Hello

Hello. You are here.

How did such a wonderful thing happen?

I don’t know who exactly you are, but I know you were born. And that you are an earthling from Earth. And that you are alive right now reading this sentence. Those are the main things I feel sure about.

It’s nice to know that there are some things we can be sure about, since there are so many great mysteries and only a few have been even slightly solved.

Here are some things we have managed to suss out about you being you:

A very particular combination of egg and sperm were required to cross paths in order for you to be exactly you, right here, right now: for you to have the exact nose and ears and allergies and hair you do or don’t have. And all the other things about you too, the ones you didn’t learn or get from your environment and experiences. We don’t always know which those are, but there are some, and they were embedded in the ancient code that runs through your blood.

For that code to be coded just the precise way it was, two other particular eggs had to meet two other particular sperm for your biological parents to come to be. And that required four more meetings for your grandparents to exist. Then eight before that, and sixteen, and thirty-two, and so on—back to the earliest humans and beyond, to creatures maybe not yet exactly human but who still came to fruition through the meeting of eggs and sperm and who were still all absolutely central to you arriving at this moment when you are reading this sentence. Before the nearly human creatures, there were slightly different but still similar tree dwellers. And before them, small scurriers living in fear of Jurassic reptiles. Before the sperm-and-egg creatures, there were other creatures who are also our ancestors: cells dividing in some sacred swamp at a time when there was not yet oxygen to breathe, microbes that would someday evolve into creatures who would spend a great deal of time and energy wondering, even piecing together a few clues, about the story of how they arrived and from where.

We’ve been pondering these things for a long time. Some of us shared stories explaining how we got here and came to be. Some of us felt uncomfortable saying, “I don’t know how we got here. I’m not even exactly sure where we are. I mean, I know we’re near the sea or in the valley or at the edge of the great desert. But beyond that, I am also at a loss.”

Some of these stories involved:

Spells and suns, the Tablet of Destinies, and a mystical cyclone.

A raven creator who goes to steal light for the unlit world.

The daughter of the sky who spent 700 years in a vast sea before she met a bird who laid six golden eggs and one of iron.

A heavenly being who travels to the realm of seawater, building the earth from the mud of the sea.

A solar system born when a giant was usurped by another god: the four eyes of the giant made two suns and two moons, and one of each was later destroyed.

A different giant who vomits up the sun, the moon, and the stars.

A sky father god who leads other divine creators in the task of forming the Earth’s crust.

A different sky father god who does the lonely work of creation for six days before a rest.

A failed attempt at making humans from wood, followed by a more successful approach: maize.

A god who makes this particular universe out of himself, even though he knows it will, like all universes, be destroyed in time.

A parentless void that longs for the magic of reproduction.

Another void from which an Earth goddess, a love god, an abyss, and primordial darkness all spring.

A pyramid-like mound that spouts the first, primordial waters, followed by our sun.

In most cases, these stories featured something like one or two or six or seven things that happened in order for the world to be the way it is: full and busy, complicated and interconnected.

Stories were told of carefully orchestrated events and occasional accidents, all leading one after the other to the ancient nows when such stories were passed on in meticulous detail. Some of these stories evolved as they were retold, until some other idea or philosophy, faction or fashion took over, and different stories were told.

Poetically at least, these stories had so much water, so many eggs and suns and other ingredients that really were required for this particular recipe. There were also parts that, on further inspection, did not stand up to scrutiny.

We started examining things very carefully: ourselves, each other, the smallest and largest fellow creatures here, the way the stars moved, the ways the days changed over the course of the year, the way we changed over the millennia, the ocean, the volcanoes, the rocks, and the clouds. Our questions got more specific. We figured out how to answer some of them. Sometimes, we were very wrong. We had to ask deeper, more difficult questions. We had to wrestle with new paradoxes. We screamed in frustration. We died without getting our answers. Sometimes, another picked up the threads of our evidence, perhaps hundreds of years later.

In the questioning and deducing, we discovered some very good clues. Yet great mysteries still abound. Often, just as we think we are about to solve one, we find that the stream of clues directs us to a river of unposed questions, which opens up to an immense sea of obscurities.

