The book of nature is written in the language of mathematics.

Our motto is a frequently cited short form of a quote from Galileo
Galilei's work *The Assayer (Il saggiatore)*, written in 1623.
(Translation supplied by
Stephen J. Summers):

Philosophy is written in that great book which continually lies open before us (I mean the Universe). But one cannot understand this book until one has learned to understand the language and to know the letters in which it is written. It is written in the language of mathematics, and the letters are triangles, circles and other geometric figures. Without these means it is impossible for mankind to understand a single word; without these means there is only vain stumbling in a dark labyrinth.

In the original Italian:

La filosofia è scritta in questo grandissimo libro che continuamente ci sta aperto innanzi a gli occhi (io dico l'universo), ma non si può intendere se prima non s'impara a intender la lingua, e conoscer i caratteri, ne' quali è scritto. Egli è scritto in lingua matematica, e i caratteri sono triangoli, cerchi, ed altre figure geometriche, senza i quali mezi è impossibile a intenderne umanamente parola; senza questi è un aggirarsi vanamente per un'oscuro laberinto.

## Featured article

### Uncertainty Relations for Angular Momentum

Prof. Dr. Reinhard F. Werner, Lars Dammeier, Rene Schwonnek#### Video Abstract

#### Abstract

In this work we study various notions of uncertainty for angular
momentum in the spin-*s* represen- tation of *SU*(2). We
characterize the “uncertainty regions” given by all vectors, whose
components are specified by the variances of the three angular momentum
components. A basic feature of this set is a lower bound for the sum of
the three variances. We give a method for obtaining optimal lower bounds
for uncertainty regions for general operator triples, and evaluate these
for small *s*. Further lower bounds are derived by generalizing
the technique by which Robertson obtained his state-dependent lower
bound. […]