Two reasons why the ancient Greeks didn't use this method are: 1. They didn't know how far away the stars were. The stars might as well be illuminated dots on

Two reasons why the ancient Greeks didn't use this method are: 1. They didn't know how far away the stars were. The stars might as well be illuminated dots on a sphere that is surrounding the earth not too far away. 2. Also you'd have to measure the time very precisely at several quite distant points on the Earth's surface. Not an easy feat.