Berlin 2012 – wissenschaftliches Programm

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AGPhil: Arbeitsgruppe Philosophie der Physik

AGPhil 1: "Condensed Metaphysics" I: Reduction and Emergence

AGPhil 1.1: Hauptvortrag

Montag, 26. März 2012, 09:30–10:15, E 020

On the Success and Limitations of Reductionism in Physics — •Hildegard Meyer-Ortmanns — School of Engineering and Science, Jacobs University Bremen

Methodological reductionism has proved to be an extremely successful approach in physics. It led to the very construction of the standard model as the theory of three of the four fundamental interactions. It allows bridging the scales from the microscopic to mesoscopic and sometimes even to macroscopic scales in the spirit of the renormalization group. It enables to predict emergent phenomena like phase transitions or self-organized pattern formation in space and time. We shall study the question of how far one can push the reductionistic approach and, along with that, we point on its limitations when it is pushed to extremes. The price then may be not only a lack of understanding in simple terms, but also a miss of emergent traits and new interactions between composed objects which arise when these composed objects are formed out of more elementary ones, and when they afterwards are considered as the new elementary units on the coarse-grained scale, on which their compositeness may be safely ignored. The very choice of what is declared as new elementary units is a matter of convention, and if phenomena on different scales should be related to each other, it is often the art in the game to find a really convenient choice. We shall illustrate the success and limitations of the reductionistic approach, in particular in view of emergent features, with a number of examples, ranging from particle physics to complex systems in biological applications.