Ok, I don't get it. The Maya who , in between rituals involving styleized executions , happened to figure out a pretty accurate (series) of calenders (365.25 days long Vs. modern day caesium clock ((which is 0.0002 seconds longer))) The long count , used to calculate long periods of time (why did the maya need this?) the Long counts basic unit was 20 days, 360 days (18 basic units ) was a 'tun' , 20 tuns was a 'katun' , 20 katuns was a 'baktun' which is 144,000 days (i see this number all over the place..) and 13 baktuns equalled a "Great Cycle". They also invented zero..!!! How can this be...forgive me if I overreact to the significance of the number zero, (romans , greeks did'nt have this number) but I'd say modern science would be screwed without it. This was a great , albeit brutal civilization. How then could they not have grasped the concept of the wheel...? I read somewhere that a mayan childs toy was discovered which rolled on two wheels. Kind of like the string of ducks that anglo children used to play with. IF they did have knowledge of the wheel, why then did they not use it? I guess one explanation could be the terrain, no sense building chariots only to get stuck in the rainforest. But what about in there great cities, surely the wealthy would have like to parade about in a cart of sorts. I just cannot figure out a decent answer. And I probably never wheel. Rm.