Big Bang, Solar System Formation and Earth's Structure

Big Bang Theory

Big bang theory:

1. Both matter and energy in space were concentrated in one point called the primeval atom, whose density and temperature must have been very high.
2. The primordial atom then expanded rapidly in a large explosion or "Big Bang" and began the expansion that generated the universe.
3. Subatomic particles formed first, and later the simplest atoms, hydrogen and then helium, were produced.
4. Temperatures fell and then formed the nebulae, galaxies, stars, planets, etc. In the stars chemical processes created the elements.

The elements appeared and different planets of the solar system formed: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Formation of the Solar System

On the formation of the solar system: The Sun and the planets revolve in the same direction. Planets travel in nearly circular orbits and are located in approximately the same plane. The rotational movement of most planets occurs in the same direction as their revolution. Planets near the Sun are small and dense; those at the outer regions are large and low in density. All show evidence of large planetary impacts.

Planetesimal theory: This theory can explain these facts and is accepted as a model for the formation of the solar system.

Historical note: The theory proposed by astronomers Carl F. von Weizsacker and Gerard Kuiper between 1944 and 1950 suggests that the solar system was formed about 4,500 million years ago from the dust and gas of a nebula located in the Milky Way.

Instruments of Observation

Instruments of observation:

• Telescopes and radio telescopes: Their use has a major limitation: Earth's atmosphere filters out different types of radiation, so these instruments can collect only partial information about the universe from the ground.
• Spacecraft and satellites: Since the start of the Space Age, satellites and space probes have been used to observe the universe and have provided much relevant information.

Indirect Observation Methods

Indirect observation methods: Measurements, laboratory tests and the study of seismic waves are indirect methods that provide data on the interior structure and composition of the Earth.

Divisions Within the Earth

Divisions within the Earth: Core, mantle and crust are the main internal layers. Within these different areas distinct regions and properties are distinguished.

Plate Tectonics

Plate tectonics:

• The Earth is divided like a jigsaw puzzle into a series of rigid pieces called lithospheric plates.
• Plates are not static; they move relative to one another, producing earthquakes, volcanic activity and the formation of mountain ranges.

Notes: Spelling, grammar and capitalization have been corrected for clarity, and names were standardized (for example, Carl F. von Weizsacker and Gerard Kuiper). All original scientific content and items have been preserved and clarified for readability.