The Zero group, too, electrified the public early on with happening-type actions. It chief exponents, Heinz Mack (born in 1931), Otto Piene (born in 1928) and Gunther Uecker (born in 1930), represented a type of artist who, after the Holocaust perpetrated by the National Socialists, was no longer interested in following ideologies but rather in creating concrete pictures. Piene, who is meanwhile world famous, has caused quite a stir all over the globe with his fire and smoke pictures and - in a particularly spectacular manner -with his sky events. Mack has received international acclaim for his light steles, light dynamos and Sahara project. Uecker has given people in many countries food for thought with his nail objects, sandmills and expressive instruments of terror.