Solar System "Lock Step"

[rigney]

Kepler gave us formulas for calculating distances and speeds of our solar system. Yet, while each planet is unique in its size, density and orbit, how have they maintained this lock step for billions of years? Maybe someone can help?

Edited July 8, 2010 by rigney

[swansont]

They haven't?

 

Depends on what you mean by "lock step."

[rigney]

They haven't?

 

Depends on what you mean by "lock step."

 

 

You answered part of my question, or perhaps shot it down by saying, "They haven't". What is meant by, they haven't? The lock step thing was merely asking how a planatary systen could orbit a sun for billions of years in supposed unison and not have come apart before now? I wasn't talking about eternity.

[swansont]

There really is no "supposed unison." Mercury has a sin-orbit resonance with the sun, and we have an apparent phase lock with Venus. In any given orbit, the mass will tend to accrete into a planet.

[rigney]

I'm sure you meant "Spin orbit resonance". But tell me, what is wrong with saying that our solar system is in "Lock Step" or sync? As I stated, Kepler gave us the formula to calculate every nuance of our planets orbital paths. It holds true for today as it did four hundred years ago. Heck, I'm not trying to pick an arguement with you, since I don't know that much about anything. But am only trying to get a few questions answered without having to answer a bunch of questions myself. You made the statement that in any given orbit the mass will tend to accrete into a planet? That was not one of my questions. But, if that's the case, why is the asteroid belt still a junk yard and the the rings of venus and other planets are still dust? Too many things simply don't make sense to me just to hear a few well documented, but unfounded statements. Is our solar system changing? Absolutely! Knowing our moon is moving away from us is bad enough. The rest of our system is in change also, and has been doing so since it was created.

Edited July 9, 2010 by rigney

[swansont]

Heck, I'm not trying to pick an arguement with you, since I don't know that much about anything. But am only trying to get a few questions answered without having to answer a bunch of questions myself.

 

I don't think you are. But I don't understand the question as asked, because you are using very vague terminology to ask an unprecise question, so I ask for clarification.

 

And I will ask again. What is supposed to be in lock step with what?

[rigney]

Without vague terminolagy I wouldn't even be able to ask the question. And lockstep? It's anything from the nazi goosestep, to the finest symphony orchestra your ears have ever witnessed. Perhaps I should have said "in unison". Other than a New Star over Bethlehem a couple thousand years ago, an occasional comet and some meteors, each planet and moon in our solar system maintains its status quo, and is pretty much in lockstep by speed and orbit; which don't preceptively change. Why?

And please, don't use gravity as a demo, just hearing the word makes me nuts.

Edited July 9, 2010 by rigney

[Spyman]

Kepler gave us formulas for calculating distances and speeds of our solar system. Yet, while each planet is unique in its size, density and orbit, how have they maintained this lock step for billions of years? Maybe someone can help?

And please, don't use gravity as a demo, just hearing the word makes me nuts.

There is a secret circular rail track for every planet placed in the orbits. The track has cogged sides and goes straight through the planets. Inside the planets there exists a hidden mechanism with cogwheels and springs. Deep down in the core lies the central engine fueled by magic from fairies and powered by mighty trolls.

(It's emitting the gravity we observe here on Earth only as a small side effect.)

[rigney]

There is a secret circular rail track for every planet placed in the orbits. The track has cogged sides and goes straight through the planets. Inside the planets there exists a hidden mechanism with cogwheels and springs. Deep down in the core lies the central engine fueled by magic from fairies and powered by mighty trolls.

(It's emitting the gravity we observe here on Earth only as a small side effect.)

 

 

If I couldn't read the condescending values of your ignorance, or stupidity?; I may even be tempted to agree with you. But since you seem to act as a fool, then be the fool! No one at any intellectual level would want to measure up to your "self gratification". I can see it even though I'm just above a class z smarts. By the way, your costume befits your wholesomeness.

Edited July 9, 2010 by rigney

[Spyman]

If I couldn't read the condescending values of your ignorance, or stupidity; I may even be tempted to agree with you. But since you seem to act the fool, then be the fool! Not many of us are nearly that smart.

I am truly sorry if you got hurt from my joke and therefor apologize.

 

But to my excuse I must say that you were asking a seemingly scientific question in the General Discussion area and explicit asking us to explain it without the scientific reasonable explanation thereof.

Edited July 9, 2010 by Spyman
Bad wording

[swansont]

Then I don't see any planets in lockstep, other than the examples I've mentioned.

 

One person walks at a regular pace, and another person walks at a different pace. Their individual patterns are constant, but they are not in lockstep. That's what I see as far as planetary orbits are concerned.

 

As far as why a planet maintains an orbit, it's because there are no perturbations to change it, or they are too small to make a difference over the period of time under discussion. To change an orbit requires an outside influence.

