Cavendish Experiment

The Cavendish Experiment effectively weighed the Earth by measuring the gravitational constant G. In 1798, Henry Cavendish used a torsion balance to detect the tiny attraction between lead spheres, yielding a G value within 1% of modern measurements (6.674×10⁻¹¹ N·m²/kg²). This accuracy is 10% higher than the average 18th-century method, and its precision outperforms #3's Cavendish's own estimate for Earth's density (5.48 g/cm³ vs. today's 5.51 g/cm³). It remains the foundation for laboratory-scale gravity measurements.