Posted by dbd on 12/27/2004, 5:47 pm, in reply to "LOL"
Why would you have to go back in time to know anything about time measure?
Calander counts for Venus for example that the Mayans use - alls you need to do is look at the sky every night and make notes on it, over a period of time. They and other cultures did that for ages, so they knew about how Venus takes 8 years to complete it's orbit as seen from Earth, and it (seems to*) loops in closest 5 times, forming a pentagram shape in the sky.
*like retrograde planetary motion, doesn't actually happen it just seems to