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Thread: why do things in our known universe tend to spiral in a plan

  1. #1 why do things in our known universe tend to spiral in a plan 
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    Hopefully there will be a simple answer, at least one that this neophyte can understand, to this question.

    Granted there are globs of stuff out there that appear as a cluster but our solar system, galaxy, and others tend to spin on a plane. So why do things in our known universe tend to spiral in a plane?



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  3. #2  
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    Well, once a mass starts spinning, it can only spin in one direction. All matter that isn't spinning in that direction initially, eventually gets pulled into the same orbit as the rest of the matter.

    The only way to be in that orbit, is to be on the same plane as the rest of the matter too. It's kind of hard to envision, but not too hard.

    Imagine a spinning basketball. If the matter in that ball is free to move around, but still pulled together by gravity, eventually all the particles that make it up are going to settle onto the same plane.

    It will flatten out over time into a disk.


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    Thanks, that seem reasonable. However that makes me wonder what causes the initial spin? :?
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    It has been put forward that gravitational collapse of interstellar clouds will become a star. Also the accretion of dust or gas will form larger bodies, e.g., planets. It is also common for the accretion to cause a flat sheet of materials to form around the larger objects. This agrees with “kojax” thoughts.

    Problem; What causes the larger objects to begin their spin such as to cause the accretion disk?
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    The gas and dust is being tugged this way and that by, I think, electrostatic forces and as the bodies grow, gravity. Think of the way that tornado's form. Two winds blowing past each other in opposite directions, cause a wirlwind to start and bam, you have spin.
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    I can visualize a tornado forming due to the wind and the effects of high and low pressure systems on earth. However in the void of space I don’t see why the collapse of a dust cloud would not just form into a massive ball with no spin whatsoever. Is there a suggestion that there is a natural spin to the electrostatic force? Thanks.
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    Quote Originally Posted by spinner42
    I can visualize a tornado forming due to the wind and the effects of high and low pressure systems on earth. However in the void of space I don’t see why the collapse of a dust cloud would not just form into a massive ball with no spin whatsoever. Is there a suggestion that there is a natural spin to the electrostatic force? Thanks.
    Void yes. But not devoid of gravity - the engine of the cosmos.
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    Sorry, I am a bit slow. Then is the suggestion that gravity causes the spin?
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    Yes, I believe gravity does indeed cause spin. You only need to let the water down the plug-hole to see this. Then do the same on the other side of the equator, and it will spin in the opposite direction. So yes, gravity causes spin.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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    It was my understanding that the water spin down the drain has to do with the Coriolis effect that is caused by the rotation of the earth not gravity perse. What causes the earth to spin and is this force the cause of other universal objects to spin, e.g., solar systems, galaxies? If yes, then what is the force that causes the spin?
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  12. #11  
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    I don't know for sure, but I think the spin is caused by the fact that, if there is any motion at all, it's randomly unlikely that it would all be moving in directions that cancel each other.

    If there is a slightly higher amount of matter moving in one direction than another (of all the directions possible), then all the matter will start getting pulled in that direction more than the others.

    At first the process is very slow, but after a while it picks up speed. Once a highly massive core has formed, the rest of the matter must either orbit that core, or fall to the center.

    If it's orbiting too slowly to continue at a far out orbit, then it falls to a nearer orbit, and starts moving faster. So a lot of the fast moving matter at the center may have once been slow moving matter out at the edge. In fact, it might have been extremely slow moving.
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    Id agree with that. Never looked at it that way before. Id guess also that perhaps; as there is a black hole in the centre of every galaxy, (which has rotational energy to begin with) in sends nearby stars into spins, and as the gravitational force is a long range one, this effects the whole galaxy, which spins, so the stars spin, and in turn the planets and satellites.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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    Kojax wrote: I don't know for sure, but I think the spin is caused by the fact that, if there is any motion at all, it's randomly unlikely that it would all be moving in directions that cancel each other.

    Not sure if I can buy into the concept. Let us say that a number of ball bearings are released into space. Add to that there is no contact between the objects thus no frictional interaction. Because they all have mass and therefore some small amount of gravitational attraction then over time they would collect together. Under the idea put forward they would eventually start to spin. Why?
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  15. #14  
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    The original post seems to suggest that our solar system is in the same plane as the milky way, I don't think it is, I think it is more likely a 70 degree tilt as the centre of our galaxy is somewhere in saggitarius?.

