# The Naked Scientists Forum

### Author Topic: why objects rotate like they do  (Read 8387 times)

#### thebrain13

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##### why objects rotate like they do
« on: 15/09/2008 04:45:28 »
Ive always thought the speed in which objects rotate seems very odd. There is no way it can be chalked up to  completely random. The nature of my gripe is simple, the angular momentum contained in objects as seen in the universe is organized, the scientific explanation for that, is not. For example consider this stat for example, the mass of the centermost object (usually a blackhole) in all galaxies is dependent on the mass of the galaxy(1.5 percent of all the mass in the galaxy usually resides in the center) so galaxies would all have to start with set amounts of angular momentum for this to be the case. And that is of course, not random. Another problem is that there is a massive difference in scale between all the rotating objects, how could you use the same logic of random rotation on a planet like earth, and then apply the same logic to a galaxy? it would be very difficult to apply a set of limits to a random motion argument that would apply to a planet and a galaxy.

So now that ive got my criticism out of the way, let me explain how I think objects obtain a more uniform rotational velocity. And I believe my answer is way more consistent with modern day observation.

Now the first step with how objects contain angular momentum, starts with another conclusion ive made. Now im not going to explain why this is the case, but just accept this as true for now. volume that is more dense, is usually on average, positively charged, and less dense areas of the universe are usually negatively charged. And the more dense, the more positive an object is, and the less dense, the more negative it is.

Now once we have that conclusion, consider this principle of electromagnetism. charges increase their relative force when they move towards one another, and when they move away, their force is decreased.

So if a planet was rotating, and a planet was positively charged, and its surrounding were generally negative, there would be a force pulling it to rotate even faster. Remember one side of the planet is moving towards the negative surroundings, while the other is moving away, that would create a greater net attraction on one side of the planet than the other, causing its rotation to speed up. Now, I'm sure this force is very small, but when were talking about billions of years to accumulate momentum, while friction is very minimal, but not completely irrelevant. You should have a pretty significant effect.

Considering my princple, planets rotation should be generally determined by their mass/density. So is that somewhat consistent with modern observation?  I think so, if you order all the planets in terms of mass 1-8, and then you ordered all the planets in terms of rotational speed, you would find that those two things correlate almost exactly. I mean there are alot of things that can affect how a planet will rotate. A meteor could hit it, tides, magnetic breaking etc. Im not saying that all large objects always rotate faster than small ones, but i am saying that usually they will, and i think my principle may help explain why. And if you took a normal group of planets, and when i say normal I mean not directly next to a large body that might affect it, like the sun, or maybe had a large collision in its recent past, barring an unusual occurence in its somewhat recent past, I believe their rotational velocities would be directly coordinated with their masses.
« Last Edit: 20/02/2009 12:00:00 by thebrain13 »

#### thebrain13

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##### Re: why objects rotate like they do
« Reply #1 on: 15/09/2008 06:06:52 »
meant to put this on new theories

#### lyner

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##### Re: why objects rotate like they do
« Reply #2 on: 15/09/2008 17:52:21 »
Are you suggesting that it is electric charge that attracts massive objects together?
Can you really disagree with the idea that the force of Gravity accounts for planetary, stellar and galactic motion? Gravity has only 'positives' when it comes to attraction forces - there are no negatives - unless you have different evidence.

#### thebrain13

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##### Re: why objects rotate like they do
« Reply #3 on: 15/09/2008 20:59:58 »
My theory doesn't have anything to do with gravity. I know gravity controlls orbits once angular momentum is in a system. My theory is about how the angular momentum gets there in the first place, not about why objects orbit.

