### Re: [Fis] Fw: Responses

Dear colleagues, This discussion and reading the beautiful book of Bob Logan entitled What is information? (shortly forthcoming) made me go back to reading MacKay (1969) once more. I cannot find the distinction that makes a difference as it is quoted by Floridi (2005) -- and thereafter repeated by many -- so that I think that the honour goes to Bateson (1973) for a difference which makes a difference. MacKay, however, makes the point, for example, on p. 136 that the sentence S is a source of information is incomplete. It must always be completed (even if sometimes implicitly) in the form 'S is a source of information to receiver R'. Two sentences later he calls this significant information that must be capable of embodying and abiding by an agreed code or symbolic calculus. Elsewhere, he distinguishes this substantive concept of information from amounts of information that can be measured using (Shannon's) information theory. It seems to me that any discourse (physics, biology, psychology, sociology, etc.) can be further informed specifically in terms that are defined within and relevant to the specific discourse. This accords with the intuitive sense of information as meaningful information: meaningful for a discourse. Shannon's definition of information is counter-intuitive, but it provides us with a calculus that has major advantages. Katherine Hayles suggested that the two concepts can be compared with the discussion of whether a glass is half-full or half-empty. A Chinese colleague (Wu Yishan) once told me that in Chinese one has two words: sjin sji and tsin bao which correspond respectively to Shannon's and Bateson's definitions of information. A substantive definition of information (e.g., as a distinction that makes a difference for a receiver) requires the specification of the concept in a theory about the receiving system. This definition is therefore a priori system-specific; for example, for some of us this system is physics; for others it is biological discourse. At this level, one can again abstract from the substance and use Shannon's IT as entropy statistics. Sometimes, this allows us to explore the use of algorithms developed in one field (e.g., biology) in another (e.g., sociology). Concepts such as autopoiesis or auto-catalysis have carried these functions. For example, in the context of Ascendency Theory, Bob Ulanowicz showed how one can use the mutual information in three dimensions as an indicator of systemness. I use that as a systems indicator when operationalizing the triple helix of university-industry-government relations. Such translations of metaphors are always in need of further elaboration because the theoretical context changes and thus the specification of what the information means. However, the advantage to be able to measure in bits (nats or dits) frees us from the philosophical confusion about what information is. In my opinion, information can only be defined within a discourse. The mathematical definition of Shannon has specific functions which enable us to combine with different discourses (among which, specifically physics since S = k(B)*H). H, however, is dimensionless and defined as the expected information content of a message *before* it is received. It is yet to be provided with meaning. One could consider this meaninglesness as the specific difference of a mathematical concept of information. (Perhaps, it is easier to use uncertainty for this mathematical concept.) Best wishes, Loet -Original Message- From: fis-boun...@listas.unizar.es [mailto:fis-boun...@listas.unizar.es] On Behalf Of Robert E. Ulanowicz Sent: Tuesday, January 21, 2014 8:45 PM To: Christophe Cc: fis@listas.unizar.es Subject: Re: [Fis] Fw: Responses The reason of being of information, whatever its content or quantity, is to be used by an agent (biological or artificial). Dear Christophe, In making this restriction you are limiting the domain of information to communication and excluding all information that inheres in structure per-se. John Collier has called the latter manifestation enformation, and the calculus of IT is quite effective in quantifying its extent. Perhaps John would like to comment? Cheers, Bob U. ___ fis mailing list fis@listas.unizar.es https://webmail.unizar.es/cgi-bin/mailman/listinfo/fis ___ fis mailing list fis@listas.unizar.es https://webmail.unizar.es/cgi-bin/mailman/listinfo/fis

