Systems of units still fail to attract the philosophical attention they deserve, but this could change with the current reform of the International System of Units (SI). Most of the SI base units will henceforth be based on certain laws of nature and a choice of fundamental constants whose values will be frozen. The theoretical, experimental and institutional work required to implement the reform highlights the entanglement of scientific, technological and social features in scientific enterprise, while it also invites a philosophical inquiry that promises to overcome the tensions that have long obstructed science studies.

chapter |6 pages


ByNadine de Courtenay, Olivier Darrigol, Oliver Schlaudt

chapter 2|16 pages

Justifying and motivating an SI for all people for all time

ByMartin J. T. Milton

chapter 3|29 pages

Reforming the International System of Units

On our way to redefine the base units solely from fundamental constants and beyond
ByChristian Bordé

chapter 4|24 pages

Strategies for the definition of a system of units

ByAlessandro Giordani, Luca Mari

chapter 5|26 pages

Relations between units and relations between quantities

BySusan G. Sterrett

chapter 6|25 pages

On the conceptual nature of the physical constants 1

ByJean-Marc Lévy-Leblond

chapter 7|30 pages

And how experiments begin

The International Prototype Kilogram and the Planck constant
BySally Riordan

chapter 8|27 pages

The SI and the problem of spatiotemporal constancy

ByIngvar Johansson