[Petrochemicals (OP)]

*NOTE* I have modifyed the title from universe, I did mean solarsystem not universe, but had to retype it due to wifi signing out. And the rest of the post.


New on here 1st post. The answers probably simple!


One of my long time queries is why do all of the planets (asteroid belt and the dwarf planets to the greater extent ) orbit the centre of the solar system on a flat (ish) plane. I cannot see any reason why the planets cannot orbit on seperate planes that are at odds to each other.


I know the planets formed from a rotating cloud and thus they orbit in the same direction, but in this formation of collisions between rocks to form the planets etc I would expect the planets to have taken on there own orbits. And why do gas clouds  rotate on a plane anyway, I know the sun has poles like the earth so i suppose the gas cloud could be polar or charged, leading to a  turbulance ignition etc.


 Galaxies orbit a black hole which unless i am very much mistaken ARE on a plane so cold be shooting ou sideways gravity, or something like that. Does the sun behave in a similar way to a black hole


Newtons gravity would say that they have been brought into allignment over many billions of years from the formation of the solar system to achieve equilibrium.


Einstiens relativity im not to sure about given that  everything is travelling in a straight line.


But given the moon  orbits the earth   at various angles along with the satalites of other planets not being perfect,and the planets orbits are elipses, it doesnt seem that gravitational force alone would account for this, and why there isnt a screwball planet that orbits at a completley different angle given it was in an accident when it was in it infancy.

[chiralSPO]

In this case your intuition is correct and your facts are wrong. Planets throughout the universe orbit on all sorts of planes. Even within our own solar system, while most of the planets orbit within planes that are fairly close, there is still some deviation (most of our planets within 1 or 2 °, but Mercury is off by about 5 degrees, and before being demoted to dwarf planet, Pluto was off by 17 °!). But we also have plenty of data on systems of planets orbiting other stars, which definitively show that there is no universal orbital plane, there are even examples of extrasolar systems that don't have an internally well-defined plane (especially if you consider binary and ternary star systems). Also galaxies that do have defined orbital planes (many do not), there is no alignment in their orientation (see attached photograph of an incredible zoom in to deep deep space, where we can see hundreds of galaxies, apparently randomly oriented).


You might be interested in reading here: https://en.wikipedia.org/wiki/Orbital_inclination

[Petrochemicals (OP)]

I have edited the post to say solar system not universe, a mistake I should not be making at this stage.  I do not really know anything about the centre of the universe!


Thank you for the link. I have read mostly about the moons on planets. Close in planets orbit on the rotation of the equator(our moon being a notable exeption), but more interestingly the further out objects are ruled by 'solar tides'.


It is a good point that galaxies do not all have an internal plane, yet some do, and given that black holes are planar too (if I have that correct, it doesn't seem like all there is at work is rotation.


Also a good point that galaxies do not rotate on a plane, but they do cluster from what I have read, vast areas of space with nothing and then masses of galaxys

[Janus]

*NOTE* I have modifyed the title from universe, I did mean solarsystem not universe, but had to retype it due to wifi signing out. And the rest of the post.


New on here 1st post. The answers probably simple!


One of my long time queries is why do all of the planets (asteroid belt and the dwarf planets to the greater extent ) orbit the centre of the solar system on a flat (ish) plane. I cannot see any reason why the planets cannot orbit on seperate planes that are at odds to each other.


I know the planets formed from a rotating cloud and thus they orbit in the same direction, but in this formation of collisions between rocks to form the planets etc I would expect the planets to have taken on there own orbits. And why do gas clouds  rotate on a plane anyway, I know the sun has poles like the earth so i suppose the gas cloud could be polar or charged, leading to a  turbulance ignition etc.



 Galaxies orbit a black hole which unless i am very much mistaken ARE on a plane so cold be shooting ou sideways gravity, or something like that. Does the sun behave in a similar way to a black hole

the different parts of galaxies actually orbit the combined mass closer to the center then they are. Even though there are super-massive black holes located at the center, they are only a small contributor to this mass.  For example, the black hole at the center of our galaxy makes up only about 1/186000 of the mass of the galaxy.  If it were "shooting out sideways gravity" the effect would be the strongest nearest the black hole, In fact, we see the opposite, the center of the galaxy consists of a spherical bulge with stars orbiting along various planes. We have even mapped a number of stars that orbit close to the black hole, and they do not share a common orbital plane

Newtons gravity would say that they have been brought into allignment over many billions of years from the formation of the solar system to achieve equilibrium.


Einstiens relativity im not to sure about given that  everything is travelling in a straight line.


But given the moon  orbits the earth   at various angles along with the satalites of other planets not being perfect,and the planets orbits are elipses, it doesnt seem that gravitational force alone would account for this, and why there isnt a screwball planet that orbits at a completley different angle given it was in an accident when it was in it infancy.

