There is the widely held view that quantum physics differs fundamentally from classical physics regarding measurements. In order to prepare the ground for settling this question we discuss the consequences it has for classical physics if one includes measurement in the theory. After explaining the terms measurement and error it is argued that every measurement can be reduced to a measurement of length and/or number. Additionally to the wellknown statistical and systematical errors we introduce the (...) concept of classical uncertainty which states that every measurement of a physical quantity _A_ carries a finite inaccuracy Δ_A_. Hence it is transempirical to assign an infinite decimal number to a measurement. This implies that, also in classical physics, only probabilistic predictions are possible and that we need ensembles for the empirical testing of theoretical predictions. Furthermore we rebut the claim that in classical physics measurements can be performed without any disturbance of the system under investigation. Finally we state that by including measurements in the theory itself classical physics like quantum physics can be formulated as an indeterministic theory. Likewise both theories can be formulated deterministically if measurements are excluded from the theory. _German_ Gemäß einer weit verbreiteten Sichtweise gibt es hinsichtlich der Messung in der Quantenphysik und in der klassischen Physik einen grundlegenden Unterschied. Um einer Klärung dieser Frage den Boden zu bereiten, versuchen wir für die klassische Physik die Folgen zu diskutieren, die sich ergeben, wenn man die Messung in die Theorie mit einbezieht. Zunächst wird dafür argumentiert, dass jede Messung auf eine Längenbzw. Zählmessung zurückzuführen ist. Wir führen zusätzlich zu den bekannten Arten von Messfehlern – statistischen und systematischen Fehlern – das Konzept der klassischen Messunschärfe ein, das abbildet, dass jede Messung einer Messgröße _A_ mit einer endlichen Ungenauigkeit Δ_A_ behaftet sein muss. Dies bedeutet insbesondere, dass die Angabe von nichtendlichen Dezimalzahlen für Messwerte transempirisch ist. Die Betrachtung der Messfehler führt zu der Folgerung, dass auch in der klassischen Physik nur mehr Wahrscheinlichkeitsaussagen getroffen werden können und Messungen an Ensembles zur empirischen Bestätigung theoretischer Vorhersagen nötig sind. Außerdem wird die Behauptung entkräftet, in der klassischen Physik seien im Prinzip Messungen möglich, die den Zustand eines Systems nicht stören. Abschließend stellen wir heraus, dass durch Einbeziehung der Messung in die Theorie die klassische Physik wie die Quantenphysik als indeterministischen Theorie formuliert werden kann, ebenso wie beide ohne Einbeziehung der Messung deterministisch formuliert werden können. (shrink)

Kaum eine Äußerung Einsteins ist so bekannt wie sein Wort, dass Gott nicht würfelt. In ähnlicher Weise, wie Einstein dies unerläutert gelassen hat, ist seine gesamte Position zur Quantenmechanik, auf die es sich bezieht, von Uneindeutigkeiten nicht frei geblieben. Für seine Würfelmetapher ergibt sich ein Spielraum von gegensätzlichen Sichtweisen. Sie lässt sich zum einen mit jüngeren Forschungsresultaten verbinden und weist zum anderen auf rückschrittliche Elemente in Einsteins Denken hin. Ich wende mich zuerst diesen Elementen zu und betrachte dann eine dazu (...) entgegengerichtete Interpretationsvariante, die an den neueren Resultaten anknüpft. (shrink)

Walter Seitters Physik der Medien setzt Gedanken seiner Aufsatzsammlung Physik des Daseins. Bausteine zu einer Philosophie der Erscheinungen fort und begründet theoretisch und systematisch eine sog. „philosophische Physik“. Ein weiterer Ausgangspunkt ist die folgende mehrfache Polemik: Seitter setzt nämlich der wissenschaftlichen Physik „seine“ Physik entgegen, die – in klassischer philosophischer Tradition – darauf abzielt, „ein eigenes Staunen aufrechtzuerhalten“, und „mit Augenschein und Umgangssprache“ arbeitet. Ein solcher Physikbegriff – die Beschreibung von sinnlichen Phänomenen aufgrund eigener Wahrnehmung (...) – knüpft ausdrücklich an Aristoteles an, aber nähert sich auch der Phänomenologie. (shrink)

