The Notebooks of Leonardo Da Vinci Complete


google search for The Notebooks of Leonardo Da Vinci Complete

Return to Master Book Index.

Page
720 721 722 723 724

Quick Jump
1 306 613 919 1225

Epicurus perhaps saw the shadows cast by columns on the walls in  
front of them equal in diameter to the columns from which the  
shadows were cast; and the breadth of the shadows being parallel  
from beginning to end, he thought he might infer that the sun also  
was directly opposite to this parallel and that consequently its  
breadth was not greater than that of the column; not perceiving that  
the diminution in the shadow was insensibly slight by reason of the  
remoteness of the sun. If the sun were smaller than the earth, the  
stars on a great portion of our hemisphere would have no light,  
which is evidence against Epicurus who says the sun is only as large  
as it appears.  
[Footnote: In the original the writing is across the diagram.]  
8
82.  
Epicurus says the sun is the size it looks. Hence as it looks about  
a foot across we must consider that to be its size; it would follow  
that when the moon eclipses the sun, the sun ought not to appear the  
larger, as it does. Then, the moon being smaller than the sun, the  
moon must be less than a foot, and consequently when our world  
eclipses the moon, it must be less than a foot by a finger's  
breadth; inasmuch as if the sun is a foot across, and our earth  
casts a conical shadow on the moon, it is inevitable that the  
luminous cause of the cone of shadow must be larger than the opaque  
722  


Page
720 721 722 723 724

Quick Jump
1 306 613 919 1225