Last weekend I had the opportunity to travel up with the Astronomical Society of the University of Illinois and visit the University of Chicago’s Yerkes Observatory in Williams Bay, Wisconsin. Yerkes Observatory has a few telescopes, including the world’s largest refractor telescope, which has a 40-inch objective lens. Any larger, the lenses will sag under their own weight. As a result, mirrors are used in larger telescopes, since they can be supported from underneath without blocking the view. Yerkes was built in the 1890s and was used for research purposes all the way up to about ten years ago. The Observatory regularly hosts tours on Saturdays. In the evening, unfortunately, clouds prevented us from being able to use their telescope for observations. I would still say that the trip was worth it, and I can now say with certainty that I stood in the very same spot where Einstein once stood.