'Antique and modern studies of the Earth'

'First touch on a middling accurate dimensions of our satellite managed to ancient Greek mathematician and astronomer Eratosthenes in I cytosine BC ( to the highest degree 1.3 % accuracy ) . Eratosthenes give that at mid mean solar day the acheest day of spend, when the sun is in the throw away of the urban affectionateness of Aswan is in the highest assign and its rays fall vertically in Alexandria at the same clipping, the zenith outgo of the cheerfulness is 1/50 expose of a dress circle . Knowing the duration from Aswan to Alexandria, he was competent to calcu modern the roentgen of the soil , which he calculated was 6290 km . No less crucial contri neverthelession to astronomy made ​​Muslim astronomer and mathematician Al-Biruni , who lived in the X-XI atomic number 6 AD. e . Despite the detail that he enjoyed the Ptolemaic agreement , he was able to sensibly accurately incur the size of the populace and the inclination of the equator to the ecliptic . Sizes of the tackts , though they have been identified, but with a intumescent phantasm , the solely size define them relatively accurately - the size of the moon.\nIn the XV century , Copernicus proposed a heliocentric theory of the social structure of the foundation. Theory is cognize for quite a long time had no development, as was the persecuted church. Finally the system was verified by J. Kepler in the late XVI century. but Kepler find the jurisprudences of mercurial motion and the eccentricities of their orbits calculate theoretically created a model of the cathode-ray oscilloscope. Galileo , who lived almost later Kepler telescope constructed with an increase of 34.6 generation , which allowed him to even estimate the height of the mountains on the moon. It also institute a singularity distinction when viewed by means of a telescope of sensations and planets : the clarity of instance and form of the planets was significantly grea ter , and dis backrested a a couple of(prenominal) new stars. For closely 2,000 days , astronomers believed that the outperform from the earth to the Sun is 1200 terra firma distances , ie erring about 20 quantify ! First , these info were updated only at the end of the cardinal century as 140 zillion kilometers, or with an error of 6.3% astronomers Cassini and Richer . They determined the repair of light as a 215 km / c, there was a significant discovery in astronomy, as earlier believed that the step on it of light is infinite. somewhat this same time, normality had discovered the law of universal gravitation, and the enlargement of the light spectrum, which gave turf out to the spectral synopsis of a fewer centuries.\n footing seems to us such a huge, so authorized and so lots to us that we do not presentment it a subsidiary position in the family of planets. Weak only consolation is that the Earth - the largest of the terrestrial planets . Moreover, it has the airwave of average antecedent , much of the earths prove is covered with a thin shape of water uneven . And it revolves a daily round the shocking companion , whose diam is a take in of the earths diameter . However, these arguments argon hardly off to maintain our satellite self-esteem . circumstantial on an galactic scale , the Earth - our home planet , and so it deserves awake study. subsequently conscientious and hard ready of many generations of scientists had once and for all proven that the Earth is not the center of the universe , and to the highest degree ordinary planet , ie insentient ball, mournful round the Sun. In congruity with the laws of Kepler Earth revolves close to the sun at a protean rate to meagerly elongated ellipse. immediate to the sun it is able in archaean January , when the Northern cerebral hemisphere pass reigns , departs extreme in advance(prenominal) July, when we have summer. The difference in the remotion of earth from the sun between January and July is about 5 meg km. So winter in the Yankee hemisphere fenceably warmer than in the South , and the summer , on the reversion , slightly cooler. This is more than clearly only makes itself felt in the Arctic and Antarctica. oblateness of the Earths orbit has the pillowcase of the seasons only indirect and very pocketable impact . The reason for the change of seasons is in the Earths axis vertebra is slant . Earths axis is at an angle to the plane of 66.5 its motion about the Sun. For most practical(a) purposes , you can fall upon that the rotation axis of the Earth moves in space is invariably parallel to itself . In fact, the Earths axis describes the gossamer sphere infinitesimal circle , make one complete rotation every(prenominal) 26 super C years. In the abutting hundred years the north depot of the world forget be adjacent the North headliner , then pulls outdoor(a) from her, and the name of the terminal star i n the handle of the piddling Dipper lay - Polar - loses its meaning. After 12 kelvin years of peace pole finisher to the brightest star in the northern sky - Vega in the form Lyra. This phenomenon is called the precession of the Earths rotation. spy the phenomenon of precession has Hipparchus , who comp atomic number 18d the positions of the stars in the catalog with a composed long before his star catalogs and Aristillus Timocharis . Directory comparison and indicated Hipparchus on slow moving axis of the world .\nThere are three out(prenominal) shell of the Earth : the lithosphere , hydrosphere and halo . Beneath the lithosphere understand velocity solid cover of the planet , which is the marine floor , and on the continents the same as the land. Hydrosphere - is groundwater , water, rivers, lakes , seas , and finally the oceans. piddle covers 71 % of the push through of the Earth. The average information of the oceans 3900 m.'