Schmidt History of Astronomy

Aristotle

384 BCE

Aristotle supported the geocentric Universe theory and believed that all the planets and stars were perfect spheres that moved in perfect circular motions. His theories were highly respected but later were proven wrong in the future.

Ptolemy

100

Ptolemy was also a supporter towards the geocentric Universe theory. Ptolemy used math to predict the movement of the planets. He attempted to prove this by saying that the planets move in epicycles and the Earth moved on an equant. In the end, none of his theories were true.

Copernicus

1473

Copernicus brought the idea of the sun being in the middle of the universe to the Renaissance. Copernicus also had the idea that the Earth rotated on it's axis. This idea was proven to be true.

Tycho Brahe

1546

Tycho Brahe's work helped show that the Sun was in the center of the universe. Tycho made armillary spheres which was able to make a representation of the sky. This helped him make celestial maps of the planets movement.

Galileo

1564

Galileo helped improve astronomers studies by developing a telescope that would make things 20 times bigger. This invention helped prove that the heliocentric theory was correct. Many other scientists took advantage of the telescope and made many other discoveries.

Hans Lippershey

1570

Historians believed that Hans was the first to create a telescope. Nobody knows who really did to this day still however. He is known for making telescopes accessible to many other people.

Johannes Kepler

1571

Kepler made 3 new discoveries about the laws of planetary motion. One of those discoveries was that the planets move in elliptical orbits with the Sun. His other laws were called Kepler's laws which also describe how the planets move.

Giovanni Cassini

1625

Giovanni was the first to observe Saturn's moons. He was also the first to observe the differential rotation of Jupiter's atmosphere. Using Galileo's methods, Cassini was able to make the first measurements of longitude. In his honor NASA sent a spacecraft to crash into Saturn to avoid future contamination of the potentially habitable moons.

Sir Isaac Newton

1643

Most famous for his work with forces and creating the universal law of gravity. There is a myth that tells that when Newton saw an apple fall from a tree he was interested in what made it fall. Newton made 3 laws of motion and one of them was how objects move at the same velocity unless another thing forces it to move differently.

William Herschel

1738

William is most notable about being the founder of sidereal astronomy. He also found Uranus and it's two moons and suggested that nebulae make up stars. He also was able to develop a much better telescope that would enlarge things by 6450 times their actual size.

Percival Lowell

1855

Lowell made a mission called Planet X where he would eventually discover pluto. He discovered galactic redshifts which suggested a n expanding universe. Another thing that he discovered was that there was canals and oases on Mars.

Ejnar Hertzsprung

1873

Ejnar was well known for the discovery that the variations in the width of stellar lines reveal that some stars have a lower density than others. He was also the first to calibrate the period-luminosity relation for Cepheid variable stars. He also determined proper motions, colors, and magnitudes of many stars in the Pleiades cluster.

Albert Einstein

1879

Einstein's studies show that light needs to be thought of as a stream of particles and not just a single wave. his "photoelectric effect" points to that electrons are ejected from the surface of metal due to incident light. He also discovered Mercury and its orbit.

Edwin Hubble

1889

Edwin discovered that the galaxies are actually moving (mostly away from Earth) but one is set to collide with the Milky Way in 5 billion years. He originally thought that the galaxies had gone from ellipticals to spirals. this was later to be proven incorrect because galaxies would appear based on their early life.

Karl Jansky

1905

Jansky is known for being the father of radio astronomy. He worked on finding a way to track German submarines in WW2 however at the end of the war he developed frequency amplifiers. Jansky also studied a radio signal that repeated every 23 hrs and 56 min which was the same amount of time that the stars took to fully rotate the Earth which means that this radio signal was coming from the other stars in the Milky Way.