The ever changing Sun's magnetic field.

[Robittybob1]

It is not.

How do you know?

[swansont]

It is not.

 

I think you're overstating things. They have to be similar in some ways.

[Robittybob1]

 

I think you're overstating things. They have to be similar in some ways.

I think the Sun's magnetic field is going to be a lot more complex. I'm mostly interested in the switching factor. (If there is such a thing.) I'm really just into trying to understand what Janus was talking about at this stage. The tidal effects of the planets on the Sun.

[swansont]

I think the Sun's magnetic field is going to be a lot more complex. I'm mostly interested in the switching factor. (If there is such a thing.) I'm really just into trying to understand what Janus was talking about at this stage. The tidal effects of the planets on the Sun.

 

The field itself has to follow Maxwell's equations, so there will be similarities. How the field is generated is different.

[Robittybob1]

 

The field itself has to follow Maxwell's equations, so there will be similarities. How the field is generated is different.

Are you still of the view that the planets have nothing to do with the generation of the field? How can I tell what is the alignment of the planets today?

I was thinking I could express the position of each planet as a sine wave and then multiply that by the gravitational and tidal effect and sum them up somehow. But I would need to know their starting positions.

Edited February 24, 2015 by Robittybob1

[Acme]

I think you're overstating things. They have to be similar in some ways.

No more than the Sun & Earth are [roughly] spherical. Big deal.

... How can I tell what is the alignment of the planets today?. ...

Interactive Orrery

Edited February 24, 2015 by Acme

[Robittybob1]

No more than the Sun & Earth are [roughly] spherical. Big deal.

 

Interactive Orrery

Very, very interesting, and very strange, for the Sun is displaced to the same side of the "center" as is Jupiter. What is the center of the system based on, do you know?

Thanks for your help on this topic.

[Acme]

Very, very interesting, and very strange, for the Sun is displaced to the same side of the "center" as is Jupiter. What is the center of the system based on, do you know?

Thanks for your help on this topic.

Given your habit of asking for information and then arguing with our answers, I am reticent to do any more than give you links to read. The center of the system at the link I provided -however- is the Sun.

 

As to the Sun's magnetic field, it is not generated by gravitational effects of orbiting bodies. Here are [yet more] links for you to read and argue over.

 

Stellar magnetic field

 

How does the Sun's magnetic field work? @ NASA

[Robittybob1]

Given your habit of asking for information and then arguing with our answers, I am reticent to do any more than give you links to read. The center of the system at the link I provided -however- is the Sun.

 

As to the Sun's magnetic field, it is not generated by gravitational effects of orbiting bodies. Here are [yet more] links for you to read and argue over.

 

Stellar magnetic field

 

How does the Sun's magnetic field work? @ NASA

I'm not dismissing the effect of the planets as yet but the thought of all the work to disprove it is rather frightening. It might just have to be left in the too hard basket at the moment.

I have been playing around with the buttons on the Solar System Live page and if you set the "Orbits" to "equal" you get the Sun dead center, but otherwise it might be a SSB view where the Sun is often off-center.

From the orbital periods and their distances we could get a rough idea of any patterns that might develop.

 

From the gravitational force equation = GmM/r^2 and plotting how the forces would add to the G force of Jupiter might work. The previous idea of making it appear sinusoidal seems dumb looking at it now. I haven't graphed things going around in a circular fashion before so it is new territory.

So I would have to add the force vectors of the other 8 planets to that of Jupiter as Jupiter orbits the Sun.

The force vectors could be kept constant for each planet so the main change moment by moment will be the direction of each planet's force vector. If they are on opposite sides of the Sun there will be a reduction, if the planet is 90 degrees to jupiter there will be no additional strength but if they both align and are on the same side the vectors will fully add.

Edited February 25, 2015 by Robittybob1

[Robittybob1]

.... From the gravitational force equation = GmM/r^2 and plotting how the forces would add to the G force of Jupiter might work. The previous idea of making it appear sinusoidal seems dumb looking at it now. I haven't graphed things going around in a circular fashion before so it is new territory.

So I would have to add the force vectors of the other 8 planets to that of Jupiter as Jupiter orbits the Sun.

The force vectors could be kept constant for each planet so the main change moment by moment will be the direction of each planet's force vector. If they are on opposite sides of the Sun there will be a reduction, if the planet is 90 degrees to jupiter there will be no additional strength but if they both align and are on the same side the vectors will fully add.

G and the mass of the Sun doesn't change so they could be dropped out of the calculations. Just the m/r^2 changes between the planets and the amount of angle change WRT Jupiter - Sun baseline.

The orbital velocity formula Vo = SQRT(GM/r) so the speed that the planets orbit the Sun is not dependent on their own mass just always inversely proportional to their distance, and the circumference is proportional to the radius as well, so the angle change must be inversely proportional to their radii as well.

Edited February 26, 2015 by Robittybob1

[Robittybob1]

Just so I can get to see what calculations could be like let the Sun have a certain mass Ms and there be two planets with the largest being 300 times as large as a smaller one. The larger one is orbiting the Sun at 3 times the radius of the smaller one.

What is the frequency of the orbital phases they go through just from gravitational force.

Ms = 2.0E+30 kg

M1 = 300 times M2

M2 = 6.0E+24

 

Radius M1 = R1 = 8E+11 m

Radius M2 = R2 = 3/8E+11m

Both have circular orbits and they follow the orbital period formula.

