PART 1: Structure and density of Material bodies

Introduction

There are number of theories on origin of Universe, among which, the most acclaimed one across the scientific community is the Big Bang theory. The other theory which is on back foot is the theory of steady state universe. As per the Wikipedia steady state universe theory is now-obselete theory.
I'm here to propose a new hypothesis which is close to steady state but would explain the recent findings where steady state theory has failed. One example is the cosmic microwave background radiation. 

The approach I used here would be surprising for many but simple to all. This idea is built upon the basic realities observed in the real world but not based on the existing theories, at least not many. Mainly two basic realities of the world used to build this hypothesis. One is the observation of celestial bodies' spheroidal structure and the other is the  decreasing density of materials from center to outer edges of each celestial body.

Here I'm not going to take the help of Gravitational or any other concepts extensively which makes my this attempt funny. But I'm not daring to challenge them yet. This strategy is followed to shields this hypothesis from most of the harsh criticism at this early stage and at the same time one drawback is it lessens the spread of this hypothesis across intellectual masses.

Section 1: Celestial bodies and their structures

If we observe Earth’s atmosphere there are several atmospheric layers and outer layers density is lesser than inner layer’s. Figure 1 shows how density changes from center of Earth to upper atmosphere.

Fig. 1. Earth’s density structure from core to lower Exosphere. In Exosphere density falls rapidly and at the outer exosphere Earth’s atmospheric particles mix with solar wind particles

The standard definition version of the Earth's Atmosphere Layers can be seen at NASA website.
http://svs.gsfc.nasa.gov/goto?20015

Mostly our celestial bodies and their material spherical structures and densities are affected by temperatures, particles generated by chemical and nuclear reactions and Electromagnetic fields. In the absence of these three factors we may expect structures density and variations very simple.

Here we can see some of the celestial bodies with their outer boundaries

Fig.2. Earth and its outer layers can be seen in this Artistic figure of European Space Agency (ESA). 

Credit: ESA

Here ion nature of particles, Earth’s Magnetic field, Solar wind and solar magnetic field all causing the ionic layers bend and elongated the manner shown in this figure. Neutral particles layers closer to Earth’s surface can be seen near spherical as shown in Fig.1.

A NASA artist's concept of outer edges of solar system picture gives much more insight into the structure of layered solar system as shown in the following figure.

Fig.3. The Heliosphere : An artist's concept of outer edges of solar system (Not to scale). Credit: NASA/IBEX/Adler Planetarium

If we try to see the solar system in higher scale it would look like in the following picture of NASA.

Fig.4. The Solar system in the vicinity of nearby stars and interstellar clouds. The bow shock (Bow shock existence is debatable) is represented by the yellow-orange, crescent-shaped structure, and the heliosheath is the faint blue teardrop shaped/elongated spheroid area in the same image. Credit: NASA/Walt Feimer

Zooming in further makes our solar system association with other neighbouring stars more clearly in following NASA’s artistic picture.

Fig. 5. Solar system along with other stellar systems and inter stellar clouds. Credit: NASA/Goddard

These figures generated for solar system after NASA's Voyager observations. With similar observations on other stellar systems prove similar structure for those systems too.
If we see the higher structures, i.e. the Milky way Galaxy it is hard to imagine it in a spherical or spheroid form.

Fig.6. NASA artist's concept illustrates the view of the Milky Way. Our sun lies near a small, partial arm called the Orion Arm, or Orion Spur, located between the Sagittarius and Perseus arms. Credit: NASA/JPL-Caltech / R.Hurt (SSC-Caltech)
In the above picture of Milky Way Galaxy it is not be possible to visualize spherical or spheroid shells in this picture. But there is one illustration which astronomers have proposed contains the spherical shells.

Fig.7. The illustration which shows the Milky Way galaxy's inner and outer halos. 

A halo is a spherical cloud of stars surrounding a galaxy. Astronomers have proposed that the Milky Way's halo is composed of two populations of stars. The age of the stars in the inner halo, according to measurements by the Paranal Observatory, is 11.5 billion years old. The measurements suggest the inner-halo stars are younger than the outer-halo population, some of which could be 13.5 billion years old. Credit: NASA, ESA and A.Feild(STScl)

There are lot of other examples which shows lot of celestial bodies are in spherical or spheroidal shape. Some of them are given below.

Fig.8. (This explanation taken as it is from website https://www.fas.org/irp/imint/docs/rst/Sect20/A5a.html )

Apparently spherical nebula, nicknamed as the Owl Nebula (NGC 3587) for its obvious resemblance to an owl's face. Located in the Milky Way ~2000 l.y. from Earth, this nebula contains three distinct layers: a faint dark blue outer ring consisting of now dispersed gases expelled in the early stages; a medium blue middle ring driven by superwinds, and an inner light blue ring, plus a purplish central filling that represents material that has migrated inward

And one more example goes here…

Fig.9. (This explanation taken as it is from website https://www.fas.org/irp/imint/docs/rst/Sect20/A5a.html )

The full extent of ring development has been revealed in an HST ACS (Advanced Camera for Surveys) image, shown below. A number of individual spherical ring fronts are evident. Based on their distance from the Cats-Eye center and estimates of their speeds, these rings appear to be generated repeatedly at intervals averaging 1500 years, by a process still uncertain. The central Cats-Eye configuration is now believed to be a later stage in the history of this nebula.
This is all to establish the spherical or spheroid structure of the celestial bodies. Celestial bodies also have the material as layers with decreasing density from centre to outer boundaries. And these bodies also exists in a way that each and every celestial body happens to exist in a layer of bigger body. Earth in stellar system, stellar system in Galaxy and Galaxy is either in Galaxy cluster or a bigger body.

