Johann Kepler was a German astronomer and mathematician who made important changes to the copernican theory of the universe. Kepler observed that when the planets revolve around the sun, they do not have circular paths. The paths are in an oval shape which we call ellipticals. He also noted that the speed of the planets as they revolve were different, when the planets are closer to the sun on their elliptical path, they sped up and slowed down when they were farther away. Kepler also believed that there was some force that held the earth close to the sun and held the moon close to the earth. (Later Isaac Newton would dub this "gravity".

William Harvey was an English physician (doctor) who correctly identified that the heart acted as a pump to circulate the blood throughout the body. He also identified the two circulatory tracts. This means that he dissected a lot of bodies!