RésuméLa probabilité présente, en Physique classique, des caractères paradoxaux; relative à un état de connaissance, et n'apportant de renseignements que sur un ensemble nombreux d'essais, elle semble pourtant se définir comme un caractère objectif de l'événement isolé; elle suppose qu'on doive répondre » peut‐ětre « à certaines questions, alors que la Logique classique n'admet d'autre réponse que » oui « ou » non «. Utilisée par la micro‐physique, elle brise l'unité des fondements physico‐mathématiques qui se manifestait dans la Logique bivalente, (...) conçue comme théorie de l'objet, de l'événement, de la théorie quelconques.L'analyse de ces caractères paradoxaux, ainsi que des notions d'objet et d'événement, montre que la Physico‐mathématique retrouve son unité de fondements si l'on substitue à la Logique bivalente, la Logique trivalente de la Composition , ou la Logique des Attitudes qui la généralise . Cette revision des notions fondamentales à laquelle la science en progrès s'oblige elle‐měme est une expérience de l'idonéisme en action.ZusammenfassungDie Wahrscheinlichkeit zeigt in der klassischen Physik paradoxe Züge; obwohl sie vom Stande des Wissens abhängt und nur über eine grosse Anzahl von Versuchen Auskünfte gibt, scheint sie als eine objektive Eigenschaft des Einzelereignisses definiert zu sein; sie nimmt an, dass gewisse Fragen mit » vielleicht « beantwortet werden müssen, obgleich die klassische Logik keine andere Antwort als » ja « oder » nein « zulässt. Durch die Mikrophysik nutzbar gemacht, durchbricht sie die Einheit der physikalisch‐mathematischen Fundamente, die sich kundtat in der bivalenten Logik, verstanden als Theorie des beliebigen Objektes, des beliebigen Ereignisses, der beliebigen Theorie. Die Analyse dieser paradoxen Züge, sowie der Begriffe des Objektes und des Ereignisses zeigt, dass Mathematik und Physik ihre einheitlichen Grundlagen wiederfinden, wenn man die bivalente Logik durch die trivalente der Komposition ersetzt oder durch die Logik der Einstellungen , welche sie verallgemeinert . Diese Revision der grundlegenden Begriffe, zu der sich die fortschrittliche Wissenschaft selbst verpflichtet, ist ein Beispiel des in die Tat umgesetzten Idoneismus.Probability shows paradoxical characteristics in classical physics; although dependent upon a state of knowledge, and yielding information only as the total result of numerous trials, it seems nevertheless to be definable as an objective characteristic of the isolated event; it assumes that one must reply » perhaps « to certain questions, whilst classical logic would allow no answer but » yes « or » no «. When used by micro‐physics, it breaks the unity of the physico‐mathematical foundations which became apparent in bivalent logic, in its conception as a theory of any object, any event or any theory.Analysis of these paradoxical characteristics and of the concepts » object « and » event « shows physics and mathematics regain their fundamental unity if bivalent logic is replaced by the trivalent logic of synthesis or the logic of attitudes, which generalises it . This revision of fundamental concepts which progressive science brings upon itself, is an example of the doctrine of suitability in action. (shrink)

