Jump to content


Photo

Quantumphysics


  • Please log in to reply
114 replies to this topic

#1 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 05 April 2006 - 04:17 PM

Ishtvan, you said you are a physics student, right? Can you recommend any good introductionary books? Which branch of physics are you studying?
Of course if others have a good recommendations, then I would also like to hear it.

I'm not looking for some popular science books, because I have enough of them. I was thinking to get the Feynman Lectures, because I heard that they were good introduction to physics, but I'm not sure wether this is yet another popular scientific book, or if it is "the real" thing. What I'm looking for is above that level, but low enough that you can get into it.
I learned most of the vector math by reading appropriate books about it, and I'm looking for something similar, so if it involves some math I'm not afraid of it. :)
Gerhard

#2 Ishtvan

Ishtvan

    Programmer

  • Development Role
  • PipPipPipPipPip
  • 14860 posts

Posted 05 April 2006 - 08:04 PM

I'm not actually in Physics but in Materials Science. I'm in Electronic & Optical materials, so there is a good deal of Physics used in terms of quantum, solid state, electromagnetism and some thermo (I don't grow crystals myself, but people who do use more thermo and mechanics).

The Feynman lectures are good. I've heard only good things about them. I didn't read all of them personally, but did read his book on Quantum Electrodynamics before I knew anything about quantum and it was still very accessible, but in-depth enough to be able to solve some conceptual problems. They're probably a bit more conceptual than mathematical, but still should be a good introduction. He was very good at teaching.

If you want something more like a textbook, the ones often used for undergraduate quantum courses are: French & Taylor, Griffith, Cohen-Tannoudji, Eisberg & Resnick and I'm sure people will mention others. I used Cohen-Tannoudji for undergrad, and found it pretty well organized (although it was translated from French I think). Later I used Eisberg & Resnick which I didn't think was that great, and French & Taylor which was very good. I haven't used Griffith but know a lot of Physics people who swear by it. Be warned though that these books will assume some knowledge of math, like some linear algebra and some differential equations. Actually, I think Eisberg & Resnick probably assumes the least amount of math, but is not that well written IMO.

You could also look at the syllabus for a "conceptual physics" class to find a book that uses less math, but it might not be as in-depth as you're looking for. What is your goal, to be able to understand quantum concepts or to solve specific quantum problems?

#3 Darkness_Falls

Darkness_Falls

    Concept Artist

  • Member
  • PipPipPipPip
  • 2558 posts

Posted 05 April 2006 - 09:40 PM

Sparhawk, a book that I found helpful is called: "Quantum: A Guide for the Perplexed" by Jim Al-Khalili. It has a lot of colorful pictures and decent explanations, imo, of things. It's a pretty dry read -- then again, what book on math/phsycis wouldn't be -- but it is probably not as dry as most, and it is pretty good at breaking things down and explaining things on a level I can understand more than other books I've seen.
Maybe you would like it? Maybe you can thumb through the pages at a local bookstore to see if it is down your alley?

I had ordered another book on Quantum Theory through Amazon.com -- I can't remember the author off-hand -- and that thing was horrendous. I couldn't even get past page 3 because of all the crazy formulae and equations it was showing. I went through Calculus and Physics, and am fairly good at math, but nothing I've ever seen prepared me for these huge, crazy equations it was showing.

Heh... in college, I even registered to take a Quantum Mechanics course, but soon learned it was out of my league when they discussed the mathematical equations we shoud already be familiar with. I promptly dropped that class.

EDIT: If you are looking for a bunch of equations, the Jim Al-Khalili book probably wouldn't be good for you. Al-Khalili's book's purpose is more to teach you the concepts regarding Quantum Mechanics, to help you better understand how it works and what it means. There aren't very many equations in it.

#4 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 06 April 2006 - 02:23 AM

(Feynman) He was very good at teaching.


