by Tony Darnell, DeepAstronomy.com
About a half a million years after the big bang, the cosmos began to cool, as it cooled, the hot subatomic particles that constituted the early universe began to slow down and stop colliding with each other long enough so that protons, neutrons and electrons could form. The universe cooled further and the hot particles slowed further still allowing these particles to stay together long enough to create atoms.
The universe was nothing but a cloud of hydrogen and helium. Slowly, the universe continued to cool and structure begins to present itself within this universal cloud. From small disturbances woven into spacetime the galaxies begin to collect, tiny variations in the primordial universe became the web that collected galaxies and gave the cosmos its form.
These galaxies become distributed along these structures, dancing within their gravitational fields, forming giant tendrils reaching out across the span of eternity.
Until just a few short decades ago, astronomers thought the universe was static and unchanging, we didn’t even know there were other galaxies until the 20th century. The heavens was a place of constancy and uniformity, the stars and planets were always there and they always would be – steady and unchanging. Instead we have learned that the cosmos is a seething cauldron of activity, as alive and vibrant as any one of us.
Stars are born, shine and explode; stellar winds blow huge storms of gas across interstellar space; black holes devour all they touch; galaxies collide with each other, spraying stars into eternity.
And spacetime itself grows larger by the minute.
The universe is far from a static place. As giant stars explode after living out their lives, they stream out the elements of life, carbon, oxygen, nitrogen, iron, all the necessary components for planets to form and for life to begin. We are more connected to the universe than we know, the stars are our ascendants, we are their progeny.