The Scale Revolution in Physics: Historical and Philosophical Perspectives

The ideal of a final theory has shaped much of modern physics and its philosophical interpretations.

Physicists have used it as a blueprint to construct theories of space, time, matter, and motion that apply in principle everywhere and under any circumstances.

Philosophers have used it as a guide to interpret existing theories and depict the entire universe in terms of a bedrock of fundamental entities.

Although this ideal still plays an important role today in quantum gravity, the situation has considerably changed since the 1950s.

Physicists now widely recognize that our best current theories work only at certain scales, and that this may well be the case for any future empirically successful theory.

Physicists also spend most of their time studying systems scale by scale and analyzing how physical effects depend on each other across scales, even in the context of quantum gravity.

How should philosophers adjust their interpretative practice if they are to take this new way of doing physics seriously? What kind of world picture would result from this?

The RESCALE project contends that the ideal of a final theory no longer provides a sensible interpretative guide, leaving us with no better option but to depict the universe one scale at a time.

More precisely, the project will show through an in-depth integrated historical and philosophical study that physicists’ new scale-based theoretical practice leads us to draw a partial picture of the world structured in a complex hierarchy of overlapping layers across scales, which is largely independent of what may lie beyond.

Besides disclosing a fundamental epistemological transformation in the recent history of science and showing how it forces us to rescale our world picture, this systematic interdisciplinary study at the crossroads of history, philosophy, and physics will have profound implications for our understanding of representation, reduction, realism, and metaphysics at the frontiers of science.