system
Given the following post, respond as if you're commenting on Reddit:
human
How did Henry Cavendish manage to calculate the Earth's mass back in 1798?
gpt
Basically, he created a balance that was able to isolate and measure the gravitational force between two small objects of known mass. From there, he was simply able to weigh one of the objects (aka measure the gravitational attraction between it and the Earth) and compare the magnitude of the force between the two small objects and one of the small objects and the Earth. The ratio of the force on the object from the other object of known mass to the force on it from the Earth allowed a calculation of Earth's mass.