Yeah. That's what I heard as well. Fortunately I have collegue who has graduated in particle physics, and even worked in scientific research for some time, before he turned to programming. Now he is working under me and I'm kind of his boss, even though he has the much better education. Crazy world. :wacko:

If you want something more like a textbook, the ones often used for undergraduate quantum courses


That's what I want.

Be warned though that these books will assume some knowledge of math, like some linear algebra and some differential equations.


I have some background in math, but not that much. Of course we learned differentiation, integration, functions and all that stuff, but it was a long time ago, so I have to brush it up. I'm not afraid of that though. Quite on the contrary I want to understand it. :)

What is your goal, to be able to understand quantum concepts or to solve specific quantum problems?


Hmm... Of course I want to understand it. :)

I just read a book from Brian Green, which was recommended in the latest issue of Scientific American (the german edition) and it was quite good. Of course it contained no math, but the author was explaining a lot and he piqued my interest (again). Actually I read some books which were higher level, but this was 20 years ago, and I want to get up to date, and maybe a little farther. Farther in relation to what I understood last time, not in relation to current physics. ;)
Gerhard

#5 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 06 April 2006 - 02:29 AM

Sparhawk, a book that I found helpful is called: "Quantum: A Guide for the Perplexed" by Jim Al-Khalili. It has a lot of colorful pictures and decent explanations, imo, of things.


I check it out. But I'm not looking for yet another popular book, even though I still like to read them. :)

It's a pretty dry read -- then again, what book on math/phsycis wouldn't be


Hmm ... The last books that I read about math and physics were pretty exciting. :) But my wife also thinks that this is boring and dry stuff. I can see her eyes going glazy by just mentioning math on an extreme high level already. :)

Maybe you would like it? Maybe you can thumb through the pages at a local bookstore to see if it is down your alley?


I definitely take a look at it. If you are interested in such stuff, then you can take a look at Brian Green (don't know the english title of the latest book). This was really excellent, and it was the first time, that I managed to understand some aspects of relativity, which I always found abstract and didn't understand. Funny thing is, that working on the darkmod helped me as well, because it forced me to brush up my math, and the understanding I gained from this book is a direct consequence of this. :)

I had ordered another book on Quantum Theory through Amazon.com -- I can't remember the author off-hand -- and that thing was horrendous. I couldn't even get past page 3 because of all the crazy formulae and equations it was showing. I went through Calculus and Physics, and am fairly good at math, but nothing I've ever seen prepared me for these huge, crazy equations it was showing.


Which one was it?

Heh... in college, I even registered to take a Quantum Mechanics course, but soon learned it was out of my league when they discussed the mathematical equations we shoud already be familiar with. I promptly dropped that class.


LOL. I can imagine that. :) I was reading a book from Roger Penrose many years ago "The emperors new mind" and there was a lot of math in it that was over my head. Still, even without understanding the math, his arguments didn't convince me. It was about trying to find an explanation of consciousness by using quantum mechanical effects.

EDIT: If you are looking for a bunch of equations, the Jim Al-Khalili book probably wouldn't be good for you. Al-Khalili's book's purpose is more to teach you the concepts regarding Quantum Mechanics, to help you better understand how it works and what it means. There aren't very many equations in it.


Ah. From your description I thought so, so this is not exactly what I'm looking for. The problem is that the equations alone will not help me anyway. I guess I can find the equations quite easily also on the internet, so I'm looking for something that can lead me to an understanding of such equations.
Gerhard

#6 Darkness_Falls

Darkness_Falls

    Concept Artist

  • Member
  • PipPipPipPip
  • 2558 posts

Posted 06 April 2006 - 10:50 AM

The Amazon.com book I mentioned (that has a bunch of math formulas in it) is called "Quantum Theory" by David Bohm. Hmm, the copyright on it is 1951... but the reviews on Amazon.com for it were good when I got it. It must still be beneficial to read for some.

