Günther Ludwig - Böcker

(translation) I was interested by the development of a new edition of the book [1] "Die Grundstrukturen einer physikalischen Theorie." This has been possible, in spite of my old age, thanks to the contributions of Dr. G. Thurler. Without his indefatigable support and his essential and fundamental propositions, this new edition would not have been possible. The new edition clari?es and formulates more precisely the fundamental ideasofphysicaltheoriesinordertoavoidasmuchaspossibleanyambiguities. One begins theoretical physics with concepts that can be explained wi- out theories. Later, one introduces other concepts by theories known as "pre-theories." Thus it does not make sense to introduce concepts such as "state" without a pre-theory. The ?eld of physics is thus determined by the basic concepts introduced without the use of pre-theories. Also, it does not make sense to speak about the position and speed of an electron at a ?xed time. "Reality" is not however only the reality which is described by physical concepts. Thus, for example, colors,tones, joy, hate, and love are not physical concepts. But the demarcation of the physical concepts, and thus the demarcation of the ?eld of physics makes it possible to know more clearly, and thus to describemoreclearlyinthe future,the structureof realitybeyondthe domain ofphysics.The?eldoflifeandnotthatofdeathshouldbethegoalofmankind. Thus, I hope that this book can also become another small step for life.

(translation) I was interested by the development of a new edition of the book [1] "Die Grundstrukturen einer physikalischen Theorie." This has been possible, in spite of my old age, thanks to the contributions of Dr. G. Thurler. Without his indefatigable support and his essential and fundamental propositions, this new edition would not have been possible. The new edition clari?es and formulates more precisely the fundamental ideasofphysicaltheoriesinordertoavoidasmuchaspossibleanyambiguities. One begins theoretical physics with concepts that can be explained wi- out theories. Later, one introduces other concepts by theories known as "pre-theories." Thus it does not make sense to introduce concepts such as "state" without a pre-theory. The ?eld of physics is thus determined by the basic concepts introduced without the use of pre-theories. Also, it does not make sense to speak about the position and speed of an electron at a ?xed time. "Reality" is not however only the reality which is described by physical concepts. Thus, for example, colors,tones, joy, hate, and love are not physical concepts. But the demarcation of the physical concepts, and thus the demarcation of the ?eld of physics makes it possible to know more clearly, and thus to describemoreclearlyinthe future,the structureof realitybeyondthe domain ofphysics.The?eldoflifeandnotthatofdeathshouldbethegoalofmankind. Thus, I hope that this book can also become another small step for life.

In the first volume we based quantum mechanics on the objective description of macroscopic devices. The further development of the quantum mechanics of atoms, molecules, and collision processes has been described in [2]. In this context also the usual description of composite systems by tensor products of Hilbert spaces has been introduced. This method can be formally extrapolated to systems composed of "many" ele­ mentary systems, even arbitrarily many. One formerly had the opinion that this "extrapolated quantum mechanics" is a more comprehensive theory than the objec­ tive description of macrosystems, an opinion which generated unsurmountable diffi­ culties for explaining the measuring process. With respect to our foundation of quan­ tum mechanics on macroscopic objectivity, this opinion would mean that our founda­ tion is no foundation at all. The task of this second volume is to attain a compatibility between the objective description of macrosystems and an extrapolated quantum mechanics. Thus in X we establish the "statistical mechanics" of macrosystems as a theory more compre­ hensive than an extrapolated quantum mechanics. On this basis we solve the problem of the measuring process in quantum mechan­ ics, in XI developing a theory which describes the measuring process as an interaction between microsystems and a macroscopic device. This theory also allows to calculate "in principle" the observable measured by a device. Neither an incorporation of consciousness nor a mysterious imagination such as "collapsing" wave packets are necessary.

