Thomas Ryckman

The reign of relativity

The reign of relativity : , The reign of relativity : , کتابخانه دیجیتال و فن آوری اطلاعات دانشگاه امام صادق(ع)

Carnap and Husserl

INTRODUCTION From a contemporary vantage point, the conjunction may appear puzzling. What could Carnap - anti-metaphysical logician, student and “legitimate successor” of Frege - possibly have in common with the founder of transcendental phenomenology? Yet, as Michael Dummett has observed, the German philosophy student of 1903 likely regarded Husserl and Frege as mathematician-philosophers remarkably similar in interests and outlook (Dummett, 1993, 26). To be sure, subsequent developments pushed apart the incipient programs of phenomenology and analytic philosophy. Husserl turned to “transcendental subjectivity” in 1905-1907, whereas analytic philosophy around 1930 took a “linguistic turn” precisely to distinguish its methods from those placing cognitive reliance upon intuition or individual subjectivity. Then again, the 1927 publication of Heideggers Being and Time inexorably changed perceptions of phenomenology as having acquired an expressly “existential” and “ontological” orientation, preempting and obscuring its original Husserlian impulses towards logic and the foundations of mathematics. Epitomizing this history in a memorable metaphor, Dummett notes that the respective influences of Frege, the “grandfather of analytic philosophy,” and Husserl, a patriarch of “continental philosophy,” run through twentieth-century philosophy like the Rhine and Danube, mighty rivers rising close together, briefly running parallel but then diverging to widely separate seas. Extending the metaphor a bit further, Carnap is a central current flowing into one of these seas, while Heidegger is the torrent surging into the other.

Invariance Principles as Regulative Ideals: From Wigner to Hilbert

Eugene Wigners several general discussions of symmetry and invariance principles are among the canonical texts of contemporary philosophy of physics. Wigner spoke from a position of authority, having pioneered (and won the Nobel prize in 1963) for recognition of the importance of symmetry principles from nuclear to molecular physics. But perhaps recent commentators have not sufficiently stressed that Wigner always took care to situate the notion of invariance principles with respect to two others, initial conditions (or events ) and laws of nature . Wigners first such general consideration of invariance principles, an address presented at Einsteins 70th birthday celebration, held in Princeton on 19 March 1949, began by laying out just this distinction, and in a way that seems to suggest that the three notions arise through abstraction in an analysis of the general problem of cognition in the natural sciences: The world is very complicated and it is clearly impossible for the human mind to understand it completely. Man has therefore devised an artifice which permits the complicated nature of the world to be blamed on something which is called accidental and thus permits him to abstract a domain in which simple laws can be found. The complications are called initial conditions; the domain of regularities, laws of nature. (…) the underlying abstraction is probably one of the most fruitful the human mind has made. It has made the natural sciences possible.

Surplus Structure from the Standpoint of Transcendental Idealism: The "World Geometries" of Weyl and Eddington

Recent discussions of “structural realism” in philosophy of science, jointly with a newly burgeoning philosophical interest in gauge aeld theories, have resuscitated in narrow compass the perennial puzzle attending the role, or roles, of mathematical representation in the formulation of physical theories. Structural realists urge that the continuity across theory change deemed characteristic of the “mature sciences” occurs only at the formal mathematical level, rather than of any particular entities posited by either preceding or successor theory. The realist intuition that science yields closer and closer “approximations” to the truth about nature is then redeemed as a growing accumulation of mathematical form or structure (Worrall 1989). The sought continuity between older and newer theory hence lies in a correspondence between their fundamental equations. In this way, mature sciences are regarded as tracking the relational structure of physical reality, the real relations among unobservable entities and not the content or nature of those entities. However, precisely which parts of a theory’s mathematical representation describe physical reality or, more modestly, could be considered to have a physical correlate, is a paramount issue in the interpretation of the gauge theories of modern particle physics. Here the presence of additional, or “surplus,” mathematical degrees of freedom introduce ambiguity into the physical system’s mathematical characterization. Famously, the four coordinate degrees of freedom im-

Hilbert’s Axiomatic Method and His “Foundations of Physics”: Reconciling Causality with the Axiom of General Invariance

In November and December 1915, Hilbert gave two presentations to the Royal G?ottingen Academy of Sciences under the common title ‘The Foundations of Physics’. Distinguished as ‘First Communication’ (Hilbert, 1915b) and ‘Second Communication’ (Hilbert, 1917), the two ‘notes’, as they are widely known, eventually appeared in the Nachrichten of the Academy. The first quickly entered the canon of classical general relativity but has recently become the object of renewed scholarly scrutiny since the discovery (Corry, Renn and Stachel 1997) of a set of printer’s proofs dated December 6, 1915 ((Hilbert, 1915a), henceforth ‘Proofs’). Hilbert’s second presentation has not received the same detailed reconsideration, with the recent exception of an extended study offered by Renn and Stachel (1999/2007). While we agree with much of their detailed technical reconstruction, we profoundly disagree with the assessment of Renn and Stachel that the second note shows that Hilbert had abandoned his own project (set out in the first note), and is working on a variety of largely unrelated problems within Einstein’s. In our opinion, this assessment rests on misunderstandings concerning the aims, content, and significance of the second communication, as well as its links to the first. Our aim in this paper is to offer an alternate narrative, according to which Hilbert’s second note emerges as a natural continuation of the first, containing important and interesting further developments of that project, and above all shedding needed illumination on Hilbert’s assessment of the epistemological novelty posed by a generally covariant physics.

