Kansas State University

Dark Energy, a type of "repulsive gravity", has been an enduring mystery in the field of cosmology ever since its discovery more than 20 years ago. What is Dark Energy? There have been few, if any, viable explanations to date. In this colloquium we first summarize those characteristics of Dark Energy, deduced from astrophysical measurements, that any successful theory must be able to describe. We then describe the unlikely trials and tribulations of a Soft Matter experimentalist in his attempts to explain Dark Energy. The arguments and concepts used in this colloquium will require no more than a freshman knowledge of Physics.