## What did Pierre-Simon Laplace invent?

Laplace announced the invariability of planetary mean motions (average angular velocity). This discovery in 1773, the first and most important step in establishing the stability of the solar system, was the most important advance in physical astronomy since Newton.

**What was Eratosthenes mathematical contribution?**

One of Eratosthenes’ contributions to mathematics was his measurement of the Earth. He calculated the circumference of the Earth to be about 252,000 stadi which is equal to about 24,662 miles.

**What did diophantus discover?**

Diophantus is known as the father of algebra. Roughly five centuries after Euclid’s era, he solved hundreds of algebraic equations in his great work Arithmetica, and was the first person to use algebraic notation and symbolism. Today we usually indicate the unknown quantity in algebraic equations with the letter x.

### What is the Laplace theory?

what is now called Laplace’s nebular hypothesis, a theory of the origin of the solar system. Laplace imagined that the planets had condensed from the primitive solar atmosphere, which originally extended far beyond the limits of the present-day system.

**What Eratosthenes is famous for?**

Eratosthenes, in full Eratosthenes of Cyrene, (born c. 276 bce, Cyrene, Libya—died c. 194 bce, Alexandria, Egypt), Greek scientific writer, astronomer, and poet, who made the first measurement of the size of Earth for which any details are known.

**What is the difference between Kant and Laplace?**

(a) The main difference between Kant and Laplace was the “nebular hypothesis” theory. Kant believed that the Earth was developed from small and cold particles. He believed all these particles kept moving around and colliding with each other to form the particles and build the Earth.

#### What is nebula theory?

The nebular hypothesis is the idea that a spinning cloud of dust made of mostly light elements, called a nebula, flattened into a protoplanetary disk, and became a solar system consisting of a star with orbiting planets [12].