This is what i was hoping to read in this article: If pi is defined as the ratio of the circumference of a circle to its diameter, then a gravitational field i

This is what i was hoping to read in this article: If pi is defined as the ratio of the circumference of a circle to its diameter, then a gravitational field indeed changes pi, and by measuring this change, its possible to measure the strength of gravity. A quick way to understand this is to realize that "straight lines" (geodesics) are defined as the path taken by a beam of light, and gravity causes the path of light to bend. Measuring the difference is the same as measuring the curvature of space time, which when multiplied by a constant IS the strength of the gravitational field according to general relativity. Another way to see it: take a sphere and draw a circle on it, then measure pi. You can determine the curvature of the sphere once you measure the difference with pi on a flat piece of paper.