Gravity is the force of action between two objects. It’s called a natural force because it acts at a distance rather than needing to be in contact. Gravity is the force that holds us down on ...

Because the bar is horizontal to the Earth’s gravitational field, Cavendish was able to remove much of the planetary force from the measurements.

The force the researchers were looking for was tiny. At about 9 × 10^minus 14 newtons, it would be the force that one-third of a human blood cell would experience in Earth's gravitational field.