AOL.com Video - How We Know Spring Has Arrived

VIDEO:Knowledge

How We Know Spring Has Arrived

Description:What causes the dramatic changes that occur in both man and nature during spring? While many ancient cultures tracked seasonal shifts, the big breakthrough in actually understanding them occurred when Nicolaus Copernicus posited that the earth revolves around the sun. (1:13)

Source: GeoBeats

Tags: earth revolves around sun , GeoBeats , nature knowledge , season change