Science on Instagram: "🌍 Diurnal Motion: Earth’s Rotation Visualized The creeping movement of a shadow is the oldest evidence of Earth’s Rotation. It is governed by the principle of Apparent Solar Motion. Since Earth rotates at a steady angular velocity of approximately 15° per hour (360^\circ / 24h), the sun appears to traverse the sky, continually altering the angle of incidence for light hitting the object. In physics, the object acts as a Gnomon. As the Solar Azimuth (horizontal direction)