Lebenswelt und Physik stehen nicht nur unverkennbar miteinander in Beziehung, sondern prägen jeweils auch eigenständig die Struktur moderner Gesellschaften. Während die Lebenswelt mit ihrem traditionellen Bezug auf unmittelbare Wahrnehmungs- und Handlungsformen immer noch die lokale Reproduktion bestimmt, begründen physikalische Verfahren und Erkenntnisse die materiellen Techniken der globalisierten Zivilisation. Den Abstand von Lebenswelt und Physik, wie die zwischen ihnen bestehenden Beziehungen, möchte ich an den für sie typischen Raumbegriffen erläutern. Meine These ist, dass jedenfalls einige Raumbegriffe der modernen (...) class='Hi'>Physik den lebensweltlichen Raumbegriffen entgegengesetzt sind. Mein Beispiel werden Aspekte des Raumbegriffes sein, die sich an Interpretationen der Quantenmechanik anschließen. Ich möchte außerdem zeigen, dass andere physikalische Raumbegriffe der Lebenswelt näher stehen als die der Quantenmechanik. Als Beispiel für einen solchen Begriff werde ich den klassischen und immer noch aktuellen aus Isaac Newtons Mechanik diskutieren. Grob gesprochen, steht Newtons Raumvorstellung zwischen der modernen physikalischen und der lebensweltlichen Raumvorstellung. (shrink)

Die erste systematische Schrift, die Ernst Cassirer veröffentlicht hat, ist das Buch »Substanzbegriff und Funktionsbegriff« von 1910, in dem er sich mit dem Problem der mathematischen und naturwissenschaftlichen Begriffsbildung auseinandersetzt. Als »Faktum« legte er den damaligen Stand der Wissenschaft zugrunde, der das klassische System der Physik noch als unbestritten galt. Mit den Fortschritten der Wissenschaften, in diesem Fall der Entwicklung der theoretischen Physik, muss die Erkenntniskritik Schritt halten. Und so drängten sich im Laufe der Zeit neue Fragen (...) auf, die der philosophischen Behandlung bedurften. Aus dieser Motivation heraus veröffentlichte Cassirer 1920 die Schrift »Zur Einsteinschen Relativitätstheorie« (ECW Bd. 10), in der er sich mit der Um- und Neubildung der modernen Physik durch die allgemeine und spezielle Relativitätstheorie beschäftigt. Um dem philosophischen Ideal der methodischen Analyse und erkenntniskritischen Grundlegung gerecht zu werden, ergab sich jedoch die Notwendigkeit, auch die Auswirkungen der Quantentheorie in die Reflexion mit einzubeziehen. Den historischen Ursachen und systematischen Gründen der Sprengkraft, die die Quantentheorie auf dem ganzen Gebiet der Physik entwickelte, geht Cassirer in der Schrift »Determinismus und Indeterminismus in der modernen Physik« nach, die er 1936 abschließt. (shrink)

Ist wirklich unser ganzes Leben vorausbestimmtes, un entrinnbares Schicksal? Oder gibt es außer der mechanischen naturwissenschaftlichen Vorstellung der Welt noch eine andere Wirklichkeit, ohne daß ein unlösbarer Konflikt beider Anschauungsweisen besteht, die im Grunde jeden Menschen, den naiven wie den gelehrtesten, angehen. Der Widerspruch besteht, daß wir uns in unserem Denken und Handeln frei fühlen und damit eine Verantwortung tragen, auch wenn wir von unserem erbbedingten Charakter und von unserem Erleben beeinflußt sind, aber doch nicht unent rinnbar an diese uns (...) versklavt scheinen. Andererseits lehrt die klassische gesamte Naturwissenschaft, daß ganz wie in der klassischen Physik eine strenge, nirgends durchbrochene Kausalität uns beherrscht. Dieser Widerspruch hat mich seit meiner Jugend nie zur Ruhe kommen lassen. Das Weltbild des Arztes mußte seit dem Altertum an der Heilbestrebung des Organismus festhalten und mußte an die rettende Tat im ärztlichen Berufe glauben. Die klassische Physik schon im Altertum, aber noch weit bewußter seit der Renaissance, lehrt dogmatisch den mechanischen Ablauf allen Geschehens unter der absoluten Herrschaft des Kausal gesetzes. Immer, wenn ich mich wissenschaftlich zu äußern hatte, bin ich dem Weltbild des Arztes gefolgt, das soll gerade diese Schrift aufzeigen. Seit aber einige Physiker von der "klassischen" Physik zu einer "modernen" Physik üb- v gegangen sind, scheint zum erstenmal das fast zweieinhalb Jahrtausende währende Rätsel lösbar. (shrink)

