 'action at a distance' violations of special relativity, anyway.

I should write up a talk I gave on Bell's Theorem a few years back.

[specious_reasons]

Originally Posted by thedoc

Hmm, a fellow hitchhiker, Just because the probability is very low, does not mean it can't happen, would certainly liven up a dull party, for a few minutes. And yes probabilities tend to average out at larger scales.

I was worried I butchered the quote beyond recognition.....

I guarantee I could not predict someone's choices if that happened.

[davidm]

Originally Posted by Dragar

I'd disagree, Michael. The equation of quantum mechanics are perfectly correct in describing a cat in a quantum-superposition of states. There's no process by which wave-functions 'collapse' (it's actually completely inconsistent with Schrodinger's equation!), nor do large, complex systems cause any such thing. Browsing wikipedia informs me that we've set up superpositions with objects of ~10 trillion atoms; at what number of atoms should we call this a 'macroscopic' effect?.

Interaction with the environment can lead to a similar thing happening in a smooth sort of way (quantum decoherence), but that's a practical point, not one of principle. And even then, the 'collapse' is not perfect; there's always a smidgen of dead-cat superposed with alive-cat, or vice-versa.

Schrodinger's goal was indeed to point out the absurdity of applying quantum mechancis to macroscopic scales; the correct response is that the absurdity is entirely correct. We don't 'experience' such absurdity because quantum mechanics doesn't predict we will. But that doesn't mean such a thing isn't a correct description of the universe in the language of quantum mechanics.

You should be trying to interpret macroscopic, classical experiences in terms of quantum mechanics, not trying to explain quantum mechancis in terms of macroscopic, classical experiences.

Which would raise the question, given this state of affairs, should we think the Many Worlds interpetation most likely correct?

[davidm]

Originally Posted by Dragar

I should write up a talk I gave on Bell's Theorem a few years back.

That would be great; happily there are quite a few good resources on the Web on this, some more clear than others.

[thedoc]

Originally Posted by Dragar

I should write up a talk I gave on Bell's Theorem a few years back.

Please do so, but if there are equations involved, please give a plane english intrepretation.

[Dragar]

Originally Posted by thedoc

They had no reason to believe otherwise, the Sun... appear[s]... to go around the Earth...

On this topic Wittgenstein is reported to have once said...what did they expect the world to look like, were it the other way around?

[Dragar]

Originally Posted by davidm

Which would raise the question, given this state of affairs, should we think the Many Worlds interpetation most likely correct?

I don't like how Many Worlds is usually described; I think it rather misses the point. The 'worlds' are all classical descriptions; these are precisely the things I don't believe are correct or exist.

Again, such an interpretation is again trying to interpret quantum mechanics classically, when you should be interpreting things the other way around!

[Dragar]

Originally Posted by davidm

That would be great; happily there are quite a few good resources on the Web on this, some more clear than others.

Originally Posted by thedoc

Please do so, but if there are equations involved, please give a plane english intrepretation.

I will see what I can do; I have been meaning to do so for some time now. The equations are sparse (deliberately so), and could probably be entirely removed for the purposes of this. My talk was heavily based on this talk by the late, great Sidney Coleman which really cleared up quantum mechanics for me. Some of you might find it enlightening (even if you don't understand the science, Coleman is an amazing (and very funny) speaker and tells delightful anecdotes throughout).

[thedoc]

Originally Posted by davidm

Quantum indeterminacy appears to go much deeper than mere unpredictably; i.e., all the way down to true, real indeterminacy in nature.

Quantum indeterminacy.

However, it should be noted that all the weird stuff about QM -- indeterminacy, spontaneous wave function collapse, and nonlocality -- diseappar if one accepts a certain interpretation of QM, the Everett Many Worlds interpretation.

After a quick glance it occures to me that an infinite number of parallel universes could have the same effect, if an event could happen in different ways then it could happen each way in different universes. There have been attempts to explain some properties of light with this kind of explination.

