"On the magnet, magnetick bodies also, and on the great magnet the earth" by William Gilbert is a scientific work published in 1600. Through experiments with his model Earth called the terrella, Gilbert explores magnetism and electricity, demonstrating how compass needles behave and why magnetic dip varies by latitude. He argues that Earth itself is a giant magnet, proposes magnetic explanations for astronomical phenomena, and boldly supports the Copernican view of Earth's rotation. This groundbreaking work established rigorous experimental methods while challenging ancient theories about the nature of magnetic and electrical forces.