In this research work the quantum theory of Ur-alternatives of Carl Friedrich von Weizsäcker is considered. In This theory all objects and interactions in nature are constituted by abstract purely quantum logical relations in time. Such structures can be devided into binary alternatives, which are called Ur-Alternatives with respect to this principle meaning, and this leads to a tensor space of many Ur-alternatives. The indistinguishability of the Ur-alternatives yields two Hilbert spaces, the tensor space of symmetric and antisymmetric states under permutations of the Ur-alternatives. It is shown how the structures in the symmetric space can be represented in a three dimensional real position space connected to time according to special relativity. Accordingly this theory obtains ultimately a deep understanding of the EPR-paradox, since logic is independent of topological structures and causal relations in space. The antisymmetric space, which because of the Pauli principle contains much less degress of freedem, yields the additional quantum numbers of the elementary particles. Based on the demand for the highest possible symmetry in the tensor space, the Yang-Mills gauge theories of the standard model as well as a translational gauge formulation of general relativity in a purely quantum logical description are derived. The equations determine entanglements of states containing many Ur-alternatives and this concept is the analogue to classical pointwise interactions between separated objects. This means that the main structures of the SU(N)-interactions of the standard model of elementary particle physics as well as gravitation according to general relativiy are unified in a purely quantum theoretical conceptional framework. Finally it is derived an extended version of the E8-group, the biggest exceptional Lie-group.
In this research work the quantum theory of Ur-alternatives of Carl Friedrich von Weizsäcker is considered. In This theory all objects and interactions in nature are constituted by abstract purely quantum logical relations in time. Such structures can be devided into binary alternatives, which are called Ur-Alternatives with respect to this principle meaning, and this leads to a tensor space of many Ur-alternatives. The indistinguishability of the Ur-alternatives yields two Hilbert spaces, the tensor space of symmetric and antisymmetric states under permutations of the Ur-alternatives. It is shown how the structures in the symmetric space can be represented in a three dimensional real position space connected to time according to special relativity. Accordingly this theory obtains ultimately a deep understanding of the EPR-paradox, since logic is independent of topological structures and causal relations in space. The antisymmetric space, which because of the Pauli principle contains much less degress of freedem, yields the additional quantum numbers of the elementary particles. Based on the demand for the highest possible symmetry in the tensor space, the Yang-Mills gauge theories of the standard model as well as a translational gauge formulation of general relativity in a purely quantum logical description are derived. The equations determine entanglements of states containing many Ur-alternatives and this concept is the analogue to classical pointwise interactions between separated objects. This means that the main structures of the SU(N)-interactions of the standard model of elementary particle physics as well as gravitation according to general relativiy are unified in a purely quantum theoretical conceptional framework. Finally it is derived an extended version of the E8-group, the biggest exceptional Lie-group.
The quantum theory of Ur-alternatives of Carl Friedrich von Weizsaecker tries to constitute general quantum theory based on the concept of logical alternatives in time. Based on this interpretation of quantum theory the existence of free objects in space, their symmetry properties and their interactions shall be inferred. The alternatives are represented by binary alternatives, which are called Ur-alternatives because of their logically fundamental character. Through Ur-alternatives as elementary quantum theoretical units of information the Copernican revolution with respect to the question of space is realized in a consequent way. This means that not the objects of nature are in a given space, but the existence of space arises as a kind of indirect representation of relations between abstract quantum theoretical objects. The Ur-alternatives do not exist in a given physical reality, but the existence of space is constituted by Ur-alternatives at all. Such a concept of reality is implicitly contained within the uncertainty relation and can be seen especially in the EPR-paradoxon. It is shown in this thesis in a mathematical consistent way that a state in the tensor space of many Ur-alternatives can directly be mapped into a real three dimensional space which means that together with the dynamics a representation in a (3+1)-dimensional space-time becomes possible. By considering the G2 an approach for the incorporation of the internal symmetries can be suggested. Furthermore the Ur-alternatives enable the constitution of a concept of interaction, which is based on quantum theoretical entanglement. By using this concept it is tried to obtain a purely quantum theoretical description of electromagnetism and gravity. This corresponds to a much more principle and in a radical sense background independent way of quantization.
