Everything So Far Summarized
This post is for those of you who like to zoom out and put things into perspective. We now know the answer to the question that gave rise to all the creation myths of the past: Where do we come from? And the real thing is a lot weirder than expected.
In this post, we’ll go through the story of everything in a way that allow us to wrap our heads around the ridiculous amount of time involved. It’s been nothing less than 13.8 billion years since our universe began, but since numbers like this are hard to visualize, we’ll scale it all down to just one calendar year, and get what is known as the Cosmic Calendar.
In the following chapters, we’ll visit each month of the Cosmic Calendar and discover the epic series of events that eventually lead to this very moment. Before we get going, here’s a cheat sheet for how to move between calendar time and real-time:
- 1 year ~ 13.8 billion years (age of our universe)
- 1 month ~ 1.2 billion years
- 1 week ~ 265 million years
- 1 day ~ 38 million years
- 1 hour ~ 1.6 million years
- 1 minute ~ 26 thousand years
- 1 second ~ 437 years
We start with the Big Bang on January 1st at 00:00 AM. The universe was smaller than an atom, and with everything squeezed into such a tiny space, you can imagine it being pretty hot and dense. A soup of subatomic particles was all there was, but the universe wasn’t in a mood to stay like this.
Less than a nanosecond later, the Cosmic Inflation kicked in — an event in which the universe increased in size by an unfathomable amount. With the newfound space, everything got a lot cooler. Particles could now stick to each other without being torn apart by the intense heat, and like drops of water in a rain cloud, the first atoms appeared. This happened about 5 minutes (real-time) after the Big Bang.
380,000 years later (which is about 15 minutes on our Cosmic Calendar) our universe had grown to a size where the fog of particles was clear enough for light to travel freely. The universe was now transparent, and some of the photons freed by this event are still visible today. We call it the Cosmic Background Radiation, and it looks something like this:
On January 4th, the first stars appeared, and on January 22nd, the stars had formed the first galaxies. At the end of January, the universe looked a lot like it does today, except for the galaxies being packed closer back then.
February, March, April, May, June, July, and August
I originally intended to accommodate one chapter per month, but that didn’t work out since almost nothing concerning us happened during the next seven months. In fact, only two things worth noting happened:
- On March 16th, the Milky Way appeared. It had no spiraling arms like today but looked more like a big blob of stars bound by gravity.
- About two months later on May 12th, the Milky Way had taken the iconic spirally disc shape it still has today.
And that’s pretty much it. Remember, this is an 8 billion year period in which countless civilizations might have risen and fallen. We can get an idea of what the universe was up to in this period using computer simulations such as the one below.
With this in mind, we set our focus on a very special star that appeared in the following month.
On September 2nd we finally got our Sun. An older star had exploded into a cloud of debris, and the solar system appeared when some of this debris collapsed in on itself under the pull of gravity.
The Sun ended up eating 99.8% of the mass in our solar system, while the last 0.2% were split among the planets like so:
- Jupiter: 71%
- Saturn: 21%
- Uranus: 3%
- Neptune: 3%
- Earth: 0.2%
- Venus: 0.2%
- Mars: 0.02%
- Mercury: 0.01%
Most of the planets, including Earth, were there at the end of September 2nd, and our moon is thought to have formed around the same time from the debris of a massive collision between Earth and a Mars-sized object.
Earth was a hellish place and kept being so due to a heavy bombardment of asteroids until things finally cooled off on September 14th. Oceans formed and the scene was set for a very special chemical reaction now known as life.
We don’t know the details of how life started, but blobs of matter were kicking around somewhere between September 14th and September 21st. These were simple life forms — so-called prokaryotes. They were single-celled and lacked the clever machinery found in modern cells, but they were alive, and evolution was hard at work on improving them.
Take a moment to recognize that the kinds of microbes we are talking about here are not the ones you wash your hands to get rid of — they are your ancestors. They withstood the struggles of life and managed to reproduce so that we can exist today. There is an unbroken line of descent connecting you to these little guys, which to me is nothing short of amazing.
For life to persevere it needed energy, and the microbes of early Earth had two methods of obtaining it. They either got it directly from chemical reactions (chemosynthesis) or they stole it from other microbes by eating them. On September 30th a third method was found. Microbes began using sunlight to fuel their growth (photosynthesis), which would later prove to be an important source of energy for life on Earth.
With so much happening in September, you would expect at least as much from the following month, but life remained single-celled for the entirety of October. Recall that a month on our Cosmic Calendar is 1.1 billion years, so what was evolution doing all this time? The answer seems to be: laying the foundations of complex life.
We might think of cells as simple blocks of life making up much more complex structures like us, but that’s not quite the case. What you see below is a realistic depiction of the assembly line that is currently copying your DNA inside your cells:
This is an unbelievable piece of machinery, which looks to have required millions of years of evolutionary tinkering. It is mechanisms like these that help explain why life had to remain single-celled for so long.
