Surfing the web this morning, I found two really interesting things.
The first is something called Antikythera Project. This is a project devoted to studying a mechanical computation device built about 150BCE It was discovered in 1900 and has taken over a hundreds to figure out what it did. Input the date, and it calculated the positions of the Sun, Moon, and other celestial bodies, plus it give the date of the olympics. You'll have to google it because the web site address was to long to read in the window...
The other interesting thing I found out today, is the jungles of the Yucatan are probably not natural, but like human agriculture and gardins going wild since the Mayan civilization collapse. To find this article google Christine Hastorf. She studied the distribution of the region and found too many plants with know human cultivation histories for a natural distribution.
CG