 

Period = T = 2 Pi()*SQRT(R^3/(G*Ms))

 

Looks like I was wrong previously about the speed being inversely proportional to radius. (I should have said inversely proportional to square root of the radius.) Let's set up the example and get the formulas ingrained.

The period for the planet further out is 5.2 times longer duration. T is proportional to the sqrt. of the radius cubed.

If they start off aligned on the same side of the Sun they are 180 degrees apart after 1.470 years (just over half the orbital period for the smaller planet.

I can see if I add in more planets there won't be many times where all planets align, so I'm going to have to develop a way of adding up influence and not just look for times of alignment.

OK a compromise might be on the cards - I'll look at the times when Jupiter and Saturn* align and add on the influence of the other planets at that time.

(* I'll choose the two planets that have the greatest gravitational influence on the Sun.)

Edited February 27, 2015 by Robittybob1

[imatfaal]

Just so I can get to see what calculations could be like let the Sun have a certain mass Ms and there be two planets with the largest being 300 times as large as a smaller one. The larger one is orbiting the Sun at 3 times the radius of the smaller one.

What is the frequency of the orbital phases they go through just from gravitational force.

Ms = 2.0E+30 kg

M1 = 300 times M2

M2 = 6.0E+24

 

Radius M1 = R1 = 8E+11 m

Radius M2 = R2 = 3/8E+11m

Both have circular orbits and they follow the orbital period formula.

 

Period = T = 2 Pi()*SQRT(R^3/(G*Ms))

 

Looks like I was wrong previously about the speed being inversely proportional to radius. (I should have said inversely proportional to square root of the radius.) Let's set up the example and get the formulas ingrained.

The period for the planet further out is 5.2 times longer duration. T is proportional to the sqrt. of the radius cubed.

If they start off aligned on the same side of the Sun they are 180 degrees apart after 1.470 years (just over half the orbital period for the smaller planet.

I can see if I add in more planets there won't be many times where all planets align, so I'm going to have to develop a way of adding up influence and not just look for times of alignment.

OK a compromise might be on the cards - I'll look at the times when Jupiter and Saturn* align and add on the influence of the other planets at that time.

(* I'll choose the two planets that have the greatest gravitational influence on the Sun.)

 

 

How do you know that the orbits are stable?

[Robittybob1]

 

 

How do you know that the orbits are stable?

At this stage I was just exploring how to set up the macros that will look at these two imaginary planets (they could nearly represent Mars and Jupiter) and once I get confidence with the math I will introduce all the real planets with their actual masses and radii.

 

I definitely needed a practice run first. It will reveal if stability of the orbitals will be that crucial. I'm just going to be surprised if there is a rhythmic pattern that comes out with an 22 year period.

[imatfaal]

I have run a sim up to about 6000 years (which is no time at all in these terms) and the earth size planet has already developed a .1pct eccentricity. Whether this will settle or keep getting worse I have no idea.

[Robittybob1]

I have run a sim up to about 6000 years (which is no time at all in these terms) and the earth size planet has already developed a .1pct eccentricity. Whether this will settle or keep getting worse I have no idea.

That could happen as every cycle of the simulation you will be adding up the errors in your calculations. Sounds like with fine tuning you could get rid of that if you wanted too, or might be real. Do planetary orbits have a way of dampening down their eccentricities?

[imatfaal]

That could happen as every cycle of the simulation you will be adding up the errors in your calculations. Sounds like with fine tuning you could get rid of that if you wanted too, or might be real. Do planetary orbits have a way of dampening down their eccentricities?

 

The simulation was running at a time step of 400 secs - perhaps as you say it would disappear with a smaller step or maybe redouble. The reason that 3 body problems are difficult is twofold - one they are not necessarily analytically solvable and two even with a simulation rather than analysis we struggle to predict whether feedback will be negative or positive. So to answer your last question - yes and no! Some arrangements act to stabilise and damp down minor changes and others exacerbate problems.

 

That said I am a complete novice in these areas and an expert might be able to say that this is a scenario with an analytical solution (ie you can just crunch numbers on initial direction, velocities and masses and get an answer), or that it is known that negative feedback will apply to these initial conditions.

Thinking more about it I think you may be ok with those figures. Problems seem to occur (in orbit and in the calcs) when the period ratio is a integer or rational - yours is of course 3^(3/2) which is irrational

[Robittybob1]

 

The simulation was running at a time step of 400 secs - perhaps as you say it would disappear with a smaller step or maybe redouble. The reason that 3 body problems are difficult is twofold - one they are not necessarily analytically solvable and two even with a simulation rather than analysis we struggle to predict whether feedback will be negative or positive. So to answer your last question - yes and no! Some arrangements act to stabilise and damp down minor changes and others exacerbate problems.

 

That said I am a complete novice in these areas and an expert might be able to say that this is a scenario with an analytical solution (ie you can just crunch numbers on initial direction, velocities and masses and get an answer), or that it is known that negative feedback will apply to these initial conditions.

Thinking more about it I think you may be ok with those figures. Problems seem to occur (in orbit and in the calcs) when the period ratio is a integer or rational - yours is of course 3^(3/2) which is irrational

Are you running that simulation on a bought in program or one you wrote yourself?

 

I am hoping the idea I am looking at has a certain forgiveness in it, for the Sun cycles will not be defined as accurately as orbits.

It would be like a clock, the hands of which will pass each other 11 times in a 12 hour period regardless whether the time is correct or it is running slow or fast. Well so I think at this stage but I am a long way from completing it as yet.