The present book is devoted to the question of what the goal of physics is. The essential result of this is the rejection of traditional proposals for such a goal in favour of a new proposal. In both the rejection of the older proposal for a goal and the endorsement of the new one, I rely on a common practice in physics - the practice of idealisation. Traditional proposals for goals must be abandoned if they cannot explain this (...) practice; my own proposal is supported by the fact that it can be shown to explain the practice of idealisation. There is a close connection between the goal of physics and some positions in the philosophy of science. van Fraassen has drawn attention to this in his The Scientific Image. If such a connection between the question of the goal and various positions in the philosophy of science exists, the result of the investigation into the goal of physics can be used to discuss positions such as empiricism, constructivism and scientific realism. This programme will be carried out in the following steps. Chapter 1 will first clarify in what sense physics can be said to have a goal. Criteria will be worked out, which an adequate explication of the goal of physics should satisfy. It will be shown that candidates for the goal of physics should be able to explain why typical actions essential to physics are carried out in the way that characterises them: They must be recognisable as means to a proposed end. In addition, various proposals for the goal of physics will be presented, and the relationship of these proposals to the philosophy of science positions of empiricism, constructivism and scientific realism will be examined. In Chapter 2, for selected, constitutive modes of action in physics - namely for idealisations – it will be investigated to what extent they can be explained by the proposed target candidates. It will be shown, firstly, that the traditional formulations of the goal of physics with respect to a particular class of of idealisations have only limited explanatory value, and secondly, that the goal of a unified description of physical systems description of physical systems makes this practice understandable. In Chapter 3 it will be shown that a second class of idealising measures - especially abstractions, but also certain experimental procedures - also cannot be made comprehensible by traditional goal ascriptions. Moreover, they cannot be integrated into a picture of theory construction which presupposes the classical, empiricist concept of the law of nature as the as the basis for an understanding of physics. I will argue that it makes sense to define natural laws as the ascription of as the attribution of dispositions to physical systems, i. e. systems, i.e. as statements about the way in which physical systems systems behave under very specific circumstances, namely when they are isolated. Such a conception allows us to present a candidate target that is able to explain all of the idealisation measures under investigation. Thus, it satisfies the condition that a candidate for the goal of physics must fulfil. The goal of physics, it will be asserted, is, is to give a unified description of the dispositions of physical systems. Now, since the traditional proposed goals, which turn out to be inadequate, are closely related to scientific realism, empiricism and constructivism, a re-evaluation of these positions becomes necessary. This will be done in chapter 4. be done. (shrink)

Der Verzicht auf absolut gültige Erkenntnis, heute in den Naturwissenschaften beinahe schon selbstverständlich, ist erst jüngeren Datums. Noch im vergangenen Jahrhundert zweifelte die experimentelle Forschung kaum an der vollkommenen Begreifbarkeit der Welt. Diesen Wandel zu erkunden und aufzuzeigen ist Thema der vorliegenden Studie. Der erste Teil präsentiert verschiedene Typen neuzeitlicher und moderner Wissenschaftsauffassungen von Galilei über Newton bis hin zu Kant. Im zweiten Teil werden Entwicklung und Wandel der Wissenschafts- und Naturauffassung bei Helmholtz (1821-1895) erstmals mittels detaillierter Textanalysen einer umfassenden (...) Rekonstruktion unterzogen. Die Relativierung des Wahrheitsanspruchs erlaubt es Helmholtz, seine Naturauffassung trotz der antimechanistischen Kritik innerhalb der Physik, die im letzten Viertel des vergangenen Jahrhunderts laut wurde, als Hypothese aufrechtzuerhalten. Auch gewährt die Studie eine neue Sichtweise des Verhältnisses zwischen Helmholtz und Kant, das in der Vergangenheit kontroverse Beurteilungen erfuhr. (shrink)

