Water is extremely simple stuff. two atoms of hydrogen – the Original Stuff – combined chemically (as opposed to fused atomically) with one atom of oxygen. Simple. “Hydrogen” means “water creator”; if you burn it in oxygen, that’s what you get.
But there wasn’t much free oxygen in Earth’s atmosphere at first. Mostly, ammonia and carbon dioxide. And, as you will soon see, we needed water to make oxygen.
There are two possible sources of water for the early Earth. One is the rocks that accreted to form the planet. Linda Elkins-Tanton, a geologist at MIT, analyzed meteorites, which are not unlike the rocks that first formed the Earth. Her results indicated that there could easily have been oceans on Earth at the time of the impact that caused the Moon merely using the water that was trapped inside the rocks. And it would have come out, too. In this time of accretion, the planet was mostly molten. The water would have immediately boiled. The atmosphere would have quickly become heavy with water vapor. Even considering the kind of splash something almost the size of Mars could make, there could have been oceans of water on the surface of the Earth within a hundred million years of its formation.
The other theory focuses on the impacts themselves. Comets are known to be mostly water ice. And there are many who believe the early earth was struck repeatedly by numerous comets.
So, there you have it. A million years of rain or a sustained barrage of comets. Think it over, while I wheel in the next diorama.
As I said: Life.
3.9 gY old fossils don’t lie, folks. If the organism showed up in a box of cream cheese you got today, it’d be called “contamination” and you’d throw it away, but there it is. A tiny fragment of a green slime called “cyanobacteria”. My great-granny and yours.
Cyanobacteria is one of several icky plants that breed in the shallows all over the planet. I’m not familiar with any of them. I’m told, though, that they are responsible for most of the oxygen in our atmosphere, and that they consume most of the carbon dioxide as well, and in that context I truly love green slime and wish it well forever. They function via the magic of photosynthesis. Just like your lawn, skunk cabbage and corn, they eat the carbon dioxide and spew out good clean oxygen,
How it got here is one of those enduring questions we may never know the answer to. If you thought you’d find it here, you’re going to have to revise your estimates. However, I see you’ve got the hookah filled and the wine jug going around, so why don’t I just sit down here on the floor with y’all for a minute and see what we can come up with?
For instance: there’s two big possibilities. Did Life spontaneously generate on Earth, or did it come from … Out There? Everything else here came from Out There; I’d guess Life did, too. Rode in on one of those meteorites, or maybe, you know, one comet splashed splashed down in a warm, nurturing ocean…
Once, years ago, I remember, somebody floated an idea that, if you made up a really thick soup of amino acids and then shot a high-voltage zetz through it, some of the aminos would begin swimming on their own Or something like that. Hmmm…
omg. I googled, “If you put lightning through amino acid soup you will create life”. Here’s what I got. Wikipedia says, Alexander Oparin and J. B. S. Haldane hypothesized “that conditions on the primitive Earth favored chemical reactions that synthesized organic compounds from inorganic [stuff].” In 1953, then, Stanley Miller and Harold Urey conducted experiments (at the U, of Chicago and U.C.S.D.) where they simulated their understanding of Early Earth’s atmosphere and sent some charge through it. They produced more amino acids than occur in nature. Nothing swam by, of course, because they weren’t silly fools like me, they were actual chemists. They had made organic substances out of inorganic material.
Since then … well, we don’t like to talk about it out loud, but there’s a Big Business in synthetic nucleotides, which are, like, the stuff DNA’s made of. No way you can make an amoeba out of it, let alone blue-green slime, but I’m not talking theory here, There’s corporations you can buy stock in that are doing this.
Making an amoeba in a laboratory isn’t the same thing as making one appear in your backyard goldfish pool, either. Let’s drift back to the primordial Shallow Sea a moment.
Let’s say that life came into existence on its own, through Cause and Effect, like everything before it and after it. That would imply either that conditions here are profoundly unique and ideally suited for life, or that conditions here are, by and large, pretty normal, and so is life. We have observed planets with very similar physio-chemical conditions as Earth. There’s a list of them, and it’s growing daily.
Let me modify my original statement. This is the Universe of Cause, Effect, and Life.
I’m going to end my Myth here. Unlike my model, the Bible, whose tale wanders into the Adventures of Adam and Eve in Paradise, and its numerous sequels, I am not concerning myself here with Good and Evil. I am concerned with the topic, as is most of our population. More and more, our survival as a species appears linked to it, and if not, the entertainment value is surely undeniable.