History of Astronomy

Discussion in 'Science and Technology' started by Jim Colyer, Jun 29, 2006.

  1. Jim Colyer

    Jim Colyer Member

    Each period in history sees the sky in a different way. The way a civilization perceives the sky is related to its travel capabilities. As man's knowledge of geography has increased, so has his understanding of the earth's place in the larger scheme.

    Greek astronomer Ptolemy lived in the second century. He wrote a book called The Almagest. He had the earth at the center with the sun and planets going around it. This view stood for 1400 years.

    In 1453, Copernicus in Poland got it right. He expounded a heliocentric doctrine. Modern science was born. Really, Copernicus revived a forgotten idea of the Greek Aristarchus. The Greeks had science. The Scientific Revolution grew out of the Renaissance which was a return to Greek ideas. The Middle Ages had been dominated by the Church, and the Bible frowned on science. It put revelation above observation. Galileo clashed with the Church when he taught the earth goes around the sun.

    The road leading from superstition and false information was long. For centuries, man's concepts of reality were shaped by the Bible. Nowhere in the Bible does it state the earth is flat, but the implications are there, Satan taking Jesus to the mountaintop to show him the world's kingdoms and references to "four corners of the earth." Heaven was above. Hell was below. Even Shakespeare retarded the growth of science with ghosts, witches and fairies. No wonder, the people who first settled in America knew so little about the nature of the cosmos.

    Things were changing. Europe was expanding, and the printing press spread new ideas. By the time of Columbus' voyages, most people knew the earth is round. It became irrefutable when Magellan sailed around it, a gruelling three-year voyage during which Magellan was killed.

    Tycho Brahe was an observer. He found a supernova in Cassiopeia in 1572. As a theorist, he was lacking. He knew the planets circled the sun but thought both planets and sun circled the earth. He built an observatory near Hamlet's castle in Denmark.

    It took Johannes Kepler, Tycho's assistant, to make sense of his work. Kepler's laws of planetary motion showed planetary orbits to be ellipses. The closer a planet is to the sun, the faster it moves.

    William Herschel was the father of stellar astronomy. He built big telescopes and made the first model of the Milky Way. Erroneously, he placed our solar system at its center.

    Isaac Newton and Albert Einstein were physicists who laid the groundwork on which modern astronomy is built. Newton introduced the concept of gravity, the tendency for two bodies to attract whether they are the earth and an apple or the earth and the moon. Einstein gave us relativity. Relativity says time is relative to speed, that the speed of light is the only absolute. While the most distant galaxies may be receding at 99% of the speed of light, they will never equal it. According to Einstein, gravity results from space being curved.

    Newton was an alchemist. Einstein did not believe the universe was expanding. Even geniuses can be wrong! There is some question about the speed of light being absolute. Why does it have to be? If we travel faster than light, would we be in the dark when we reach our destination?

    Astronomy is studied as a series of levels proceeding outward. Space has depth. There are motions within motions. Perspective rules. We explore the solar system. We reach for the stars. The Milky Way becomes one of countless galaxies. We question the origin and destiny of the universe. We search for extraterrestrial life.

    ASTRONOMY http://jimcolyer.com/papers/entry?id=2
     
  2. fat_tony

    fat_tony Member

    I think that the vaticans objections to Gallileo were financial but they used science vs. religion as a convenient cover. Thats nothing new the belief that science and religion are in some way mutually exclusive still exists today.
     
  3. Occam

    Occam Old bag of dreams

    Fat tony

    We are going to have to admit that religion 'in general terms'
    IS exclusive to science.
    It's about earthly power
    Religion wants earthly power 1st ,all else latter
    Science wants understanding 1st, earthly power later

    But many 'of' religion become so to find meaning and answers.
    And THAT is what science is about.
    And many 'of' science' do the same thing.
    Thus resulting in gallileo, einstein, aquinas.

    Occam feels that we walk a very similar path.. but with eyes conditioned to see
    things differently

    Hopefully we can be brothers in the one true quest

    To understand.

    Occam

    PS..sorry but occam finds it hard to put these concepts into words
    hope u can see them
     
  4. bamboo

    bamboo Hip Forums Supporter HipForums Supporter

    The only objections to traveling faster that the speed of light are 1) Having a rest mass greater that 0, and 2) that needling little problem of having a negative rest mass...or is the square root of negative one really an imaginary number and if so what the hell is an imaginary number. Traveling faster that the speed of light is easily solved once these issues are solved
     
  5. fat_tony

    fat_tony Member

    Well there is no particle with a rest mass lower than 0 and indeed only the photon has a rest mass of 0 although that gets a little bit more complex when trying to unify it with other forces. I have no idea what a negative mass is even less idea what an imaginary mass is but Hawking has introduced the idea of imaginary time, so why not. There is another way to have a particle travel faster than light, the Tachyon is a hypothetical particle that exists on the v>c side of a velocity vs. gamma plot, wiki Tachyon.
     
  6. bamboo

    bamboo Hip Forums Supporter HipForums Supporter

    doing the math in relativity as based on the lorenz equations involves the use of the square root of negative one if you exceed the speed of light. The square root of negative one is called an imaginary number in physics and mathmatics. Any particle traveling greater than c has to have a rest mass less than zero or negative mass (back to the square root of negative one thing). Taychons are said to posses this however they have never been observed so...

    The peculiar properties of taychons are such that applying energy to them would slow them down and the less energy the posses the faster the travel. The would have to always be traveling faster than c and could be slowed to speeds infinitly close to but never equal to or less than c...kind of our mirror image in the hyperspace realm. All just speculation.
     
  7. bamboo

    bamboo Hip Forums Supporter HipForums Supporter

    By the way, the relativistic side of Einstein's theory was based on the work of another physicist named Lorenz. His equations dealt with accelerating charged particles to near the speed of light and the resulting increase in mass, etc. Einstein applied this to particles with mass in general. A lot of what Einstein was refinement of and further rendition of work by other mathmaticians and physists. He also did some interesting work on why rivers meander and the physics behind that.
     
  8. bamboo

    bamboo Hip Forums Supporter HipForums Supporter

    Another problem that PEOPLE have with faster than light travel is the supposed time travel paradox. I am not sure that the universe really gives a damn about it but a lot people seem to care. I have never heard a convincing reason why the universe would care one way or another if you killed you grandfather in a time travel scenerio.
     

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