In Into the Unknown (Basic, Oct.), astronomer Kelsey Johnson probes the limits of scientific knowledge about the universe.
You suggest that “if more people had a visceral understanding of the vastness of the universe, the world would be a better place.” Could you expand on that?
My sense is that as we spend more time inside and connected to our devices, we are collectively becoming more disconnected from the universe. I think this is really bad for all kinds of reasons that have to do with our need for exposure to awe and wonder. I don’t think we’ve really internalized or gamed out what that means for us as a species, and I don’t think it’s good.
When you talk about connecting to the universe, for many people that’s pretty abstract. What can overcome that abstractness?
These topics are super abstract and outside normal human experience, which makes them easy to ignore. What I tried to do in this book is overcome that distance by helping people feel curious about things they never knew they could be curious about. For instance, the night sky is dark, but if you’ve never stopped to think about why, you’d never be curious about it. If you were, you’d realize there’s this paradox: if the universe is infinite and populated by an infinite number of stars, every line of sight into space would land on a star, and the night sky should be bright. One of the things I’ve learned as a teacher is that I can’t put knowledge in someone else’s brain, but what I can do is make them curious so they seek out that information for themselves.
You note that it was challenging to decide which cosmic mysteries to explore. Was there one in particular you wish you’d had space for?
I would love to have a whole chapter, maybe even a book, on symmetries in the universe. I mention that all the familiar conservation principles—such as conservation of mass, conservation of energy, and conservation of momentum—are related to an underlying symmetry in the universe, but I never really gave that subject room to breathe. The fact that our universe has the symmetries that it does, sitting there in plain sight, is mind-boggling.
What cosmic mystery are you most eager to see solved?
This is kind of like picking a favorite child, but I will say the one mystery that causes me the most sleep deprivation and puts me in the deepest existential crisis is, why do we have our universe to begin with? Why do we have something instead of nothing?
Why that one?
Many of the other mysteries in the book are probably going to be solved in the future, but for this one, I just don’t see a philosophical way out. What this mystery does is force me to realize that there are limits to what we, as humans, can comprehend.