By the time the planets started forming, the cloud from which they formed had already taken a disk-like shape.   Any other large bodies forming at the same time that could have possibly collided with an early planet would have been orbiting close to the same plane as the planet.  The collision would have resulted in an orbital change that would have left it still orbiting in much the same plane.    Uranus may have been involved in some type of event in its past, as its axial tilt and the orbits of its moon's are close to 90 degrees from what you would expect.  That event tipped Uranus "on its side" but obviously had little effect on its orbital inclination.

[Petrochemicals (OP)]

Well the point around uranus is the thing that gives rise to disquiet, why if it has been hit that badly why is it still in aproximate consensus with the solar plane. And the moon being at a strange solar neutral inclination and not a planitary neutral inclination orbit at a short distance . And why the moon has not been coopted into earth like the other matter in the vacinity of earth. And why some moons orbit planets on the solar inclination  and some on the planitary polar inclination.

It seems like cenrtepedal action of the disc is is still under way, anlost a rectifying force,but the planets singularly would not account for this. Solar tides seem like a good explination, or the bulge in the centre of the sun making the gravitational maximum at its equator and thus the solar system orbital plane. If its good enough for moons qround planets it should be good enough for planets around the sun ?

[evan_au]

I know the planets formed from a rotating cloud and thus they orbit in the same direction,

If we start with a cool, 3D cloud of dust and gas, gravity can bring it together to form a 2D (flat) protoplanetary disk, shaped a bit like a fried egg, where the central bulge contains the protostar (see images at the link below).
Initially, movement of gas within the 3D cloud is random, but as random molecules and specks of dust collide with each other, this interacting part of the cloud takes on the average angular momentum of the gas and dust making up the protoplanetary disk. When angular momentums cancel to near-zero, matter falls into the central protostar. This is why the protostar has most of the mass.


Any gas or dust moving in a very different plane will collide with the majority of the protoplanetary disk, and take on the plane of the majority of the dust and gas.

A large, cool dust cloud with a mass a thousand or a million times the mass of the Sun will have many non-interacting regions each forming their own protoplanetray disks at a similar time. Each disk takes on the average angular momentum of its small part of the cloud, so there is random orientation of the protoplanetary disks even within the same gas cloud. 
See: https://en.wikipedia.org/wiki/Protoplanetary_disk

Newtons gravity would say that they have been brought into alignment over many billions of years from the formation of the solar system to achieve equilibrium.

Astronomers find that protoplanetary disks can form quite quickly in the life of a star (perhaps 100,000 years), and be dispersed by violent stellar winds in 1-10million years after the star ignites.
So it doesn't take billions of years. The upcoming James Webb infra-red telescope will be able to peer deep into these dust clouds, and should give us a much better idea of how quickly these regions form.

I cannot see any reason why the planets cannot orbit on separate planes that are at odds to each other.

Any planets forming out of the same protoplanetary disk will form in the same plane (ie more strongly constrained than just rotating in the same general direction).
However, there is a large region between the forming protostars where the matter was less dense, and did not form a protoplanetary disk. We see the remains of this in the Oort cloud, which is thought to surround the Sun in all directions, not confined to the solar system disk.
If an object from the Oort Cloud (or a planet ejected from another planetary system) came into our Solar system, it could come in at a random angle, and could cause an impact that turned a planet on its side, or be captured as an outer moon of a planet, in a randomly-oriented orbital plane.
See: https://en.wikipedia.org/wiki/Oort_cloud

Galaxies orbit a black hole which unless i am very much mistaken ARE on a plane

Spiral galaxies like our own Milky Way are also shaped like a fried egg, with much of the matter in a flat plane; the central bulge contains the massive black hole at the heart of the galaxy. This probably forms a flat disk because of similar mechanisms to the protoplanetary disk, where colisions cause it to take on the average angular momentum of the total.

There are other galaxy types like elliptical galaxies, where the stars are oriented in random directions, with no obvious plane. Some astronomers think that elliptical galaxies may form from the merger of two spiral galaxies, which would cause stars to be thrown into a variety of trajectories, especially in the region surrounding the massive black holes at the center of the two galaxies.
Over time, the two black holes approach each other, leaving a smaller disturbed region around them - perhaps our own galactic bulge is the remainder of a previous galactic merger?
See: https://en.wikipedia.org/wiki/Galaxy_morphological_classification

Does the sun behave in a similar way to a black hole?

The Sun (or any protostar) forms at the center of mass of a protoplanetary disk.
A supermassive black hole forms at the center of mass of a galactic disk.
So in this sense they are similar.

so cold be shooting ou sideways gravity, or something like that.

As far as we know, the gravitational well of a mass extends radially out from the mass (the same in every direction).
There is a relativistic "frame dragging effect" close to the event horizon of a black hole, which would affect the motion of an accretion disk of a black hole, but this is not enough to affect the growth of a protoplanetary disk (the protostar is too light to cause significant frame dragging), or the overall structure of a galaxy (far outside the accretion disk of the central black hole).