### Re: [Fis] Fw: Responses

At 09:45 PM 2014-01-21, Robert E. Ulanowicz wrote: The reason of being of information, whatever its content or quantity, is to be used by an agent (biological or artificial). Dear Christophe, In making this restriction you are limiting the domain of information to communication and excluding all information that inheres in structure per-se. John Collier has called the latter manifestation enformation, and the calculus of IT is quite effective in quantifying its extent. Perhaps John would like to comment? I developed this concept in order to reply to Jeff Wicken's complaint that Brooks and Wiley did not distinguish properly between the complement of entropy and structural information, but I used it in print to discuss, in the context of cognitive science and especially John Perry's use of information (see Barwise and Perry Situations and Attitudes and his What is information?, as well as Dretske's book on information and perception) what the world must be like in order to make sense of information coming from the world into our brains. The article can be found at Intrinsic Information (1990) In P. P. Hanson (ed) Information, Language and Cognition: Vancouver Studies in Cognitive Science, Vol. 1 (originally University of British Columbia Press, now Oxford University Press, 1990): 390-409. Details about information are there, but the gist of it is that can be measured, is unique, and depends on time scale to distinguish it from informational entropy in information systems. The uniqueness hypothesis was developed very carefully in my former student, Scott Muller's PhD thesis, published as Asymmetry: The Foundation of Information (The Frontiers Collection) by Springer in 2007. I am rather busy now at a conference, or else I would say more here. John Professor John Collier colli...@ukzn.ac.za Philosophy and Ethics, University of KwaZulu-Natal, Durban 4041 South Africa T: +27 (31) 260 3248 / 260 2292 F: +27 (31) 260 3031 Http://web.ncf.ca/collier ___ fis mailing list fis@listas.unizar.es https://webmail.unizar.es/cgi-bin/mailman/listinfo/fis

### Re: [Fis] Fw: Responses

Dear Bob U, If your are talking about resident information, as available for usage, I take it as being part of information that can be used by the agent. Let me go through John's paper (thanks John). Best Christophe Date: Tue, 21 Jan 2014 14:45:15 -0500 Subject: Re: [Fis] Fw: Responses From: u...@umces.edu To: christophe.men...@hotmail.fr CC: lo...@physics.utoronto.ca; fis@listas.unizar.es The reason of being of information, whatever its content or quantity, is to be used by an agent (biological or artificial). Dear Christophe, In making this restriction you are limiting the domain of information to communication and excluding all information that inheres in structure per-se. John Collier has called the latter manifestation enformation, and the calculus of IT is quite effective in quantifying its extent. Perhaps John would like to comment? Cheers, Bob U. ___ fis mailing list fis@listas.unizar.es https://webmail.unizar.es/cgi-bin/mailman/listinfo/fis

### Re: [Fis] Probability Amplitudes

Dear Hans, I would like just to point that 99,99% of people working in quantum theory would say that the complex amplitude of quantum probability is the main its intrinsic property, so if you try to exclude amplitudes from the model you can in principle do this and this is well known long ago in so called quantum tomographic approach of Vladimir Manko, but in this way quantum theory loses its simplicity and clarity, yours, andrei Andrei Khrennikov, Professor of Applied Mathematics, International Center for Mathematical Modeling in Physics, Engineering, Economics, and Cognitive Science Linnaeus University, Växjö-Kalmar, Sweden From: fis-boun...@listas.unizar.es [fis-boun...@listas.unizar.es] on behalf of Hans von Baeyer [henrikrit...@gmail.com] Sent: Wednesday, January 22, 2014 12:21 AM To: fis@listas.unizar.es Subject: [Fis] Probability Amplitudes Dear Dino and friends, thanks for bringing up the issue of probability amplitudes. Since they are technical tools of physics, and since I didn't want to go too far afield, I did not mention them in my lecture. The closest I came was the wavefunction, which, indeed, is a probability amplitude. In order to make contact with real, measurable quantities, it must be multiplied by its complex conjugate. This recipe is called the Born rule, and it is an ad hoc addition to the quantum theory. It lacks any motivation except that it works. In keeping with Einstein's advice (which he himself often flouted) to try to keep unmeasurable concepts out of our description of nature, physicists have realized long ago that it must be possible to recast quantum mechanics entirely in terms of probabilities, not even mentioning probability amplitudes or wavefunctions. The question is only: How complicated would the resulting formalism be? (To make a weak analogy, it must be possible to recast arithmetic in the language of Roman numerals, but the result would surely look much messier than what we learn in grade school.) Hitherto, nobody had come up with an elegant solution to this problem. To their happy surprise, QBists have made progress toward a quantum theory without probability amplitudes. Of course they have to pay a price. Instead of unmeasurable concepts they introduce, for any experiment, a very special set of standard probabilities (NOT AMPLITUDES) which are measurable, but not actually measured. When they re-write the Born rule in terms of these, they find that it looks almost, but not quite, like a fundamental axiom of probability theory called Unitarity. Unitarity decrees that for any experiment the sum of the probabilities for all possible outcomes must be one. (For a coin, the probabilities of heads and tails are both 1/2. Unitarity states 1/2 + 1/2 = 1.) This unexpected outcome of QBism suggests a deep connection between the Born rule and Unitarity. Since Unitarity is a logical concept unrelated to quantum phenomena, this gives QBists the hope that they will eventually succeed in explaining the significacne of the Born rule, and banishing probability amplitudes from quantum mechanics, leaving only (Bayesian) probabilities. So, I'm afraid dear Dino, that the current attitude of QBists is that probability amplitudes are LESS fundamental than probabilities, not MORE. But the story is far from finished! Hans ___ fis mailing list fis@listas.unizar.es https://webmail.unizar.es/cgi-bin/mailman/listinfo/fis

