Yes, you. Come.
Take my hand.
Come on. Just take my hand.
Now, together we shall embark on a journey.
Ah, but don’t look at me with that face!
Yes, I know you have responsibilities, a family, a job… yes, I already know that.
But I’d like to steal just a couple of minutes of your valuable time, because this journey is VERY important.
Don’t worry. This is not your typical trip in which suitcases and all sorts of preparations are required.
Instead, it is a timeless adventure where you and I will pretend for a moment that the vastness of the universe shrinks before our eyes.
For that, we’re going to be sent back to a previous time in the cosmos, further away from the existence of space-time itself.
It will be an exhaustive and long journey. At times tedious, but without a doubt interesting.
And even though I can’t promise I have all the answers, I hope I can paint an acceptable portrait of the unknown through my words.
Are you ready?
Fine, I’ll let you accommodate yourself. Sat in the best couch found at your home, with cookies and milk on the side.
Are you ready now?
Follow me then to the start of our incredible story.
In the beginning, around 13.8 billion years ago, all of the space, matter and energy of the known universe was condensed within a volume less than a trillionth the size of the point of a pin.
The universe was in a state of incredibly high heat and density. Only the four fundamental forces prevailed in space, unified among themselves.
But for reasons unknown, something special was about to happen: a singularity that allowed the expansion of the universe and gave rise to space-time.
At this time, our conceptions of physics hold no importance for the youth of the cosmos.
Black holes are generated spontaneously in a constant cycle of destruction and creation due to the energy concentrated in the unified field. These holes severely curve the fabric of space-time.
On the other hand, the universe began to cool itself down, allowing the separation of the first force: gravity.
Next, the nuclear strong and nuclear weak forces decided to part ways, causing the growth of the universe and the acceleration of its expansion.
But the universe remained sufficiently hot so as to allow photons to form particles of matter and antimatter in equal pairs. And these couples would annihilate each other immediately, returning their energy to the photons.
But for reasons unknown, after a certain time, the symmetry in which these pairs were generated was broken and, for every billion particles of antimatter, a billion plus one particles of matter were produced.
And while this might seem like a small asymmetry, this fact is incredibly important for the future of the universe.
It would be thereafter that the weak nuclear force and electromagnetism would separate from each other thanks to the continuous cosmic freezing. In the wake of this, the photons ceased to be able to create matter and antimatter. The remaining particles could only destroy themselves.
But given their previous asymmetry, the universe conserved certain particles of matter in a ratio of 1 per every billion photons. Had this event not occurred, the expanding universe would only be composed of light.
At the end of the annihilation, matter joins itself through protons and neutrons, forming the primitive atomic nuclei.
Afterwards, electrons would join these primordial particles, giving origin to the atoms of the first elements: hydrogen, helium and lithium.
During its first billion years, the universe continued its expansion and cooling, causing the atomic matter to come together in groups.
It would be these groups the ones that would constitute the first galaxies, where the initial massive stars emerged.
Said stars would incur thermonuclear fusion at their cores, reaching the necessary pressure levels for the manufacture of the distinct kinds of elements.
And it was propitious for these stars to eventually explode, sprinkling their elemental richness throughout the cosmos. The spreading of these elements, in turn, induced the appearance of planets and the rest of celestial bodies. It was here that life finally became a possibility.
After 7 or 8 billion years of cosmic enrichment, a star would emerge. Not an imposing or prominent star, but one that is fundamental to this narrative.
Its beginnings would be humble in a faraway galaxy, situated at the outskirts of the Virgo galactic supercluster. Our star’s galaxy would be baptised as the Milky Way millions of years later when a couple of apes thought its appearance was similar to that of spilt milk.
Continuing thus with the story of our star, it was born from the gravitational collapse of a colossal molecular cloud and the coupling of part of its mass to its centre. Although at this time our stellar friend would not have the shape in which we know it today.
The rest of its surrounding mass became the primitive disks that would give rise to a fine set of protoplanets.
Soon enough the star would evolve, positioning itself as the object with the greatest gravitational force of the system that was in formation. And it was called Sun; a small tribute to a then nonexistent Latin past.
Shortly thereafter, larger fragments of dust and debris would come together with the remaining protoplanetary mass to give rise to the properly established planets.
