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Post by paulh on May 11, 2009 11:02:23 GMT
I was reading a book and it asked: Why does the Earth spin?
So why does it?
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imakegarb
Member
One wee, sleeket, cowran, tim'rous beastie
Posts: 3,573
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Post by imakegarb on May 11, 2009 13:11:39 GMT
I wouldn't depend too much on Google. It is a delightful tool and, in my mind, the true marketplace of ideas. But there's good and bad stuff there. In any case, this is a Masonic forum. Which means we're free to speculate. A lot I've heard that, at the big bang, the force of it caused the planets, and everything else, to start spinning. And because there's no gravity in space, it just keeps spinning. In Masonry, at least in my Obedience, this constancy finds its way inot the EAs proficiency. And explains why the sun is al*ys at its M*n. Interesting lesson, that.
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Post by maximus on May 11, 2009 14:38:34 GMT
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Post by paulh on May 11, 2009 22:43:20 GMT
The usual answer of: "just started that way" of course has various problems such as the retrograde and very slow rotation of Venus.
But all is not lost as we can hypothesize a variety of collisions that varied the planetary rotations from the original pattern.
And around 6 planetary satellites (moons) also orbit in retrograde motion so we could hypothesize further events to explain those as well.
There still remains the problem of the various tilts of the planets so I am not too sure that "just started that way" really gets us too far.
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Post by paulh on May 12, 2009 0:07:29 GMT
Just look at the formation of twisters; not all of them are rotating as predicted or expected. How twisters decide which way to rotate may be closely related to the question of why the planets rotate. As for the planets, the usual image of dust rotating around the sun condensing into planets gives no hint that the planets should rotate let alone that they should rotate in the same direction as the orbit. This last seems very strange as retrograde planetary rotation would seem to result in a lower angular momentum of the system. I conclude that some factor other than gravity is present.
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Post by maximus on May 12, 2009 1:07:57 GMT
The usual answer of: "just started that way"Nowhere in the piece I posted was this so stated.
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Post by paulh on May 12, 2009 1:30:51 GMT
>Nowhere in the piece I posted was this so stated.
I did not intend to imply that you provided the "usual answer" I suppose my thoughts went to the usual answer when I read "The Earth keeps spinning because it was born spinning,"
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Post by maximus on May 12, 2009 2:15:00 GMT
I did not intend to imply that you provided the "usual answer" I suppose my thoughts went to the usual answer when I read "The Earth keeps spinning because it was born spinning,"I see. That it keeps spinning is a result of inertia. An object in motion tends to remain in motion unless acted upon by an outside force.
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Post by paulh on May 12, 2009 3:08:29 GMT
. That it keeps spinning is a result of inertia. Quite so. I still do not understand why it started to spin - and in such a peculiar direction
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Post by maat on May 12, 2009 3:49:24 GMT
"Earth's predominant field of magnetics has a simple dipolar shape. It is the rotation of earth around the molten inner core that generates an excess of electrons within crustal layers. Following the laws of classical physics, a proportional field of magnetics is generated at right angles to the flow of electrons, yielding the shape of donut-like magnetic fields (measured as gauss). These fields are a function of the rotation of earth around the iron core in general, and specifically the motion of the outer core relative to the inner core. The more rapid the rotation, the greater intensity of the magnetic field. So, the more rapidly earth rotates, the denser the fields of magnetism become. Conversely, the slower the planet rotates, the less dense the fields of magnetism. Measurements over the last 130 years indicate a decline in magnetics from 8.5x10 to the 25th gauss units to 8.0x10 to the 25th gauss units. The lessening in the intensity of magnetics would seem to indicate a lessening of the rate of earth's rotation. Time is slowing down, or becoming more compressed. Because time is becoming more compressed, we have the sense that everything is speeding up. It's a little like trying to take a sip of water from a fire-hose.
Greg Braden Awakening to Zero Point
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Post by maat on May 12, 2009 3:53:50 GMT
The usual answer of: "just started that way" of course has various problems such as the retrograde and very slow rotation of Venus. But all is not lost as we can hypothesize a variety of collisions that varied the planetary rotations from the original pattern. And around 6 planetary satellites (moons) also orbit in retrograde motion so we could hypothesize further events to explain those as well. There still remains the problem of the various tilts of the planets so I am not too sure that "just started that way" really gets us too far. If you check out Tiamet and treat 'her' as a planet and not as a goddess you may get some clues. She was 'killed' by Marduk, described as a Sun calf (?) .. en.wikipedia.org/wiki/Tiamat
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Post by paulh on May 12, 2009 5:37:09 GMT
The proposition that a rotating Earth produces a field is fine except that it does not tell us why the Earth rotates originally.
