It's well accepted that our universe came into being about 13.7 billion years ago with a bang. A big bang, in fact. So big, and yet so small.
Because the energy which became at least 100 billion galaxies each containing about 100 billion stars, supposedly was contained within a singularity of infinite density and temperature that wasn't even a point in time and space – since a singularity is where the laws of nature (including general relativity) break down.
This helps explain why the Catholic Church has looked with favor on the big bang theory, as have theologians of other faiths.
Time is considering to come into existence with the big bang. Before it, there was nothing. So it's easy to consider that God was behind the big bang, kicking creation into existence in a "let there be light" fashion.
Now, though, a big bounce theory is gaining adherents. Last night I read a Scientific American article, "Big Bang or Big Bounce?: New Theory on the Universe's Birth," by Martin Bojowald.
Here's the Key Concepts summary of the article:
- Einstein's general theory of relativity says that the universe began with the big bang singularity, a moment when all the matter we see was concentrated at a single point of infinite density. But the theory does not capture the fine, quantum structure of spacetime, which limits how tightly matter can be concentrated and how strong gravity can become. To figure out what really happened, physicists need a quantum theory of gravity.
- According to one candidate for such a theory, loop quantum gravity, space is subdivided into "atoms" of volume and has a finite capacity to store matter and energy, thereby preventing true singularities from existing.
- If so, time may have extended before the bang. The prebang universe may have undergone a catastrophic implosion that reached a point of maximum density and then reversed. In short, a big crunch may have led to a big bounce and then to the big bang.
Cool. There still was a big bang, but it probably wasn't the first. In fact, there could be an infinity of universe-creating moments, since the big bounce theory suggests that the beginning of time is a myth.
The cosmos always has existed. It just bounces around, oscillating between big bangs and big crunches, wiping out all traces of what came before each seemingly one-of-a-kind creation of a universe.
I like (but don't claim to understand) the loop gravity theory. What's not to like about a notion that makes you think "loopy"? And, "far out."
In the quantum theory of gravity, a vacuum is the absence of spacetime – an emptiness so thorough we can scarcely imagine it. Loop gravity describes how each increment of energy added to this vacuum generates a new atom of spacetime.
The spacetime atoms form a dense, ever shifting mesh. Over large distances, their dynamism gives rise to the evolving universe of classical general relativity. Under ordinary conditions, we never notice the existence of these spacetime atoms; the mesh spacing is so tight that it looks like a continuum. But when spacetime is packed with energy, as it was at the big bang, the fine structure of spacetime becomes a factor, and the predictions of loop gravity diverge from those of general relativity.
… Because of the quantum-gravitational change in the balance of forces, no singularity—no state of infinite density—can ever arise. According to this model, matter in the early universe had a very high but finite density, the equivalent of a trillion suns in every proton-size region. At such extremes, gravity acted as a repulsive force, causing space to expand; as densities moderated, gravity switched to being the attractive force we all know. Inertia has kept the expansion going to the present day.
Who can fathom infinity? But the mass of a trillion suns shrunk to the size of a proton … that's mind-boggling, yet at least minimally comprehensible.
Lying in bed after reading the article, musing about the mystery of the universe before falling asleep, I pondered a cosmos that has always been, and just keeps banging/bouncing away, forever.
My ponder ran up against what it always does in such speculating: awe, pure and simple. My train of thought falls over an abyss of mystery. I'm left with nothing but Wow.
I'm pretty sure this is the same feeling religious believers have when they contemplate an omnipresent, omniscient, omnipotent God. They and I fall on our non-comprehending knees before the ultimate.
The thing is, science points the way to the mystery of always was, always is, always shall be with a lot more believability than religion does.
So if you want to feel cosmic awe, there's no need to pick up a holy book. Just Scientific American.