Here is a fun textbook I found on astronomy http://gron.ca/math/dupuis_1910/dupuis.pdf http://gron.ca/math/dupuis_1910/dupuis.pdf that is written in a more prag

Here is a fun textbook I found on astronomy http://gron.ca/math/dupuis_1910/dupuis.pdf http://gron.ca/math/dupuis_1910/dupuis.pdf that is written in a more pragmatic style.