As users of a solar calendar, we rely on the sun to tell us how long a year is and when each of the four seasons begins. It was devised to match our farming habits and as a reliable — and visible — guide to the passing of time. The sun’s position on the horizon as it rises and sets moves over the course of a year, further south in the winter, and further **rth in the summer. This significant change is used to mark midwinter or midsummer at famous locations such as Stonehenge and New Grange. Read more...
02-23-2016, 10:32 PM
Why do we have leap years? Here's the science behind that strange extra day.
العرض الشجري