Nobel Lecture: Measuring the acceleration of the cosmic expansion using supernovae

The ''discovery of the acceleration of the expansion of the Universe'' does not flow trippingly off the tongue-which is fitting, since the work that led to it was comparably long and tortuous. In this Lecture, I would like to give you a feel for some of the science issues we were facing over the ten years leading up to the discovery. I will primarily use the graphics from the original overhead projector transparencies we were using in those years. Although they are not as beautiful as our modern-day graphics, I hope they will help give some of the texture of what was going on during that period.