The author investigates which methods of naming objects are possible in the language of physics on the basis of the real physical conditions and to which extend objects thereby can be identified. It is shown that in the language of classical physics naming by designation is always possible. But this implies only the temporal identity of objects, not the "trans - world" - identity, which is important for modalities. In the language of quantum physics naming by (...) designation is no longer applicable to individuals but only to classes of equivalent objects. And for these classes temporal identity as well as the "trans - world" - identity can be produced, which means that an adequate semantics can be specified for the concept of possibility necessary in this language. (shrink)

In modern physics, the constant "c" plays a twofold role. On the one hand, "c" is the well known velocity of light in an empty Minkowskian space—time, on the other hand "c" is a characteristic number of Special Relativity that governs the Lorentz transformation and its consequences for the measurements of space—time intervals. We ask for the interrelations between these two, at first sight different meanings of "c". The conjecture that the value of "c" has any influence on the (...) structure of space—time is based on the operational interpretation of Special Relativity, which uses light rays for measurements of space—time intervals. We do not follow this way of reasoning but replace it by a more realistic approach that allows to show that the structure of the Minkowskian space—time can be reconstructed already on the basis of a restricted classical ontology (Mittelstaedt, Philosophie der Physik und der Raum-Zeit, Mannheim: BI-Wissenschaftsverlag, 1988 and Mittelstaedt, Kaltblütig: Philosophie von einem rationalen Standpunkt, Stuttgart: S. Hirzel Verlag, pp. 221-240, 2003), and that without any reference to the propagation of light. However, the space—time obtained in this way contains still an unknown constant. We show that this constant agrees numerically with "c" but that it must conceptually clearly be distinguished from the velocity of light. Hence, we argue for a clear distinction between the two faces of "c" and for a dualism of space—time and matter. (shrink)

Symmetry, intended as invariance with respect to a transformation (more precisely, with respect to a transformation group), has acquired more and more importance in modern physics. This Chapter explores in 8 Sections the meaning, application and interpretation of symmetry in classical physics. This is done both in general, and with attention to specific topics. The general topics include illustration of the distinctions between symmetries of objects and of laws, and between symmetry principles and symmetry arguments (such as (...) Curie's principle), and reviewing the meaning and various types of symmetry that may be found in classical physics, along with different interpretative strategies that may be adopted. Specific topics discussed include the historical path by which group theory entered classical physics, transformation theory in classical mechanics, the relativity principle in Einstein's Special Theory of Relativity, general covariance in his General Theory of Relativity, and Noether's theorems. In bringing these diverse materials together in a single Chapter, we display the pervasive and powerful influence of symmetry in classical physics, and offer a possible framework for the further philosophical investigation of this topic. (shrink)

An informal theory is set forth of relations between abstract entities, includingcolors, physical quantities, times, andplaces in space, and the concrete things thathave them, or areat orin them, based on the assumption that there are close analogies between these relations and relations between abstractsets and the concrete things that aremembers of them. It is suggested that even standard scientific usage of these abstractions presupposes principles that are analogous to postulates of abstraction, identity, and other fundamental principles of set theory. Also (...) discussed is the significance of important disanalogies between sets and physical abstractions, including especiallymodal andtemporal aspects of physical abstractions, which is related to the problem of the characterizingconstancy, of colors, physical attributes, and locations in space. (shrink)

In 1912, Henri Poincaré published an argument which apparently shows that the hypothesis of quanta is both necessary and sufficient for the truth of Planck''s experimentally corroborated law describing the spectral distribution of radiant energy in a black body. In a recent paper, John Norton has reaffirmed the authority of Poincarés argument, setting it up as a paradigm case in which empirical data can be used to definitively rule out theoretical competitors to a given theoretical hypothesis. My goal is to (...) dispute Norton ''s claim that there is no theoretical underdetermination problem arising between classical physics and early quantum theory. The strategy I use in defending my view is to adopt a suggestion made by Jarrett Leplin and Larry Laudan on how to assess the relative merits of competing theoretical alternatives, where each alternative has an equal capacity to save the phenomena. In the course of the paper, I distinguish between two branches of classical physics: classical mechanics and classical electromagnetism. The former is claimed by Norton and Poincaré to be determinately ruled out by the black body evidence; and it is the former that I argue is compatible with this evidence. (shrink)

