Scientist

1. Aristotle 4. Eratosthenes 7. Claudius Ptolemy 10. Nicolaus Copernicu 13. Tycho Brahe 15. Johannas Kepler 2. Galileo Galilei 5. Sir Isaac Newton 8. Immanuel Kant 11. William Hershell 14. Christian Doppler 16. Edwin Hubble 3. Jan Oort 6. Einstein 9. Gerald Kuiper 12. Einar Hertzsprung/Henry Russell
 * Origin of Modern Astronomy Timeline -** **Scientist, Major contribution, and in what time period**
 * //Technology/Major NASA missions//**

1. __**Aristotle**__ believed that there was a force in the stone that impelled it towards the ground. He said that if you want a cart to keep moving, you have to push it. He was a Greek philosopher; pupil of Plato, tutor of Alexander the Great. 2. __**Galileo Galilei**__ was an Italian physicist, mathematician, and astronomer. He was the first person to use a telescope to study the stars and planets. Galileo Galilei is considered to be the father of modern experimental science. -**Alyssa Walker**, 1,085 words. 3.__**Einstein**__ was a german born physicist. He developed the theory of general relavitity. He recieved the nobel prize in 1921. He also published more than 300 published scientific papers.He visited the United states right around the time hitler was in rein, and never returned back to germany where he worked at the berlin academy of sciences. While in the united states he help the president with information about germany and its forces.


 * Gerard Kuiper:** he was an American astronomer living between the years of 1905-1973. He was considered thee father of modern planetry science for his study of our solar system. Kuiper developed new ways of seeing the solar system and he had the Kuiper belt named after him because of his theory of it that was proven 20 years after his death. -**Amani A**


 * __Edwin Hubble__-** He was an American astronomer. He was born in Marshfield, Missouri U.S. and lived from November 1889 to September 1953. He contributed to science because he was the person who found and confirmed that there are other galaxies out in the universe besides the one we live in, the Milky Way.
 * __Johannes Kepler__**- He was German Mathematician, astronomer, and astrologer. He was born in Germany and lived from December 1571 to November 1630. He was the person who created the Kepler laws about the universe that we use today. - **David Meneses.**

**Jan Oort-** f irst measured the distance between our solar system and the center of the Milky Way Galaxy and calculated the mass of the Milky Way. Another contribution of his was the proposal of a large number of icy comets left over from the formation of the solar system, which is now known as the Oort Cloud. **Eratosthenes**- calculated the circumference of the Earth -- **Kira Turner** **__William Hershell__-** Hershells contribution to science was the refracting telescope. During his career he constructed more than 400 telescopes but the largest, most popular telescope is the refracting telescope which he modified to make use easier and more efficient. He also discovered two moons belonging to Uranus and discovered the martai ice caps of Mars. He was a talented scientist who's contributions are greatly appreciated. -**//Allyson Fancher//**

__**Sir Isaac Newton**__- He was born on December 25, 1642, and died on March 20, 1727. He was an English physicist, astronomer, mathematician, philosopher, alchemist, theologian. He made and described universal gravitation. - **Josh Branker**

-Carlos Davila //**10. Nicholas Copernicus**//-he is an astronomer that lived in the Reniassance period. He was the first scientist to propose the idea that the world was heliocentric not geocentric, with the Earth as the center. He had a model of the solar system with the sun as the center, but his ideas were never taken seriously. -Shayam Patel
 * Christian Doppler-** He was a writer that published many articles. He published over 50 articles on math and astronomy. Christian was also known for the Doppler effect.
 * Tycho Brahe-** He was a nobleman known for his astronomical observations. He was also a alchemist. Tycho also helped create the laws of planetary motion.

Ptolemy made astronomical observations from Alexandria in Egypt during 127 to 141A.D. He described his veiw on the universe showing that the world is based on a fixed earth around which the sphere of the fixed stars rotates every day, this carrying with it the spheres of the sun, moon, and planets Based on his observations of solstices and equinoxes, Ptolemy found the lengths of the seasons. And based on these, he proposed a simple model for the sun which was a circular motion of uniform angular velocity, but the earth was not at the centre of the circle but at a distance called the eccentricity from this centre The most important of Ptolemy's work is the "Almagest", a treatise in 13 books. It gives in detail the mathematical theory of the motions of the Sun, Moon, and planets. Ptolemy made his most original contribution by presenting details for the motions of each of the planets. His theories were not superseded until 1543. Kant is best known for his view called transcendental idealism.Kant's contribustion to astronomy was the theory of the origin of our universe through the nebular theory and also making the hypothesis of what is known today as the black hole. -Antoneta Cici
 * __7.Claudius Ptolemy__**
 * __8.Immanuel Kant__**

__**Galileo Galilei**__ He was watching a lamp one day and counted the time it took to swing. He had noticed that the time of each swing was exactly the same. He discovered the law of the pendulum, which was than used to regulate clocks and he name famous. -Andrej Gavric

__**Henry Russell**__ Henry Russell was known for his research which later leads to the Hertzsprung-Russell diagram. The Hertzsprung-Russell diagram is used to separate giants and dwarfs in to two groups. Using the Hertzsprung-Russell diagram Henry discovered over 50 elements in the solar system. Henry’s theory was eventually proven wrong. Scientists still use Hertzsprung-Russell diagram. - Brandy Gibson

Einar Hertzprung- A danish astronomer who noticed that the luminosity of stars decreased from spectral type O to M. This occured in 1905, where he collaborated with Henry Russell to make the Hertzsprung-Russell diagram. The diagram plots luminosity on the y-axis and stellar temperature on the x-axis, as shown below. -Kayleah Beltran