It would be in this way that our home, affectionately called Earth, would come into form 4.54 billion years ago; reaching its current state between 10 to 20 million years later.
The proto-Earth grew by accretion until its interior was hot enough to melt heavy metals and siderophiles. Having densities higher than silicates, these metals sank.
As a result, the separation of a primitive mantle and a metallic core occurred, generating the layered structure of the Earth and establishing its magnetic field. A time best known as the first terrestrial aeon, the Hadean.
Shortly after the formation of this initial crust, a smaller protoplanet impacted with the proto-Earth.
This collision forced the Earth to send into outer space parts of its crust and mantle, creating in the process a new celestial object: the Moon.
But the difficulties would not end here for our young planet. This collapse was followed by a great bombardment of meteorites and severe volcanic activity happening throughout the planet.
The only fatality-free aspect of this era is the possible presence of the first great bodies of water on land.
It was then that the Earth’s primitive crust, formed during the first solidification of the earth’s surface, disappeared completely. An act that occurred thanks to the movement of the first tectonic plates and the intense continuity of meteorite impacts.
Thus, this stage ended with the development of contiguous bodies of land. And, although shaped like a craton, these were undoubtedly the first continental masses.
Then comes the Archaic Eon. The Earth cooled considerably during this time, but no life forms were yet present. After all, the Earth’s atmosphere lacked oxygen as well as a protective ozone layer.
But life, so eager to exist, was not going to give up. And to its fortune, neither would the Earth.
Up next, the appearance of two different atmospheres happened, and right after their demise, the first clouds would form. And it is these clouds the ones that would give rise to the primordial oceans.
For reasons unknown, this is when living matter would emerge from the inert.
The first step in the emergence of life occurred in chemical reactions, producing many of the simplest organic compounds. The additional complexity of these initial compounds would have three starting points: self-replication, metabolism and external cell membranes.
Enter then the Proterozoic Eon.
In this period of time, cratons became what we now know as modern-sized continents. But the most important event was the change to an oxygen-rich atmosphere. A crucial fact for the development of prokaryotes and, subsequently, eukaryotes (the fertilising cells of multi-cellular life).
Although not everything would be perfect during this aeon. A couple of significant ice ages would take place; eras better known under the term Snowball Earth. Fortunately, these frozen times would not stop the continuous evolution of life on Earth’s surface.
We, therefore, enter the current aeon of our planet: the Phanerozoic, divided into three eras: the Paleozoic, the Mesozoic and the Cenozoic. And during these eras, multi-cellular life diversified extensively to produce the organisms known today.
Throughout the Paleozoic, many modern groups of living beings came into existence. Life colonised the Earth; first through the plants and then through the animals.
At the same time, two major extinctions occurred, and the Pangaea super-continent emerged.
This era was followed by the Mesozoic; an era marked by tragedy.
Its beginning occurred at the end of the Great Dying, an extinction event that caused a massive loss of terrestrial biodiversity. Nearly 95% of marine species and 70% of terrestrial vertebrate species disappeared.
The recovery of subsequent life took much longer than for any other extinction event (possibly up to 10 million years).
Sadly, this era would end as it began. A new mass extermination event took place, and it took away the live’s of the largest entities that ever roamed the Earth: the dinosaurs.
Fortunately, the animal kingdoms of mammals, birds, amphibians, and certain reptiles survived, prolonging life until the Cenozoic era.
Mammals would eventually position themselves as the most important land kingdom. But it would be a particular species of apes that would rise above all other animals and evolve to become the dominant species on the planet.
And these apes were granted, for reasons unknown, some sort of blessing and curse, a matter best known as conscience.
And it is because of this aspect that many of them ask themselves numerous questions. To some of these they have found an answer, but to the majority, they can only offer mere attempts at a response.
As the ape that I am, though I do not know how complex the universe really is, this fact does not discourage me.
It seems to me rather a reason for infinite hope, because we arose from the improbable and continue to overcome the chances of survival in a universe that was not created for us.
And so long as this faint ray of hope exists within a pale blue dot, there will also be apes; apes better known as humans; humans better known as us.
Thanks for the read. ♥
* This story was based on multiple studies, both speculative and objective, that are subject to change as we attenuate a greater understanding of the universe itself.
** The images presented here are, for the most part, artistic impressions that should not be taken as exact representations of the events recalled.