The quantum theory of ur objects postulates that all existing physical objects and their properties are constructed from fundamental objects called ur objects being described by an element of a two dimensional complex Hilbert space. This approach is based on the assumption that quantum theory represents a theory being constitutive for human knowledge. Physical objects are characterized by the information one can gain from them being contained in the quantum state they are described by. Since every Hilbert space can be represented as a tensor product of two dimensional Hilbert spaces, one is led to the ur objects. According to this approach relativistic quantum fields and thus the existence of a Minkowski space-time are the consequence of an iteration of a quantization of binary alternatives. In the original formulation there was only obtained a description of quantum fields on a flat Minkowski space-time. In this work there is made the attempt to incorporate general relativity and to describe the gravitational field within this approach. Thus the existence of a (3+1)-dimensional space-time in the sense of general relativity is assumed to be a consequence of quantum theory interpreted in an abstract sense.
The quantum theory of ur-objects proposed by C. F. von Weizsaecker has to be interpreted as a quantum theory of information. Ur-objects, or urs, are thought to be the simplest objects in quantum theory. Thus an ur is represented by a two-dimensional Hilbert space with the universal symmetry group SU(2), and can only be characterized as ''one bit of potential information''. In this sense it is not a spatial but an ''information atom''. The physical structure of the ur theory is reviewed, and the philosophical consequences of its interpretation as an information theory are demonstrated by means of some important concepts of physics such as time, space, entropy, energy, and matter, which in ur theory appear to be directly connected with information as ''the'' fundamental substance. This hopefully will help to provide a new understanding of the concept of information.
Carl Friedrich von Weizsaecker's thinking has always crossed the borders between physics and philosophy. Being a physicist by training he still feels at home in the physics community, as a philosopher by passion, however, his mind cannot stop thinking at the limits of physics. His physical ideas are based on the general conceptual and methodological preconditions of physical theories. Such a line of reasoning about the foundations of physics has brought Weizsaecker into an abstract program of a possible reconstruction of physics in terms of yes-no-alternatives, which he called "ur-theory." I shall start this paper with a review of the basic ideas of ur-theory: the definition of an ur and the connection between ur-spinors and spacetime. I then go over to some of ur-theory's present borders: the construction of quantized spacetime tetrads and the difficulties to incorporate gravity and gauge theories. Finally, I shall discuss the possible prospects of ur-theory -- partly with a view to modern quantum gravity approaches, but mainly in connection with its philosophical implications. Here, one of the crucial questions is, whether form, or, modern, information is an entity per se and what particular consequences this may have.
The way, in which quantum information can unify quantum mechanics (and therefore the Standard model) and general relativity, is investigated. Quantum information is defined as the generalization of the concept of information as to the choice among infinite sets of alternatives. Relevantly, the axiom of choice is necessary in general. The unit of quantum information, a qubit is interpreted as a relevant elementary choice among an infinite set of alternatives generalizing that of a bit. The invariance to the axiom of choice shared by quantum mechanics is introduced: It constitutes quantum information as the relation of any state unorderable in principle (e.g. any coherent quantum state before measurement) and the same state already well-ordered (e.g. the well-ordered statistical ensemble of the measurement of the quantum system at issue). This allows of equating the classical and quantum time correspondingly as the well-ordering of any physical quantity or quantities and their coherent superposition. That equating is interpretable as the isomorphism of Minkowski space and Hilbert space. Quantum information is the structure interpretable in both ways and thus underlying their unification. Its deformation is representable correspondingly as gravitation in the deformed pseudo-Riemannian space of general relativity and the entanglement of two or more quantum systems. The Standard model studies a single quantum system and thus privileges a single reference frame turning out to be inertial for the generalized symmetry U(1)XSU(2)XSU(3) “gauging” the Standard model. As the Standard model refers to a single quantum system, it is necessarily linear and thus the corresponding privileged reference frame is necessary inertial. The Higgs mechanism U(1) → U(1)XSU(2) confirmed enough already experimentally describes exactly the choice of the initial position of a privileged reference frame as the corresponding breaking of the symmetry. The Standard model defines ‘mass at rest’ linearly and absolutely, but general relativity non-linearly and relatively. The “Big Bang” hypothesis is additional interpreting that position as that of the “Big Bang”. It serves also in order to reconcile the linear Standard model in the singularity of the “Big Bang” with the observed nonlinearity of the further expansion of the universe described very well by general relativity. Quantum information links the Standard model and general relativity in another way by mediation of entanglement. The linearity and absoluteness of the former and the nonlinearity and relativeness of the latter can be considered as the relation of a whole and the same whole divided into parts entangled in general