[thedoc]

Originally Posted by specious_reasons

Your underwear doesn't typically jump 3 feet to the left at parties.

Well I have been told that there are parties where this does happen, I've never been invited to any of them, and I think now I'm a bit past it. Of course the exact distance and direction may be a bit more random, but I do think it happens.

[thedoc]

Originally Posted by specious_reasons

I was worried I butchered the quote beyond recognition.....

I guarantee I could not predict someone's choices if that happened.

I think you did pretty good, but I think at certain parties the choices would be easily predictable.

[davidm]

Originally Posted by Dragar

I will see what I can do; I have been meaning to do so for some time now. The equations are sparse (deliberately so), and could probably be entirely removed for the purposes of this. My talk was heavily based on this talk by the late, great Sidney Coleman which really cleared up quantum mechanics for me. Some of you might find it enlightening (even if you don't understand the science, Coleman is an amazing (and very funny) speaker and tells delightful anecdotes throughout).

Is there a transcript version of that? At work and can't view the video just now.

[davidm]

Originally Posted by Dragar

I don't like how Many Worlds is usually described; I think it rather misses the point. The 'worlds' are all classical descriptions; these are precisely the things I don't believe are correct or exist.

Again, such an interpretation is again trying to interpret quantum mechanics classically, when you should be interpreting things the other way around!

What, then, would be the ontology described by QM, do you think?

I don't quite follow why you think MW gets it backward; as I see it it takes what QM seems to be showing seriously: no wave function collapse, no non-locality, and determinism restored; superpositions are real worlds in, well, superposition. The problem with non-MWI interpretatons seems to be that they treat the observer and his equipment as classical but the what is being investigated as quantum, whereas MWI treats everything as quantum. And of course non-MWI interpretations have to account for this mysterious wave function collapse, which seems to have no cause or mechanism to it.

There are some good papers online that show how non-locality goes away under MWI and a whole book on the subject, called Schroedinger's Kittens, I think. This is all a layman's observations, of course, so take them with a pinch of salt.

[davidm]

Here is a paper I read sometime back on the violations of the Bell's Inequalities by a professor of physics and astronomy at Brigham Young Univeristy. It's definitely geared toward the layman and mostly math-free if the math is a problem. Note that the lecturerer teaches at Brigham Young and sticks some God talk in there, but atheists can safely ignore that; the descriptions of the experiments and their mind-bending implications all seem fine and quite accessible even to someone hearing of this stuff for the first time.

Was Einstein Wrong? The Difference between Things We Don’t Know and Things We Can’t Know

[Dragar]

Originally Posted by davidm

Is there a transcript version of that? At work and can't view the video just now.

Not one that I know of. If you were to find one, I'd be grateful for a link myself.

[Dragar]

Originally Posted by davidm

What, then, would be the ontology described by QM, do you think?

I don't quite follow why you think MW gets it backward; as I see it it takes what QM seems to be showing seriously: no wave function collapse, no non-locality, and determinism restored; superpositions are real worlds in, well, superposition. The problem with non-MWI interpretatons seems to be that they treat the observer and his equipment as classical but the what is being investigated as quantum, whereas MWI treats everything as quantum. And of course non-MWI interpretations have to account for this mysterious wave function collapse, which seems to have no cause or mechanism to it.

There are some good papers online that show how non-locality goes away under MWI and a whole book on the subject, called Schroedinger's Kittens, I think. This is all a layman's observations, of course, so take them with a pinch of salt.

I think the ontology described by QM is close to MW.

But the point where MW goes wrong is where it says (or you say) "superpositions are real worlds in, well, superposition". I think that's a daft thing to say; there's one real world; it involves superposition. I don't think you need to start splitting things up into 'worlds' to make sense of our experiences in quantum mechanics. Unless you secretly want a classical world to talk about.

