Why does the Earth have layers?

Despite our advanced technology, we have only managed to penetrate one-third of Earth's crust. This leads us to question whether it is solid, liquid or hollow. Nevertheless, Earth has a rare tendency to tremble violently and sometimes erupt its inner contents; this phenomenon has given scholars ample insights about the planet's internal organs without physically exploring them.

We are familiar with the concept of density. This is why the atmosphere, which is the least dense part of our planet, can be found on its outer layer while Earth's second least dense portion -the crust- lies beneath us. Due to my lower density compared to dirt, I remain afloat and do not sink into it even though there may be around one ton of atmospheric pressure exerted above me.

Geologists classify the main layers of Earth in a similar manner based on their composition or plasticity. These varying characteristics give rise to different nomenclatures for each layer. To comprehend why such an arrangement exists, we must delve into our planet's preexistence.

They compacted and transformed into stars, initiated the nuclear fusion cycle, and later perished by expelling heavier components. These included carbon, oxygen as well as trinkets such as nickel and gold that dispersed throughout the cosmos. One of these weighty elements is iron which epitomizes constancy among those born beyond supernovas. The primordial sphere engendered a substantial amount of this element whose relevance shall become apparent in a moment.

New stars similar to our sun were created from fresh hydrogen and helium, while the heavier elements fused together to produce dust and fragments that later evolved into planets, moons, asteroids as well as other celestial bodies in our solar system. The initial hot temperatures within the inner region of the solar system led light volatile components only able to diminish further outwards resulting in four dense rocky planets closest towards us whereas farther gas giants like Saturn could potentially float if placed within a spacious swimming pool.

As proto-Earth expanded in size, a combination of radioactivity, gravity and explosive activity caused the jumbled assortment of rocks and minerals to melt. This marked the beginning of an organized process as denser materials such as iron and nickel settled towards the core while lighter ones like silicon and aluminum remained closer to its surface.

With pressure levels exceeding three million times that which we experience on Earth's upper layer, temperatures at our planet’s inner sphere are equivalent to those found on the sun's surface; however it is likely made up of solid iron instead of liquid matter.

In contrast with this intense environment lies an outer core most likely composed entirely out-of-liquid due only being heated so much by comparison. Evidence supporting this hypothesis originates from seismic disturbance data collected through earthquake readings where specific recurring patterns helped determine multiple sections blocked or refracted certain kinds waves depending their internal compositionality differences toward them unlike others emitting similar types across entire superficial expanse played observed differently leading studies believing into conclusions these different layers must be situated somewhere else within depths below us!

To melt metal using pressure at home, simply collect 16 million pennies and stack them up. The penny on the bottom should liquefy quickly! While Mercury lost its atmosphere due to proximity with the sun, Earth's liquid outer core creates deep metallic convection currents that produce a magnetic field shielding us from solar wind. This keeps our atmosphere intact and Earth hospitable for life. However, as we continue cooling over time, more of our liquid outer core solidifies making us slightly smaller each year - earthquakes being indicators of this process. As Carl Sagan has expressed: "We are star stuff who has taken density into [our] own hands". So let's embrace curiosity along with an accurate understanding of science – "I'm your destiny!".