Introduction

Abstract

The idea that all matter is made of not further divisible particles dates back to the greek philosopher Democritus and his teacher Leucippus, who called these fundamental particles atoms. The actual beginning of what today is known as elementary particle physics, however, can rather be placed in 1897, when J.J. Thomson discovered that cathode rays were actually made of negatively charged particles, which he initially called corpuscles (Thomson, Philos Mag 44:293–316, (1897), [1]). He thought of the atom as a “plum pudding”, with the electrons immersed in a positively charged paste.