#### lyner

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##### Re: why objects rotate like they do
« Reply #4 on: 15/09/2008 21:43:19 »
Stars and everything else are the result of lots of atoms coming together by gravitational attraction. It would be extremely unlikely for all the constituent particles to be moving on a course which made them converge at a single point (their centre of mass). Some will be aimed above, below, to left or right - you know what I mean.
The total angular momentum of the original mass is given by the sum of the angular momenta about this cm, defined as  ∑ωI.
where I is the moment of inertia and ω is the angular velocity of each mass around the cm.
This will most certainly not be zero. There's your original angular momentum, which is conserved and which ends up with the star spinning. All the things in a particular vicinity are likely to have originated from the same distributed mass and it is reasonable to expect that they will mostly end up rotating around roughly parallel axes and in the same direction. There will be exceptions due to collisions and near collisions.
This angular momentum stuff is all  A level Maths / Physics content - no real mystery here. Angular momentum is a simple, classical mechanics property of any set of masses which happen to be moving relative to each other. The resulting motion may not always be obvious but it makes sense and can be confirmed by experiment - a good point in  favour of the theory.
« Last Edit: 15/09/2008 21:46:05 by sophiecentaur »

#### thebrain13

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##### Re: why objects rotate like they do
« Reply #5 on: 16/09/2008 05:23:48 »
I know that angular momentum will almost never be completely zero, but we are splitting hairs here. If the rotations of planets were decided by random amounts of angular momentum, then by deffinition, the amount of angular momentum would be random. And simply put there are patterns that exist when you look at a larger sample size. This whole random argument is annoying to argue against because you can explain anything using a random argument. You could say gravity doesnt exist, objects have just randomnly decided to fall. I've pointed out that there is a correlation between mass, and rotation. Sure it could be random but I doubt it.

Answer this question using the random hypothesis. All galaxies centermost masses (blackholes) make up i think 1.5% of the entire galaxies mass. If the way a galaxy rotated was only determined by its initial angular momentum, and that angular momentum is random, why would a specific percentage of mass reside in its center?

You understand what I mean, if two equal sized galaxies had differing amounts of initial angular momentum, the one with the smaller amount would develope a more massive center.

#### lyner

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##### Re: why objects rotate like they do
« Reply #6 on: 16/09/2008 14:10:25 »
Quote
This whole random argument is annoying to argue against because you can explain anything using a random argument. You could say gravity doesnt exist, objects have just randomnly decided to fall. I've pointed out that there is a correlation between mass, and rotation.
etc. etc
Mass and rotation have different units so there can hardly just be a 'correlation'.  It is true that a massive object cannot spin as fast as a small object because there is a limit beyond which it will fly apart - (School Science)

Unless you are prepared to do individual calculations on every atom involved in a process you have to treat them on a statistical basis and accept that you can't know about each one in detail. That doesn't invalidate the Science.
Who would want to say that gravity doesn't exist - not these days, anyway? What has that got to do with anything?
I wonder if we are talking about the same 'Angular Momentum". The one I refer to is what I was taught in School. I mentioned it in an earlier post.
What, precisely are you finding fault with? Is it planetary, stellar or Galactic explanations about angular momentum?
Your figure for the proportion of all galaxies which constitutes the CBH - how accurate is it and what is the spread? There must be limits for the initial mass of material needed for Galaxy formation - too little and nothing will happen before hitting something else - too much and the distances may be too great for the attraction to work.  Hence, you would expect a finite range for your figure.
I have no idea how to do the calculations (conventionally based) which could show what would happen but do you? You really must be able to 'disprove' that the conventional ideas explain a phenomenon by supplying an alternative which, in its turn, you would need to prove.
Btw, you have not yet explained what your original talk of positive and negatives was all about and how (quantitatively) it could be part of an explanation of how things are. Electrically neutral bodies at large distances have no mutual electric force afaik. Electrically charged bodies pretty rapidly become neutral.

#### yor_on

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##### Re: why objects rotate like they do
« Reply #7 on: 28/01/2009 23:04:42 »
Positively charged is an entropic default of electrons in a given system.
Negatively charged is the opposite as I understands it.

Space is neither.
It's just 'neutral'.

Although. " Space around Earth--except for the lower atmosphere--does conduct electricity. In the ionosphere--say 120 kilometers up (70 miles) and higher, sunlight rips off electrons from atoms, creating a "plasma," a mixture of free floating electrons and positive ions (left-over atoms, which miss an electron or more), and a plasma conducts electricity. If a free electron collides with an ion, the two may recombine again--but densities are so low that in most regions recombination does not catch up with "ionization" (the break up of atoms), even during the night, when the ripping-off of electrons stops. Also, higher up in space additional sources of plasma exist, e.g the "solar wind" blowing from the Sun.