As for the molten core, as far as I know we have no samples from further down than a few miles below the surface so what is further down is hypothesis.
I am familiar with the arguments about Tiamat, and they might answer how rotation started for the Earth, but the other planets also rotate.
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Post by paulh on May 12, 2009 20:14:17 GMT
All that stuff that it was made of was in motion already. This seems to be the standard answer: the Earth spins because it was spinning before But why was it spinning at all? If I put a weight on a string and whirl it around like a planet around the sun, the weight does not show any tendency to spin - as can be seen by the perfect straightness of the string. Even if I let the string go there is no sign of spinning. How does the spinning of the Earth arise in the first place? Might I suggest we need to go beyond a Newtonian model to discover an answer?
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Post by maximus on May 12, 2009 20:40:33 GMT
Your tin can is being acted upon by a gravitational field strong enough to stop it's motion, in addition to drag caused by air pressure, which you are not taking into account. Planets, and the debris they were formed out of were in a vacuum. In the absence of atmospheric drag, the inertia will continue uncheck, unless acted upon by an outside force - a meteoric impact or some such incident. Eventually, entropy takes over and all systems break down - but on a scale of billions of years. The rotation seems to be a result of gravitational field, or in other words, objects are drawn to a localized gravitational attractor. Here is a representation of a gravitational field: You can see how an object orbiting a larger object, trapped in it's gravity field, is like a marble spinning round and round in a funnel, the difference being that, rather than being drawn downward into the funnel, the smaller object find a point of balance and continues to orbit, inertia gradually moving the object away from the point of gravity at an almost impreceptable rate. It is this motion around a strong gravitational attractor that causes the spin, and inertia that continues it, in a vacuum.
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Post by paulh on May 12, 2009 22:15:17 GMT
It is this motion around a strong gravitational attractor that causes the spin So how does the gravitational attractor decide which direction should the spin take?
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Post by maximus on May 12, 2009 23:33:59 GMT
It is this motion around a strong gravitational attractor that causes the spin So how does the gravitational attractor decide which direction should the spin take? [/size][/quote] I would venture to guess that the orbiting body rotates in the direction that the attractor rotates. Most celestial bodies seem to rotate and orbit widdershins.
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Post by paulh on May 13, 2009 7:53:30 GMT
an object orbiting a larger object, trapped in it's gravity field, is like a marble spinning round and round in a funnel, On the computer I used previously I could not see your image. I suggest that in the discussion previously the word orbit was used for rotation around a larger object and the word spin was used for a body rotating around its own axis. Thus my question is: why does the Earth rotate on its own axis? And the standard answer is that when it was formed it was spinning on its axis. This does not seem to me to be a satisfactory answer and I can find no gravitational experiment to suggest that an orbiting object must spin.
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Post by billmcelligott on May 13, 2009 8:47:06 GMT
I think this is answered by asking a question.
Take a large mass of a near sphere shape and throw it into a void, where there is little or no traction force. It would be I suggest impossible that it did not spin, to make it land so that it had no spinning action would be the greatest trick.
Throw a rubber ball say 20 feet away from you, it will roll or bounce in the direction of the throw , but it will experience traction that will slow it's momentum and eventual it will stop. But what would happen if there was no traction ? Throw it into water and it will spin longer, Less traction more spin.
Orbiting objects are caught in the Gravitational pull of the larger object, take away the Gravitational pull and the object will carry on at its original trajectory.
Simples
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Post by paulh on May 13, 2009 10:11:16 GMT
Take a large mass of a near sphere shape and throw it into a void, where there is little or no traction force. It would be I suggest impossible that it did not spin, Generally speaking every action generates an equal and opposite reaction. Hence if the Earth starts to spin at fairly high speed I would look for a suitably large force to make that happen. This might be hard to find in a void under conventional theories of solar systemic formation.
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Post by billmcelligott on May 13, 2009 11:06:46 GMT
How about the action of being propelled 50,000 light years ? the more effort you put into throwing the ball the longer it will spin.
Or are you are saying that you throwing a large ball into a void is not a complicit force ?
Newton wrote: "That one body may act upon another at a distance through a vacuum without the mediation of anything else, by and through which their action and force may be conveyed from one another, is to me so great an absurdity that, I believe, no man who has in philosophic matters a competent faculty of thinking could ever fall into it."
And in Newton's 1713 General Scholium in the second edition of Principia: "I have not yet been able to discover the cause of these properties of gravity from phenomena and I feign no hypotheses... It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies.
So if he is not sure then neither am I.
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