A whooping 7.9 billion people, 8.7 million discovered eukaryotic species and an estimated 1 trillion microbes- How did it all came into being? How did our Earth or even better, the solar system or the whole universe came into being?
So, it all began about 13.8 billion years ago. There existed a single point, a minute, hot and really dense point which violently exploded-‘The Big Bang’, and it is how everything came into being- Matter, Energy space, universe, stars, solar system, me, you-everything. After the explosion took place, it expanded into what we today call the universe. And, what’s more interesting is the fact that it is still expanding, and this is how the scientists came to believe that it all began with a big bang.
Scientists divide the period after the big bang into 2 era-
- Radiation era
- Matter era
The period between 10^(-43) seconds (after the explosion took place)-the Planck era(here, the current laws of physics do not apply), to about 30,000 years after the big bang is referred to as the radiation era. During this period, the temperature of the atmosphere was soo high that there was no distinction between matter and radiation ,or even better, no matter existed.
It is divided into 7 era or epoch-
- Grand unification epoch- Named for the unification of 3 grand forces of nature- Electro-magnetic forces, Weak forces, Strong nuclear forces. With a temperature greater than 1029 K, it began 10−43 s after the big bang. At the end of this epoch, the strong nuclear force broke away from the other two.
- Inflationary epoch- With a temperature greater than 1032 K, it began 10−36 s after the big bang. As the name suggests, the universe rapidly expanded in this epoch. The universe, ta this time had electrons, quarks and antiquarks.
- Electroweak epoch- Here, now all the 4 forces of nature have split off. Temperature- 10^20 K and time after big bang- 10^(-32)s.
- Quark epoch- Temperature here is 10^16K and 10^-12 s have passed since the big bang. All of the ingredients required to form subatomic particles were present but the universe still was too hot and dense.
- Hadron Epoch- Temperature- 10^10 K and Temperature-10^-6 s. The universe has not finally cooled down enough for subatomic particles to form and hence, quarks bind to form protons and neutrons.
- Lepton epoch- Temperature- 10^ 12 K and finally, about1 sec have passed since the big bang.
- Nuclear epoch- Temperature-10^9 K and 100 s approximately have passed since the big bang.
In these last two epoch, when the universe has cooled down quite a lot, the protons and neutrons fuse together to form the very first chemical elements- Hydrogen and Helium. And now that our universe is capable of forming elements, it brings us to the end of radiation era and the matter era begins.
Matter era includes 3 epoch that spread over billions of years and include the formation of our galaxy, solar system and even the present day.
- Atomic epoch- With the temperature of 3000 K and time after big bang- 50,000 years, this epic marks the beginning of attachment of electrons to nuclei. This process is known as recombination.
- Galactic epoch- Now, 200 million years have passed since the formation of our universe. With the ability of universe to now form Hydrogen and Helium molecules, the universe is dotted with atomic clouds. Within the clouds, due to gravity, clusters were formed which later led to the formation of galaxies.
- Stellar epoch- 3 billion years have now passed. Within those clusters of clouds, now stars will be formed. Stars begin their lives as proto-stars. These are formed as a result of gravitational forces between particles of dust and gas and heat is generated due to friction and collision. When the proto-star becomes extremely hot, the process of thermonuclear fusion starts taking place. This is how stars generate heat and electricity. This heat within the clouds convert the already exiting elements into all others that are currently known to humankind. When stars burn themselves and are destroyed in explosion know as supernova, it destabilizes the heat cloud, which then begins to rearrange itself in the shape of a flattened disc. At the center a proto-star forms (eg.- our sun). The clumps of dust are flash heated and form chrondules that later from planetesimals by cohesion. These planetesimals then, later accrete to form what we call today as planets.
And this is how our solar system was formed about 4.5 billion years ago. It is located in the Milky Way galaxy’s Orion Star Cluster and has about 8 planets with a total of 63 moons. The inner 4 planets (also known as terrestrial planets) are separated form the outer 4(also known as jovian planets) by a belt of asteroids. Terrestrial planets are known as such because they are made of rocky material, have solid surface, do nor have rings and are relatively small. Earth, among these, is the only one to have a moon.
The jovian planets, on the other hand, have multiple moons, support ring system, have no solid surface and are immense in size. The Oort Cloud, a collection of icy debris, marks the edge of our solar system as the gravitational and physical influence of sun diminishes .
This is how our solar system and our Earth were formed. Now, can our solar system end? If yes, then how and by when? It’s a question for a later time.