Universe Today
(This is Part 3 of a series exploring the mythic side of the Big Bang. Check out Part 1 and Part 2!)
The early universe was a very different place than today. And by “early” I don’t mean a billion or even ten billion years ago. The universe is about 13.77 billion years old, and when it was only a handful of seconds old, it was completely unrecognizable.
We currently know of four fundamental forces of nature, gravity, electromagnetism, strong nuclear, and weak nuclear. And we know that at high energies, the forces begin to merge together. In our largest particle colliders, we can temporarily recreate the conditions of the early universe. At high enough energy, electromagnetism and weak nuclear are the first the first to combine, becoming what is called the electroweak force.
And it’s not just two forces stuck together. It’s literally a new force. The photon goes away, and so do the particles that carry the weak force. They are replaced by new particles that carry this new force. At lower energies, like the energies of the everyday world, these forces split apart into the two that we’re familiar with.
At even higher energies, we strongly suspect, but have not yet proven, that the strong nuclear force joins the unification party. We have an entire class of theories, known as GUTs, or grand unified theories, that attempt to explain this merging of three forces.
And last on the hierarchy, at the very largest of energy scales, at scales so big that we couldn’t hope to probe it even with a particle collider that loops around the Sun at the orbit of Jupiter, we believe that gravity joins in, merging all four forces into a single, unified whole. Our theories that describe this state of the universe are called theories of everything, of which we only have bare sketches of candidates that MIGHT be viable theories, but probably aren’t, like string theory.
I can’t emphasize strongly enough how strange the earliest moments of the universe were. All the forces that we know of were gone. So were all the particles. There were no electrons, no quarks, no neutrinos, no dark matter, no photons, no gluons.
There was…something else. We’re not sure yet what that something else, but it was, in many ways, pure. An essence that suffused all of reality, existing in a state of graceful equilibrium and homogeneity.
But that state of affairs couldn’t last forever. As the universe continued to expand and cool, that symmetry, that perfect equilibrium, broke apart. And this didn’t just lead to the separation of the forces. It wasn’t a clean and easy break – this was the most violent epochs ever to happen in the entire history of the universe, and it was all over and done with in less than the tiniest fraction of a second.
We have only a vague picture of what might have happened during these tumultuous epochs. Matter and antimatter went out of balance, going their separate ways with matter going on to dominate the cosmos. The electrons and neutrinos and dark matter appeared. Tiny black holes may have flooded the cosmos. And when the last forces split apart, fields, quantum objects that soak all of space and time, may have ignited in a furious release of energies, providing the momentum behind inflation, the rapid expansion of the entire universe in a superluminal headlong rush.
Once inflation ended, the universe was a formless substance, cold and empty. But as the field the powered inflation died, it decayed, flooding the universe with matter and radiation – the matter and radiation that persists to the present day. In those early fires, the first protons and neutrons congealed together out of the hot, dense plasma, and they would quickly, in a matter of minutes, fuse together to create the first light elements.
It was a transformative, chaotic epoch, one that would lay the foundations for the ensuing billions of years of evolution.
To be continued...