Section 2: Density variation in celestial bodies

Density of Earth sub-surface layers have been shown in Fig.1.
The density variations in earth atmosphere are shown in following figure.

Fig. 10. Earth atmosphere structure and the particle density curve. With the altitude Neutral atmospheric densities for various molecular and atomic species falls drastically compared to ionic particles. But overall density falls with altitude.

Density within Sun to varies in similar manner. Following figure depicts the same.

Fig.11. Density and temperature variation inside Sun, Credit: fas.org

Dust density distribution in solar system.

Fig.12. Dust particle density can be a measure for the density of the layers around the Sun. The Overal density is decreasing with distance from the Sun.  Credit: NASA

Density at the Core of the Sun is 150,000 kg/m³ = 150 g/cm³ ,  Density of Sun's corona is (2.0 × 10⁻¹⁷ g/cm3 or 2.0 × 10⁻¹⁷  x 10³ kg/m3 ), and it further reduces in Heleosphere.

Atomic nuclei and neutron stars is 2 × 10¹⁷ kg/m³, Observed density of space in core of galaxy is 1 × 10⁻¹⁸ kg/m³ (600 hydrogen atoms in every cubic centimetre), and Probable lowest observed density of space in galactic spiral arm is 1 × 10⁻²² kg/m³ (1 hydrogen atom every 16 cubic centimeters)  and beyond Galaxy disk it further declines. http://en.wikipedia.org/wiki/Orders_of_magnitude_(density)

Conclusion

From the above two sections we can conclude that Celestial bodies have layered structure with varying densities. And the density varies from centre to outer edges in decreasing manner.

Section 3: Behaviour of Layers with varying density

Layered nature is common feature for all celestial bodies ranging from Moon like satellites to Galaxies. Every celestial body has a dense centre and successive low density layers away from the centre. Lowest density layer is the outermost layer and most of it merges into the bigger celestial body’s equivalent density layer.

When we throw a stone in water it goes down. It doesn’t float. When we keep gasoline and water together, gasoline floats on water as they are immiscible and gasoline density is less than water density.

What happens if we lower a small heavy beaker with oil and water in it into a bigger beaker with same liquids?

Fig. 3.1. Through (a) to (c) beaker models it is explained how a less dense material leaves its native place making way for its denser materials to move further

Less dense liquid leaves the small beaker and mix with the same liquid in the big beaker and the small beaker pass down as high dense liquid replaces the low dense liquid.

The same scenario is applicable when a small planet with atmospheric layers is injected into the atmosphere of the big planet. The layers of gases merge with the same dense layers of the big planet one by one on passing to the respective layers.  This process goes on until the central mass of the small planet lands on the surface of the big planet, or until the center of the small planet merges into the same dense layer of the big planet.

In an ideal scenario where these above mentioned two bodies happen to be with only gases and/or liquids, the small planet travel towards the centre of the big planet until it’s all layers mix with that of the same materials one by one and its central part merges with the bigger planet. Same is shown in following figure with two Earth and Moon like celestial bodies with similar density layers coming together. Through a to e stages moon C loses all its materials into the layers of planet M and merges with planet M.

Fig.3.2. Planet M and moon C are having same number of layers with similar densities. Stages a through e moon C loses its layers into similar layers of the planet M or in other way Planet M consumes all layers of moon C one by one.

The logic of ‘lower density outer layers of moon C merge with the same density layer of the  planet M while C passing through the layers of M to its centre can be expanded further to make following conclusions.

1. 1.      If a sub moon or 2^nd order moon c’ happens to exist in outer layer of moon C, while C passing towards the centre of M, c’ leaves C and along with its outer layer and merges into the planet M’s outer layer.
   2.      c’ can still exist inside C space provided c’ gives up its outer layer too to M space.

For more look into Part 2.

Reference:

1. http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry57.html

2. http://www.universetoday.com/40451/exosphere/

3. http://en.wikipedia.org/wiki/Orders_of_magnitude_(density) 

4. http://sci.esa.int/cluster/40994-cluster-reveals-the-reformation-of-the-earth-s-bow-shock/ 

5. http://www.ibex.swri.edu/planetaria/IBEX_lithograph.pdf 

6. http://www.spaceflightnow.com/news/n0311/05voyager/ 

7. http://www.nasa.gov/centers/goddard/images/content/96465main_galaxy3_lg_web.jpg