Thursday, July 20, 2023

Back to the beginning...

This one is difficult. Just bear with me...

In the beginning, there was nothing. The picture that probably brings up is empty space and that isn't what I mean. I mean, nothing....

no vacuum, no empty space, no space, no time. There was absolutely nothing. If you can talk about it, there's something. When I say "nothing", that's a thing that wasn't.

In the beginning, there was absolutely nothing....

except...

a singularity.

Everything that exists now existed then compacted into a place with the volume of exactly zero. And the singularity was unstable so at a point in time....no, that's wrong ...there was no point and there was no time....

But the singularity exploded....um, there wasn't anything to exploded into. It expanded rapidly into....well, itself. All of the potential for time and space became actual.

This "Big Bang" happened around 13.8 billion years ago. (Before that, there was no time that would provide a "before"). In the first 10^-10 second (sorry, I don't know how to do exponents with Blogger) the four fundamental energies: gravity, electromagnetic energy, and the nuclear strong and weak forces, were unified and had to unravel themselves. There was no cap on the speed of light, so there was no limit on how quickly the universe expanded.

In the first second, the material component of the universe condensed into the fundamental particles and the universe began sorting itself out into atoms of stuff. It took a few minutes for hydrogen and deuterium to form but after that, things slowed down and it was, oh, a few hundred million years (get used to the big numbers. A hundred million years is a blink of the eye on the geological time scale.) before other elements began to appear. 

You see, hydrogen and deuterium make up stars. Other elements are formed in stars. You have to have stars to have larger atoms in any significant amount. If you don't do something in our universe, things fall apart...they don't stick together and stay stuck. The something that has to happen is stars.

Gravity pulls things together in the universe. It's a weak force but given enough time, it will pull enough hydrogen atoms together to form a huge mass of gas. The pressure at the center becomes so great that it ignites and a star is born.

Okay, there have been whole books written outlining (just outlining!) the process of cosmogenesis, and that's not the purpose of this blog. I'm attempting a "big history" of Walnut Hills.

So I'm going to jump ahead to about 4.6 billion years ago...the birth of our sun. We call it Sun or Sol but it's a fairly mediocre star about halfway through it's life cycle.

At the beginning of our solar system, space debris - gas, dust, and larger particles - had been drifting around for a long time. Under the influence of gravity, the universe had become...chunky. When stuff in a region of space starts attracting each other, they begin as a spherical cloud, but the particles tend to spiral in toward the center and they flatten into a disk (astronomers call it an accretion disk). You can see much of the effect if you spin around in an office chair and hold your arms and legs out in different positions. As you bring them in toward the center of your body, you spin faster. It also matters whether you hold them perpendicular to the axis of spin.

Most of the debris is drawn to the center, but smaller clumps forms along the disk. The central mass collapses until the intense pressure at the center begins crushing hydrogen atoms together to ignite a fusion chain reaction. The center of the dust cloud becomes a star. The clumps of matter spinning around the star become planets and other bodies.

Heavier matter fall further to the center of the disk to form Rocky planets and the outer clumps become icy or gaseous bodies, many of them huge like Jupiter and Saturn. The process is complicated and interesting features form like ring systems, moons, asteroids, and comets.

There is nothing that could be pinpointed as where-Walnut-Hills-will-be, but the third big clump from the sun has started to collapse in on itself, transitioning from a big ball of space debris to a solid ball. That will be our planet, Earth.


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