That's interesting: could you briefly provide some evidence to support this?
The above ontological example models the zero premise to BB theory. It does so by applying the relative uniformity assumption that the alleged zero event eventually ontologically progressed from the compressed alleged sub-microscopic chaos to bloom/expand into all of the present observable order, more than it models the Biblical record evidence for the existence of Jehovah, the maximal Biblical god designer. -Attributed to Buzsaw Message 53
The explain to them any scientific investigation that explains the existence of things qualifies as science and as an explanation -Attributed to Dawn Bertot Message 286
Does a query (thats a question Stile) that uses this physical reality, to look for an answer to its existence and properties become theoretical, considering its deductive conclusions are based against objective verifiable realities. -Attributed to Dawn Bertot Message 134
Inadequate, your tirade against the cat is all very well but you still confuse the nurse with all your randomness and probabilities talk. He is asking what do you mean exactly by fully caused and fully undetermined? What is the difference between an effect that is perfectly determined and the one that is perfectly not? He is a very considerate nurse so is asking you whether or not you would love your undetermined quantum world be given a separate bed in a separated ward from the ordinary fully determined one. Should the random fellow be placed in a padded room?
This post is just reqesting clarification of the particular example you've given. I don't fully understand what people mean when they use this example and just have a few questions.
Dr Adequate writes:
One of the exercises they give to people starting out in quantum mechanics is to calculate the probability that if you run hard at a brick wall you'll pass through it rather than breaking your nose. This probability is small but non-zero, and there would be no cause of you succeeding rather than failing in running through the wall.
I may be using the wrong terminology, so I'll try to define my use of the term "particle" by using "ping-pong balls" as a visualization.
Onto my questions...
1. A particle running into a "wall of particles (one particle-thick)" is kind of like a ping-pong ball being thrown at a wall of ping-pong balls if the wall of ping-pong balls had large spaces in between them representing the distance that particles are from each other due to all the forces that holds things together and keep things being "mostly empty space."
2. Going "through the wall" is considered just making it across? That is, lets say we have a group of 10 ping-pong balls that are thrown against the wall of ping-pong balls. As the group of 10 is being thrown at the wall, they have their own forces holding them together (but still keeping them "mostly empty space"). 2.a)Let's say the 10 ping-pong balls make it through to the other side, but all the forces holding them together are dispersed in some way such that the 10 balls now act more like individual balls than a group of 10 together. Is this considered "making it through"? And is the solution for which the probability is calculated? 2.b)Let's say the 10 ping-pong balls make it through completely in-tact (all their forces holding them together are still there, so they still look like a group of 10 ping-pong balls all together). Is this even possible? Or is the probability of this just even more smaller (and more complicated)?
If 2.a) is "correct"... then I understand the idea.
If 2.b) can actually "happen"... then I need to do some more learnin'.
I really don't know which is correct, and would appreciate an answer. "Me needing some more learnin'" is certainly a perfectly acceptable answer and I don't proclaim to have much knowledge on the subject.
That is, the way I understand it... even though the possibility of you running into a brick wall and making it through the other side can be calculated and is extremely small... such an idea involves all the "particles" that make you up getting through to the other side... but they are no longer in such an order as to identify "you" in the sense we all know and love. And, as long as the bonds between particles that make up "you" are strong enough not to disperse when they come up agains the brick wall (and all it's bonds and forces...) ...then you really don't have much to worry about at all.
He's also trying to claim that Pauli's exclusion principle applies to bosons (e.g. alpha particles and U238 nuclei). And all this time I was thinking the principle was applicable to fermions.
Alfred's participation in every group he has posted to recently is to claim that the entire discussion is meaningless because there is no real way to talk about the past. Therefore there is no origin for life, the universe, no reasonable way to talk about death or anything happening before anything else. All because some nuclei are separated by a few Angstroms or because Tom and Mary are separated by a few meters.
And what is his technique for convincing us? Well so far it seems to consists of being wrong about physics, giving concepts he does not like funny names, and mangling the posting handles in rib tickling ways. All this while referring to himself in the third person as a cat.
