In these days of specialization it is important to bring together physicists working in diverse areas to exchange and share their ideas and excitement. This leads to cross-fertilization of ideas, and it enriches, as in biological systems, a specialized field with new strength, development and direction derived from another area. Although this might be an uncommon thing, it is an important step in our under­ standing of the physical world around us, which is, after aIl, the main purpose of physics. The seed for this conference was really sowed when one of us (MB) and Mr. Manngärd showed some a-scattering data at backward angles to FBM one summer about four years ago. That occasion led to a long research collaboration between the Abo Akademi physicists and other scientists in several countries. The actual idea to explore the possibility of holding a conference, however, crystallized in the summer of 1989 during a visit of FBM to Abo Akademi. The final decision to organize a conference was made after MB visited Profes­ sor Ben Mottelson in Copenhagen and Professor Anagnostatos in Athens. At this point it was recognized that there are similarities as weIl as differences between clustering phenomena in nuclei and systems consisting of atoms. It was therefore conjectured that it could be very stimulating to bring together these groups to exchange their ideas and to leam from each other's fields. A conference along these lines, we hoped, would contribute to an increased mutual understanding.