Cosmic Curiosities: A Journey Through the Universe’s Greatest Mysteries with Astronomer Kelsey Johnson
What is time? Does extraterrestrial life exist? Are there other dimensions, and are there limits to what we can know and discover?
In her latest book, Into the Unknown: The Quest to Understand the Mysteries of the Cosmos, University of Virginia astronomy professor Kelsey Johnson takes readers on a whirlwind journey through the vast expanse of the universe. With a blend of storytelling and scientific rigor, Johnson explores profound questions that have puzzled humanity for centuries and continue to shape scientific inquiry today. From the enigmatic nature of black holes to the intricate dance of galaxies, she delves into the frontiers of modern astrophysics, shedding light on the latest discoveries and the enduring mysteries that continue to challenge our understanding and our imagination. This book is not just a scientific exploration but a testament to the relentless human spirit and our relentless quest to comprehend the unknown.
From Into the Unknown: The Quest to Understand the Mysteries of the Cosmos
We can do, and have done, an impressive amount with our brains and logic. But there are limits. Sometimes these limits go away if we keep at it for long enough—we just need better facilities and experiments to get the answer. Often, we are pretty confident that if we could actually perform such-and-such experiment, we could resolve this-or-that mystery. Breaking new ground in modern science in this way often (but not always) comes with a big associated price tag. Next-generation supercolliders or overwhelmingly large telescopes are not cheap, but these may be required to come up with answers to some of the unsolved mysteries of the cosmos.
Sometimes our limits reflect the (relatively) extremely short time we’ve been doing modern science. After all, the Scientific Revolution was less than four hundred years ago, which is only 0.00000003 × the age of the universe or 0.0000001 × the age of Earth. Heck, we’ve only had the two pillars of modern science, general relativity and quantum mechanics, for about a century. Not only does that mean we haven’t had a lot of time to figure things out, but the universe isn’t set up to do a dog and pony show whenever we need data on something. The universe will take its own sweet time. Need to study a supernova in detail for your PhD thesis? Well, sit tight, odds are we will have one in our galaxy sometime in the next fifty years or so.
Sometimes the limits we encounter in trying to unlock the nature of the cosmos are cognitive. As in our own brains. Think about this: human DNA is only about 1.2 percent different from that of chimps. Chimps are smart, no question. But could you teach one calculus (not to mention general relativity and quantum mechanics)? What if our DNA were another 1.2 percent further evolved than it is? What might our brains be capable of then? The level of abstract thinking (and other types of thinking we don’t even have words for) might be astounding. To be clear, I am not advocating for transhumanism. Rather, I want to flag the pure unbridled hubris involved in thinking that our brains are even capable of totally understanding the cosmos in its entirety. But that sure as heck isn’t going to stop us from trying to understand what we can.
Sometimes the limits we hit are fundamental (or appear to be). There are laws of nature that we may never be able to understand, no matter how advanced our brains might become. Which means there are experiments we might never be able to perform (though I use the word “never” lightly and the word “might” with optimism). We may never be able to test what actually happens inside a black hole. We may never be able to probe (let alone interact with) other dimensions (if they exist). We may never be able to break the infinite regression of what caused the universe to be created, and what caused the cause of the universe being created, and what caused the cause of the cause of the universe being created. Turtles all the way down (we will come to the famous story of the infinite stack of turtles shortly). This is where we run smack into the boundaries of science.
For something to be considered scientific, it must, by definition, be testable. There is a tiny little loophole here: it may not need to be testable right now, but it must, at least in principle, be testable at some point in the future by some experiment that could realistically happen. If an idea or hypothesis isn’t testable, that doesn’t mean that it is wrong. It means it isn’t testable. If it isn’t testable, how do we know if it is correct? These (potentially) untestable ideas also happen to be (in my opinion) some of the most interesting ones, probably because they’ve been vexing humanity for millennia.
Because of the unknown, and potentially unknowable, nature of the topics in this book, we will often find ourselves at the convergence of empirical inquiry (aka science), philosophy, and theology. This can be an uncomfortable space to be in, but this is also where some of the most interesting questions dwell, so let’s not shy away and avoid talking about complex and loaded topics just because they are complex and loaded. The fact that they are complicated and have significance in myriad belief systems means that they really deserve to be talked about, but with a hefty dose of care and respect.
