(11-30-2020, 03:24 AM)guohua Wrote: Yes, Our Magnetic Field is Reversing again and faster than before, also I read our North Pole is moving faster, so True North is in a different place.
No, True North (Geographic North) is in the same place, and always will be. It's determined by the spin axis of the Earth, like a giant top spinning. It would take the destruction of the Earth itself for that to change at all.
I think a lot of the confusion out on the internet is because there are 3 "North" components relative to Earth. There is true or geographical north, and magnetic north, and astronomical north (indicated by the north star) Right now, they all roughly coincide. The Earth spins on it's axis, and that axis it spins on is "true" or "geographical" north. that never changes. Then there is magnetic north, and that wanders around, migrates, and occasionally flips it's polarity entirely.
Astronomical north migrates, albeit more slowly. Over millennia, the Earth's spin axis wobbles, like a top does. The north geographical pole points to different stars over the length of that cycle. the cycle is roughly 24,000 or 25,000 thousand years long, and during those years, the north pole slowly describes a circle on the sky until it returns to it's starting point, and starts over again. Where Polaris is currently the "north star", in the past it has been other stars, and in the future will be again as the cycle proceeds.
To make it even more complicated, the Earth axis periodically "straightens up" and "lays back down", changing it's angle with respect to the ecliptic, the plane of the solar system, called it's "obliquity". That affects how much sunlight gets to the equator and the poles at different times of the year, and so affects climate as well. More direct sunlight as the pole tips towards the sun makes for more extreme temperature differences between summer and winter. I'm really not sure how long that particular cycle is, but I know it varies from as much as 25 degrees to less than 10 or 15 degrees, with major climactic results. Not only does it affect climate and temperature, it also affects just which star can currently be "the north star". when the Earth's axis "lays down", it makes a bigger circle in the stars, and when it "straightens up", it makes a smaller circle.
I do know that tsunami producing earthquake in 2004 affected the obliquity by several thousandths of a degree - it was that powerful.
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Diogenes was eating bread and lentils for supper. He was seen by the philosopher Aristippus, who lived comfortably by flattering the king.
Said Aristippus, ‘If you would learn to be subservient to the king you would not have to live on lentils.’ Said Diogenes, ‘Learn to live on lentils and you will not have to be subservient to the king.’
Said Aristippus, ‘If you would learn to be subservient to the king you would not have to live on lentils.’ Said Diogenes, ‘Learn to live on lentils and you will not have to be subservient to the king.’