I've read Schrodinger's Kittens (and In Search of Schrodinger's Cat), and enjoyed them both. I bumped into the author at one of my postgrad interviews, actually! Sadly I didn't realise until after he'd left who he was, I'd have tried to speak to him. I preferred the first book to the second.

[peacegirl]

Originally Posted by specious_reasons

Yeah - don't care.

I didn't mean to hurt your feelings. I just want to explain this discovery so people can understand what Lessans is saying. Can you imagine if a teacher was giving a demonstration about a math equation and everyone started giving their opinions on whether it will work or not, and the teacher never had a chance to finish?

Originally Posted by Specious_reasons

If you don't like what I'm posting on your thread, you can report me to the moderators.

You know I wouldn't do that because there's no reason to.

Originally Posted by Specious_reasons

So, I spent a little bit of time reading about compatibilism and incompatibilism - interesting. I would probably fall into the compatibilist camp myself, even though I'm not entirely willing to admit that the universe is deterministic.

Somebody in one free will thread suggested a thought experiment where you can roll back the universe to a specific point in time, and then start it up again. We have free will if, at this new starting point, a person can and will make a different decision.

I'm inclined to think that we can't - if we roll back the universe to a moment just before a decision is made. I'm also inclined to think that the chance of random quantum changes in the universe will start to build over time, and maybe the universe is different enough that the conditions that influenced a decision have changed enough to allow a different outcome.

So, if we roll back to 1930, we still win WWII, but if we roll back to the last ice age, maybe we're living in the world of the Man in the High Castle.

If anything in the Universe could be different, then of course the outcome would be different because the determinants leading up to someone's choice would be different. But we're talking about a Universe where we cannot go back in time and change the past. Being able to change the past is complete fantasy, and I'm discussing reality.

[peacegirl]

Originally Posted by LadyShea

Then go do it.

WordPress.com — Get a Free Blog Here
Blogger: Create your free Blog

I wrote the websites down. I am interested in creating a blog but the only problem is that the type of people that would even come close to understanding this discussion are those in these type forums, not in just some blog out in left field. So I'm between a rock and a hard place.

[peacegirl]

Originally Posted by davidm

The reason it failed the first time is because you spent nearly 600 pages defending something that was repeatedly shown to be false.

Falsity has a way of making things not work out the way you want them to.

And truth has a way of making things work out because of its veracity.

[peacegirl]

Originally Posted by The Lone Ranger

It's very simple, by the way. To evaluate the logic and validity of a claim, it's first necessary to evaluate the premises upon which it is built.


So let's see them.

I already gave them numerous times. It is a fact that if the premises are not valid, the claim will be thrown out. But they are valid. The problem is that without understanding what led him to each of these premises, they will appear invalid. He stated that conscience works in a very specific way and will control behavior but only under certain conditions. People balk at that and say that's not true. So who's right? I know that Lessans is right and in order for you to see that he is right I have to go in a step by step fashion that will allow you to see the entire picture, not just a few stated premises. Can't you see how misconstrued this whole demonstration can get?

[peacegirl]

Originally Posted by ceptimus

Are you saying it would be impossible to translate Lessans' observations into another language? German, say, or Japanese?

If it is possible to translate them into other languages, then all we're asking is that you translate them into simple English - as if you were trying to get the message over to a child.

If a new world order is to be built as a result of the ideas in the book, then it will presumably be useful to have a child-friendly version of the book, so your efforts won't have been wasted.

But as Stephen Maturin said, a simple list of the observations would be a better place to start.

If it were the gospels of the bible, the list would include items like:

• Birth of Jesus
• Return of young Jesus to Nazareth
• Ministry of John the Baptist
• First disciples of Jesus
• Beatitudes

Could you do something similar for this book? And then we could discuss each of the observations in turn, in greater detail.

I can give you the name of the chapters in the book which gives an overview of where the book is headed, but I cannot explain the first two chapters in this simple way. Too much is left out and then people will tell me he's wrong. Been there, done that.