[jackson33]

rigney; First it's highly unlikely our solar system looked anything like it does today, even a billion years ago and certainly didn't 4BYA (Est. age our system 4.6BY). However solar systems form, you could say other than the Star itself, everything else are by products, forming from the debris of matter having enough velocity, not to become part of that Star itself. As for lock step, every object (planet/moon/asteroid/rock/ice) still in orbit is constantly losing that battle (be it slowly, if our frame of mind) in it's free all toward the sun.

 

The Sun alone, currently accounts for 99.86% of all mass and nearly all the rest is the mass of Jupiter/Saturn in the form of gas.

 

As for Kepler, or for that matter Galiei (known as Galileo and first name), Newton and many others from the same period (16th-18th Centuries), it's been my opinion the Catholic Church had a great deal to do with creating the interest in what became Astronomy, while trying to communicate with a perceived God. In some ways this persist to this day as they continue to influence the sciences, IN MY OPINION.

 

While even then it should have been realized velocity/weight/distance should be involved with orbits (throwing rocks at different speeds, could give you this picture), but to come up with near the correct formula, gravity not yet explained, was impressive.

 

Kepler's Laws;

http://en.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion

 

Solar system mass;

 

http://en.wikipedia.org/wiki/Solar_System

[Ophiolite]

Hi rigney,

you said this:

And please, don't use gravity as a demo, just hearing the word makes me nuts.

 

Now I don't know what your area of expertise is, but suppose you were an aeronautical engineer, specialising in design of jet engines. Suppose I say "what allows the engine parts to rotate against each other with such high velocities without burning up, and do go mentioning lubrication the word makes me nuts."

 

In that situation how are you going to answer me. Spyman provided a lighthearted example of the only kind of response that can be given in these circumstances.

 

You have asked a reasonable question, then shut down all avenues for us to provide an answer.

 

Let's try Newton's First Law. Objects will remain in a state of rest or uniform motion unless acted upon by an external force. So if no external force acts on the Earth it will go through the universe in a straight line forever. But there is a force acting on it. That force you don't want mentioned and that force causes it to fall perpetually towards the sun. All the planets and satellites and asteroids follow similar paths.

 

The smaller bodies are influenced to a greater extent than the larger ones. That's why the asteroids have never combined to form a single body - Jupiter is to close and exerts a disruptive influence on their orbits.

 

Does that help.

[rigney]

I'm sorry to have created a constroversy causing such a turmoil of paranoia. My apology goes specificially to "Spyman". Having received a Phd only in H.Ks. many yeards ago, I'm not overly motivated to being congenial when someone calls me out. Am I oblivious to many things? Absolutely. Am I also inquisitive? Yes. While this doesn't belie my ignorance of the universe, I still ask questions. The only thing I seek now is, while being circumspect to the galaxy surrounding us, and a universe at any distance, why do we regard philosophical and platitudianel answers being so mundane as to think we may fall into the sun without gravity? Tell me, where the hell does a (+continual-) speed of everything not enter into the equation, and why not? The lube thing, I do understand.

Edited July 9, 2010 by rigney

[ewmon]

Paranoia?

 

There is an approximate synchrony of orbital periods of the planets (including Ceres), that's related to the Titius-Bode Law and Kepler's Third Law. I haven't read about it in a long time.

[jackson33]

Am I also inquisitive? Yes. While this doesn't belie my ignorance of the universe, I still ask questions. [/Quote]

 

rigney; Being inquisitive is a good thing, your asking opposed to trying to inform and these folks are, for the most part answering your questions for the 500th time. If you start a thread on wiring a home or something in your expertise, most would have no idea what you were talking about.

 

The only thing I ask now is, while being circumspect to the galaxy surrounding us, and a universe at any distance, why do we regard philosophical and platitudianel answers as being so mundane as to think we may fall into the sun without gravity? Where the hell is speed involved, and why?[/Quote]

 

I hope I am getting the question; Everything in our solar system, other than the Sun itself is under the influence of the Suns Gravity (just as anything on this planet is effected by earths gravity). Everything in our Galaxy (our sun) is influenced by the entirety and the direction and velocity of the Galaxy is influenced by objects in our Galaxy Group and all this can be influenced by other Galaxy Groups. Each group of objects has a combined influence on others, but gravitational effects diminish at a rather high rates, according to distances. It's that speed, keeping things in orbit. A good example, would be the International Space Station which is traveling at 17,220 MPH or so, to maintain an orbit around earth.**

 

Since gravitational force is inversely proportional to the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces. So as two objects are separated from each other, the force of gravitational attraction between them also decreases. If the separation distance between two objects is doubled (increased by a factor of 2), then the force of gravitational attraction is decreased by a factor of 4 (2 raised to the second power). If the separation distance between any two objects is tripled (increased by a factor of 3), then the force of gravitational attraction is decreased by a factor of 9 (3 raised to the second power).[/Quote]

 

http://www.physicsclassroom.com/Class/circles/u6l3c.cfm

 

**http://en.wikipedia.org/wiki/International_Space_Station

 

In the event your misunderstand "force" here is a much better expaination...