Two seemingly contradictory tendencies have accompanied the development of the natural sciences in the past 150 years. On the one hand, the natural sciences have been instrumental in effecting a thoroughgoing transformation of social structures and have made a permanent impact on the conceptual world of human beings. This historical period has, on the other hand, also brought to light the merely hypothetical validity of scientific knowledge. As late as the middle of the 19th century the truth-pathos in the natural (...) sciences was still unbroken. Yet in the succeeding years these claims to certain knowledge underwent a fundamental crisis. For scientists today, of course, the fact that their knowledge can possess only relative validity is a matter of self-evidence. The present analysis investigates the early phase of this fundamental change in the concept of science through an examination of Hermann von Helmholtz's conception of science and his mechanistic interpretation of nature. Helmholtz (1821-1894) was one of the most important natural scientists in Germany. The development of this thoughts offers an impressive but, until now, relatively little considered report from the field of the experimental sciences chronicling the erosion of certainty. (shrink)

This paper differs from any previous view in discussing quantum pure possibilities as individuals, existing independently of any observer or mind. These pure possibilities are also absolutely independent of any metaphysical or logical view that endorses the notion of possible worlds. In my view, the relationship between quantum possibilities and classical physical reality is not between reality as such, as it is in itself, and its phenomena. It is rather between fundamental or primary reality, consisting of quantum pure possibilities, (...) on the one hand, and its actualization in what classical physics has discovered so far, on the other. As individual pure possibilities, quantum entities must be, at least ontologically, distinct and different from one another, regardless of the epistemological standing of quantum physics. Hence, quantum metaphysics is committed to the principle of the identity of indiscernibles. Finally, I analyze the two-slit experiment, interference, and entanglement in the light of my approach. (shrink)

In this paper we analyse the approach to interpreting atomic spectra in the framework of classical physics from the discovery of the electron in 1897 to Bohr's atomic model of 1913. Taken as a whole, efforts in this direction are part of a remarkable intellectual endeavour in which the classical theoretical framework seems to have been exploited to its full potential. By demonstrating the limits and weaknesses of classical physics in solving the problem of spectral (...) emissions, these attempts opened the way to a complete break from traditional thought and the introduction of the new quantum ideas. (shrink)

Substantivalism is the view that space exists in addition to any material bodies situated within it. Relationalism is the opposing view that there is no such thing as space; there are just material bodies, spatially related to one another. This paper assesses this issue in the context of classical physics. It starts by describing the bucket argument for substantivalism. It then turns to anti-substantivalist arguments, including Leibniz's classic arguments and their contemporary reincarnation under the guise of ‘symmetry’. It (...) argues that these anti-substantivalist arguments are stronger than is often acknowledged. (shrink)

Here I explore a novel no-collapse interpretation of quantum mechanics that combines aspects of two familiar and well-developed alternatives, Bohmian mechanics and the many-worlds interpretation. Despite reproducing the empirical predictions of quantum mechanics, the theory looks surprisingly classical. All there is at the fundamental level are particles interacting via Newtonian forces. There is no wave function. However, there are many worlds.

In summary, then, I have presented a program for analysis of physical causal statements in terms of the following metaphysical primitives: space (made up of ordered points), time (also ordered and punctiliar), causal density, haecceity and causal necessity. These can be ‘read off’ the theories in question. I claim that theevent-singular cases are crucial, and that other cases can be reduced to this via set theory and (causal) modal logic. I have given several examples of this sort of translation and (...) a rough indication of how more complicated cases could be dealt with. (shrink)

