Great Year

The term Great Year has two major meanings. It is defined by scientific astronomy as 'The period of one complete cycle of the equinoxes around the ecliptic, or about 25,800 years'. A more precise figure of 25,772 years is currently accepted. The position of the Earth's axis in the northern night sky currently almost aligns with the star Polaris , the North Star. This is a passing coincidence and has not been so in the past and will not be so again until a Great Year has passed.'The difficulty with the term 'great year' lies in its ambiguity. Almost any period can be found sometime or somewhere honored with this name.'And so people are all but ignorant of the fact that time really is the wanderings of these bodies, bewilderingly numerous as they are and astonishingly variegated. It is none the less possible, however, to discern that the perfect number of time brings to completion the perfect year at that moment when the relative speeds of all eight periods have been completed together and, measured by the circle of the Same that moves uniformly, have achieved their consummation.'On the diverse motions of the planets the mathematicians have based what they call the Great Year,' which is completed when the sun, moon and five planets having all finished their courses have returned to the same positions relative to one another. The length of this period is hotly debated, but it must necessarily be a fixed and definite time.'Some time around the middle of the second century BC, the astronomer Hipparchus discovered that the fixed stars as a whole gradually shifted their position in relation to the annually determined locations of the Sun at the equinoxes and solstices... Otto Neugebauer argued that Hipparchus in fact believed that this was the maximum figure and that he also computed the true rate of one complete precession cycle at just under 26,000 years...God afforded them a longer time of life on account of their virtue, and the good use they made of it in astronomical and geometrical discoveries, which would not have afforded the time of foretelling unless they had lived six hundred years; for the great year is completed in that interval. The term Great Year has two major meanings. It is defined by scientific astronomy as 'The period of one complete cycle of the equinoxes around the ecliptic, or about 25,800 years'. A more precise figure of 25,772 years is currently accepted. The position of the Earth's axis in the northern night sky currently almost aligns with the star Polaris , the North Star. This is a passing coincidence and has not been so in the past and will not be so again until a Great Year has passed. The Platonic Year, which is also called the Great Year, has a different more ancient and mystical meaning. Plato hypothesized that winding the orbital motions of the Sun, Moon and naked eye planets forward or back in time would arrive at a point where they are in the same positions as they are today. He called this time period the Great Year and suggested that such a unified return would take place about every 36,000 years. There is no evidence that such a re-alignment has ever or ever will take place. By extension, the term 'Great Year' can be used for any concept of eternal return in the world's mythologies or philosophies. Historian Otto Neugebauer writes.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 40px}.mw-parser-output .templatequote .templatequotecite{line-height:1.5em;text-align:left;padding-left:1.6em;margin-top:0} The plane of the ecliptic is the plane described by the apparent motion of the Sun against the starry background. It is the Earth's orbital motion about the Sun which causes this apparent motion to occur. The Earths axis of rotation is not set perpendicular to this plane but at a present angle of 23.5 degrees to the perpendicular. The alignment of the axis is maintained throughout the year so that the point of sky above the north or south poles remains unchanged throughout the Earth's annual rotation around the Sun.A slow conical motion of the earth's polar axis about its normal to the plane of the ecliptic, is caused by the attractive force of the other heavenly bodies on the equatorial protuberance of the Earth. A similar conical motion can also be observed in a gyroscope that is subjected to lateral forces.The resultant motion of the Earth's axis is called general precession and the equinox points in the ecliptic move westward along the ecliptic at the rate of about 50.3 seconds of arc per year as a result. In 25,772 years the points are once again at the same point in the sky where observations began. In addition the tilt, or obliquity, of the Earths axis is not constant but changes in a cycle of its own. During a cycle that averages about 40,000 years, the tilt of the axis varies between 22.1 and 24.5. Plato (c 360 BC) used the term 'perfect year' to describe the return of the celestial bodies (planets) and the diurnal rotation of the fixed stars (circle of the Same) to their original positions, there is no evidence he had any knowledge of axial precession. The cycle which Plato describes is one of planetary and astral conjunction, which can be postulated without any awareness of axial precession. Hipparchus (c 120 BC) is the first Greek credited with discovering axial precession roughly two hundred years after Plato's death (see below). Cicero (1st century BC) followed Plato in defining the Great Year as a combination of solar, lunar and planetary cycles. Plato's description of the perfect year is found in his dialogue Timaeus