Most researchers who investigate matter or material at PSI, want to elucidate the links between the inner structure and observable properties of various materials. This is because the diverse properties of materials are determined by the atoms that make up the materials, how they are arranged and how they are able to move. The researchers at the Laboratory of Particle Physics are interested in the fundamental question about the basic structures of matter. To this end, they examine the structure and properties of elementary particles – the smallest building blocks of matter.
In a dark room you see what is normally concealed from the naked eye: cosmic particles are registered and converted into visible light. These particles rain down on us everywhere. We are more or less standing in permanent cosmic rain, and we don't notice.
«Every single body falls at the same speed irrespective of its mass», Galileo Galilei once said (1564–1642). The psi forum proves it: in the glass vacuum tower – with its four metre height of drop, the largest demonstration facility on free fall in the world – we let golf balls and snippets of paper to fall unimpeded.