On October 29th a mutation caused some microbes to produce oxygen as a byproduct of their photosynthesis — much like plants do today. This marked the first time oxygen was introduced to our atmosphere, and because it was toxic to almost every living thing at that time, it led to a mass extinction known as the Oxygen Catastrophe. As unfortunate as that was, we now know that oxygen would later be of great use to most of life on Earth.
With an atmosphere now partly made of oxygen and most of life extinct, we move on to November.
You may be surprised to hear that life remained single-celled for yet another month to come.
On November 9th some of the cells had developed a range of highly complex organs (called organelles) and their DNA was enclosed in a central container (called the nucleus). Today we call these complex cells eukaryotes, and colonies of these can form some pretty spectacular things. In fact, every form of life visible to the naked eye is a colony of eukaryotes — you and I included.
The complexity of eukaryotes is mind-boggling, and it’s no wonder they required over 2 billion years of evolution to appear. Take for instance the signaling system that is partly responsible for splitting the cell in two when it is time to duplicate. What you see below are proteins walking across fibers of protein while carrying other proteins.
With the added complexity it was time for life to diversify, and somewhere around November 20th the tree of life split into three important branches; one for plants, one for fungi, and one for us, the animals.
With only one month left it was time to kick evolution into high gear.
On December 5th the first multicellular life appeared. By grouping up, the cells were able to perform specialized tasks. Some formed a protective layer on the outside, while others broke down nutrients on the inside.
On December 14th the state-of-the-art organism looked like a coral. Some of them floated freely as juveniles but were attached to the ocean floor as adults.
On December 15th something called the Cambrian Explosion happened. We don’t exactly know why, but life suddenly diversified into a wealth of different species, and the oceans were now teeming with beings resembling worms, shrimps, millipedes, and slugs. Among them were, of course, our great-great-really-great-grandfather. He probably looked like something between an eel and a worm — nothing glorious, but a specialized survivor nonetheless.
The Cambrian Explosion marked the emergence of a lot of cool features such as a nervous system, eyes and vision, and an efficient gut with separate mouth and anus (before that, they had to eat and poop from the same hole ☹).
Life on Earth really started looking like something, but with only 15 days left on our calendar, it had better do so.
On December 17th fish appeared in the oceans.
On December 20th plants began growing on land.
On December 21st insects invaded dry land and soon after learned to fly.
On December 22nd our ancestors finally crawled onto land in the form of amphibians. They had lungs but were tied to a water source as their squishy amphibian eggs had to be submerged.
On December 23rd the eggs-in-water-problem was solved when some of the amphibian descendants had evolved to become the first reptiles. Their hard-shelled watertight eggs enabled them to conquer even the driest of deserts.
On December 24th the worst mass extinction in the history of Earth wiped out 90% of all species — Merry Christmas indeed.
On December 25th the dinosaurs appeared and the continents on which they roamed were packed together forming one big supercontinent known as Pangaea.
On December 26th the first mammals appeared. Our ancestors probably looked like rodents at this point.
On December 27th some of the dinosaurs had evolved to become the first birds.
On December 28th insects entered into a symbiotic relationship with plants where they would spread the plant’s spores in exchange for nectar. As a consequence, the plants now began competing for the attention of insects which lead to the oddly beautiful evolution of colorful fragrant structures now known as flowers.
On December 30th the dinosaurs had reigned at the top of the food chain for 150 million years (almost 4 days on our calendar!), but as we all know they weren’t meant to last. At 06:24 AM December 30th an asteroid the size of Mount Everest, likely moving at 30 kilometers per second, came crashing down on Earth. Other than killing plenty on impact, the ejected debris darkened the skies and caused a thousand-year winter.
Some of the warm-blooded birds and mammals survived the ordeal while all non-bird dinosaurs went extinct along with a wealth of other species.
With the dinosaurs out of the way, the age of mammals had begun and a few million years later, still on December 30th, our rodent-like mammalian ancestor was now the proud mother of a wide variety of mammals, which included cats, bears, elephants, monkeys, and even whales.
And with that, we’ve reached the final day on our Cosmic Calendar. We could end this by simply mentioning that on December 31st humans appeared and formed the first global civilization, but that wouldn’t do the final day justice. A lot happened here, so let’s zoom in and see exactly how a single species of mammal managed to spread to all parts of Earth and beyond.
At the beginning of the final day mammals and birds had invaded close to all parts of Earth. Primates resembling modern-day monkeys were growing increasingly intelligent on the continent we now call Africa.
At 02:00 PM (16 million years ago) the first of the great apes appeared which is a group of primates today split into chimpanzees, humans, gorillas, and orangutans.