#7 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 06 April 2006 - 11:08 AM

Bohm is certainly a name I know. :) No doubt that it has a lot of formulas in it. :)
Gerhard

#8 Ishtvan

Ishtvan

    Programmer

  • Development Role
  • PipPipPipPipPip
  • 14860 posts

Posted 06 April 2006 - 06:39 PM

Oh yeah, I forgot: There's also an out of print book by Walter Heitler. I forget what it's called but it's not the one on quantum theory of radiation, it's an introduction. As I recall that used a bit more simple math and intuitive approach when going through some of the standard quantum problems. It's pretty old though (~1930?) and out of print.

I think French & Taylor, Griffith or Cohen-Tannoudji are all pretty good. Eisberg & Resnick is okay but takes more of an engineering approach. It's just a matter of what style you like. I'd suggest going to a book store and flipping through those before deciding which one to buy.

#9 demagogue

demagogue

    Mod hero

  • Active Developer
  • PipPipPipPipPip
  • 5475 posts

Posted 06 April 2006 - 07:37 PM

I went Googling on this a few months back ... and I found a LOT of full class lectures on-line, with all the math and notes and explanations on the notes, and many times linked with online .pdf files to fill it out even more.

A textbook may be more compact, but having all the resources of a class to me is just as valuable; it's more oriented towards actual students and their dumb questions, tends to have more "fun" examples, and just fills things out. Probably good to have both. But anyway, best of all it's all free.

It may depend on your goals in doing it, too. For me, it's the random little articles and bon mots in a lecture that really bring the topic alive for me. And as for the math, one word: redundancy, hearing the same thing explained 12 different ways through the lectures of different profs really pounds the point home, and different homeworks that make you look at the same math in different ways. And sometimes a textbook just gives one explanation, and a thin one at that. It does take more time to sift through, but I'm not in any rush anyway, and sort of have fun "exploring" through the morass. Unfortunately, I don't have links on this computer, but a google for "quantum physics lectures" is a good place to start.

I read Penrose's Emporer's New Mind and found the physics part interesting because I thought it was an elegant explanation, but the mind part I didn't buy at all and found it a terrible argument through and through. I was a philosophy student studying phil of mind, though ... so I was extra critical because it was my home-turf. Anyway, most of what goes on with cognition, even at the "lowest" levels, is still *way* above the quantum level (although your photoreceptors can detect the purterbation of even a single photon).

By the way, a good article online somewhere is the "transactional interpretation" of quantum physics, which is great as a primer to give your mind a visual image to work with when going to the math, something physical that is actually going on you can put your hands on so-to-speak, and has made "visualizing" things so much easier. Whether it's true or not doesn't matter since the math is the same either way; but it helps in visualizing things so much it's worth the effort. So I recommend googling that.
Posted Image

#10 Maximius

Maximius

    Advanced Member

  • Member
  • PipPipPip
  • 1239 posts

Posted 06 April 2006 - 10:46 PM

I read Penrose's Emporer's New Mind and found the physics part interesting because I thought it was an elegant explanation, but the mind part I didn't buy at all and found it a terrible argument through and through. I was a philosophy student studying phil of mind, though ... so I was extra critical because it was my home-turf. Anyway, most of what goes on with cognition, even at the "lowest" levels, is still *way* above the quantum level (although your photoreceptors can detect the purterbation of even a single photon).


Did Penrose say anything about free will and quantum mechanics? And what kind of work did you do in philo of mind?

Edited by Maximius, 06 April 2006 - 10:56 PM.


#11 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 07 April 2006 - 02:45 AM

A textbook may be more compact, but having all the resources of a class to me is just as valuable; it's more oriented towards actual students and their dumb questions, tends to have more "fun" examples, and just fills things out. Probably good to have both. But anyway, best of all it's all free.


If you can post some links that would be great. It will probably take away a lot of questions or missunderstandings that I certainly will have.