What does History Matter to Philosophy of Physics

AbstractNaturalized metaphysics remains a default presupposition of much contemporary philosophy of physics. As metaphysics is supposed to be about the general structure of reality, so a naturalized metaphysics draws upon our best physical theories: Assuming the truth of such a theory, it attempts to answer the “foundational question par excellence”, “how could the world possibly be the way this theory says it is?” It is argued that attention to historical detail in the development and formulation of physical theories serves as an ever-relevant hygienic corrective to the “sentiment of rationality” underlying the naturalistic impulse to read ontology off of physics.

Hermann Weyl and “First Philosophy”: Constituting Gauge Invariance

The current vogue of naturalism – whether of a pragmatist, instrumentalist or realist variety – in philosophy of physics is largely attributable to a fiction promulgated by logical empiricism, but surviving the latters demise. It states that relatively theory (especially general relativity) comprised a decisive refutation of Kant, and transcendental idealism more broadly. A closer look at the early years of general relativity reveals a considerably different picture. Here we trace how transcendental idealism informed Weyls construction of a “purely infinitesimal geometry” whose additional (gauge) degrees of freedom enabled incorporation of electromagnetism into the spacetime metric.

Hilbert on General Covariance and Causality

Einstein and Hilbert both struggled to reconcile general covariance and causality in their early work on general relativity. In Einstein’s case, this first led to his infamous “hole argument”, a stumbling block that persuaded him early on that generally covariant field equations for gravitation could never be found. After his breakthrough to general covariance in the fall of 1915, the resolution came in form of the “point-coincidence argument.” Hilbert from the beginning took a different view of the “causality problem,” though he shifted his position somewhat in the light of Einstein’s breakthrough in November 1915. Nevertheless, his aim was to establish initial conditions that would lead to a well-defined Cauchy problem in general relativity. Hilbert consistently advocated the use of coordinate conditions in order to obtain solutions of the field equations that would maintain the causal ordering of events. Einstein’s “causality problem” thus differs from that of Hilbert, and the latter was never a victim of Einstein’s “hole argument.”

What Carnap Might Have Learned from Weyl

Aufbau §176 “demonstrating” the non-constructability of the real (as a mind-transcendent) concept had §17 of Weyl’s 1926 book, Philosophie der Mathematik und Naturwissenschaften squarely in its sights. Weyl had argued that postulation of a real, external world is both necessary for natural science and that such an objective world can be constructed, but only in abstract mathematical symbols far removed (“distilled”) from immediately given content. This objective world is a “symbolic construction of exactly the same kind as that which Hilbert carries through in mathematics”. For Hilbert and Weyl, symbolic construction is the twentieth century manifestation of Kant’s regulative idea of unity of nature.

Otto Neurath: Philosophy between Science and Politics.

Introduction Part I. A Life Between Science and Politics: 1. Before Munich 1.1. Early years 1.2. War economics 1.3. During the First World War 2. The socialisation debate 2.1. Setting the problem 2.2. Bauer and Korsch 2.3. The standard of living 2.4. Neurath on the structure of the socialist economy 2.5. The road to socialisation 2.6. Neuraths position in the debate 3. In the Bavarian revolution 3.1. The appointment 3.2. In office 3.3. On trial 4. In Red Vienna 4.1. Peoples education 4.2. The Housing Movement 4.3. The Museum of Economy and Society 4.4. The Vienna Circle 4.5. Exile in The Hague and Oxford Part II. On Neuraths Boat: 1. The Boat: Neuraths image of knowledge 2. In the First Vienna Circle 2.1. Three hypotheses 2.2. Machs legacy 2.3. The 1910 programme 3. From the Duhem Thesis to the Neurath Principle 3.1. Normative antifoundationalism 3.2. Radical descriptive antifoundationalism 3.3. Metatheoretical antifoundationalism 4 Rationality without foundations 4.1 The primacy of practical reason 4.2. Determining the conventions of science 4.3. The second Boat: one world 5. A theory of scientific discourse 5.1. Anti-philosophy, Marxism and radical physicalism 5.2. The forward defense of naturalism 5.3. Science as discourse: the theory of protocols 6. Towards a theory of practice Part III. Unity on the Earthly Plane: 1. Two stories with a common theme 2. Science: the stock of instruments 2.1. From re-represention to action 2.2. Unity without the pyramid 3. The attack on method 3.1. Boats and Ballungen 3.2. Protocols, precision and atomicity 3.3. The two Neurath Principles 4 Where Ballungen come from 4.1. Duhems symbols 4.2. The congestion of events 4.3. The density of concepts 4.4. The separability of planning and politics 4.5. How Marxists think of history 5. Negotiation, not regulation Conclusion.