A study has found that in order to build the Great Pyramids Egyptians created points-of-reference using the sun during the autumn equinox - a day halfway between the summer and winter solstices when day and night are of equal length.

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A study has found that in order to build the Great Pyramids Egyptians created points-of-reference using the sun during the autumn equinox - a day halfway between the summer and winter solstices when day and night are of equal length.