Founded in 1954, CERN is one of the world's largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the universe is made of and how it works. The world's largest and most complex scientific instruments are used to study the basic constituents of matter - the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of nature. One of Europe's first joint ventures, it has 22 member states.