In dieser stark verbesserten und erweiterten Neuauflage seines bekannten Buches bietet der Verfasser vertiefte, neue Einsichten in die Strukturen physikalischer Theorien. Er erklärt den Zusammenhang zwischen einer mathematischen Theorie und ihrer Anwendung auf Experimente. Um den physikalischen Inhalt der in der mathematischen Theorie als Axiome formulierten Naturgesetze zu erkennen, wird eine neue Form einer physikalischen Theorie vorgeschlagen, die "einfache axiomatische Basis", und die Naturgesetze werden nach Begriffsnormen, Handlungsnormen und empirischen Gesetzen klassifiziert. Ein besonderes Ziel dieses Buches ist es, eine bessere Klärung von Begriffen wie "wirklich" und "möglich", angewandt auf physikalische Prozesse, zu erreichen. Der Autor richtet sich an Dozenten und Studenten der Physik und Mathematik sowie an Wissenschaftstheore- tiker.

Mehrere Gründe bewogen mich, den Plan zu einem Buch über Quantenmechanik zu entwerfen, obwohl es in der Literatur schon manche Darstellung dieses Gebietes gibt. Einmal traf man bei den Lernenden immer wieder auf die Auf­ fassung, daß die Quantentheorie nur ein Provisorium der theoretischen Physik sei, aber zumindest noch einer genaueren Begründung bedürfe, da sowohl der mathematische Formalismus nicht exakt fundiert sei als auch die physikalische Interpretion sehr "nach Gefühl" in jedem Einzelfall durchgeführt würde. Nachdem das Buch von J. v. NEu­ MANN, Mathematische Grundlagen der Quantenmechanik, vergriffen war, konnte man kaum ein entsprechendes Werk empfehlen, das im physikalischen Zusammenhang die mathematischen Grundlagen klar­ legt. In dem vorliegenden Buche ist die eigentiiche Quantenmechamk (also ohne Feldtheorie) in der Weise dargestellt, daß man sie als em mathematisch wohlbegründetes und in sich genauso widerspruchs­ freies und abgeschlossenes System erkennt, wie die klassische Punkt­ mechanik. So wie die Kräfte, d. h. so wie die HAMILTON-Funktwn, in der klassischen Mechanik gegeben sein müssen, so m der Quanten­ mechanik der HAMILTON-Üperator. Die Herleitung eines Ansatzes für den HAMILTON-Operator eines Problems aus anderen Gebieten der Physik wird deshalb hier nicht näher begründet. Neben dem Wunsch, die Quantenmechamk als ein in sich geschlos­ senes Gebiet darzustellen, bestand ein zweiter Grund für die Abfassung des Buches in der inneren Harmonie zwischen mathematischer und physikalischer Struktur. Je größer die abstrakte Schönheit einer Theo­ rie, desto größer auch ihr Wahrheitsgehalt. Die innere Harmonie m der Struktur der Materie zu erkennen, d. h.

In this second volume on the Foundations of Quantum Mechanics we shall show how it is possible, using the methodology presented in Volume I, to deduce some of the most important applications of quantum mechanics. These deductions are concerned with the structures of the microsystems rather than the technical details of the construction of preparation and registration devices. Accordingly. the only new axioms (relative to Volume I) which are introduced are concerned with the relationship between ensemble operators W, effect operators F, and certain construction principles of the preparation and registration devices. The applications described here are concerned with the measurement of atomic and molecular structure and of collision experiments. An additional and essential step towards a theoretical description of the preparation and registration procedures is carried out in Chapter XVII. Here we demonstrate how microscopic collision processes (that is, processes which can be described by quantum mechanics) can be used to obtain novel preparation and registration procedures if we take for granted the knowledge of only a few macroscopic preparation and registration procedures. By clever use of collision processes we are often able to obtain very precise results for the operators Wand F which describe the total procedures from a very imprecise knowledge of the macroscopic parts of the preparation and regis­ tration processes. In this regard experimental physicists have done brilliant work. In this sense Chapter XVII represents a general theoretical foundation for the procedures used by experimental physicists.