The universe and earth and the planets began forming from nothing around 13.8 billion years ago.
Although the universe, earth and planets was not formed from literal nothing, but instead was formed from an absence of space and time.
And as space rapidly expanded and cooled, matter condensed.
Then gravity subsequently pulled the gas and dust together to form the stars, planets and the Earth we live on.
Around 13.8 billion years ago is when the universe started, where all matter, energy and space were compressed into an infinitely dense point.
Then the expansion occurred, a the universe was not an explosion in space, by instead an explosive expansion of space itself also known as the Big Bang.
And as the universe expanded and cooled, energy then converted into fundamental particles.
These particles then bonded to form the simplest elements, mostly hydrogen and helium.
The sun and the solar system began forming around 4.6 billion years ago.
The sun and solar system forming started with cloud collapse, where a massive, swirling cloud of interstellar gas and dust, which was triggered by the shockwave of a nearby exploding star, collapsed under it's own gravity.
And for the igniting of the sun, the vast majority of this material also condensed at the center and created immense pressure and heat, eventually lighting the sun.
And then finally the Earth formed around 4.5 billion years ago.
Earth forming around 4.5 billion years ago started with dust to planets, where leftover dust and debris swirling around the infant sun collided, stuck together and then gradually grew into larger bodies called planetesimals.
And for the formation of earth, these bodies collided and merged over millions of years to build the rocky, terrestrial planets.
And earth formed as a molten ball of rock and metal.
And as it cooled down, heavier elements like iron sank to the core, while lighter materials also rose to form the crust and mantle.
Earth and all the planets and even all life on earth including us humans has always fascinated me and it's really amazing and mind boggling to think about.
Even the fact that a man and a woman can have intercourse or sex and a new human can be made inside a woman's body as a result of sperm and eggs and the process that it goes through.