|The star Polaris is huge,it has big stars orbiting it.
α UMi Aa is a 4.5 solar mass (M☉) F7 yellow supergiant (Ib). This is the first classical Cepheid to have a dynamical mass determined
from its orbit. The two smaller companions are α UMi B, a 1.39 M☉ F3 main-sequence star orbiting at a distance of 2400 AU, and α UMi
Ab (or P), a very close F6 main- sequence star with an 18.8 AU radius orbit and 1.26 M☉. There are also two distant components: α
UMi C and α UMi D which have been shown not to be physically associated with the three other stars.
Polaris B can be seen even with a modest telescope. William Herschel discovered the star in 1780 while using a hand-built reflecting
telescope, one of the most powerful telescopes at the time. In 1929, it was discovered, by examining the spectrum of Polaris A, that it
was a very close binary with the secondary being a dwarf (variously α UMi P, α UMi an or α UMi Ab), which had been theorized in earlier
observations (Moore, J.H and Kholodovsky, E. A.). In January 2006, NASA released images, from the Hubble telescope, that showed
the three members of the Polaris ternary system. The nearest dwarf star is in an orbit of only 18.5 AU (2.8 billion km from Polaris A,
about the distance between our Sun and Uranus), which explains why its light is swamped by its close and much brighter companion.
Thuban has a spectral class of A0III, indicating its similarity to Vega in temperature and spectrum, but more luminous and more
massive. Thuban is not a main sequence star; it has now ceased hydrogen fusion in its core and is fusing helium. That
makes it a white giant star, being 250 times more luminous than our Sun but over 300 light-years distant.
Due to the precession of Earth's rotational axis, Thuban was the naked-eye star closest to the north pole from 3942 BC, when it moved
farther north than Theta Boötis, until 1793 BC, when it was superseded by Kappa Draconis. It was closest to the pole in 2830 BC, when
it was less than ten arc-minutes away from the pole.
The 4.2 kiloyear BP aridification event was one of the most severe climatic events of the Holocene period in terms of impact on cultural
upheaval. Starting in about 2200 BC, it probably lasted the entire 22nd century BC. It is very likely to have caused the collapse of the
Old Kingdom in Egypt as well as the Akkadian Empire in Mesopotamia. The drought may have also initiated southeastward habitat
tracking within the Indus Valley Civilization.
The aridification of Mesopotamia may have been related to the onset of cooler sea surface temperatures in the North Atlantic (Bond
event 3), as analysis of the modern instrumental record shows that large (50%) interannual reductions in Mesopotamian water supply
result when subpolar northwest Atlantic sea surface temperatures are anomalously cool. The headwaters of the Tigris and
Euphrates Rivers are fed by elevation-induced capture of winter Mediterranean rainfall.
The Akkadian Empire—which in 2300 BC was the second civilization to subsume independent societies into a single state (the first
being ancient Egypt at around 3100 BC) —was brought low by a wide-ranging, centuries-long drought. Archaeological evidence
documents widespread abandonment of the agricultural plains of northern Mesopotamia and dramatic influxes of refugees into
southern Mesopotamia around 2170 BC. A 180-km-long wall, the "Repeller of the Amorites," was built across central Mesopotamia
to stem nomadic incursions to the south. Around 2150 BC, the Gutian people, who originally inhabited the Zagros Mountains, defeated
the demoralized Akkadian army, took Akkad, and destroyed it around 2115 BC. Widespread agricultural change in the Near East is
visible at the end of the third millennium BC.
Resettlement of the northern plains by smaller sedentary populations occurred near 1900 BC, three centuries after the collapse.
Today across Syria a Draught and the main cause of the fighting.
Vega was the northern pole star around 12,000 BCE
16,000 - 13,000 BC Oldest Dryas cold, begins slowly and ends sharply (B-S)
12,700 BC Antarctic Cold Reversal warmer Antarctic, sea levels rise
12,400 BC Bølling oscillation warm and wet in the North Atlantic, begins the Bølling-Allerød period (B-S)
12,400 - 11,500 BC (much discussed) Older Dryas cold, interrupts warm period for some centuries (B-S)
12,000 - 11,000 BC Allerød oscillation warm & moist (B-S)
11,400 - 9,500 BC Huelmo/Mascardi Cold Reversal cold in Southern Hemisphere
11,000-8,000 BC Late Glacial Maximum, or Tardiglacial (definitions vary)
10,800 - 9,500 BC Younger Dryas sudden cold and dry period in Northern Hemisphere (B-S)
|Study published Friday, April 8, 2016, in the journal Science Advances.
Melting ice sheets — especially in Greenland — are changing the distribution of weight on Earth. And that has caused both the North Pole and the
wobble, which is called polar motion, to change course, according to a study published Friday in the journal Science Advances.
Scientists and navigators have been accurately measuring the true pole and polar motion since 1899 and for almost the entire 20th century they
migrated a bit toward Canada. But that has changed with this century and now it's moving toward England, said study lead author Surendra Adhikari at
NASA's Jet Propulsion Lab.
Since 2003, Greenland has lost on average more than 600 trillion pounds of ice a year and that affects the way the Earth wobbles in a manner similar to
a figure skater lifting one leg while spinning, said NASA scientist Eirk Ivins, the study's co-author.
Ivins said he likes to think of it as a billion trucks each year dumping ice out of Greenland. On top of that, West Antarctica loses 275 trillion pounds of ice
and East Antarctica gains about 165 trillion pounds of ice yearly, helping tilt the wobble further, Ivins said.
|There has been five major Ice Ages starting 2400,000,000 years ago, as a result the earth has
flattened at the poles. This deformation is caused by the weight of billions of tons of water/ice at
the poles. Today the weight has shifted from pole to the equator because of local mass the
biggest being the sun and moon. The tide is a bulge that fallows the sun and moon on the
ecliptic, the moon rises 5 degrees above and below the tropics, so 28 degrees above and below
the equator. When the ocean rises this bulge takes most of the water. In fact the moon is speeding
up because of this massive bulge. The moon is the second fastest object in the solar system, one
orbit is just short of one rotation of the earth this causes the bulge to proceeds the moon pulling
the moon faster. My point is the weight of water has flattened the earth at the poles and is now
mostly in the tropics. The earth will start a deformation back into a circle, today we are seeing
islands disappearing in the tropics and a fractional growth above or below. When this weight
causes an earth quake along an induction fault water will be permanently displaced.