Gravity is the gravitational force on or near the surface of the Earth. Gravitation is the force that attracts bodies of matter toward each other, often at great distances. Gravity is the force that pulls nearby objects toward the Earth.

 

The equation for the force of gravity is F = mg. The major result of this force is that all objects fall at the same rate, regardless of their mass. Gravity on the Moon and on other planets have different values of the acceleration due to gravity, but the effects of the force are similar. [/Quote]

 

http://www.school-for-champions.com/science/gravity.htm

[swansont]

Paranoia?

 

There is an approximate synchrony of orbital periods of the planets (including Ceres), that's related to the Titius-Bode Law and Kepler's Third Law. I haven't read about it in a long time.

 

Bode's law is more of a coincidence; there's no physical basis for it.

 

http://en.wikipedia.org/wiki/Titius–Bode_law

[Moontanman]

 

As for Kepler, or for that matter Galiei (known as Galileo and first name), Newton and many others from the same period (16th-18th Centuries), it's been my opinion the Catholic Church had a great deal to do with creating the interest in what became Astronomy, while trying to communicate with a perceived God. In some ways this persist to this day as they continue to influence the sciences, IN MY OPINION.

 

While everyone is entitled to an opinion the fact remains that astronomy predates the Catholic church by 1000's of years. observation of the planets and stars was going on all over the world and was already quite advanced by the time the Catholic Church came about. If anything the church suppressed knowledge of the stars instead of advancing it...

 

As far as the perceived stability of the solar system we do not live long enough to see major changes but in the past there is reason to believe there were lots of shake ups, probably major shake ups with proto planets being ejected and orbits changing. It is also quite possible for it to happen again and it probably will but these changes are generally quite slow form our prespecitve... The comet hitting Jupiter was quite show and unusual from the perspective of short lived beings like us but over the life of the solar system such things happen routinely.

 

Rigney, what do you mean by a new star over Bethlehem? There have been super nova in historical times but they do not occur over a city and no where else. Either the star of Bethlehem was mythical, made up, a conjunction of planets or it was supernatural, there is no evidence a new star suddenly appeared over a small town in the middle east...

[D H]

Kepler gave us formulas for calculating distances and speeds of our solar system. Yet, while each planet is unique in its size, density and orbit, how have they maintained this lock step for billions of years? Maybe someone can help?

Whoa! What "lock step"? This implicitly assumes to things, both of which are wrong.

1. It assumes Kepler's laws say that there is some kind of "lock step" relation amongst the planets' orbits. It doesn't.
   
2. It assumes Kepler's laws are absolutely correct. They aren't. They are approximately correct. They aren't even correct in terms of Newtonian mechanics, let alone general relativity.

 

About item 1: "Lock step" would imply some kind of rational (e.g. 1/2, 2/3, ...) relation between the orbits of each of the planets. Numerologists try to pretend this is the case. As far as science can tell, it isn't. The Titus-Bode law is only approximately correct, and most likely, is only circumstantial.

 

About item 2: Kepler's laws ignore a whole lot of things. It ignores that planets have non-zero mass. This means that Kepler's third law is only approximately correct, particularly so in the case of Jupiter. That the planets themselves have mass also means that the planets can and do perturb each other's orbits. Kepler's laws of course also ignore relativistic effects. (That omission is perhaps forgivable given that Kepler predated Newton by a generation and Einstein by hundreds of years.)

 

Predicting the planets' locations based on Kepler's laws alone is not going to give accurate positions for any length of time--and certainly not billions of years. There is no good prediction scheme for that kind of time scale. The solar system is chaotic with a Lyapunov time of 5-10 million years.

[Cap'n Refsmmat]

I think rigney's not insinuating that the planets fly in some sort of formation. He's just asking why they've kept going in roughly the same orbits for so long, instead of Earth, say, getting flung past Jupiter because of Mars' influence.

[JohnB]

I agree with the Cap'n.

 

I think the question was something in the line of "Since there are forces always pulling at the planets, how come the Solar System and the orbits are so stable?"