I think we all agree that participation in these discussion is not worth the time of someone who knows better. I don't intend to waste any more of AMs time.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
The apathy of the people is enough to make every statue leap from its pedestal and hasten the resurrection of the dead. William Lloyd Garrison.
Well, you may still have time to register to vote. Even North Carolinians can still register for early voting. State Registration Deadlines
1. A particle running into a "wall of particles (one particle-thick)" is kind of like a ping-pong ball being thrown at a wall of ping-pong balls if the wall of ping-pong balls had large spaces in between them representing the distance that particles are from each other due to all the forces that holds things together and keep things being "mostly empty space."
You cannot understand tunneling using this kind of analogy. Attempt to model particles as ping pong balls is likely to fail to describe quantum mechanical behavior, because it is the wave nature of matter that is being investigated. Passing through spaces in a wall is entirely the wrong way to look at things.
I would suggest looking at the wikipedia article on Quantum tunneling. Some of the articles that show up in a google search for the term may also be helpful.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
The apathy of the people is enough to make every statue leap from its pedestal and hasten the resurrection of the dead. William Lloyd Garrison.
Well, you may still have time to register to vote. Even North Carolinians can still register for early voting. State Registration Deadlines
Passing through spaces in a wall is entirely the wrong way to look at things.
I would suggest looking at the wikipedia article on Quantum tunneling.
Thanks for that, I found it very helpful. So, tunnelling isn't so much as I was describing it as it is more like a wave bumping into a barrier which causes reflection and transmition. Except... this isn't for things such as light reflecting off and also transmitting through glass... it's for actual particles because of their wave-and-particle nature.
So, in taking the "guy running into a brick wall and coming out the other side" example to the absurd lengths I'm talking about... what we would really end up with is a half-a-guy on the far side of the wall and the other half-a-guy bouncing back as normal. Because of conservation of energy.
Closer? If so, I feel like I can understand that a lot better than I could the other way I was thinking about it anyway.
So, in taking the "guy running into a brick wall and coming out the other side" example to the absurd lengths I'm talking about... what we would really end up with is a half-a-guy on the far side of the wall and the other half-a-guy bouncing back as normal. Because of conservation of energy.
Closer?
Much closer. But you aren't applying conservation the proper way. The amplitude "wave" in quantum theory is related to the probability of finding the particle in one location or the other rather than to the energy of a transmitted or reflected beam of light. A low transmission probability through the brick wall corresponds to a low probability of finding the particle on the other side rather than a 100% probability of finding a tiny part of the particle on the other side of the wall.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
The apathy of the people is enough to make every statue leap from its pedestal and hasten the resurrection of the dead. William Lloyd Garrison.
Well, you may still have time to register to vote. Even North Carolinians can still register for early voting. State Registration Deadlines
You don't get it, Nuke. The cat does not steal your personal arrow of time, silly. No way. You can keep it for personal use. Just don't project it on the universe. That's all.
I guess that I have to conclude that QM is simply beyond my capacity to understand. When reading about the KS theorem nearly every sentence requires 3 more pages of reading. It is like falling down a fractal well and after about 2 iterations I forget what the hell it was that I was trying to understand.
Is it fair to say that the issue has not actually been resolved and that there are some people who understand this stuff and who support the idea that the universe is deterministic all the way down? Or is there a consensus?
Thanks for that, I found it very helpful. So, tunnelling isn't so much as I was describing it as it is more like a wave bumping into a barrier which causes reflection and transmition. Except... this isn't for things such as light reflecting off and also transmitting through glass... it's for actual particles because of their wave-and-particle nature.
So, in taking the "guy running into a brick wall and coming out the other side" example to the absurd lengths I'm talking about... what we would really end up with is a half-a-guy on the far side of the wall and the other half-a-guy bouncing back as normal. Because of conservation of energy.
No, those are probability waves. The higher the amplitude the higher the odds that the particle will be found in that spot.
