There is a mathematical constant $\pi$ that is known to a gazillion decimal places. Based on the usual axioms of geometry this value is coincident with the ratio of the circumference of a circle to its diameter. Are there any large-scale experiments to confirm the ratio of a circle's circumference to its diameter?
For example, there have been many experiments to measure the speed of light in a vacuum $c$. There are ongoing experimental efforts to measure $c$ with ever increasing precision. Are there similar efforts focused on measuring the ratio of the circumference of a circle to its diameter and comparing this to the computed values for $\pi$?