ABSTRACT. The objectivity of physics has been called into question by social theorists, Kuhnian relativists, and by anomalous aspects of quantum mechanics. Here we focus on one neglected background issue, the categorical structure of the language of classical physics. The first half is an historical overview of the formation of the language of classical physics, beginning with Aristotle's Categories and the novel idea of the quantity of a quality introduced by medieval Aristotelians. Descartes and Newton (...) at-tempted to put the new mechanics on an ontological foundation of atomism. Euler was the pivotal figure in basing mechanics on a macroscopic concept of matter. The second scientific revolution, led by Laplace, took mechanics as foundational and attempted to fit the Baconian sciences into a framework of atomistic mechanism. This protracted effort had the unintended effect of supplying an informal unification of physics in a mixture of ordinary language and mechanistic terms. The second half treats LCP as a linguistic para-site that can attach itself to any language and effect mutations in the host without chang-ing its essential form. This puts LCP in the context of a language of discourse and sug-gests that philosophers should concentrate more on the dialog between experimenters and theoreticians and less on analyses of theories. This orientation supplies a basis for treating objectivity. (shrink)

I explain in what sense the structure of space and time is probably vague or indefinite, a notion I define. This leads to the mathematical representation of location in space and time by a vague interval. From this, a principle of complementary inaccuracy between spatial location and velocity is derived, and its relation to the Uncertainty Principle discussed. In addition, even if the laws of nature are deterministic, the behaviour of systems will be random to some degree. These and other (...) considerations draw classical physics closer to Quantum Mechanics. An arrow of entropy is also derived, given an arrow of time. Lastly, chaos is given an additional, objective meaning. (shrink)

The analysis of this article is entirely within classical physics. Any attempt to describe nature within classical physics requires the presence of Lorentz-invariant classical electromagnetic zero-point radiation so as to account for the Casimir forces between parallel conducting plates at low temperatures. Furthermore, conformal symmetry carries solutions of Maxwell’s equations into solutions. In an inertial frame, conformal symmetry leaves zero-point radiation invariant and does not connect it to non-zero-temperature; time-dilating conformal transformations carry the Lorentz-invariant zero-point (...) radiation spectrum into zero-point radiation and carry the thermal radiation spectrum at non-zero temperature into thermal radiation at a different non-zero temperature. However, in a non-inertial frame, a time-dilating conformal transformation carries classical zero-point radiation into thermal radiation at a finite non-zero-temperature. By taking the no-acceleration limit, one can obtain the Planck radiation spectrum for blackbody radiation in an inertial frame from the thermal radiation spectrum in an accelerating frame. Here this connection between zero-point radiation and thermal radiation is illustrated for a scalar radiation field in a Rindler frame undergoing relativistic uniform proper acceleration through flat spacetime in two spacetime dimensions. The analysis indicates that the Planck radiation spectrum for thermal radiation follows from zero-point radiation and the structure of relativistic spacetime in classical physics. (shrink)

In this paper we introduce a variational principle from which the fundamental equations of classical physics can be deduced. This principle permits a sort of unification of the gravitational and the electromagnetic fields. The basic point of this variational principle is that the world-line of a material point is parametrized by a parameter a which carries some physical information, namely it is related to the rest mass and to the charge. In particular, the (inertial) rest mass will not (...) be a property of a material point, but it will be a constant of the motion which is determined by the initial conditions. In this framework the equality between the inertial and gravitational mass can be deduced. (shrink)

Measurement is said to be the basis of exact sciences as the process of assigning numbers to matter (things or their attributes), thus making it possible to apply the mathematically formulated laws of nature to the empirical world. Mathematics and empiria are best accorded to each other in laboratory experiments which function as what Nancy Cartwright calls nomological machine: an arrangement generating (mathematical) regularities. On the basis of accounts of measurement errors and uncertainties, I will argue for two claims: 1) (...) Both fundamental laws of physics, corresponding to ideal nomological machine, and phenomenological laws, corresponding to material nomological machine, lie, being highly idealised relative to the empirical reality; and also laboratory measurement data do not describe properties inherent to the world independently of human understanding of it. 2) Therefore the naive, representational view of measurement and experimentation should be replaced with a more pragmatic or practice-based view. (shrink)

Physicists have suggested what I call symmetry fundamentalism: the view that symmetries are fundamental aspects of physical reality and that these aspects are more fundamental than what one might ordinarily think of as the fundamental building blocks of the world, such as elementary particles. The goal of this paper is to develop an ontology for classical particle mechanics that provides a precise instance of symmetry fundamentalism.

