FEATURE: A short history of astronomy.

Early Man

There is little recorded information on early man’s impressions and ideas about the sky’s.  We have some cave panting’s such as those discovered in the Lascaux caves, dated to around 15,280 B.C. that seem to depict the summer triangle.  There are other drawings of eclipses comets and supernova such as the Pueblo petrogath, early man probably held the heavens in reverence and fear, believing that the stars held power over earthly existence.

England 2000 B.C	Construction of stone hedge begins in 2600 B.C and was finally completed in 2000 B.C; essentially it was built to be a computer of sorts for calculating the positions of the planets and the sun.
Babylonians 1600 B.C	The Babylonian’s where the first to keep Written records of astronomical observations.  They recorded the positions of planets and the times of eclipses.

 

Hellenistic culture.

“Philosophy is the science which considers truth.”

Aristotle

The ancient Greeks inherited astronomical records from the Babylonians, this then was applied to construct a cosmological framework, which was used for navigation and to think of new experiments. The end of this period was when the library at alexander burns, Rome falls and humanity enters its dark age.  Little is known about what discovery’s where made during this time.  But the loss of the millions of books at the library at alexander was a blow to mankind’s knowledge.
 

Thales 624 B.C – 546 B.C	Used the information from the Babylonians to predict eclipses. Thales rejection of mythological explanations became an essential idea for the scientific revolution.
Aristotle 384 B.C – 322 B.C	Aristotle presented a model of the universe in which the distant stars and planets execute perfectly circular motions.
Heraclites 397 B.C – 312 B.C	Developed the first solar system model and began the geocentric vs heliocentric debate. In the geocentric models of the solar system all of the planets have perfectly circular orbits.
Aristarchus 310 B.C – 230 B.C	Developed Heliocentric theory, when it was first proposed heliocentric theory was not universally accepted, it flew in the face of everything that classical society thought it knew about the way the universe works.   A few philosophical problem that the theory faced where: ·         If the earth is in motion, why can’t we feel it? ·         No Parallax seen in the stars ·         Geocentric ‘felt’ right, it put mankind at the very centre of everything
Eratosthenes 276 B.C – 194 B.C	The early Greeks where able to work out that the earth was a sphere, by studying the shadow of the moon during Luna eclipses. Eratosthenes, nick named beta by his contemporise (as in second best at everything) took this a step further and used this information to help him work out the circumference of the earth.  He knew that a stick placed in the ground at a certain time in Syene, on a particular day cast no shadow.  He also knew that if you placed a stick in the ground at the same time at Alexandria it had cast a shadow at 7°; lastly he hired a man to pace out the distance between the two city’s (4900 stadia).  Given that information, Eratosthenes was able to work out, almost exactly, the circumference of the earth.
Hipparchus 190 B.C – 120 B.C	Produced the first star catalogue and recorded the names of the constellations, recording the position of at least 850 stars.
Babylonian astronomers 164 B.C	First recorded sighting of halyes comet.
Ptolemy 90 -168 A.D	Liberian of the university of Alexandria. He combined geocentric theory with hundreds of records containing as much planetary data as he had available to him, using this he was able to formulate a complete mathematical description of the solar system. Ptolemy came to the realisation that the planets where much closer than the stars, however he also believed on crystalline spheres that he thought where tethered to the heavenly bodies, the resulting model of the solar system had 28 epicycles to account for the motion.  This began the first mathematical paradigm for understanding nature.
China 1054 A.D	Astronomers in China are the first to record the crab nebula who noted it as a guest star.  This has also been recorded in rock painting by the native amreicans.
Ulugh Beg 1394-1449	Bulit a three story observatory, the observatory produced astronomical tables conataion 1000 stars, perhaps the most important astronomer of the 15th century.

 

The Renaissance

“Philosophy is written in that great book which ever is before our eyes – I mean the universe – but we cannot understand it if we do not first learn the language and grasp the symbols in which it is written. The book is written in mathematical language and the symbols are triangles, circles and other geometrical figures, without whose help it is impossible to comprehend a single word of it; without which one wanders in vain through a dark labyrinth.”