It may depend on your goals in doing it, too. For me, it's the random little articles and bon mots in a lecture that really bring the topic alive for me. And as for the math, one word: redundancy, hearing the same thing explained 12 different ways through the lectures of different profs really pounds the point home, and different homeworks that make you look at the same math in different ways.


That's right. :) I noticed this effect too. :)

And sometimes a textbook just gives one explanation, and a thin one at that. It does take more time to sift through, but I'm not in any rush anyway, and sort of have fun "exploring" through the morass.


That's the same for me. I'm in no hurry to do a major or something, so it's jut fopr a hobby.

I read Penrose's Emporer's New Mind and found the physics part interesting because I thought it was an elegant explanation, but the mind part I didn't buy at all and found it a terrible argument through and through.


That was my problem as well. :) I was reading it more because I was interested in the mind aspect, but this was totally insatisfactory. I assumed that the math was correct, since Penrose is a mathematician, but the conclusions were pretty strange imo.

I was a philosophy student studying phil of mind, though ... so I was extra critical because it was my home-turf. Anyway, most of what goes on with cognition, even at the "lowest" levels, is still *way* above the quantum level (although your photoreceptors can detect the purterbation of even a single photon).


That's also my believe. Some books claim that there is no such invisible barrier, that seperates the microscopic world form the macrospe, but I don't think that such a barrier is needed. Statistics would be sufficient to explain why we only see classical behaviour in our world even though it is different in the quantum world.

By the way, a good article online somewhere is the "transactional interpretation" of quantum physics, which is great as a primer to give your mind a visual image to work with when going to the math, something physical that is actually going on you can put your hands on so-to-speak, and has made "visualizing" things so much easier. Whether it's true or not doesn't matter since the math is the same either way; but it helps in visualizing things so much it's worth the effort. So I recommend googling that.


I wonder if this is the same interpretation that I just finished reading. I totally dislike this interpretation, because it sounds more like an arbitrary crutch made up to explain something just to have ANY explanation.
Gerhard

#12 Ishtvan

Ishtvan

    Programmer

  • Development Role
  • PipPipPipPipPip
  • 14860 posts

Posted 07 April 2006 - 05:07 AM

Anyway, most of what goes on with cognition, even at the "lowest" levels, is still *way* above the quantum level (although your photoreceptors can detect the purterbation of even a single photon).


I'll admit I don't know much of anything about neuroscience, but can't refuse to take this bait. If what you say is the case, then why are people studying shot noise in neurons? (Shot noise is a direct consequence of charge being quantized) http://www.ncbi.nlm....5&dopt=Abstract

#13 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 07 April 2006 - 05:46 AM

Probably for the same reason why computers already have to take quantum effects into account because of the dimensions. Of course is a neuron susceptible to quantum effects, but the question is, wether this is enough to make it really act upon and has any influence on the overall brain activity.
Gerhard

#14 OrbWeaver

OrbWeaver

    Mod hero

  • Active Developer
  • PipPipPipPipPip
  • 7598 posts

Posted 07 April 2006 - 05:56 AM

Wasn't Penrose the puveyor of some ridiculous theory about quantum affects in certain cellular structures ("nanotubules" IIRC) being responsible for "free will"?

Basically the theory was "free will is a bit weird and mysterious, and so is quantum theory, therefore perhaps they are related, who knows?".

#15 Maximius

Maximius

    Advanced Member

  • Member
  • PipPipPip
  • 1239 posts

Posted 07 April 2006 - 08:37 AM

Wasn't Penrose the puveyor of some ridiculous theory about quantum affects in certain cellular structures ("nanotubules" IIRC) being responsible for "free will"?

Basically the theory was "free will is a bit weird and mysterious, and so is quantum theory, therefore perhaps they are related, who knows?".