Standard Boolean logic is based on ideas taken from classical, first-order set theory. The first-order logic of quantum mechanics introduced by von Neumann is not a classical one. It is therefore natural to ask whether it is possible to formulate the corresponding theory of quantum sets, their (quantum) topology and higher-order structures. Once we have quantum sets and quantum topologies we can try to quantize essentially anything: phase space, groups, spacetime, etc. In his book Finkelstein reports results of some 40 years of studies in this direction. The book is not addressed to specialists, but to `thoughtful students of physics, mathematics and philosophy', which may justify the fact that this review is written by a person who is not actively working in the field of quantum logic. From this layman's position I must say that the book does not read very well. First of all, the standard language of physics is not naturally suited for speaking about such problems, so Finkelstein invents a new one. Obviously, it is not easy to read a difficult text which, in addition, is written in a language we do not know. It seems that the author should have tried to depart as little as possible from the standard terminology, but he could not resist coining new terms even for things we already know under different names. When I first looked into the table of contents I felt both curiosity and some intimidation since I did not understand the words. To give an example, we find there spinors, cospinors, anti-spinors, anti-cospinors, ambi-spinors, ambi-cospinors, etc. It turned out that they are simply upper- and lower-index, primed or unprimed ordinary spinors, or their second-rank tensor products. Fortunately higher-rank spinors were not needed. The notation also does not help to understand the text. For example, on p 148 the symbol denotes a spacetime index, but three lines later, in equation (11), it is a gauge group parameter, and no comment is made on this. On the other hand, the same object is often denoted in different ways (see, for instance, equation (1) on p 44 and (7) on p 47) and if we add a number of typographical errors the first reading of the book is really tiring. A general philosophy advocated in the book is to use a kind of two-time description which replaces continuous dynamics with discrete algebraic `activity'. The construction begins with a bi-modal logic of initial and final actions and the preclusion (or `occlusion' ) relation ` ' (essentially iff a transition between and is forbidden). A Hilbert space and a field of coefficients are derived from . Discretization of time goes hand-in-hand with the idea that spacetime should be quantized and, finally, an outline of its construction is given. An intriguing consequence of the Finkelstein formalism is the appearance of internal local gauge groups of the standard model just from the spacetime structure. It seems that some results presented in the book are subject to limitations which are not mentioned by the author. For example, the construction based on will not work correctly if the dynamics between the initial and final acts is nonlinear. This is so because mutually precluding acts do not have to correspond to orthogonal vectors if we use nonlinear eigenvalue problems. So details of evolution between initial and final acts may be more important than one would expect naively. The same concerns the proof that transition probabilities must be of the form . Such subtleties can be ignored in standard quantum mechanics but here we aim at generalization. I find some parts of the text misleading. A canonical example illustrating mathematical and physical meanings of the Finkelstein formalism is a Malusian experiment (i.e. the one involving photons and polarizers), but the Bell theorem given on p 251 cannot distinguish between its single-photon and two-photon versions. Physically the two systems are essentially different and a purely classical Aerts model that gives the Malus law for a single particle is known, even though the theorems and discussion on pp 251 - 3 suggest that this is impossible. Perhaps the original work the theorems were taken from clarifies this point but a reader will not find it for two reasons. First, the name of its author is misprinted. Second, there is no reference to the paper. This is quite typical of the book; the results which are regarded as inessential from the viewpoint of the main argument are oversimplified and quoted without references to original works. The clarity of the presentation would be improved if the author did not try to briefly summarize what he knows about physics (and certainly he knows a lot) but, instead, were more detailed about the material that is really new. In spite of all these minor critical remarks I think the book may be inspiring and opens an entirely new perspective on physics. Many of the problems discussed by Finkelstein remain unsolved but the strategy he proposes looks at least promising and, hopefully, some readers will join the author in his brave attack on the most difficult questions of modern science.