### Re: [Fis] Probability Amplitudes

Dear Joseph, you are going toward quantum probability theory where probabilities are determined by vectors; moreover, the vectors belong to complex Hilbert space, i.e., roughly speaking each probability has not only the direction but even the phase, andrei Andrei Khrennikov, Professor of Applied Mathematics, International Center for Mathematical Modeling in Physics, Engineering, Economics, and Cognitive Science Linnaeus University, Växjö-Kalmar, Sweden From: fis-boun...@listas.unizar.es [fis-boun...@listas.unizar.es] on behalf of Joseph Brenner [joe.bren...@bluewin.ch] Sent: Wednesday, January 22, 2014 8:54 AM To: Dino Buzzetti; Hans von Baeyer; fis Subject: Re: [Fis] Probability Amplitudes Dear Hans and Dino, This is a direct question to both of you, to which I have not found a clear answer: are value and amplitude the only parameters that have been assigned to probability? In my theory, the changing value of actuality and potentiality of specific antagonistic process elements are probability-like in not including 0 and 1, as I have said. Can, in addition, probabilities have some vector-like properties, that is, include a /direction/? This concept would be moving toward (and past) Dino and away from Hans . . . Your comments and those of others would be welcome. Best wishes, Joseph - Original Message - From: Dino Buzzettimailto:dino.buzze...@gmail.com To: Hans von Baeyermailto:henrikrit...@gmail.com ; fismailto:fis@listas.unizar.es Sent: Wednesday, January 22, 2014 3:53 AM Subject: Re: [Fis] Probability Amplitudes Dear Hans, Thank you for your explanation about probability amplitudes, that clarifies a lot. My only worry was about the *epistemological* implications of quantum mechanics in its standard formulation, that in my opinion point to a paradigm shift, which is felt not only in this domain, but in all fields where *emergent* phenomena are accounted for—a process that I thought was hinted to by Wheeler's famous words It from Bit, that I remember reading for the first time precisely in your book on information. That's the ground for expressing my worry that reverting to classical probability theory might entail a drawback to this decisive epistemological turn. But I might misunderstand the whole story, that is certainly not over yet :-) -dino On 22 January 2014 00:21, Hans von Baeyer henrikrit...@gmail.commailto:henrikrit...@gmail.com wrote: Dear Dino and friends, thanks for bringing up the issue of probability amplitudes. Since they are technical tools of physics, and since I didn't want to go too far afield, I did not mention them in my lecture. The closest I came was the wavefunction, which, indeed, is a probability amplitude. In order to make contact with real, measurable quantities, it must be multiplied by its complex conjugate. This recipe is called the Born rule, and it is an ad hoc addition to the quantum theory. It lacks any motivation except that it works. In keeping with Einstein's advice (which he himself often flouted) to try to keep unmeasurable concepts out of our description of nature, physicists have realized long ago that it must be possible to recast quantum mechanics entirely in terms of probabilities, not even mentioning probability amplitudes or wavefunctions. The question is only: How complicated would the resulting formalism be? (To make a weak analogy, it must be possible to recast arithmetic in the language of Roman numerals, but the result would surely look much messier than what we learn in grade school.) Hitherto, nobody had come up with an elegant solution to this problem. To their happy surprise, QBists have made progress toward a quantum theory without probability amplitudes. Of course they have to pay a price. Instead of unmeasurable concepts they introduce, for any experiment, a very special set of standard probabilities (NOT AMPLITUDES) which are measurable, but not actually measured. When they re-write the Born rule in terms of these, they find that it looks almost, but not quite, like a fundamental axiom of probability theory called Unitarity. Unitarity decrees that for any experiment the sum of the probabilities for all possible outcomes must be one. (For a coin, the probabilities of heads and tails are both 1/2. Unitarity states 1/2 + 1/2 = 1.) This unexpected outcome of QBism suggests a deep connection between the Born rule and Unitarity. Since Unitarity is a logical concept unrelated to quantum phenomena, this gives QBists the hope that they will eventually succeed in explaining the significacne of the Born rule, and banishing probability amplitudes from quantum mechanics, leaving only (Bayesian) probabilities. So, I'm afraid dear Dino, that the current attitude of QBists is that probability amplitudes are LESS fundamental than probabilities, not MORE. But the story is far from finished! Hans

