The Earliest Known Conceptual Discoveries (Pre-Newton):

  • 7th Century (India): Astronomer Brahmagupta is credited with first proposing that gravity is an attractive force. In 628 CE, he stated that "all heavy things fall down to earth by a law of nature" and described it as a force inherent to the planet.
  • 11th/12th Century (Persia/India): Scholars like Abu Rayhan al-Biruni and Bhaskaracharya expanded on this. Bhaskaracharya (1114–1185) explicitly stated in his treatise Siddhanta Shiromani that the earth attracts objects towards it.
  • 300s BC (Greece): Aristotle introduced a primitive concept of "natural motion" or "gravitas" arguing that heavy objects fall toward their "natural place" which he believed was the center of the universe.

What Newton Actually Discovered:
Newton is credited with the first mathematical, universal theory of gravity. Rather than just observing that things fall, he proved:

  1. Universality: Gravity applies to all objects in the universe, not just on Earth (i.e., the moon is "falling" around the Earth).
  2. The inverse-square law for gravity is most famously known as Newton's law of universal gravitation . The formula is: $$ F = G \frac{m_1 m_2}{r^2} $$
    1. Where:
      1. \(F\) is the force of gravity between two objects.
      2. \(G\) is the gravitational constant.
      3. \(m_1\) and \(m_2\) are the masses of the two objects.
      4. \(r\) is the distance between the centers of the two objects.