Introduction to Archaeoastronomy - Lecture Notes

‭Introduction to Archaeoastronomy‬ ‭Pre-Historic:‬‭Time before history‬ -‭ Mosaic of a photograph of the‬ ‭sun at different times of the year.‬ ‭(same place)‬ ‭ rchaeoastronomy:‬‭The study of ancient sites and how‬‭people in the past‬ A ‭have understood the phenomenon in the sky and its cycles.‬ ‭ ncient sites with an obvious connection to the sun:‬ A ‭(The Sun is important for survival and to tell the time)‬ ‭ .‬ ‭Newgrange - 3200 BC‬ 1 ‭-‬ ‭Located East cost in Ireland‬ ‭-‬ ‭Large stone tomb‬ ‭-‬ ‭Over 5000 Years old‬ ‭-‬ ‭Comprised of a Roofbox that is aligned with the winter solstice sunrise‬ ‭-‬ ‭On this day a beam of sunlight hits the Roofbox and illuminates the floor‬ ‭Why would they align it on the shortest day of the year?‬ ‭-‬ T ‭ he shortest day of the year has been associated with a day of‬ ‭“Rebirth”‬ ‭-‬ ‭This civilization believed in some form of reincarnation‬ ‭-‬ ‭For someone to some God to be commemorated internally by sunlight‬ ‭ .‬ ‭Sundagger of Chaco Canyon - 1000 AD‬ 2 ‭-‬ ‭Spiral Carving made by native Americans in New Mexico‬ ‭-‬ ‭Through the canyon are rock formations (One called Fajada Butte)‬ ‭-‬ T ‭ he summer solstice is the only day of the year when the ‘dagger’‬ ‭perfectly bisects (divides) the spiral‬ -‭ ‬ T ‭ hey were able to do very precisely understand when these days occur‬ ‭-‬ ‭Theorized to be a sun shrine to worship the sun on these special days‬ ‭ .‬ ‭Stonehedge - 4000 BC‬ 3 ‭-‬ ‭Ring of stones‬ ‭-‬ ‭Located in southern England‬ ‭-‬ ‭On the longest day of the year the‬ ‭summer solstice, if you are standing‬ ‭inside the stone structure and are‬ ‭facing the‬‭heel stone‬‭, you would see‬ ‭the sun rising behind the stone.‬ ‭-‬ ‭Stonehenge was likely used for‬ ‭ancient rituals, timed by the rising or‬ ‭setting of the sun behind special‬ ‭stones on special days of the year.‬ ‭-‬ T ‭ hey believe that the‬‭heel stone‬‭had a partner stone‬‭beside it and that‬ ‭the sun was framed on this day.‬ ‭Sun’s day Cycles:‬ ‭-‬ D ‭ ue to Earth's 24-hour‬ ‭eastward spin, the Sun‬ ‭moves westward across the‬ ‭sky at the same rate,‬ ‭reaching its highest point at‬ ‭noon.‬ ‭-‬ T ‭ his happens because the earth spins every 24 hours, making the sun‬ ‭appear to spinning the other way.‬ ‭-‬ N ‭ -hemisphere: The Sun is mostly seen in the southern sky, reaching‬ ‭due south‬‭(exact south) at noon. (opposite in S-hemisphere)‬ ‭-‬ ‭-‬ L ‭ ocal time (Timezones‬‭): defined by the Sun's‬ ‭position in the sky relative to your location.‬ ‭The Sun's Annual Cycle:‬ ‭ all & Spring Equinox (~Sep 23,‬ F ‭~Mar 21):‬‭sunrise is due E, sunset‬ ‭is due W; equal day & night‬ ‭Equinox:‬‭Latin for Equal Night‬ ‭ inter Solstice/ "solar standstill"‬ W ‭(~Dec 22):‬‭S-most rise & set;‬ ‭sun traverses a short, low arc‬ ‭(shortest day, lowest noon sun)‬ ‭ ummer Solstice/ "solar‬ S ‭standstill" (~Jun 22):‬‭N-most rise‬ ‭& set; Sun traverses long, high arc‬ ‭(longest day, highest noon sun)‬ ‭ -hemisphere:‬‭Sun's dally path arcs‬ S ‭toward N rather than S‬