Nicolaus Copernicus 1) demonstrated that Earth and the other planets revolved around the sun. This was known as heliocentric theory, and contradicted the teachings of the Catholic Church at the time.
Sir Isaac Newton is famous for 2) explaining how gravity is universal in nature. This is known as universal gravitation. In order to solve more difficult mathematical problems, Newton also developed calculus.
Johannes Kepler 3) derived three laws to explain the motion of planets in the universe. Using these laws, Kepler was able to prove that planets move in elliptical orbits around the sun. Prior to this, it was speculated by Copernicus that planets moved in a circular pattern.
Andreas Vesalius 4) identified that humans and animals had different anatomy. It had been thought since ancient times that human and animal body organs and systems worked similarly. Vesalius proved this to be incorrect by performing autopsies and dissections on corpses, which was viewed as unlawful by some at the time. However, his work led to some of the greatest discoveries in understanding human anatomy at tge time.