That just shows that there's a small chance that the particle will tunnel through the barrier, its not a portion of the particle making it through.
That's just looking at the same graph from the top down. The amplitute is the brightness of the white part. The portion of the dim white part that makes it through is the probability of the electron being found in that spot. There's a small chance of the electron tunneling through, but that is not a portion of the election tunneling through.
Edit: Oh, that's for a wave packet so we're talking multiple electrons. But its still the same for just one.
I guess that I have to conclude that QM is simply beyond my capacity to understand.
I think you're selling yourself short, I really think most people can understand the main facts about quantum mechanics, the only problem might be us experts providing poor explanations, so if there are any questions please ask.
When reading about the KS theorem nearly every sentence requires 3 more pages of reading. It is like falling down a fractal well and after about 2 iterations I forget what the hell it was that I was trying to understand.
That's natural, a lot of the concepts build on other concepts. Eventually you make it through though.
Is it fair to say that the issue has not actually been resolved and that there are some people who understand this stuff and who support the idea that the universe is deterministic all the way down? Or is there a consensus?
I would say there is near universal consensus that we cannot recover our old picture of the world and that only something very bizarre like quantum mechanics can accurately describe experimental results.
There are several theorems to this effect.
What the particular brand of weirdness needs to be though is a little more debatable. The Kochen-Specker theorem combined with Bell's theorem tell you that to match experimental results, under certain assumptions, a theory has to break either:
(A) Value Definiteness.
That is, physics is about objects with definite real properties.
(b) Non-Contextuality.
Non-Contextuality is a statement the human mind considers so obvious that it might seem odd to explain it. Basically non-contextuality assumes that physical parameters have no context, that when I decide to measure the spin of an electron, that measurement results are not influenced by other measurements I might perform. For example if I decide to take two electrons and measure the spin of the first and either energy of the second or its charge, the spin measurement of the first is unaffected. It is not influenced by what other measurements I choose to do.
So, either (a) or (b) have to go. Quantum Mechanics chooses (a).
People have designed theories where you get rid of (b), but they are full of problems. First of all, what if the second electron was located in Andromeda. To learn about the context of that electron, the first electron would have to send a faster-than-light signal to Andromeda. So if you drop (b) and keep (a) your theory has faster-than-light communication. In order not to break relativity, this communication must be undetectable physically, it's only used to access information without any influence.
Secondly, any particle being measured will not just require information on a single other particle. Particles are constantly interacting, which counts as being measured, all over the universe. These all count as information the particle requires to know its "context". Hence the particle must be interacting with every other particle in the universe faster-than-light in order to have this information. These interactions are themselves physical properties of the particle and it turns out there are infinitely many of them, hence any particle has an infinite numbers of properties. This is Hardy's excess ontological baggage theorem.
So either, under the assumptions of the theorems:
(1) Objects do not possess definite properties.
(2) They do, but it involves every particle in the universe communicating with every other faster than light, causing every particle to contain an infinite amount of information.
That was the position we were in until 2011, when a major new paper showed that (2) is just flat out impossible.
So with the assumptions of the theorems (Bell/Kochen Specker), only (1) is possible.
So the only questions now are: What does (1) mean? What if the assumptions are false?
The assumptions assume no retrocausal influence or relational properties. No retro-causal influence means the particles are not influenced by their own futures, signals travelling back in time to influence the particle by telling it which measurements will be performed. No relational properties means that individual systems or particles have a meaning in and of themselves. If properties were relational, there would be no "electron" and "equipment", but only "the electron and the equipment".
What about the meaning of (1)? Particles might have no definite properties for only two reasons: (i) They don't have definite properties, because there is no underlying reality, there is "just" probabilities. (ii) They don't have definite properties because all histories play out, one where each value for a property occurred. This is the many-worlds picture.
To sum up, there are only four possibilities consistent with the mathematics and experimental support of quantum mechanics. The world is either:
A collection of many-worlds, one where each possibility occurs.
