This process is broken down into seven layers; Application Layer, Presentation Layer, Session Layer, Transport Layer, Network Layer, Data Link Layer, and Physical Layer. When a person communicates to another person on a network the information passes through these layers.
Ptolemy was an astronomer and mathematician. He believed that the Earth was the center of the Universe. The word for earth in Greek is geo, so we call this idea a geocentric theory.
Making the world better, one answer at a time. The early astronomers were Nicolaus Copernicus, Tycho Brahe, Johannes Kepler, Galileo Galileo, and Sir Isaac Newton. Copernicus concluded that Earth is a planet.He proposed a model of the solar system with the sun at the center.Brahe's observations, especially of Mars, were far more precise than any made previously. Kepler discovered three laws of planetary motion.e proposed a model of the solar system with the sun at the center. Brahe's observations, especially of Mars, were far more precise than any made previously. Kepler discovered three laws of planetary motion.