I've heard of this theory. I've seen it used to defend a particular position in the free will debate, that in order to be considered free an agent has to be free of her will. There has to be an "alternative possibility" to what the agent is willing at any given time. Quantum activity's effect on our neurons is thought to be an event that takes the determinism out of our wills, it allows us to zig when everything else in the world is dictating that we zag. It introduces a moment when the agent can do otherwise than what it is willing, which for libertarian incompatibilists (those who argue freedom is incompatible with a determined universe) is a necessary condition to consider a being as being free willed.

There are some problems with this. For one, a quantum events causal chain is every bit as deterministic as a non-quantum event, its just not predictable. Secondly, why would you consider a random event as freedom producing? If you are willing to run out of a burning house but at the last second a quantum event zigs your will and you sit down to die, is that freedom producing?

#16 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 07 April 2006 - 08:50 AM

I don't think that quantum events can achieve that. :) I understand it more on a basis like that it can affect a decision in one way or another. Kind of: You are undecided about an issue. Either option A or option B. A quantum effect could be that tiny difference that makes your decision final.
Another thing where I could see quantum effects having an influence could be in that Dennetts proposal. In his book "Consciousness explained" that favoured an idea that your mind is a kind of constantly fluctuating mass. All possible options are represented. Now when some options become more realistic then others, they are kind of growing (like a mathematical function that has several maximas). The quantum effect could be that tiny seed that is needed to create such a option in the first place and if you have several maximas and you need to make a decision the quantum effect could decide which one is really taken in the end.
Unfortunately I'm not as good as writing these ideas down, as some of you are, so it might be hard to understand what I mean.
Gerhard

#17 OrbWeaver

OrbWeaver

    Mod hero

  • Active Developer
  • PipPipPipPipPip
  • 7598 posts

Posted 07 April 2006 - 09:01 AM

There are some problems with this. For one, a quantum events causal chain is every bit as deterministic as a non-quantum event, its just not predictable. Secondly, why would you consider a random event as freedom producing? If you are willing to run out of a burning house but at the last second a quantum event zigs your will and you sit down to die, is that freedom producing?


The major problem was that the theory made absolutely no attempt to explain HOW these mysterious quantum effects could affect consciousness. It was just replacing one mystery (free will) with another (quantum effects), without postulating any scientific link between the two.

The problem is that there is not a shred of scientific evidence that points to the existence of genuine free will, in most cases it appears that the brain is just a complex machine that processes inputs and generates outputs. Although very little is known about the detailed mechanisms involved, there is little to suggest a lack of determinism other than "OMG OF C0URS3 I CAN CONTRL MY 0WN BRA!N!!!LOL".

Another thing where I could see quantum effects having an influence could be in that Dennetts proposal. In his book "Consciousness explained" that favoured an idea that your mind is a kind of constantly fluctuating mass. All possible options are represented. Now when some options become more realistic then others, they are kind of growing (like a mathematical function that has several maximas). The quantum effect could be that tiny seed that is needed to create such a option in the first place and if you have several maximas and you need to make a decision the quantum effect could decide which one is really taken in the end.


I find Dennett's theories to very well-thought out and reasonable. He doesn't make any assumptions based on the way things seem to be (like there is someone in control at the top of the brain with ultimate authority over everything else). The problem with relying on quantum effects is that they are absolutely tiny when compared to the (very deterministic) behaviour of neurons - they are no more likely to have an effect at the brain level than individual molecules in a gas could override the pressure equations.

#18 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 07 April 2006 - 09:25 AM

I find Dennett's theories to very well-thought out and reasonable. He doesn't make any assumptions based on the way things seem to be (like there is someone in control at the top of the brain with ultimate authority over everything else). The problem with relying on quantum effects is that they are absolutely tiny when compared to the (very deterministic) behaviour of neurons - they are no more likely to have an effect at the brain level than individual molecules in a gas could override the pressure equations.