### [Fis] TWO MESSAGES PER WEEK

ONLY TWO MESSAGES PER WEEK ARE ALLOWED IN THE FIS LIST -- - Pedro C. Marijuán Grupo de Bioinformación / Bioinformation Group Instituto Aragonés de Ciencias de la Salud Centro de Investigación Biomédica de Aragón (CIBA) Avda. San Juan Bosco, 13, planta X 50009 Zaragoza, Spain Tfno. +34 976 71 3526 ( 6818) pcmarijuan.i...@aragon.es http://sites.google.com/site/pedrocmarijuan/ - ___ fis mailing list fis@listas.unizar.es https://webmail.unizar.es/cgi-bin/mailman/listinfo/fis

### Re: [Fis] Probability Amplitudes

Dear Andrei, Hans and all I agree with Andrei. And why make quantum theory more complex than it is? One may use all kinds of mathematical tools in a scientific theory, and the more these tools simplify calculations the better. I see no reason to avoid using amplitudes or matrices in quantum theory. Using a mathematical concept for making calculations doesn't entail that I accept that that concept represent a physical property. To Hans: Where exactly did Einstein wrote that one should avoid unmeasurable concepts in the description of Nature? I can't remember having read that. The issue is how we should interpret quantum theory, in particular the wave function, i.e., probability amplitudes; are they just mathematical tools, or do they describe real physical features of quantum systems? I believe the latter alternative is true and so did Schrödinger. But there are formidable difficulties to give a realistic interpretation of wave functions, and Schrödinger didn't succeed. But I think the difficulties can be overcome and I have published my views about these things (Lars-Göran Johansson: Interpreting Quantum Mechanics. A realist view in Schrödinger's vein, Ashgate, Aldershot 2007). Lars-Göran 22 jan 2014 kl. 10:59 skrev Andrei Khrennikov andrei.khrenni...@lnu.semailto:andrei.khrenni...@lnu.se: Dear Hans, I would like just to point that 99,99% of people working in quantum theory would say that the complex amplitude of quantum probability is the main its intrinsic property, so if you try to exclude amplitudes from the model you can in principle do this and this is well known long ago in so called quantum tomographic approach of Vladimir Manko, but in this way quantum theory loses its simplicity and clarity, yours, andrei Andrei Khrennikov, Professor of Applied Mathematics, International Center for Mathematical Modeling in Physics, Engineering, Economics, and Cognitive Science Linnaeus University, Växjö-Kalmar, Sweden From: fis-boun...@listas.unizar.esmailto:fis-boun...@listas.unizar.es [fis-boun...@listas.unizar.esmailto:fis-boun...@listas.unizar.es] on behalf of Hans von Baeyer [henrikrit...@gmail.commailto:henrikrit...@gmail.com] Sent: Wednesday, January 22, 2014 12:21 AM To: fis@listas.unizar.esmailto:fis@listas.unizar.es Subject: [Fis] Probability Amplitudes Dear Dino and friends, thanks for bringing up the issue of probability amplitudes. Since they are technical tools of physics, and since I didn't want to go too far afield, I did not mention them in my lecture. The closest I came was the wavefunction, which, indeed, is a probability amplitude. In order to make contact with real, measurable quantities, it must be multiplied by its complex conjugate. This recipe is called the Born rule, and it is an ad hoc addition to the quantum theory. It lacks any motivation except that it works. In keeping with Einstein's advice (which he himself often flouted) to try to keep unmeasurable concepts out of our description of nature, physicists have realized long ago that it must be possible to recast quantum mechanics entirely in terms of probabilities, not even mentioning probability amplitudes or wavefunctions. The question is only: How complicated would the resulting formalism be? (To make a weak analogy, it must be possible to recast arithmetic in the language of Roman numerals, but the result would surely look much messier than what we learn in grade school.) Hitherto, nobody had come up with an elegant solution to this problem. To their happy surprise, QBists have made progress toward a quantum theory without probability amplitudes. Of course they have to pay a price. Instead of unmeasurable concepts they introduce, for any experiment, a very special set of standard probabilities (NOT AMPLITUDES) which are measurable, but not actually measured. When they re-write the Born rule in terms of these, they find that it looks almost, but not quite, like a fundamental axiom of probability theory called Unitarity. Unitarity decrees that for any experiment the sum of the probabilities for all possible outcomes must be one. (For a coin, the probabilities of heads and tails are both 1/2. Unitarity states 1/2 + 1/2 = 1.) This unexpected outcome of QBism suggests a deep connection between the Born rule and Unitarity. Since Unitarity is a logical concept unrelated to quantum phenomena, this gives QBists the hope that they will eventually succeed in explaining the significacne of the Born rule, and banishing probability amplitudes from quantum mechanics, leaving only (Bayesian) probabilities. So, I'm afraid dear Dino, that the current attitude of QBists is that probability amplitudes are LESS fundamental than probabilities, not MORE. But the story is far from finished! Hans ___ fis mailing list fis@listas.unizar.esmailto:fis@listas.unizar.es

