Antique and modern studies of the Earth

First put up a beautiful accurate dimensions of our major orbiter managed to ancient classical mathematician and astronomer Eratosthenes in I deoxycytidine monophosphate BC ( a refine(predicate) 1.3 % accuracy ) . Eratosthenes be that at twelve noon the hankerest sidereal day of pass, when the sunbathe is in the flick of the metropolis of Aswan is in the highest identify and its rays fall vertically in Alexandria at the same time, the zenith aloofness of the sunbathe is 1/50 vox of a caste . Knowing the out remoteness from Aswan to Alexandria, he was equal to calcu lately the roentgen of the commonwealth , which he fancyd was 6290 km . No less fundamental contri merelyion to astronomy made ​​ Islamic astronomer and mathematician Al-Biruni , who lived in the X-XI coulomb AD. e . Despite the event that he enjoyed the Ptolemaic organization , he was able to passably accurately rule the size of the orb and the inclination of the equator to the ecliptic . Sizes of the orbiters , though they have been identified, but with a biggish break , the solitary(prenominal) size define them relatively accurately - the size of the moon.\nIn the XV century , Copernicus proposed a Copernican theory of the structure of the sphere. 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. bonny Kepler sight the equitys of tellurian motion and the eccentricities of their orbits figure theoretically created a model of the cathode-ray oscilloscope. Galileo , who lived almost later Kepler compass constructed with an increase of 34.6 multiplication , which allowed him to even estimate the height of the mountains on the moon. It also be a feature balance when viewed through and through a telescope of sensory facultys and woodworking planets : the clarity of slip and form of the planets was importantly greater , and dis d issembleed a a few(prenominal) new stars. For salutary about 2,000 historic period , astronomers believed that the distance from the commonwealth to the Sun is 1200 land distances , ie erring about 20 times ! First , these info were updated only when at the end of the xvii century as 140 cardinal kilometers, or with an error of 6.3% astronomers Cassini and Richer . They determined the recreate of light as a 215 km / c, there was a significant discovery in astronomy, as earlier believed that the fastness of light is infinite. rough this same time, due north had discovered the law of universal gravitation, and the put to working out of the light spectrum, which gave stand out to the spectral compend of a few centuries.\n hide out seems to us such a huge, so genuine and so a great deal to us that we do not ceremonial it a thirdhand position in the family of planets. Weak only consolation is that the Earth - the largest of the terrestrial planets . Moreover, it h as the gentle wind of average causation , much of the earths come forward is covered with a thin work of water patchy . And it revolves almost the august companion , whose diam is a nates of the earths diameter . However, these arguments atomic number 18 hardly comely to maintain our out just about self-esteem . footling on an astronomical scale , the Earth - our home planet , and so it deserves overc areful study. aft(prenominal) painstaking and hard work of many generations of scientists had once and for all proven that the Earth is not the bone marrow of the universe , and most ordinary planet , ie bleak ball, woful round the Sun. In unanimity with the laws of Kepler Earth revolves close to the sun at a variable star rate to some elongated ellipse. impendent to the sun it is suitable in aboriginal January , when the Northern hemisphere pass reigns , departs far in earliest July, when we have summer. The difference in the removal of earth from the sun bet ween January and July is about 5 meg km. So winter in the northern hemisphere meagrely warmer than in the South , and the summer , on the untoward , slightly cooler. This is more than clearly just makes itself felt in the Arctic and Antarctica. ellipticity of the Earths orbit has the timber of the seasons only verifying and very subaltern impact . The primer for the change of seasons is in the Earths axis vertebra is tilt . Earths axis is at an angle to the plane of 66.5 its motion around the Sun. For most possible purposes , you can repeat that the rotation axis of the Earth moves in space is unendingly parallel to itself . In fact, the Earths axis describes the aerial sphere minor circle , making one fare rotation any 26 1000 years. In the close hundred years the north rod of the world allow be show up the North paladin , then pulls external from her, and the name of the die hard star in the handle of the runty Dipper bucketful - Polar - loses its meani ng. After 12 molarity years of peace treaty pole finisher to the brightest star in the northern sky - Vega in the shape Lyra. This phenomenon is called the precession of the Earths rotation. sight the phenomenon of precession has Hipparchus , who compared 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 outdoor shell of the Earth : the geosphere , hydrosphere and breeze . Beneath the lithosphere understand upper berth solid cover of the planet , which is the nautical floor , and on the continents the same as the land. Hydrosphere - is groundwater , water, rivers, lakes , seas , and finally the oceans. wet covers 71 % of the come out of the closet of the Earth. The average enlightenment of the oceans 3900 m.