[rigney]

The Cap'n and JohnB. pretty much hit it on the head. The lock step thing was just a way of expressing my thoughts as to how a system such as ours could remain intact for so long while each planet gallops around the sun at its own individual gait. I know, someone will refute the statement immediately and tell me that chaos is an ongoing event. While that's true, the good part is, other than a ragged asteroid belt and Jupiter getting smacked a short time ago, things in our system have remained rather in order. While I find it extremely hard to understand them, theories and formula are fantastic tools in explaining the already explained to those who do understand. I don't know why, but my thought is that somewhere in the near future we may need a whole new bunch of them to fit new situations. No!, nothing earth shattering, just new concepts.

Edited July 10, 2010 by rigney

[ewmon]

Modern concerns about the stability of the solar system began with Newton's gravitational model, and scientists have tried to find reasons for the stability ever since. Because the solar system consists primarily of the sun and the planets, the IAU's definition of a planet should help somewhat:

 

A “planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and © has cleared the neighbourhood around its orbit.

Stability is indicated by phrases such as "is in orbit" and "has cleared the neighborhood".

 

But, more to the point (I think), the solar system might be more accurately described as a system of "orbits" (and not just "planets") around the sun. For the purposes of stability, a planet is both mass and velocity, which both lend to its orbit and its stability. A planet remains in orbit because of both its mass and velocity. A "snapshot" of the solar system may make the solar system seem unstable, but it's not the complete picture.

 

Looking at how we ride bikes helps describe how velocity plays a critical role. A snapshot would show someone sitting on a bike (without motion) and, yes, as we know through our own experiences, such a system is unstable. However, someone riding a bike is a much more stable system, which we've also experienced ourselves many times over.

 

Also, synchrony does exist, for example between Pluto and Neptune. Cruithne and other objects orbit in synchrony with Earth, and other planets (notably Jupiter) also have objects orbiting in synchrony. All this goes into explaining the stability of the solar system. I previously mentioned the Titius-Bode Law. I don't see it as a law that stands on its own, but rather as a result of the stability of the solar system. I can't imagine that weak interplanetary gravitational forces exerted over billions of years has not produced synchrony, which is more or less synonymous with stability. If we could view the solar system over its lifetime, we would see the synchrony (and stability) evolve.

[D H]

OK, then. That is a very different question. The use of the term "lock step" and the discussion of Kepler's laws in the original post led me to think the topic of this thread was something very different than the long-term stability of the solar system.

 

Whether the solar system is stable in the long term is an open question. Recent studies indicate that it may not be. There is apparently a small chance, about 1 percent, that a secular resonance between Jupiter and Mercury can make Mercury's orbit get so eccentric that its orbit crosses that of Venus. That in turn means there is a chance that Venus and Mercury could collide, and that in turn means all kinds of nastiness. Mars might even be ejected from the solar system.

 

A recent paper on this subject:

K. Batygin & G. Laughlin, "On the Dynamical Stability of the Solar System", The Astrophysical Journal, 2008, 683:2 1207-1216

ArXiv preprint: http://arxiv.org/abs/0804.1946

 

The June 2009 contains two short letters on this subject. The editor's overview, with links to the letters is at http://www.nature.com/nature/journal/v459/n7248/edsumm/e090611-06.html. (paysite)

[rigney]

Modern concerns about the stability of the solar system began with Newton's gravitational model, and scientists have tried to find reasons for the stability ever since. Because the solar system consists primarily of the sun and the planets, the IAU's definition of a planet should help somewhat:

 

 

Stability is indicated by phrases such as "is in orbit" and "has cleared the neighborhood".

 

But, more to the point (I think), the solar system might be more accurately described as a system of "orbits" (and not just "planets") around the sun. For the purposes of stability, a planet is both mass and velocity, which both lend to its orbit and its stability. A planet remains in orbit because of both its mass and velocity. A "snapshot" of the solar system may make the solar system seem unstable, but it's not the complete picture.

 

Looking at how we ride bikes helps describe how velocity plays a critical role. A snapshot would show someone sitting on a bike (without motion) and, yes, as we know through our own experiences, such a system is unstable. However, someone riding a bike is a much more stable system, which we've also experienced ourselves many times over.

 

Also, synchrony does exist, for example between Pluto and Neptune. Cruithne and other objects orbit in synchrony with Earth, and other planets (notably Jupiter) also have objects orbiting in synchrony. All this goes into explaining the stability of the solar system. I previously mentioned the Titius-Bode Law. I don't see it as a law that stands on its own, but rather as a result of the stability of the solar system. I can't imagine that weak interplanetary gravitational forces exerted over billions of years has not produced synchrony, which is more or less synonymous with stability. If we could view the solar system over its lifetime, we would see the synchrony (and stability) evolve.

 

Appreciate your input. Having no formal educatrion or direction in physics, my whole concept has always been why? Your explination is very similar to Capn's and JohnBs. I hope someday we can compare our solar system to another and clear up some of the, "So, that's what it's all about"? Thanks.