### [Fis] Frequentists, Bayesians and Jaynesians - assumptions and consequentces

Dear colleagues, Encouraged by your recent exchanges, which show that the topic of Hans' New Year Lecture is far from exhausted, I would like to think a bit more on the fundamental change from Frequentist to Bayesian statistics. Hans writes: “On the one hand each individual agent assembles the totality of her experiences (experimenting, reading, talking, calculating...) into a web of probability assignments that is as coherent and comprehensive as possible. That's the easy part, and, as usual, physicists have picked it as their domain. But the hard part is the effort of agents to correlate their private experiences -- i.e. to communicate with each other in order to develop a common scientific worldview. Agent A's description of an experience serves as input for updating B's personal probability assignments via Bayes' law. And this is done through language as well as math.” (Hans mail from Saturday, January 18, 2014 6:47 PM) Reading the above I conclude that QBist change of perspective is not only relevant for quantum physics, or physics in general. It is relevant for all sciences based on observations and experiments. And indeed, among others, brain researchers are using Bayesian statistics. However, there are brain researchers arguing for the necessity of going beyond Bayes: http://www.mdpi.com/2078-2489/3/2/175 Beyond Bayes: On the Need for a Unified and Jaynesian Definition of Probability and Information within Neuroscience by Christopher D. Fiorillo Are there any comments to this claim? Would Jaynesian statistics make a difference for Qbism? I would like to learn more. With best wishes, Gordana http://www.mrtc.mdh.se/~gdc/http://www.mrtc.mdh.se/%7Egdc/ ___ fis mailing list fis@listas.unizar.es https://webmail.unizar.es/cgi-bin/mailman/listinfo/fis