At 09:30 PM (4 million years ago) some of the great apes had risen up and were now walking permanently on their hind legs. In time, walking upright proved to be advantageous in at least three ways:
- With our heads higher we could see further.
- Moving on two feet required less energy, allowing us to run down prey and walk greater distances.
- Most importantly, it freed our hands to carry things like food, weapons, tools, and our newborn.
This was a turning point — soon modified stone tools were used to crack nuts, break bones, cut trees, hunt for food, defend the tribe, and prepare the fur of slain animals for bags and clothing. Fire was used for warmth, scaring off predators, and cooking — and cooking unlocked extra nutrients, giving us more calories per gram of food, allowing our brain to grow even bigger. Combine this with the appearance of a primitive form language and you have some serious contenders for the top spot of the food chain.
Early versions of human spread to both Asia and Europe at around 22:45 PM (2 million years ago), but these weren’t our ancestors. Our ancestors stayed in Africa and evolved to become the first Homo Sapiens at 11:52 PM (200,000 years ago). We don’t know exactly what set Sapiens apart from other humans, but it may have been our ability to cooperate flexibly in large numbers.
Earth was struck by an ice age starting at 11:56 PM (110,000 years ago)and ending at 11:59:32 PM (12,000 years ago). We, Sapiens, did surprisingly well in this period and had by the time the ice thawed spread to Europe, Asia, Australia, and even the Americas. Not only did we force all other human species into extinction, but we also hunted and killed most of Earth’s megafauna (large land animals), thereby setting off the Holocene Mass Extinction.
As Earth got warmer we began transitioning from a lifestyle of hunting and gathering to one of agriculture and settlement. Settlements lead to towns, towns lead to cities, and cities lead to complex civilizations with thousands of people working and living together.
The Sumer civilization was arguably the first civilization on Earth, and it appeared around 11:59:47 PM (5,500 years ago) in what is now Iraq. Soon thereafter came the Indus Valley civilization in what is now Pakistan and the Ancient Egypt civilization in what is now, you guessed it, Egypt.
Evolution had one billion years earlier brought together eukaryotes to form beings such as you and I, and it was now doing the same thing again, just one level higher. In other words: Civilizations were for humans what multicellular organisms were for eukaryotes. And just as this new level of being caused the singular cells to group up and specialize into “professions” such as heart cells, skin cells, brain cells, etc., the once hunter-gatherers were now identified as tailors, butchers, woodworkers, fishers, farmers, guards, kings, queens, and slaves.
Civilizations are the most capable beings to have ever come out of evolution — ever-changing, ever-expanding, ever-improving colonies of colonies of eukaryotes — and these are the giants that came to dominate Earth during the final 10 seconds (4,400 years) of our Cosmic Calendar.
10 seconds ago
The Great Pyramid of Giza is built, and it will remain the tallest man-made structure for another 8 seconds (3,800 years) to come.
9 seconds ago
Hammurabi, the 6th king of Babylon, enacts his code of law in which he, among other things, writes: an eye for an eye, a tooth for a tooth.
8 seconds ago
The Shang Dynasty, which is the earliest known Chinese dynasty with a developed form of writing, appears around the Yellow River.
7 seconds ago
Iron overtakes bronze as the preferred material for tool- and weapon crafting.
6 seconds ago
Buddha reaches enlightenment in ancient India. Confucius authors his philosophical texts in ancient China. Socrates teaches Plato; Plato teaches Aristotle; and Aristotle tutors Alexander the Great, who goes on to create an empire stretching from Greece to northwestern India.
5 seconds ago
Jesus is born and crucified in Judea.
4 seconds ago
The Roman Empire falls apart after having ruled the Mediterranean for almost 1000 years.
3 seconds ago
Muhammad authors the Quran in Arabia and gunpowder is invented in China.
2 seconds ago
Genghis Khan expands the Mongol Empire to cover 16% of the total land area of Earth, making it the largest contiguous empire to have ever existed.
1 second ago
The Black Plague kills around half the European population. Columbus rediscovers the Americas and kicks off the Colonial Period. The Maya, Aztec, and Inca civilizations fall to the Spanish conquistadors, and Isaac Newton makes his contributions to math and science.
Less than a second ago
The industrial revolution supercharges the capabilities of civilizations, while Darwin resolves the mystery of life. International tensions culminate in two World Wars, and as a consequence of Einstein’s insights, nuclear warfare becomes an all too real danger.
We then set foot on the Moon, envelope the Earth in satellites and send out robots to explore the rest of our solar system.
We create the internet and use it to connect close to all humans on Earth. A moment later you stumble upon this post and decide to read it… And here we are — back in the present moment.
Thank you for reading! I hope you enjoyed. In future posts, we’ll deep dive on some of the many topics we only just managed to brush over here.