The concept of parallel rays and divergent rays, in relation to the light source, is necessary to validate hypothesis 2 of Eratosthenes.
Hypothesis 1: The Earth is flat and the Sun is close | | Hypothesis 2: The Earth is curved and the Sun is very far away. |
![](http://twinspace.etwinning.net/files/collabspace/4/04/004/149004/images/c39addba8.jpg) | | ![](http://twinspace.etwinning.net/files/collabspace/4/04/004/149004/images/c4a467128.jpg) |