The world is just probabilities, there are no real properties of particles, no actual spin or energy for example, just probabilities to produce a value at a random, which comes from nowhere, when an experiment is performed or an interaction takes place.
The world contains signals travelling backward in time, informing particles of their future.
Things only exist in relation to other things. "An electron" or "A water molecule" is not meaningful statement.
The only debate is which of the above is the physical picture underneath the mathematics, but it can only be these four.
There's a small chance of the electron tunneling through, but that is not a portion of the election tunneling through. Edit: Oh, that's for a wave packet so we're talking multiple electrons. But its still the same for just one.
Okay. Let me try again.
If we have only one electron (or "particle")... there is a probability distribution for whether or not it will tunnel through a potential barrier. (That's "potential" as in electrical potential... right? Not potential as in "a possible barrier"). However, after interfacing with the barrier, the electron will either be on the "other" side, or reflected back... but not both... and not "half an electron here, and half there."
Now, if we have a wave packet (a bunch of electrons/particles)... and they come across a potential barrier... then there is a probability distribution predicting the result, as shown in the *.gif. -It is possible, but not likely, that "most" of the electrons will appear on the other side, while only a few will reflect back. -It is possible, but not likely, that "most" of the electrons will reflect back, while only a few will "tunnel" through (they don't actually tunnel through... that's just what it's called when they show up on the other side). -It is possible, and likly, that roughly half (maybe a bit less) will tunnel through, and roughly half (maybe a bit more) will reflect back. -It is possible to calculate the probability for all the electrons to tunnel through... but this is very small (has it ever been observed?) -It is possible to calculate the probability for none of the electrons to tunnel through... but this is also very small (has it ever been observed?).
And, the example of the dude going through the brick wall is the same as the wave packet, right? That is, because the barrier is so thick, and the "wave packet" is so large (the dude). The probability of even *any* electrons/particles tunneling through is very small. The probability of *all* the electrons/particles going through is still calculable (if you can estimate how many electrons are in the guy?)... but that's even incredibly smaller still.
How's that?
Edited by Stile, : "with" to "will" as pointed out below. Typo is kind of a funny word... because it contains "po" which is close to "poo". And poo is always a funny word. Always!!!
(That's "potential" as in electrical potential... right? Not potential as in "a possible barrier").
No, I thinks its as in "a possible barrier", not electrical potential.
However, after interfacing with the barrier, the electron with will either be on the "other" side, or reflected back... but not both... and not "half an electron here, and half there."
Fixed it for ya, but yeah.
Now, if we have a wave packet (a bunch of electrons/particles)... and they come across a potential barrier... then there is a probability distribution predicting the result, as shown in the *.gif. -It is possible, but not likely, that "most" of the electrons will appear on the other side, while only a few will reflect back. -It is possible, but not likely, that "most" of the electrons will reflect back, while only a few will "tunnel" through (they don't actually tunnel through... that's just what it's called when they show up on the other side). -It is possible, and likly, that roughly half (maybe a bit less) will tunnel through, and roughly half (maybe a bit more) will reflect back. -It is possible to calculate the probability for all the electrons to tunnel through... but this is very small (has it ever been observed?) -It is possible to calculate the probability for none of the electrons to tunnel through... but this is also very small (has it ever been observed?).
If you send a packet, I don't think its possible that most of the electrons will tunnel through. You'll only get a minority of them tunneling through, and the odds of the ones that do get through are given by that probability wave. I may be wrong.
And, the example of the dude going through the brick wall is the same as the wave packet, right?
I thought the dude was represented by a single particle, not a packet of them. Perhaps I'm not getting it either.
That is, because the barrier is so thick, and the "wave packet" is so large (the dude). The probability of even *any* electrons/particles tunneling through is very small. The probability of *all* the electrons/particles going through is still calculable (if you can estimate how many electrons are in the guy?)... but that's even incredibly smaller still.
How's that?
That's not how I thought it was supposed to go, but now you're having me doubt myself!
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