What is symmetry? Something possesses symmetry—or is symmetric—if it can be manipulated in some way, possibly mentally, that leaves it unchanged. Among the entities that possess symmetries are geometric shapes; creatures in our natural environment; paintings, sculptures, and buildings; atoms; and elementary particles. The manipulations that establish their symmetries include rotations, reflections, translations in space, and time reversal. If you are interested in symmetry and how it is manifested, you are invited to attend a 90-minute lecture on this topic by Frank Levin, a retired Brown University professor of physics who has taught adult education courses on symmetry.