Cultural Techniques

Can Flare Stars Explain the Annihilation Line from the Galactic Bulge?

“…Extensive observations by INTEGRAL observatory [4,5] permit to determine properties of the annihilation line from Galactic bulge. The observations confirmed the steady state of the line, and estimate production rate of positrons (e + ) in the bulge as 2 × 10 43 [6]. Possible sources of e + already discussed are supernovae explosions [7,8], microquasars [9], gamma-ray bursts [10], tidal disruption events [11], activity near black hole of Sgr A*, e.g.…”

“…One remarkable feature of the line emission is an absence of resolved point like sources [6]. Any model should take into account this feature.…”

“…Accepting the mass of the bulge M b = 2 · 10 10 M ⊙ , [24] one can estimate the total number of stars of G,K,M -types as N stars = M b /(0.3 · M ⊙ ) ≃ 6 · 10 10 . Then we can write a total production rate of positrons in the bulge N + e as N e + = N stars · E tot · η = 1.8 · 10 48 η e + /year (7) The estimated rate of e + e − annihilation in the bulge is R e + = 2 · 10 43 s −1 ≈ 6 · 10 50 year −1 [6]. Such rate of positron generation should be present at steady state.…”

Modernism's media theory

“…His emphasis on the exclusion of noise as a trigger-mechanism has since been incorporated into the theory of cultural techniques. 53 That is how change happens. Or so many writers thought.…”

Close to the metal: Towards a material political economy of the epistemology of computation

“…Here representing the computer as a person, rather than as a machine, he writes: 'every … operation consists of some change in the physical system consisting of the computer and his tape' (Turing, 1937, p. 250). Indeed, ever since the Pascaline invention by Blaise Pascal, the history of computation is also the history of tools for computation (Jones, 2016): 'Counting or writing' argues Bernhard Siegert, 'always presuppose technical objects capable of performing … these operations' (Siegert, 2015, p. 11, in Hayles, 2020. Hence 'by virtue of their material properties, technological artifacts are part of the normative order rather than external to it' (Miller, 2021, p. 61).…”