In this way, we got even grander stories, on a larger scale.

And now, we think there were not just one or two or six or seven steps but too many to count.

It’s hard to imagine the Earth not being here since most of us are always on it. Most, but not all: There are 566 members of our species who have been elsewhere—namely space. The rest of us might take for granted our round, wet, stormy, sunny, buzzing, erupting, life-filled world.

And to answer the questions of how and why life began on our world, we must take into account the whole wide universe.

How does a world come to be?

Likely, the first thing that needed to happen was the creation of the universe. At the very least, it was an important step. And we’ve discovered some real clues about how such a large and finicky thing occurs.

They involve:

• A very large explosion—we think. But what was before that? Nothingness in every direction forever? Something else we may soon decipher? Something else we will never understand? Something we might comprehend but not for a very long time?

• Heat and density of proportions so large that “mythic” would barely begin to describe it.

• Expanding, expanding, expanding, slowing, slowing, slowing but still expanding, even now.

• Sometime between no seconds at all and 10−43 seconds, four great forces were unified despite their difference: electromagnetism, gravity, strong nuclear forces, and weak nuclear forces.

• The universe kept bursting out of itself, faster and faster, faster than anything can go anymore.

• Things got colder, quickly.

• Quarks. Electrons and protons and neutrons. All matter of profoundly tiny ingredients to make everything you ever saw and more.

• 13.8 billion years have passed since then, but there was no such thing as “years” for the first 9.2 billion of them because there was no Earth and no star for it to orbit steadily, in a reliable, elliptical fashion every 365.2422 days.

Every moment was required to happen exactly as it did for you to arrive at this particular now. But a universe alone wouldn’t do the trick. We still needed, among other things, our aforementioned star, which is lovely and yellow and middle-aged these days.

Its arrival involved:

A solar nebula (a vast gas and dust cloud) that began to collapse when its own gravity became too much.

Hydrogen atoms that had no choice but to combine and become helium.

So much energy our sun couldn’t help but be born.

And it’s a good thing, too, because we really needed a sun just like this one. But a sun is not much help without somewhere a little cooler nearby to live.

Luckily for us, there was also a great deal of clumping. I would like to call it something more elegant, but that’s what it was: clumping. The constant clumping made messy shapes, but gravity—perhaps the most elegant force of all—molded those shapes into neat, tidy, magnificent spheres.

Those spheres were large and small planets and large and small moons. Just the right ingredients for a nice little solar system.

Setting up this lovely one involved:

Colder outer reaches, where ice and gas could form into great swirling marbles.

And inner parts, where only rocks could withstand our star’s intensity. Here, four smaller, craggier worlds fell into the routine of revolving and rotating in the bright light.

A lot of collisions. Craters were made. Moons were born from the debris of crashes.

Spare parts too small to be anything neatly spherical. These became asteroids, comets, meteoroids, and other bumpy (sometimes dangerous) objects.

Finally, a pattern. It became a little safer and a little calmer. Not as safe and calm as now, but the kind of place where something new could start to grow on a rocky, wet sphere nearish to a sun—like the place we inhabit.

A sphere happens to be a very good shape to live on. And for us to arrive at this moment, we needed a place for our evolution to flow down the astonishing tributaries to this particular now.

How did something completely new begin? How did something start moving and seeking and shape-shifting? How did the very first ones of our kind—the alive ones—come to be? Did it only happen here? Can it only happen here? Does it always happen like this? Does it never happen like this? Why and how? These are still some of the most mysterious mysteries, the questions whose answers might involve digging the deepest.

We do have some real clues for the very first time. They involve:

Volcanoes bursting through the floors of vast oceans.

Nitrogen, carbon dioxide, a little hydrogen, some methane, and water. Always water.

Then, lightning strikes. Asteroids and our star’s ultraviolet light.

Changing chemistry. Rains came and brought elements to places they had not been before. The new ingredients led to new reactions. Slowly, slowly, slowly, something started.

A few nucleotides joined forces, and little by little, they linked up to become that very first strand of RNA.