Experimental Value of G by Cavendish

Introduction:
The gravitational constant (G) is a fundamental constant in physics that is used to quantify the strength of the force of gravitational attraction between two objects. It is an important parameter in many areas of physics and astronomy, such as celestial mechanics, general relativity, and cosmology.

Cavendish Experiment:
Henry Cavendish was an English physicist and chemist who conducted the first scientific experiment to determine the value of G in 1798. The experiment, now known as the Cavendish experiment, involved measuring the gravitational attraction between two lead spheres using a torsion balance.

The apparatus consisted of a wooden frame supporting a horizontal rod suspended by a wire. The two lead spheres were attached to the ends of the rod, and two smaller lead spheres were placed near the larger spheres to provide a gravitational attraction. The torsion balance was used to measure the twisting of the wire due to the gravitational force between the spheres.

Results:
Cavendish's experiment provided the first experimental value of G, which he estimated to be 6.754 x 10^-11 N m^2 kg^-2. This value was later refined by other experiments, and the current accepted value is 6.67430(15) x 10^-11 N m^2 kg^-2.

Conclusion:
Cavendish's experiment was a groundbreaking achievement in the field of physics, and his determination of the value of G paved the way for further research in celestial mechanics and astrophysics. His work also laid the foundation for the development of modern experimental techniques and instrumentation.