General Discussion

Indeterminism and Undecidability

“…15 See also Bub (2011), Dieks (2016), and forthcoming work by Chris Mitsch for balanced accounts. 16 The idea of contextuality was first formulated by Grete Hermann (Crull & Bacciagaluppi, 2016). 17 See Kochen & Specker (1967).…”

“…The difference is that in Bohmian mechanics the total state (which consists of the hidden configuration plus the "pilot wave" ψ) determines the measurement outcomes given the settings, whereas in 't Hooft's theory the hidden variable determines the outcomes as well as the settings. 23 More specifically:…”

“…This difference is immaterial for my discussion. 23 In Bohmian mechanics, the hidden state q ∈ Q just pertains to the particles undergoing measurement, whilst the settings a are supposed to be "freely chosen" for each measurement (and in particular are independent of q). The outcome is then fixed by a and q.…”

Review of Konrad Kleinknecht’s Werner Heisenberg: Reality and Its Order - Konrad Kleinknecht, ed., Werner Heisenberg: Reality and Its Order, with introduction by H. Rechenberg and commentary by E. P. Fischer, translated by M. B. Rumscheidt, N. Lukens, and I. Heisenberg. Cham, Switzerland: Springer (2019), 148 pp., $129.99.

“…For instance, Rechenberg’s extensive discussion of Heisenberg’s philosophical influences wholly neglects one of the most important figures in this context: mathematician and neo-Kantian Grete Hermann. Echoes of Hermann’s sophisticated philosophical stance reverberate throughout “Reality and Its Order.” This is unsurprising; recent scholarship on Hermann (e.g., Crull and Bacciagaluppi 2017), in tandem with a newly published collection of her essays and scientific correspondence (Hermann 2019), not only demonstrates the depth and clarity of Hermann’s thought but also reveals the extent to which Heisenberg was aware of, and explicitly influenced by, her writing. Several of the main theses in “Reality and Its Order” are taken nearly verbatim from Hermann’s 1935 essay on the philosophy of quantum mechanics (translated into English in Crull and Bacciagaluppi [2017]), published with Heisenberg’s benediction while she was briefly part of his Leipzigkreis .…”

“…Echoes of Hermann’s sophisticated philosophical stance reverberate throughout “Reality and Its Order.” This is unsurprising; recent scholarship on Hermann (e.g., Crull and Bacciagaluppi 2017), in tandem with a newly published collection of her essays and scientific correspondence (Hermann 2019), not only demonstrates the depth and clarity of Hermann’s thought but also reveals the extent to which Heisenberg was aware of, and explicitly influenced by, her writing. Several of the main theses in “Reality and Its Order” are taken nearly verbatim from Hermann’s 1935 essay on the philosophy of quantum mechanics (translated into English in Crull and Bacciagaluppi [2017]), published with Heisenberg’s benediction while she was briefly part of his Leipzigkreis . The same is true of her 1937 essay on the epistemology of modern science (reprinted in German in Hermann [2019]), which was submitted for—and won—the Avenarius Prize, with Heisenberg on the adjudication panel.…”