I think the first question is, wether a single neuron can affect the thought process in such a strong way that it makes a difference? I doubt this. AFAIK it requires more neurons to work in unision to have any result. Neurons are firing all the time in your brain, and many of them are not ncessarily in sync until they really start to work together. There are all kind of thoughts, inputs from your body and outside events that are handled and constantly going on. So if a single neuron can NOT have such a strong influence on the brain, then it is a moot point to speculate about quantum effects, because they would operate on only single neurons any way. Otherwise you would have to assume that multiple quantum effects would happen across different neurons and how likely is that?
Gerhard

#19 Maximius

Maximius

    Advanced Member

  • Member
  • PipPipPip
  • 1239 posts

Posted 07 April 2006 - 12:09 PM

spar:
I don't think that quantum events can achieve that. :) I understand it more on a basis like that it can affect a decision in one way or another. Kind of: You are undecided about an issue. Either option A or option B. A quantum effect could be that tiny difference that makes your decision final.

Why not? If Q events play a role in our decision making process, whats to stop them from generating utterly random decisions? Whats to say that you are considering A or B, but a Q event comes along and pushes you to C? Whats to say you actually decide to DO A or B but then a Q event comes along and makes you do C or the opposite of what you decided? Nothing.


spar:
Another thing where I could see quantum effects having an influence could be in that Dennetts proposal. In his book "Consciousness explained" that favoured an idea that your mind is a kind of constantly fluctuating mass. All possible options are represented. Now when some options become more realistic then others, they are kind of growing (like a mathematical function that has several maximas). The quantum effect could be that tiny seed that is needed to create such a option in the first place and if you have several maximas and you need to make a decision the quantum effect could decide which one is really taken in the end.

I havent read Consciousness Explained yet, but I could see a role for Q events in forming +possible+ reasons for decisions. IIUC, our minds are filled with possible reasons for actions and Q events stir up the pot by injecting doses of randomness. So you were thinking of A or B but now along comes the possibility of C thanks to a Q event. But this still requires a non-random level of processing that would mitigate the decision to go with A, B, or C or the results could be that you are considering A, B, and C but do D because a Q event threw you a curveball. In other words their role is restricted to presenting new possibilities but not to actually enacting those possibilities. THis is a much different thing than saying they play a direct role in the actual process of decision making.

Edited by Maximius, 07 April 2006 - 12:50 PM.


#20 Darkness_Falls

Darkness_Falls

    Concept Artist

  • Member
  • PipPipPipPip
  • 2558 posts

Posted 07 April 2006 - 12:20 PM

So if a single neuron can NOT have such a strong influence on the brain, then it is a moot point to speculate about quantum effects, because they would operate on only single neurons any way. Otherwise you would have to assume that multiple quantum effects would happen across different neurons and how likely is that?

In the quantum world, I don't think two completely separate events happening at the same time, or a collective comprised of individuals (like neurons) behaving in a similar way, is all that unheard of.

Individual atoms can behave a certain way until they are measured, at which time they then collectively (yet as individuals) all the sudden behave a different way.

What explains a bacterium mutating a certain way at one moment in time, with a separate one on the opposite side of the globe mutating at the same time? Do they classify that as quantum? (I can't remember). At any rate, I don't think multiple quantum effects happening across different neurons would be that unheard of in the quantum world.

#21 Maximius

Maximius

    Advanced Member

  • Member
  • PipPipPip
  • 1239 posts

Posted 07 April 2006 - 12:40 PM

orb:
The problem is that there is not a shred of scientific evidence that points to the existence of genuine free will, in most cases it appears that the brain is just a complex machine that processes inputs and generates outputs. Although very little is known about the detailed mechanisms involved, there is little to suggest a lack of determinism other than "OMG OF C0URS3 I CAN CONTRL MY 0WN BRA!N!!!LOL".

It depends on your definition of a free will. And genuine. I dont think science can describe a free will, its a philosophical point because it emerges out of a process of our brain/mind its not an material aspect of them per say. Its something that can only be abstracted, not concretely analyzed.