Such magnetic forces try to make the plasma "co-rotate" with the Earth. Their effect turns out to be the same as would occur, if magnetic field lines which thread the plasma are viewed as attached to it. Then everything--Earth, plasma and field lines attached to it--rotate together. Once more--be aware that this only happens when space is filled with a good conductor of electricity. Without electric conductivity, the magnetic field does not transmit rotation. Iron does conduct electricity, but iron filings scattered on paper are not enough, they do not provide a good enough path for electric currents. "

That is electromagnetic fields around our Earth created by its rotation.
And one of the explanations to it being so strong should be our molten iron core inside the Earth.

"This layer allows the solid inner core to rotate freely with respect to the outer mantle and crust. Thus every twist and torque exerted by the atmosphere, oceans, Moon, Sun, other planets and the rest of the universe stirs that inner iron ocean, affecting the great dynamo that drives the Earth's magnetic field."
And its interaction with the sun primary, (and the moon too).

But that is our magnetic field creating charges as I understand it.
(Interacting with the Sun's, and our other planets fields)
So I guess one can see the Earth as a dynamo.

But what 'drives' its rotation is the absence of any force stopping it.
Not Electricity.

---

I don't know how far an electron can 'live/travel' in a vacuum?
But as it has mass it's not timeless.
« Last Edit: 28/01/2009 23:31:20 by yor_on »

#### Vern

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##### Re: why objects rotate like they do
« Reply #8 on: 28/01/2009 23:54:34 »
Quote from: thebrain13
Considering my princple, planets rotation should be generally determined by their mass/density. So is that somewhat consistent with modern observation? Well lets consider our solar system, the largest planet, jupiter, rotates the fastest, while mercury the smallest, rotates the slowest. Also if you order all the planets in terms of mass 1-8, and then you ordered all the planets in terms of rotational speed, you would find that those two things correlate exactly.
Do you have a reference for this. Is it true that the size of the body determines its rotational speed? Mercury, for example, rotates in sync with its orbit around the sun. The reason for this is well known to be the tidal effects between the sun-mercury system. So you lose one example there. Same with the moon-earth system.

#### jerrygg38

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##### Re: why objects rotate like they do
« Reply #9 on: 01/02/2009 01:04:56 »
Are you suggesting that it is electric charge that attracts massive objects together?
Can you really disagree with the idea that the force of Gravity accounts for planetary, stellar and galactic motion? Gravity has only 'positives' when it comes to attraction forces - there are no negatives - unless you have different evidence.

Gravity is positive when we exist in linear space-time and space pushes objects together. Once we enter areas of non-linear space time gravity can turn negative or zero. Thus once space has no ability to push objects together, gravity is non-existant. At the big bang, most everything was inside the small volume. With nothing outside the small volume,. gravity was zero for a split second. After the bang, gravity became quite positive.

#### Vern

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##### Re: why objects rotate like they do
« Reply #10 on: 01/02/2009 01:11:06 »
Are you suggesting that it is electric charge that attracts massive objects together?
Can you really disagree with the idea that the force of Gravity accounts for planetary, stellar and galactic motion? Gravity has only 'positives' when it comes to attraction forces - there are no negatives - unless you have different evidence.

Gravity is positive when we exist in linear space-time and space pushes objects together. Once we enter areas of non-linear space time gravity can turn negative or zero. Thus once space has no ability to push objects together, gravity is non-existant. At the big bang, most everything was inside the small volume. With nothing outside the small volume,. gravity was zero for a split second. After the bang, gravity became quite positive.

Hi jerry38gg, I think you typed inside the quote codes so that your contribution seemed to be within sophiecenteur quote. It is easy to miss that bottom quote exit I think I fixed it in the repeated quote here.

#### thebrain13

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##### Re: why objects rotate like they do
« Reply #11 on: 09/02/2009 13:35:46 »
Okay sorry for being away, I got a little annoyed with some condescending remarks in recent posts (cough...sophie) and stopped responding but let me clarify what I'm saying. There is in my opinion a definite trend between mass and rotational speed. I believe it is larger than just our solar system, and my logic applies to more things than just planets. However, I dont have a ton of info on planets and stars masses and rotational speeds outside of our solar system, if somebody has more info on this I'd love to hear about it.

