HipparchusAstronomical Model of the universe
Hipparchus worked on the epicycle, which was a geocentric model that help explain the variations in speed and direction.
He developed trigonometry and constructed trigonometric tables, and he solved several problems of spherical trigonometry. With his solar and lunar theories and his trigonometry, he may have been the first to develop a reliable method to predict solar eclipses. His other reputed achievements include the discovery of Earth's precession, the co
Aristarchus Of Samos - 310BC - 230 CAAristarchus, or more correctly Aristarchos (Greek: Ἀρίσταρχος, Arístarchos; 310 BC – ca. 230 BC), was a Greek astronomer and mathematician, born on the island of Samos, in Greece. He presented the first known heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe. He was influenced by the Pythagorean Philolaus of Croton, but, in contrast to Philolaus, he identified the "central fire" with the Sun, and put the other planets in their correct ord
Aristotle- 384 BC - 322 BCGeocentric model: Earth is situated and is stationary at the centre of the universe
All the planets and stars had a perfect sphere
The moon, planets sun and stars orbited the earth in a simple circular motion No technology available at the time, so everything was determined from what could be seen by the human eye
It was generally based on philosophical speculations and scientific observations
It was modified later in correspondence with the catholic theology of the universe
Dec 14, 1546
Tycho BraheBelieved in the sun and moon revolving the Earth and the planets revolving around the sun. All motions along circular paths.
1572 discovered a new star which was the result of a nova.
Tycho’s observations later contributed to Keplers research
Technology a sextant measures the angle of two visible objects. Quadants an instruments used by Tycho Brahe to determine the attitude of objects.
Feb 15, 1564
Galileo7 Members in family
Father was a monk, In 1581 at the age of 17 he entered the University of Pisa to study medicine as his father wished
Needed money to support siblings. In Venice on a holiday in 1609, Galileo Galileo heard rumors that a Dutch spectacle-maker had invented a device that made distant objects seem near at hand. The Dutch spyglass he built a 3-power telescope. He become a man of wealth and leisure. To his astonishment, viewed a surface that was uneven, rough and full of cavities.
Dec 27, 1571
Johannes KeplerJohannes Kepler December 27, 1571 – November 15, 1630) was a German mathematician, astronomer and astrologer. A key figure in the 17th century scientific revolution, he is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. These works also provided one of the foundations for Isaac Newton's theory of universal gravitation. During his caree
Isaac NewtonSir Isaac Newton PRS (25 December 1642 – 20 March 1727 [NS: 4 January 1643 – 31 March 1727]) was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, has been "considered by many to be the greatest and most influential scientist who ever lived
His monograph Philosophiæ Naturalis Principia Mathematica, published in 1687, lays the foundations for most of classical mechanics. In this work, Newton described universal gravitation and the three laws
Albert EinsteinAlbert Einstein 14 March 1879 – 18 April 1955) was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history.He received the 1921 Nobel Prize in Physics "for his services to theoretical physics, and especially for his discovery o
Alexander FriedmannAlexander Friedmann was born to the composer and ballet dancer Alexander Friedman He lived much of his life in Saint Petersburg. He fought in World War I (on behalf of Imperial Russia) as a bomber and later lived through the Russian Revolution of 1917.
Friedmann obtained his degree in St. Petersburg State University (1910), became a lecturer in St.-Petersburg State College of Mines, and a professor in Perm State Univ
Edwin Powell HubbleWorked in Mt Wilson Observatory In California has most powerful telescope
With the telescope, Hubble was successful in locating individual stars in nebulae Noticed a particular type of pulsating star in the Andromeda Nebula, this type of star was called a “Cepheid Variable” These stars are so predictable that their distance can easily be calculated
Hubble successfully showed that the Andromeda was really a separate galaxy (Some nebulae are clouds of gas, however prior to Hubble, astronomers.
Nicolaus CopernicusPolish astronomer born on 19th Feb in 1473 , Died on 24th May 1543 + Roman catholic Great desire on astronomy, living in a home of a mathematics professor who influenced him to question the astronomy beliefs of the day. Studied mathematics and astronomy at University.Universe based on his readings of the work of Aristarchus. He proposed that the sun was stationary in the centre. Heliocentric model.The earth rotates daily on its axis and the Earth’s motion affected what people saw in the heavens