To Dennetts thinking, as well as my own, there is room for freedom in the formation of our wills. Our wills are certainly not free in the sense that they are somehow above or able to ignore the deterministic processes of our brains, they are the product of those processes and are utterly determined by them. They are complex machines but machines whose actions can be determined by something no other machine can, by the equally complex web of conscious reasons that our minds generate. We act, our actions are determined, but part of that determining process are the reasons that develop in our consciousness. To be free of this would be literally to be free of being oneself, which makes no sense. We want to be determined by the things that we have reasons for wanting. Thats our degree of freedom of the will, the freedom to be determined by a complex of reasons and wants that are uniquely our own. No other mind can generate the determining factors that your own mind will.

Edited by Maximius, 07 April 2006 - 01:08 PM.


#22 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 07 April 2006 - 01:13 PM

Why not? If Q events play a role in our decision making process, whats to stop them from generating utterly random decisions? Whats to say that you are considering A or B, but a Q event comes along and pushes you to C? Whats to say you actually decide to DO A or B but then a Q event comes along and makes you do C or the opposite of what you decided? Nothing.


There is. That was what I tried to explain. The problem is the size. As I said before, a single neuron doesn't make a difference. A neuron is constructed of molecules and as such is way beyond bigger than a quantum particle. So if you say that a particle could influence the entire brain, it means that it has to influence the neuron. It would take a lot of particles to do this because a neuron is so much bigger. If we say that a particle can have an effect, what are we talking about? Do we mean that a single particle can switch over a neuron? A neuron requires some activty to change it's state, so we would need a big number of particles achieving this. And the chances are pretty slim, because supposedly, particles are not working to a common effort. And now that this big number of particles has managed to influence the neuron enough that it starts to change it's activity, what did we achieve? We have a single neuron doing something crazy out of how many? Millions? So how could quantum effects REALLY make a difference?

I havent read Consciousness Explained yet, but I could see a role for Q events in forming +possible+ reasons for decisions. IIUC, our minds are filled with possible reasons for actions and Q events stir up the pot by injecting doses of randomness.


Yeah, that's what I mean, but when I look at the number, I don't see how this realisitcially can happen. if that were the case, then we should see quantum effects also in other objects.

So you were thinking of A or B but now along comes the possibility of C thanks to a Q event.


I don't see how the possibillity of C should ever arise because of a quantum effect. Just think of the sheer numbers that it requires to have a decision.

In my opinion, introducing quantum effects in the thought processes, is like describing the activity of the sun on the level of quantum mechanics. You could do it, but the sheer number of calculations required makes it impossible.
Gerhard

#23 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 07 April 2006 - 01:30 PM

In the quantum world, I don't think two completely separate events happening at the same time, or a collective comprised of individuals (like neurons) behaving in a similar way, is all that unheard of.


Not sure what you mean by that. Are you talking about non-locaility effects?

Individual atoms can behave a certain way until they are measured, at which time they then collectively (yet as individuals) all the sudden behave a different way.


If we are talking about quantumeffects we are talking about particles and not atoms. Atoms are much bigger than particles and they behave quite well. Shroedingers Uncertainty Principle, what you are talking of, operates on quantum level. We already can even photograph and manipulate individual atoms, and the (supposed) size is much bigger. Also I never heard that atoms would have spontanous creation as particles are supposed to be able to.

What explains a bacterium mutating a certain way at one moment in time, with a separate one on the opposite side of the globe mutating at the same time?


How would you know that? Mutations are pretty much random. So how would you know that one bacterium mutates and does it in the same way, at the same time, in some totally dislocated one.

Do they classify that as quantum? (I can't remember). At any rate, I don't think multiple quantum effects happening across different neurons would be that unheard of in the quantum world.


If you say "multiple" here, we would be talking of billions of effects.