### [Fis] Probability Amplitudes in Macroscopic Processes

Dear Lars-Göran, Andrei and Hans, As you (I hope) have seen, I am trying to see how the evolution of macroscopic processes can be described in terms of changing probabilities, and I am encouraged to believe this is possible. If you allow the extension from QM, all of the following would seem to allow this (I am not concerned about whether QM itself becomes more or less complex): 1. Andrei confirms that the probability (in LIR, degree of potentiality or actuality) of a phenomenon can have a direction. 2. Lars-Göran says that probability amplitudes can represent real physical features. 3. Even though /a contrario/, Hans wrote: In order to make contact with real, measurable quantities, it (the probability amplitude) must be multiplied by its complex conjugate. This recipe is called the Born rule, and it is an ad hoc addition to the quantum theory. It lacks any motivation except that it works. In my Logic in Reality, since there is a reciprocal relation between actuality and potentiality, each should be the complex conjugate of the other. I have no problem in the two summing to 1 if the values of 0 or 1 are excluded for either of them. This non-quantum aspect of reality could provide the missing motivation for the recipe in quantum theory ;-) I am certainly looking for a measurable (or estimatable) quantity of the actuality and potentiality of interactive processes that is not a standard probability of outcomes, but of changing macroscopic states. This is of course an 'underdeveloped' concept, but I am encouraged to believe that this idea of another set of very special probabilities is neither totally wrong nor totally trivial. Many thanks, Joseph - Original Message - From: Lars-Göran Johansson To: fis@listas.unizar.es Sent: Wednesday, January 22, 2014 12:45 PM Subject: Re: [Fis] Probability Amplitudes Dear Andrei, Hans and all I agree with Andrei. And why make quantum theory more complex than it is? One may use all kinds of mathematical tools in a scientific theory, and the more these tools simplify calculations the better. I see no reason to avoid using amplitudes or matrices in quantum theory. Using a mathematical concept for making calculations doesn't entail that I accept that that concept represent a physical property. To Hans: Where exactly did Einstein wrote that one should avoid unmeasurable concepts in the description of Nature? I can't remember having read that. The issue is how we should interpret quantum theory, in particular the wave function, i.e., probability amplitudes; are they just mathematical tools, or do they describe real physical features of quantum systems? I believe the latter alternative is true and so did Schrödinger. But there are formidable difficulties to give a realistic interpretation of wave functions, and Schrödinger didn't succeed. But I think the difficulties can be overcome and I have published my views about these things (Lars-Göran Johansson: Interpreting Quantum Mechanics. A realist view in Schrödinger's vein, Ashgate, Aldershot 2007). Lars-Göran 22 jan 2014 kl. 10:59 skrev Andrei Khrennikov andrei.khrenni...@lnu.se: Dear Hans, I would like just to point that 99,99% of people working in quantum theory would say that the complex amplitude of quantum probability is the main its intrinsic property, so if you try to exclude amplitudes from the model you can in principle do this and this is well known long ago in so called quantum tomographic approach of Vladimir Manko, but in this way quantum theory loses its simplicity and clarity, yours, andrei Andrei Khrennikov, Professor of Applied Mathematics, International Center for Mathematical Modeling in Physics, Engineering, Economics, and Cognitive Science Linnaeus University, Växjö-Kalmar, Sweden From: fis-boun...@listas.unizar.es [fis-boun...@listas.unizar.es] on behalf of Hans von Baeyer [henrikrit...@gmail.com] Sent: Wednesday, January 22, 2014 12:21 AM To: fis@listas.unizar.es Subject: [Fis] Probability Amplitudes Dear Dino and friends, thanks for bringing up the issue of probability amplitudes. Since they are technical tools of physics, and since I didn't want to go too far afield, I did not mention them in my lecture. The closest I came was the wavefunction, which, indeed, is a probability amplitude. In order to make contact with real, measurable quantities, it must be multiplied by its complex conjugate. This recipe is called the Born rule, and it is an ad hoc addition to the quantum theory. It lacks any motivation except that it works. In keeping with Einstein's advice (which he himself often flouted) to try to keep unmeasurable concepts out of our description of nature, physicists have realized long ago that it must be possible to recast quantum mechanics entirely in terms of probabilities, not even mentioning probability amplitudes or

