The above image explains the start of the universe with the big bang and what major events happened in the universe and what resulted in shaping of the universe. This image is a bit explanatory but it doesn’t give much information about how our solar system, the earth, the moon and especially we came into existence. Let’s take a dive into the timeline of cosmos from Big Bang to Humans.

The Big Bang Theory is the leading explanation about how the universe began. At its simplest, it says the universe as we know it started with a small singularity, then inflated over the next 13.5 billion years to the cosmos that we know today. And the universe is still expanding at a much faster rate and the rate at which it is expanding is increasing with the passage of time. The matter won’t even exist at this time when the bang happened, not even atoms as we know the building blocks of matter.

It is speculated that all the matter that we see around, stars, planets, black holes, galaxies were all fit inside a dimensional less place called Primeval Atom. We still don’t know what triggered the big bang but it is assumed that at some point the heat inside got out of control and it exploded with a Big Bang and all the matter was thrown out in all directions. Within a fraction of seconds the universe cooled down and expanded by a factor of 10^78. Here we will “consider “T” as the time when the Big Bang happened and all the time duration will be relative to this time“. 

Let’s take a dive into the timeline of cosmos from Big Bang to Humans.

T + 1 second – Fundamental particles were created such as quarks, electrons, protons and neutrinos were created and as the universe got further cooled down the fundamental forces came into existence: Gravity, Strong nuclear force, weak nuclear force and electromagnetic force.

T + 3 minutes – Protons and neutrons began to come together to form the nuclei of simple elements. The temperature of the universe was still incredibly high at about 10^9 Kelvin.

T + 10,000 years – Radiation dominated the universe. During this time, the expansion of the Universe was dominated by the effects of radiation or high-speed particles (at high energies, all particles behave like radiation). The lepton era and the hadron era are both subdivisions of the radiation era. The radiation era was followed by the matter era, during which slow-moving particles dominated the expansion of the Universe.

T + 24,000 years – Matter dominated the universe. For the first time there was more matter than energy in the universe.

T + 380,000 years – The temperature of the universe had cooled to about 3000 K. Electrons began to combine with hydrogen and helium nuclei.

T + 1,000,000,000 years – The pull of gravity began to amplify irregularities in the gas in the universe. As the universe expanded, pockets of gas became denser and stars began to ignite. Group of these stars formed galaxies.

T + 3,000,000,000 years – Many small galaxies merged to form larger ones. Often these mergers were so violent that the stars and gas collapsed and formed black holes. The gas flowing into these black holes became hot and glowed brightly before it disappeared into these black holes. This light was bright enough that it can be seen across the universe. These bright lights are called quasars.

T + 6,000,000,000 years – Supernova explosions created the heavier elements such as Nickel, Gold, Silver and lead in the universe.

T + 8,000,000,000 years – Our Solar system began from a dust cloud. Our Sun was about to start its first nuclear reaction in its core and rise in the arm of the spiral galaxy – Milky Way.

T + 9,200,000,000 years – The cluster of gases revolving around the sun turned into planets due to gravity interacting within each other. And our Earth started its first step towards its formation.

T + 9,700,000,000 years – Moon took its crown in the Night sky.

T + 10,300,000,000 years – Water formed on Earth due to the chemical reaction process of the planets and asteroids which were bombarding on earth for millions of years.

T + 10,500,000,000 years – Life took its first breath as a single cellular organism in the vast oceans of Earth.

T + 10,700,000,000 years – Photosynthesis process started and we all know what’s in future now.

T + 11,000,000,00 years – Atmosphere of Earth got filled with Oxygen and now life is ready to take its first breath on land and will leave water.

T + 12,300,000,00 years – Life evolved from single cellular life to multicellular. Now life has a body which is controlled by multiple cells inside them.

T + 13,100,000,000 years – Over the course of millions of years Evolution worked on multicellular organism and first vertebrate and land animals appeared

T + 13,300,000,000 years  – First non-avian dinosaur appeared

T + 13,435,000,000 years  – The great impact happened and all the dinosaurs got wiped from Earth but life still remain intact inside the ground.

T + 13,498,000,000 years  – Evolution again worked on the rest of the mammals and the first human look alike took its step on earth.

T + 13,500,000,000 years  – Right Now!!!

And this is how space, time and us came into existence.