Just to give you an idea. The human brian consists of about 100 billion NEURONS! NEURONS! Now think how many it requires to make a decision. It's not enough to influence a single one. A neuron is substiantially bigger than molecules. Molecules are constructed from atoms and this goes down until we have particles, where quantum effects can operate. So any quantum effect must be strong enough to propagate up the chain all the way. And not only in one neuron, it would have to have this effect in many many neurons.
Gerhard

#24 Darkness_Falls

Darkness_Falls

    Concept Artist

  • Member
  • PipPipPipPip
  • 2558 posts

Posted 07 April 2006 - 11:40 PM

DF wrote: Individual atoms can behave a certain way until they are measured, at which time they then collectively (yet as individuals) all the sudden behave a different way.


SH wrote: If we are talking about quantumeffects we are talking about particles and not atoms. Atoms are much bigger than particles and they behave quite well. Shroedingers Uncertainty Principle, what you are talking of, operates on quantum level. We already can even photograph and manipulate individual atoms, and the (supposed) size is much bigger.

Nope, I'm talking atoms. And I just verified in Jim Al-Khalili's book again. There are diagrams showing atoms shooting out of a gun through a slit(s) and hitting a surface. They disperse in one way when not being observed, and then in a different way when being observed. Two different behaviors.

DF wrote: What explains a bacterium mutating a certain way at one moment in time, with a separate one on the opposite side of the globe mutating at the same time?

SH wrote: How would you know that? Mutations are pretty much random. So how would you know that one bacterium mutates and does it in the same way, at the same time, in some totally dislocated one

I don't know this, I hear or read it in the news. I'm not some scientist conducting elaborate microscopic tests on bacteria (or atoms, for that matter). How do you know anything? You hear or read about it. See below for a quick blurb I found on the net ot help support my statement (a statement/observation I've heard multiple times, from multiple sources)...

In another study, James Musser at the National Institute of Allergy and Infectious Disease showed different strains of staph could steal genes and transform themselves simultaneously in different places around the world. He analyzed genes in 36 strains of staph to determine their evolutionary relationships and showed that many had picked up the same virulence and resistance genes independently. The gene for methicillin resistance, for example, had been acquired by five separate strains in five different places. Source: http://www.discover....tures/medicine/



#25 sparhawk

sparhawk

    Repository Manager

  • Active Developer
  • PipPipPipPipPip
  • 21776 posts

Posted 08 April 2006 - 12:26 AM

Nope, I'm talking atoms. And I just verified in Jim Al-Khalili's book again. There are diagrams showing atoms shooting out of a gun through a slit(s) and hitting a surface. They disperse in one way when not being observed, and then in a different way when being observed. Two different behaviors.


Can you point me to the article? I'm pretty sure you are confusing the terms here. This experiment is done with light rays. Scientists were able to create devices where a single phtono was emited at a time, and this experiment shows that even then the interference effect takes places. This can be observed with electrons as well, but not with atoms. At least I have never read anywhere that you can do this interference test also on the level of an atom. If you reread that article, it would be intersting to see wether they are talking about photons (which I assume) which are NOT atoms.

I don't know this, I hear or read it in the news. I'm not some scientist conducting elaborate microscopic tests on bacteria (or atoms, for that matter). How do you know anything? You hear or read about it. See below for a quick blurb I found on the net ot help support my statement (a statement/observation I've heard multiple times, from multiple sources)...


Having mutations is nothing spectacular. Since there are quite a lot of bacterias, it would also not surprising if multiple bacterias have the same mutation and even at the same time. I was merely wondering about the statemten that two bacterias have the same mutation at the same time and they are seperated across the world. I'm not wondering about the fact itself, only about how they verified that claim.

I noticed your link to late as your quoting was a bit strange. I don't read that "simultanouos" in that article as "exactly the same time". From the context it seems more to me that it is meant that they happen around the same time. Anyway. Depending on the circumstances there might be only a limited number of how that particular resitance could be built, so it would not be surprising to see the same resistance evolving if exposed to the same threat.
Gerhard




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users