Why This Universe?

In 19 70, the cosmologist allan sandige wrote a highly influential essay in which he argued that for decades to come, the science of observational cos ology would be essentially a mission to measure two numbers. In this episode, we're going to talk about one of these two important pyrimeters, the current expansion rate of our universe. We have with us windy freeman, who is one of the most important figures in the history of making these measurements.