Okay so lets look at the planets and the sun. I'll start with the largest object in our solar system and end with the smallest. the first number is the rank of an objects mass and the second number is the rank of its rotational velocity.

the sun 1,1 it is the heaviest and rotates the fastest
Jupiter 2,2
saturn 3,3
Neptune 4,4
Uranus 5,5
earth 6,6
Venus  Venus is the first planet to break the trend, however I believe there is valid reason why Venuses day is very similar to its year, the same can be said for mercury. I'm proposing that since they have large tidal effects, due to the fact that they are the two closest planets to the sun their days and years more or less match. Just like the earth and the moon, like vern has suggested. If you considered these planets as general outliers, like i do. I could complete my list and add mars.
mars 7,7

I think that is a pretty strong correlation, the chances this would happen on random is pretty low, and since I had a previous theory which suggests this should be the case, I cant help but wonder if I'm on to something.

Okay now secondly, let me re explain my gripe. I think that it is pretty tough to understand why this is a problem in the first place which probably is a good explanation for why I've found no answer. Now just try to follow me for a second. I believe there is no such thing as completely random, or what I really mean is "devoid of pattern". Being completely devoid of any pattern is a pattern in itself.

So what is the pattern of objects momentum at the beginning of the universe? I've never seen any attempt at an explanation to that question. And I think if you tried it would really point out why the logic I've given above is necessary.

For starters there is a massive amount of objects in the universe,  how would this pattern address all these on an individual scale. Think about it, how would this pattern address these things on an individual scale? take an object in the universe the size of a marble, what would be the likely parameters of its rotation? Now think about how many marbles are in a house, what would the parameters be for the house, and how would it relate to the marbles? How many houses can fit in the earth, how many earths can fit in the solar system, how many solar systems in a galaxy, how many galaxies in a galaxy cluster? Yet all these things seem to have sizeable rotations. (barring marbles and houses of course) how could you use the same logic for a planets rotation as you could on a galaxy cluster?

I really believe, if anybody stepped up to the plate and tried to answer that, there would be obvious problems with their conclusions. what they came up with for planets wouldn't work for galaxy clusters.

so what are we suggesting, did each an every individual atom come with a specific momentum all by itself? If that were the case, these atoms must of started with humongous differentials in speed in order to be able to randomly combine to form the earth with 1000 mph of rotational velocity left over, and then of course if it were possible for the earth to rotate at the speed of 1000 mph what should we expect a galaxy to rotate?

Obviously, that scenario just wouldn't work. There are so many atoms in the earth, there is no way they could individually combine to create any sort of significant rotation.

Okay and I know what some of you are thinking, well conservation of angular momentum says that when gravity collapses a cloud it will rotate faster and faster, well my rebuttal to that is there is still an absurdly large number of atoms in a planet. I dont think the extra amount of speed added by c.o.a.m really compares to the nullifying affect of the truly ridiculously large amount of atoms you could find in an entire planet! And do I need to expand this idea to rotating galaxy clusters?

To even try to answer this you would have to say that objects came into the universe rotating in groups already. You couldn't explain it by saying all atoms entered the universe with independent velocities. You would have to proclaim that there was some other larger scale pattern, that basically would say groups of atoms joined the universe with differing velocities, in relation to the whole universe but like velocities with the atoms in its immediate area. Basically there would have to be planet sized clouds rotation at one speed, within galaxy sized clouds at another within galaxy cluster type clouds, rotating at their own differing speed. to me this kind of thinking seems a little absurd.

The other problem I have with this is how similar in speeds the planets rotate at. Outside of the slow rotating mercury and venus (whose periods closely match their revolutions) the variance in periods(days) ranges from mars 1.03 earth days to jupiter at .41 earth days) if they were truly random they could range from 10 billion earth days to .001 earth days. Why are they so close if their revolutions came from "random" sources? Also the chances that the top six planets in our solar system have masses that match their rotational speed is 1:720 And if I threw out mercury and venus which would allow me to add mars the chances would be 1:5040 I mean, sure all this is possible but its just not likely.

