The Danish physicist Niels BOHR was a Nobel Prize-winning scientist who made significant contributions to the field of atomic structure and quantum mechanics. He is best known for his model of the atom, which proposed that electrons orbit the nucleus in distinct shells. He also developed the concept of complementarity, which states that certain physical phenomena can be described from multiple perspectives. The term 'Danish PASTRY' is often used to refer to a type of sweet PASTRY originating in Denmark. It is typically made with layers of dough, butter, and sugar, and is often filled with fruits or nuts.