When people ask me what I write about, and I answer “cosmology,” I often get a blank stare. So, I tend to follow it up with, “You know, space, planets, black holes and stuff.” Then, they start to take an interest. Lately, though, I’ve been reflecting on something that Einstein said. “If you can’t explain it simply, you don’t understand it well enough.”
With that in mind, I picked up an excellent book called About Time: Cosmology and Culture at the Twilight of the Big Bang by Adam Frank. The book explains how every culture from hunter-gatherers to digital hipsters has a cosmology. That cosmology is closely linked to their way of life, or as he calls it their “material engagement.”
Our material engagement drives how we perceive time. For example, Einstein was a patent clerk who reviewed a lot of inventions for synchronizing clocks. That got him thinking about time and space and led to his Theory of Special Relativity.
What I’m most indebted to Adam Frank for is his precise definition of the word cosmology. For Frank, cosmology consists of these 5 questions:
Question 1: Is there a universe or a multiverse?
Question 2: Is space infinite or bounded?
Question 3: Does space exist by itself?
Question 4: Does time exist by itself?
Question 5: Does the universe have a beginning and/or an ending in time?
This is a very concise summary of what cultural cosmology entails. I’m not a scientist. What little pure science I took in school was meant for non-scientists, and I wasn’t very good at it. My background is in the social sciences. My interest in cosmology stems from our cultural need for stories. Every culture has a set of stories that answers the above 5 questions. I agree with Thomas Berry that our modern, scientific society has been stripped of its stories and that we need new, science-based narratives to answer our questions in a meaningful way.
For today, here is the state of thinking scientific cosmology gives us for Frank’s 5 questions
Question 1: Is there a universe or a multiverse?
Adam Frank doesn’t think there can be more than one universe, but Stephen Hawking believed there could be. I respect and admire both of them, and I’m in no position to argue. Hawking was a big fan of what’s known as M-theory. Proponents of M-theory claim that there could be as many as 10500 parallel universes, all with their own set of laws.
Frank’s main arguments against the idea of a multiverse are based on the scientific method. We have no empirical evidence for any other universe. So, critics argue that the approach is unscientific. In a parallel universe, I might have an answer for all this!
Question 2: Is space infinite or bounded?
If we stop and imagine either of these possibilities, we get overwhelmed. How can something go on forever? Yet, how can our universe just stop? This depends partly on what shape the cosmos is. For example, we know that the earth is round and has no edges. You can’t sail off the globe. It’s boundless, and at the same time, it’s finite. When it comes to the universe, if it had an edge, what would be beyond its boundaries? I’m not going any further with this right now!
Question 3: Does space exist by itself?
What is empty space? You might say your closet is empty (lucky you!). It isn’t, though. It’s filled with air and particles that you can’t see. Outer space has no atmosphere, but we define it in terms of the matter it contains. For example, between the earth and the moon, there is space. But if there were no matter in the universe, would there be space or just nothing? Is space a thing in itself, or just the relationship between objects? No one knows what “nothing” is. I have nothing more to contribute to this right now!
Question 4: Does time exist by itself?
We measure time by observing some sort of instrument. It could be a stick in the ground, a sundial, an hourglass, a mechanical timepiece, a quartz crystal in a modern watch or the signal from electrons in an atomic clock. Our instruments get more and more accurate, but we always rely on them rather than perceiving time itself. Again, if there were no matter in the universe, would there be time? I need more time to think about this!
Question 5: Does the universe have a beginning and/or an ending in time?
The challenge to the Big Bang Theory is always, “What happened before the Big Bang?” Hawking maintained that time began at the big bang. He famously said that asking what was before the Big Bang was like asking what’s north of the north pole. It’s a meaningless question, like dividing by zero. As for the ending, the expansion of the universe is accelerating. In the standard model, the expansion will end by eventually pulling itself apart in what cosmologists call the Big Rip. That will be the end of time.
Others, like Frank, aren’t convinced. They think that the Big Bang Theory has reached its “best before” date (just like the sitcom). They expect new theories to replace it before long. The questions of what happened before the Big Bang and what will happen after the Big Rip may not be as meaningless as Hawking contended. We certainly haven’t reached the end of this debate!
As readers can see, none of these questions have
final answers. Writing about cosmology
should keep me busy for many years to come.
We always have more to learn if we dare to know.
Learn more:
About Time: Cosmology and Culture at the Twilight of the Big Bang
The Grand Design
