Some conceptual theories about gravity and the big bang.

[TheDarkImmortal]

So, I'm sure that somewhere out there, these things have been discussed, possibly on this very forum. But if you've read my intro, you already know I'm not the most educated person. And try as I might, a Google search just won't take me in the right direction.

We all know how a solar system is formed. My basic view is this: Dust clouds condensing. Micro-gravity begins to pull individual dust particles together, slamming together, and eventually beginning to spin, the first puzzle pieces of what will become solar rotation. The place with the highest concentration of dust and other atoms slowly start to form a basic structure with its own gravity well, all the while pulling in more and more dust. After what ever amount of time (millions or billions of years? I just don't know.) there is enough mass, pressure, and force on the insides of the ball to kickstart fusion. The star is born.

All the while, though, before the star is finished forming, the dust and other atoms farther away from the center have been doing the same thing. Gravity has pulled them together as well, beginning the creation of astroids, planets, moons, what have you. During the creation of these objects, the forces applied upon them from the central gravity well, that of the forming star, has begun to spin the entire cloud; all the dust, and the objects they have begun to form, start to spin. The dust continues to collect among itself, with certain areas becoming larger faster. These largest pockets eventually become planets, and then catch other concentrations within their own wells, giving us moons. With in certain places, were the dust was not as thick to begin with, you get the formation of smaller objects such as astroids, which then smash into each other, sometimes fusing into larger objects, sometimes ripping each other apart.

Eventually, all the dust is consumed, and we are left with what our solar system looks like today. My multi-part question starts with this: What if the process isn't done? We like to think of the orbits in our solar system as stable - the opposing forces of gravity and centrifugal force keep us in a steady orbit at a nice, comfy distance from the sun. But what if that's not so true? What if, over many billions of years, long after our sun has gone red giant (or worse by that point), the planets and other remaining debris are still being pulled into its gravity? The bodies of the solar system now act as the dust did in the formation of the system, just on a much larger and slower scale.

Now, lets take a step out even farther. Picture all the dust in the early points of the creation of a system. Really picture it, and visualize it your minds eye. Now, replace that dust with STARS. I've always found it odd that the Milky Way resembles a young solar system, in terms of it's shape. What if the same physical processes that form solar systems is EXACTLY the same as what is happening in spiral galaxies? Again, just on a much, MUCH grander scale and longer timeline? What if the billions of stars in our region of space are slowing pulling themselves together, through their own gravity, to create "superstars", like Canis Majoris, much the same way bits of debris were pulled together to create Earth? And if this could truly be the case, what is being formed within the super-massive at the center of our galaxy, which, by my theory, would eventually "eat" the entire galaxy?

Now, lets flash forward so many years, we don't even have a name for the number, or a concept of it. This process has happened all throughout the universe. So much time has passed, that almost all matter has been pulled into these super-massives, which now contain the mass and matter of entire galaxies. They have such a strong amount of gravity, they have begun to exhort this force on each other, across billions of light years. Now, with nothing remaining but black holes, the singularities themselves have begun to attract, and the process starts all over. They spin and collide, sometimes fusing, and sometimes destroying themselves, but eventually becoming one ultra-massive collection of all known energy and matter in the universe. And under such great forces that would been seen here, much like the starting of the fusion in a star, it finally explodes. Big Bang.

So... just the thoughts of an undereducated, wannabe scientist. Thoughts? Discuss.

[Folkert]

Not all gas clouds condense, it depends on total mass and temperature (= speed of the individual particles). A gas cloud must surpass the so-called Jeans-mass to condense, I.e be heavy and cold. If a cloud is in equilibrium of gravity and kinetic energy it is called a viralized system, and is, as said, in equilibrium, it will neither contract nor disintegrate. Globular star clusters and elliptical galaxies are often assumed to be viralized systems.

The galaxy as a whole is more complex than that: on a grand scale we have gravity pulling all mass (and space) together, but dark energy ( or the Cosmological Constant) pushing it apart. Current understanding is that the Cosmological Constant is winning, and the universe is expanding at an excellerated pace. So the universe will probably end up as a sat empty space.

What this dark energy is exactly we don't know for now. But it's effects are clearly measured, and the cosmological theories have a place for it. Work is ongoing to understand what it is. Fascinating stuff!

[Capricorn]

We all know how a solar system is formed

Not quite correct, we have an idea of how it is formed, but there are probably 3 or 4 theories, one might be predomionent at the moment but could be incorrect in the future.

During the creation of these objects, the forces applied upon them from the central gravity well, that of the forming star, has begun to spin the entire cloud

The central star does not supply the force to spin the cloud, the central star is simply a mass with gravity, That gravity is pulling towards the centre of itself not at a tangent to it. Actually the cloud is the source of the spin.

What if the process isn't done?

Of course the process isn't done, we are only 13.5ish billion years through the process and have many times that yet to go.

The question is What is the process?

One basic problem is that the amount of matter is whatever it is and waiting several hundred billions of years will not make any difference (actually it is decreasing as stars fuse and masss is converted to energy), so if it was going to form one big mass then it has no reason not to have formed one now. As gravitational force gets weaker as distance increases then these attractive forces are stronger now then they will be in a seconds time and a second after that and so on. They will not get greater in the future but lessen.

The milky way does not resemble a solar system, have a look at the structure of the two, any arms of the solar system? Also have a look at Galaxyzoo, there are more eliptical galaxies then spiral ones and they have less resemblance to the solar system.

the singularities themselves have begun to attract

They are attracting now, gravity does not switch on and off as time progresses, and as they are closer now then they will be in the future - expansion of the universe - the attractive forces are stonger now then in the future.

Two black holes colliding do not destroy themselves. 2 cars crashing ends up as lots of bits of 2 cars but the mess is the same weight/mass as the 2 original cars. 2 black holes will not even make bits they will simply form one bigger black hole.

So... just the thoughts of an undereducated, wannabe scientist. Thoughts? Discuss.

Become an educated scientist.

Oh yes: A google search will take you there.

[ollypenrice]

There are interesting differences between galaxies and solar systems. One of the strange things about galaxies is that the outer stars and the inner stars have about the same orbital velocities, whereas the outer planets have slower orbital velocities than the inner. So the two systems behave very differently. You could Google The Density Wave Theory to find out more about how galaxies rotate.

When, in around 5 billion years, the sun goes red giant and then white dwarf with planetary nebula, the fate of the planets is not clear. If the sun loses a lot of mass in its late unstable stages then the planets may move onto wider orbits. Mass loss is not well understood at the moment so this is an area of doubt.

Olly