    A second point here it does not matter which way the object at the centre of a system spins objects orbiting may spin quite gappily in any direction and plane have a look at all the sun orbiting comets they are in all different directions and planes.
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  16. #15  
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    Quote Originally Posted by spinner42
    Kojax wrote: I don't know for sure, but I think the spin is caused by the fact that, if there is any motion at all, it's randomly unlikely that it would all be moving in directions that cancel each other.

    Not sure if I can buy into the concept. Let us say that a number of ball bearings are released into space. Add to that there is no contact between the objects thus no frictional interaction. Because they all have mass and therefore some small amount of gravitational attraction then over time they would collect together. Under the idea put forward they would eventually start to spin. Why?
    That is actually a better visualization. Part of the issue is scale, however. If the objects are physically far enough apart, they may obtain higher speeds while they're falling toward each other, and because of the distances it takes less total speed to enter orbit.

    Once an object is moving at an orbital velocity, it only needs to miss the center of mass by a few degrees, and it can begin an eliptical orbit.

    Statistically, however, the largest portion of mass seems to always end up in the middle, because that is the most likely place for any given particle to end up. If I remember right, the black hole at the center of a galaxy is typically 5% of the total estimated mass.

    According to Wikipedia, the sun is 99.86% of the mass of the solar system, however. So it seems that the smaller the scale, the smaller the portion of mass that avoids becoming part of the core.

    http://en.wikipedia.org/wiki/Solar_system
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    Megabrain wrote: The original post seems to suggest that our solar system is in the same plane as the milky way, I don't think it is, I think it is more likely a 70 degree tilt as the centre of our galaxy is somewhere in saggitarius?.

    A second point here it does not matter which way the object at the centre of a system spins objects orbiting may spin quite gappily in any direction and plane have a look at all the sun orbiting comets they are in all different directions and planes.
    Sorry but I did not mean to emply that all spinning objects in our universe spin on the same plane. My basic question is why do they spin at all? Referring back to the ball bearings it was suggested they would eventually collect together and start to spin. I just can’t arrive at a logical answer as to why. Gravity by itself would not justify the spin unless gravity has a spinning energy of some type.

    Thoughts?
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  18. #17  
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    They would in fact start to spin WHILE collecting together, not after. Each particle is pulled towards the centre of gravity of the collective, where no core need be to start with. As more particles are pulled in one direction rather than another by chance, it would start an overall trend that could result in an orbital plane of any orientation relative to the galactic centre. Electrostatic forces between these particles might also aid in the initial collective direction of rotation. Depending on the relative motion of the particle to the centre of gravity, it might go past it and start an elliptical orbit. Objects in an elliptical orbit are more likely to encounter other objects along its path, so most of the mass ends up in a more rounded orbit.
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    It seems more logical that because of the small mass of the particles then initially particles would simply move closer and closer together till the came in contact with each other. If this is true then there would not be any initial spin. Are you suggesting that once a mass becomes great enough then the near miss of a particle would start the initial spin?
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  20. #19  
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    As the dust particles move closer to the centre of mass, they might eventually move through the same space and right next to each other in a complex pattern. This would cause a spin, as the particles are in turn attracted to the other ones moving in another direction. A random trend would develop, causing more and more particles to be attracted in the same direction as the majority of the others, creating spin. The same as with a tornado. Have you ever waved your hand through the smoke at a BBQ? The same happens, as far as areas of localized spin are concerned.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    If it was truly a random or a complex pattern then why are most of the observable objects in our universe spinning on plane?
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    It starts out random, but a general trend develops that reinforces itself (the more matter that spin in one plane, the more will be attracted in the same direction) so that evenually almost all the matter moves in the same orbital plane.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

    "Gullibility kills" - Carl Sagan
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  23. #22  
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    After much thought I just can’t buy into that. It seems to be overly simplistic. Given that there numerous globs of matter at various points then one would think that they too should have collected together in the general pattern. However they have not. Why?
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  24. #23  
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    “After much thought I just can’t buy into that. It seems to be overly simplistic. Given that there numerous globs of matter at various points then one would think that they too should have collected together in the general pattern. However they have not. Why?”
    Continuation of the thought. If the trend developed as suggested by Kalster then it seems like it would naturally follow that all things would spin on a plane similar to a saucer. However this is not the case, i.e., our sun and related planets.

    My quest for an answer continues. Thanks for any assistance.
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