Cavendish Experiment

Definition

The Cavendish Experiment is a scientific experiment conducted by Henry Cavendish in 1798 to measure the force of gravitational attraction between masses and determine the density of the Earth. This groundbreaking experiment provided one of the first quantitative measurements of gravitational force, allowing scientists to calculate the gravitational constant and significantly advancing the understanding of Newton's Law of Universal Gravitation.

5 Must Know Facts For Your Next Test

1. Cavendish used a torsion balance in his experiment, which allowed him to detect tiny forces acting between lead spheres due to gravity.
2. The experiment measured the deflection of the torsion balance caused by gravitational attraction, leading to calculations of both 'G' and Earth's density.
3. Though Cavendish did not directly measure the mass of the Earth, his findings provided a means to calculate it indirectly.
4. The results were remarkably accurate for his time and laid the groundwork for future studies in gravitational physics.
5. Cavendish's work remained largely unrecognized until decades later when its significance was fully appreciated within the scientific community.

Review Questions

• How did Cavendish's use of a torsion balance contribute to the accuracy of his measurements in the experiment?
  • The torsion balance was crucial for Cavendish's measurements because it was sensitive enough to detect small gravitational forces between the lead spheres. By suspending a bar from a thin wire, he could measure slight deflections caused by gravity, allowing for precise calculations. This sensitivity enabled Cavendish to achieve results that were unprecedented at the time, providing an early quantitative analysis of gravitational attraction.
• Discuss how the results of the Cavendish Experiment advanced our understanding of Newton's Law of Universal Gravitation.
  • The Cavendish Experiment provided empirical evidence that supported Newton's Law of Universal Gravitation by quantifying gravitational forces between masses. By measuring these forces and calculating 'G', Cavendish effectively confirmed that gravity could be measured and predicted mathematically. This work not only reinforced Newton’s theories but also provided a more accurate method for calculating the mass and density of celestial bodies, further deepening our understanding of gravitational interactions in the universe.
• Evaluate the impact of Cavendish's findings on modern physics and how they paved the way for future research in gravitation.
  • Cavendish's findings had a profound impact on modern physics as they established a reliable method for measuring gravitational force, which is fundamental to many branches of physics. His accurate determination of 'G' allowed subsequent scientists to refine theories around gravity and explore concepts such as general relativity and cosmology. Additionally, Cavendish’s work inspired future experiments that would lead to advancements in understanding not just terrestrial gravitation but also celestial mechanics, making it a cornerstone for both theoretical and applied physics.

Related terms

Gravitational Constant: A fundamental physical constant that represents the strength of the gravitational force between two objects, denoted by the symbol 'G'.

Newton's Law of Universal Gravitation:

A law stating that every point mass attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

Torsion Balance: An instrument used in the Cavendish Experiment, consisting of a bar suspended from a thin wire, used to measure small forces like gravitational attraction.