Cavendish Experiment

Definition

The Cavendish Experiment, conducted by Henry Cavendish in 1797-1798, was a groundbreaking scientific experiment designed to measure the force of gravitational attraction between masses and, ultimately, to determine the density of the Earth. This experiment was pivotal in providing a quantitative understanding of gravitational forces, leading to the calculation of the gravitational constant and establishing foundational concepts in gravitational theory.

5 Must Know Facts For Your Next Test

1. Cavendish used a torsion balance to measure the tiny forces between lead spheres, making it possible to detect gravitational attraction that is normally imperceptible.
2. The experiment provided an early measurement of the Earth's density, which was estimated to be about 5.5 times that of water.
3. Cavendish's meticulous work helped confirm Isaac Newton's law of universal gravitation, adding significant empirical evidence to the theoretical framework.
4. The apparatus designed by Cavendish was innovative for its time and laid the groundwork for future experiments related to gravity and mass measurements.
5. Although Cavendish did not publish his findings until 1798, his work remained largely unrecognized until later scientists validated and built upon his results.

Review Questions

• How did Cavendish's method using a torsion balance improve our understanding of gravitational forces?
  • Cavendish's use of a torsion balance allowed for precise measurement of the weak gravitational forces between two lead spheres. This method was innovative because it minimized external influences and increased sensitivity to small forces. By detecting these tiny gravitational attractions, Cavendish was able to provide concrete evidence for Newton's law of universal gravitation and quantify the strength of gravity in a way that had never been achieved before.
• Discuss the significance of Cavendish's findings on Earth's density in relation to contemporary gravitational theories.
  • Cavendish's determination of Earth's density was significant because it offered one of the first empirical measurements supporting theoretical physics regarding gravity. By establishing that Earth’s density was approximately 5.5 times that of water, Cavendish's work provided crucial data that aligned with Newtonian physics and confirmed that gravity varies with mass and distance. This not only validated existing theories but also opened doors for further research into gravitational forces and celestial mechanics.
• Evaluate how the Cavendish Experiment contributed to advancements in both classical mechanics and modern physics, particularly regarding measurements and constants.
  • The Cavendish Experiment was a pivotal moment in both classical mechanics and modern physics as it provided a clear methodology for measuring gravitational forces, resulting in the determination of the gravitational constant 'G'. This experiment set a precedent for precision measurements in physics and influenced how scientists approach experiments involving weak forces. Furthermore, it paved the way for future explorations into gravity, leading to advancements such as Einstein's theory of general relativity, which builds upon the principles established by Cavendish's work.

Related terms

Gravitational Constant: A fundamental constant denoted as 'G', it quantifies the strength of the gravitational force between two masses separated by a distance.

Torque: A measure of the rotational force applied to an object, essential for understanding how the Cavendish apparatus operated to measure gravitational attraction.

Mass vs Weight: Mass is a measure of the amount of matter in an object, while weight is the force exerted by gravity on that mass; both concepts are crucial in discussions surrounding gravitational experiments.