### Re: [Fis] Probability Amplitudes in Macroscopic Processes

Let me clarify one point: by saying that probability amplitudes represent real physical features I reject the instrumentalist idea that they are mere calculational devices. But of course, the probability amplitude is no observable. But there is no need to claim that only observables have any physical significance. Robert Chen has, in a couple of papers argued that the square of real part of the wave function could be interpreted as the system's kinetic energy, whereas the square of the imaginary part represents the potential energy of the system. It is as far as I can see a possible and reasonable interpretation. Lars-Göran 22 jan 2014 kl. 15:14 skrev Joseph Brenner joe.bren...@bluewin.chmailto:joe.bren...@bluewin.ch: Dear Lars-Göran, Andrei and Hans, As you (I hope) have seen, I am trying to see how the evolution of macroscopic processes can be described in terms of changing probabilities, and I am encouraged to believe this is possible. If you allow the extension from QM, all of the following would seem to allow this (I am not concerned about whether QM itself becomes more or less complex): 1. Andrei confirms that the probability (in LIR, degree of potentiality or actuality) of a phenomenon can have a direction. 2. Lars-Göran says that probability amplitudes can represent real physical features. 3. Even though /a contrario/, Hans wrote: In order to make contact with real, measurable quantities, it (the probability amplitude) must be multiplied by its complex conjugate. This recipe is called the Born rule, and it is an ad hoc addition to the quantum theory. It lacks any motivation except that it works. In my Logic in Reality, since there is a reciprocal relation between actuality and potentiality, each should be the complex conjugate of the other. I have no problem in the two summing to 1 if the values of 0 or 1 are excluded for either of them. This non-quantum aspect of reality could provide the missing motivation for the recipe in quantum theory ;-) I am certainly looking for a measurable (or estimatable) quantity of the actuality and potentiality of interactive processes that is not a standard probability of outcomes, but of changing macroscopic states. This is of course an 'underdeveloped' concept, but I am encouraged to believe that this idea of another set of very special probabilities is neither totally wrong nor totally trivial. Many thanks, Joseph - Original Message - From: Lars-Göran Johanssonmailto:lars-goran.johans...@filosofi.uu.se To: fis@listas.unizar.esmailto:fis@listas.unizar.es Sent: Wednesday, January 22, 2014 12:45 PM Subject: Re: [Fis] Probability Amplitudes Dear Andrei, Hans and all I agree with Andrei. And why make quantum theory more complex than it is? One may use all kinds of mathematical tools in a scientific theory, and the more these tools simplify calculations the better. I see no reason to avoid using amplitudes or matrices in quantum theory. Using a mathematical concept for making calculations doesn't entail that I accept that that concept represent a physical property. To Hans: Where exactly did Einstein wrote that one should avoid unmeasurable concepts in the description of Nature? I can't remember having read that. The issue is how we should interpret quantum theory, in particular the wave function, i.e., probability amplitudes; are they just mathematical tools, or do they describe real physical features of quantum systems? I believe the latter alternative is true and so did Schrödinger. But there are formidable difficulties to give a realistic interpretation of wave functions, and Schrödinger didn't succeed. But I think the difficulties can be overcome and I have published my views about these things (Lars-Göran Johansson: Interpreting Quantum Mechanics. A realist view in Schrödinger's vein, Ashgate, Aldershot 2007). Lars-Göran 22 jan 2014 kl. 10:59 skrev Andrei Khrennikov andrei.khrenni...@lnu.semailto:andrei.khrenni...@lnu.se: Dear Hans, I would like just to point that 99,99% of people working in quantum theory would say that the complex amplitude of quantum probability is the main its intrinsic property, so if you try to exclude amplitudes from the model you can in principle do this and this is well known long ago in so called quantum tomographic approach of Vladimir Manko, but in this way quantum theory loses its simplicity and clarity, yours, andrei Andrei Khrennikov, Professor of Applied Mathematics, International Center for Mathematical Modeling in Physics, Engineering, Economics, and Cognitive Science Linnaeus University, Växjö-Kalmar, Sweden From: fis-boun...@listas.unizar.esmailto:fis-boun...@listas.unizar.es [fis-boun...@listas.unizar.esmailto:fis-boun...@listas.unizar.es] on behalf of Hans von Baeyer [henrikrit...@gmail.commailto:henrikrit...@gmail.com] Sent: Wednesday, January 22, 2014 12:21 AM To: