Geocentric Theory- an astronomical theory that described the universe as a geocentric system which put Earth as the center of the universe. Euxodus proposed the theory and he was one of Plato's pupils. It was also known as the Ptolemaic Theory because its most strongest supporter was the astronomer Ptolemy. The theory lasted until the Renaissance.
Copernicus Heliocentric Theory- theory that stated that the sun was the center of the universe and was proposed by Nicolas Copernicus. The theory was first proposed in his book De revolutionibus orbium coelestium which was released in 1543 which meant on the revolution of the heavenly bodies. He noticed that the sun did not have the same annual movements like the planets did.
Francois Viete was a mathematician who introduced the first systematic algebraic notation and contributed to the theory of equations. Viete's mathematical laws applied to triangles was probably the first western European work that had to do with a systematic work of methods which used all six trigonometric functions which was meant for computing plane and spherical triangles
Andreas Vesalius is credited for influencing modern Anatomy. His book De Humini Corporus Fabrica released in 1543 illustrated anatomy of the human body. It was the most accurate and comprehensive text up to that point. The book pretty much discredited long human beliefs from so long ago about human anatomy which was from Galen. He studied cadavers in order to unearth our bodies' secrets and he was also the first person to apply the scientific method to the human body.
Francis Bacon who lived from 1561 to 1626 popularized the scientific method. In order to test the idea that sickness came from outside causes, he argued that scientists should expose healthy people to outside influences such as coldness, wetness or other sick people to see if any of the outside variables made more people get sick. He wanted scientists to do the experiments repeatedly in order to expose the truth.
Galileo Galilei is credited for inventing the first thermometer in 1606. He also built the hydrostatic balance. It was a balance that could weigh objects both in water and in air. The telescope was made famous by Galileo. His discoveries convinced him that the sun was the center of the universe and not the Earth.
Rene Descartes came up with analytical geometry. He also introduced skepticism as a part of the already invented scientific method. He is considered as one of the greatest philosophers of all time. The field between algebra and geometry was basically linked by him. He converted many unsolved geometry problems into algebra problems which made the easier to do.
Johannes Kepler invented the modern glasses in the 1600's. He came up with a solution for the lenses in eye glasses to fix farsighted and nearsightedness with the use of technology by bending light through mirrors. One of the first original log books was created by him in order to keep track of the sun and the moon whenever he would use the telescope. Today captains use it at sea and so do astronauts keeping track of their space progress.