And finally, Im sure there are specific examples where the mass rotational speed correlation does not match. I mean, I dont think the existence of the grand canyon and mt. Everest disproves the theory that planets are generally round due to gravity. This is a large scale thing.

#### lyner

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##### Re: why objects rotate like they do
« Reply #12 on: 09/02/2009 16:58:45 »
thebrain13
Quote
Everest disproves the theory that planets are generally round due to gravity. This is a large scale thing.
Everest is TINY, compared with the Radius of the Earth. The irregularites in the thickness of the lithosphere and the mantle are at least as big.

Talking in terms of rotational speed in mph is not as much use as using angular velocity (or rpm) - in conjunction with moment of inertia.

Small planets, near the Sun experience much more tidal drag effects.
Quote
I dont think the extra amount of speed added by c.o.a.m really compares to the nullifying affect of the truly ridiculously large amount of atoms you could find in an entire planet!

The angular momentum of a system is proportional to the radius squared. The radius of  an atom (nucleus, actually) is so much smaller than the radius of rotation of just two atoms in mutual orbit that the relative magnitudes of angular momentum of a single atom compared with even just a pair od atoms is miniscule. For a speck of dust - even more of a ratio and, for a planet, EVEN more. Each of the individual atoms you are considering has its own  bit of angular momentum but, as part of a larger system, it has much much more. So it is the macroscopic rotation which dominates hugely over the individual atomic rotations.

The total angular momentum, by definition, must be zero.
« Last Edit: 09/02/2009 17:01:26 by sophiecentaur »

#### thebrain13

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##### why objects rotate like they do
« Reply #13 on: 20/02/2009 12:12:26 »
sophie, I said Everest doesn't disprove the theory that planets are generally round due to gravity. So no need to argue against that. Also sure two atoms is way more likely to have more angular momentum than one, since one atom can only have a very small radius, obviously. but I was talking about extremely large groups of atoms not one or two, so the argument seems pretty irrelevant.

#### lyner

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##### why objects rotate like they do
« Reply #14 on: 21/02/2009 00:29:39 »
So are you treating the problem macroscopically or microscopically? You must know that there is a huge range of molecular speeds in a gas and that's what it starts with.

I think the correlation you are finding is simply that. Because of the way solar systems form, the gas giants tend to be further out - proportionally more dense material near the central attractor.

As well as rotational speed - (do you mean revs per Earth year or mph - which, as I pointed out, is not a suitable measure for anything here?) there is the orbital angular momentum. Compared with the Sun's angular momentum due to its spin, the orbital angular momentum of Jupiter is high. There are so many factors here and I think you have just picked a few which suit your model - what about Mars, btw - does it fit your system?

#### thebrain13

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##### why objects rotate like they do
« Reply #15 on: 21/02/2009 10:44:40 »
Honestly sophie, I think if I said two plus two is four you would try to disagree with me. I swear to god, every time I post something you respond in a way that is totally irrelevant to what I'm talking about. I seriously wish that you would either develop some sort of objectivity in response to what I post, or you would just stop posting in response to what I say all together. And btw I know this makes me look like an a hole but the thing that really pisses me off is that every time I post something, which usually takes a decent amount of thought, you spam it up with irrelevant predecided arguments that have nothing to do with what I'm talking about.

#### lyner

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##### why objects rotate like they do
« Reply #16 on: 21/02/2009 13:55:03 »
Sorry. I am just finding it hard to see where you are getting your thesis from - except from some apparently random statistics.
Can you make it clear what your model actually is, please? You may think you've done it already but there is some confusion about the actual quantities you are using and units.
I though that you, initially, were trying to get it straight as to how a Nebula can come together and form solar systems and other structures with rotation (spin and orbital). That's what interests me, too. There are some basic bits of Physics that any description must be expected to follow, though.
Shall we start again? I will not give you a hard time - I may point out inconsistencies, though. BTW, at times, you have been saying two plus  two equals four point one!
« Last Edit: 21/02/2009 16:54:03 by sophiecentaur »

#### The Naked Scientists Forum

##### why objects rotate like they do
« Reply #16 on: 21/02/2009 13:55:03 »