Special Phenomenan of autumnal equinox
Special Phenomenan of The autumnal equinox
Cannot find our own shadow
because the sun shines is direct on the equator impartial . When you come to the equator line , you will find any object that cannot find its shadow .
North and South Poles have the same daylight.
At this day, the sun is direct to the equator, north and south poles can see the sun at the same day and sharing the same day.
Height and Shadow are same Long
At 45 degrees north latitude line you can measure the height of the building without climbing high. Because it seems to have discussion with its shadow to become the same long. On that day the height and shadow are same long, so we know the shadow length and then can know the height of the building at the same time too.