Evidence for the Earth’s rotaton

If we aim a camera at the at the North Star and set it for a long time exposure, we see that the stars apparently move in arcs circling the North Star.

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Explanation: The North Star is almost exactly above the north pole of the Earth.  If, from our time-laps photo, we calculate the time that would be required for a star to make a complete circle, we find–24 hours. The apparent movement of the stars is given by the rotation of the Earth. Have kids model this effect sitting in a swivel  chair as described in the text.

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