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.
William Herschel Sir William Herschel was a German-born British astronomer and composer, who is widely credited as the founder of sidereal astronomy for observing the heavenly bodies. He found the planet Uranus and its two moons, and formulated a theory of stellar evolution. Knighted in 1816, Herschel was also the first astronomer to