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Issac Newton
Isaac Newton was the greatest scientist of his time. He perfected the theory of mechanics, created the first dynamical theory of gravity, and made fundamental experimental discoveries in optics. His principal work was the Mathematical Principles of Natural Philosophy (1687), in which he set out the laws of motion, and deduced from astronomical observations (and particularly Keplers Laws both the universality of gravity as a force function and its form: the inverse square law. -
William Herschel
William Herschel was a German-born British astronomer. He was the founder of sidereal astronomy for the systematic observation of the heavens. He discovered the planet Uranus, hypothesized that nebulae are composed of stars, and developed a theory of Stellar Evolution. -
Pierre-Simon Laplace
Pierre-Simon Laplace was an influential French scholar whose work was important to the development of mathematics, statistics, physics and astronomy. He summarized and extended the work of his predecessors in his five-volume Mécanique Céleste (Celestial Mathematics 1799-1825). He restated and developed the nebular hypothesis of the origin of the Solar Systems and was one of the first scientists to postulate the existence of black holes and the notion of gravitational collpase. -
George Lemaitre
Georges Lemaître was a Belgian Roman Catholic priest, physicist and astronomer. He is usually credited with the first definitive formulation of the idea of a expanding universe and what was to become known as the Big Bang theory of the origin of the universe, which Lemaître himself called his “hypothesis of the primeval atom” or the “Cosmic Egg”. -
Henrietta Swan Leavitt
Henrietta Swan Leavitt was an American astronomer who discovered the relation between the luminosity and the period of Cepheid variable stars. Leavitt started working at the Harvard College Conservatory, examining photographic plates in order to measure and cataloge the brightness of stars. It was her discovery that first allowed astronomers to measure the distance between the Earth and faraway galaxies. Her discovery was that "A straight line can readily be drawn among each of the two series of -
Percival Lowell
Lowell's greatest contribution to the field of astronomy was made during the last eight years of his life. He was the first to realize the discrepancies between the calculated and observed positions of Uranus and Neptune. He believed that a ninth planet beyond the orbit of Neptune was responsible for the anomalies. He began to examine photographs of the regions of sky where he suspected the new planet might be found. The search for the ninth planet continued for several years after Lowell's dea -
William de Sitter
De Sitter made major contributions to the field of physical cosmology. He co-authored a paper with Albert Einstein in 1932 in which they discussed the implications of cosmological data for the curvature of the universe. He also came up with the concept of the de Sitter space and de Sitter universe, a solution for Einstein's general relativity in which there is no matter and a positive cosmological constant. This results in an exponentially expanding, empty universe. De Sitter was also famous f -
Fred Hoyle
Fred Hoyle was an English astronomer and cosmologist, primarily remembered today for his contribution to the theory of stellar nucleosynthesis , and his controversial stance on other cosmological and scientific matters, such as his rejection of the Big Bang theory in favour of a steady state universe and the panspermia theory of the origin of life on earth. -
Edwin Hubble
In the 1920s, the small, diffuse patches in the sky were termed nebulae, and were thought to exist within
the Milky Way. While examining the images, Hubble noticed a pulsating star known as a Cepheid variable inside each one. Cepheids are special because their pulsation allows for precise measurements of distance. Hubble calculated how far away each Cepheid lay and thus how far to each nebula, realizing that they were too distant to be inside of the Milky Way. Thus astronomers realized that th -
Albert Einstein
Albert Einstein and Cosmology go hand in hand. There have been some remarkable discoveries by some other scientist have only been made because of the Special and General Theories of Relativity that Albert Einstein released. -
Arno Penzias and Robert Wilson
The accidental discovery of cosmic microwave background radiation in 1964 is a major development in modern physical cosmology. Although predicted by earlier theoretical work around 1950, it was first discovered accidentally by American radio astronomers Arno Penzias and Robert Wilson as they experimented with the Holmdel Horn Antenna. The discovery was important evidence for the Big Bang theory of the creation of the universe and was evidence against the Steady state theory.