A two boundary quantum mechanics without time ordered causal structure is advocated as consistent theory. The apparent causal structure of usual “near future” macroscopic phenomena is attributed to a cosmological asymmetry and to rules governing the transition between microscopic to macroscopic observations. Our interest is a heuristic understanding of the resulting macroscopic physics.

Various fault modes of determinism in classical physics are outlined. It is shown how quantum mechanics can cure some forms of classical indeterminism. †To contact the author, please write to: Department of HPS, University of Pittsburgh, 1017 Cathedral of Learning, Pittsburgh, PA 15260; e‐mail: [email protected].

In this paper, I examine the claim that any physical theory will have an extremely limited domain of application because 1) we have to use distinct theories to model different situations in the world and 2) no theory has enough textbook models to handle anything beyond a highly simplified situation. Against the first claim, I show that many examples used to bolster it are actually instances of application of the very same classical theory rather than disjoint theories. Thus, there (...) is a hidden unity to the world of classical physics that is usually overlooked (by, for example, Nancy Cartwright who argues for the claims above). Against the second claim, I show that the practice of classical physics involves an enormous (infinite) number of models the use of which cannot be written off as merely ad hoc. Thus, although classical physics cannot, of course, model every situation in nature, it has a much larger domain than some would have us believe. (shrink)

The concept of inertial frame of reference in classical physics and special theory of relativity is analysed. It has been shown that this fundamental concept of physics is not clear enough. A definition of inertial frame of reference is proposed which expresses its key inherent property. The definition is operational and powerful. Many other properties of inertial frames follow from the definition, or it makes them plausible. In particular, the definition shows why physical laws obey space and (...) time symmetries and the principle of relativity, it resolves the problem of clock synchronization and the role of light in it, as well as the problem of the geometry of inertial frames. (shrink)

To make out in what way Einstein’s manifold 1905 ‘annus mirabilis’ writings hang together one has to take into consideration Einstein’s strive for unity evinced in his persistent attempts to reconcile the basic research traditions of classical physics. Light quanta hypothesis and special theory of relativity turn out to be the contours of a more profound design, mere milestones of implementation of maxwellian electrodynamics, statistical mechanics and thermodynamics reconciliation programme. The conception of luminiferous ether was an insurmountable obstacle (...) for Einstein’s statistical thermodynamics in which the leading role was played by the light quanta paper. In his critical stand against the entrenched research traditions of classical physics Einstein was apparently influenced by David Hume and Ernst Mach. However, when related to creative momenta, Einstein’s 1905 unificationist modus operandi was drawn upon Mach’s principle of economy of thought taken in the context of his ‘instinctive knowledge’ doctrine and with promising inclinations of Kantian epistemology presuming the coincidence of both constructing theory and integrating intuition of Principle. (shrink)

Starting from logical structures of classical and quantum mechanics we reconstruct the logic of so-called no-signaling theories, where the correlations among subsystems of a composite system are restricted only by a simplest form of causality forbidding an instantaneous communication. Although such theories are, as it seems, irrelevant for the description of physical reality, they are helpful in understanding the relevance of quantum mechanics. The logical structure of each theory has an epistemological flavor, as it is based on analysis of (...) possible results of experiments. In this note we emphasize that not only logical structures of classical, quantum and no-signaling theory may be treated on the same ground but it is also possible to give to all of them a common ontological basis by constructing a “phase space” in all cases. In non-classical cases the phase space is not a set, as in classical theory, but a more general object obtained by means of category theory, but conceptually it plays the same role as the phase space in classical physics. (shrink)