Galileo Galilee

Nicolas Copernicus 1473-1543	Copernicus challenged the established doctrine of an earth centric universe.  This went much deeper than solving retrograde motion in fact it was seen as tantamount to heresy as a number of biblical passages seem to indicate a geocentric universe. Copernicus challenged and brought about change, a paradigm shift that ushered in the scientific revolution.  However circular orbits where still present in his new model of the universe, as where the epicycles of Ptolemy, in fact his model called for more.  Copernicus model would have failed Occam’s Razor, that a scientific model should be as simple as possible.
Tycho Brahe 1546 – 1601	Tycho Brahe used sextants (Telescpoes had not been invented yet) to build a observatory in his natavie Denmark.  He used relatively simple equipment to measure the position of the stars and planets to a very high dgree of accuracy.  This information constituted the first modern database.  Brahe was able to prove for the first time, using triganomitry, that the sun was much father from the sun  than the moon was from the earth.  In 1572 Brahe discovered a supernova in the consterlation of Cassiopeia.
Johann Bayer 1572-1625	Made a complete caterlouge of all the stars, allocateing a letter of the greek alphabet to each with Alpha being the brightest.  It has gone under many revisions but we still use ‘Bayer designations’ to this day.
Johannes Kepler 1571-1630	Used the database formulated by Brahe to formulate the laws of planetary motion, these laws resolved the problems of epicycles in heliocentric thory by using elipses in place of circles  for planetary orbits.  This was the origin of the clock work universe concept  and marked another paragdim shift in the philosophy of science .   Keplers laws.   1)       Planetary orbits are elliptical with the sun at of the two foci 2)       A planet sweeps out in equal areas in equal times as it orbits the sun 3)       The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit.
Galileo Galilei 1564 – 1642	Galileo with a tiny telescope, no more powerful than a entry level pair of modern binoculars (a 3x refracting) proved that the universe did not conform to perfict orbits, and also proved that the universe was not geo centric.  Alogth he was the first to use a telescope for the purpous of astronomy he was not the inventor of the device, it was invented a year before by Hans Lipperhey, a German spectacle maker.  He did however build his own telescope.  Other descoverys by Galileo where:   o    Sun spots o    Mountains and ‘seas’ on the moon o    Our galaxy is made of many thousands of stars o    Venus has phases o    The moons of Jupiter (still called the jovian moons) Io, Europa, callisto and Ganymead.
Isaac Newton 1643-1727	Developed the law of universal gravitation, accelerated motion. Invented calculus and the first reflecting telescope the basis of which is still used to this day.
Heninrich Wilhelm Matthias Olbers 1758-1840	In 1826 Olbers formulated a paradox that seemed to call newtons modle of the universe into question. Thew paradox states that the universe can not be infimnate and eternal. Essentulay the paradox gose:   Why is the night sky dark? In an infinite and unchangeing universe every line of sight should from an observer should hit a star, as in a forist where all lines of sight hit a tree

Modern Era

“If you wish to make an apple pie from scratch, you must first invent the universe.” 

Carl Sagen

Edwin Hubble 1889 - 1953	Edwin Hubble; using a 100” telescope, at that time the largest in the world, proved that country to current ideology the milky way was not the only galaxy in the universe.   In 1929 he published finding that led to our understanding that the universe was expanding.
1957 Russia	Sputnik, a name that translates to “Fellow traveller of Earth” is launched and becomes the first manmade object to leave earths atmosphere
1959 Russia	The probe “first cosmic ship” later to be renamed ‘Luna I’ launched and despite missing its mark becomes the first manmade object to come close to the moon.  Originally meant to impact with the Luna surface due to an issue with ground control it instead flew by the moon at 5,900km at its closest point.
1961 Russia	Yuri Gagarin becomes the first man in space his craft, Vostok I, carries him on a 108 minute flight.
1969 The moon	Buzz Aldrin and Nile Armstrong become the first men to walk on the moons
1990 USA	The Hubble space telescope launched and is still in use today.  The images sent back have been as awe inspiring as they have been scientifically important.