On a small island in Maine, Alan Lightman looks at his computer’s screen and speaks. His image—kind face, dark-gray hair, pale-blue hoodie—is converted into zeros and ones. His voice, which still holds a vestige of an accent from his youth in Memphis, is too. Those zeros and ones travel from his home to the laptop of a reporter in Kingston, N.Y., which reproduces his image and voice.

In other words, Lightman is doing an interview on Zoom. He’s discussing his new book, Probable Impossibilities: Musings on Beginnings and Endings (Pantheon, Feb. 2021), a philosophical exploration of breathtaking discoveries about the universe and ourselves. He’s also patiently explaining how this interaction is happening. “The amazing thing is that these waves are traveling through space all the time,” he says. “Only a very tiny fraction of them are visible to the eye—just a narrow frequency range in the visible spectrum, which we call visible light. Everything else is invisible to us but passing through space all the time. We’re oblivious to it.”

Lightman’s awe about the physical world is infectious. He speaks with the authority of a scientist, specifically a former Harvard astrophysicist, and the eloquence of a novelist—he has published eight works of fiction. Probable Impossibilities is a follow-up to his 2018 nonfiction book Searching for Stars on an Island in Maine, a meditation on the human quest for truth and meaning through religion and science. In Probable Impossibilities, he continues his exploration of the relationship between what scientific research has revealed and what our souls yearn to understand.

Our bodies are composed of material made from stars. Our human consciousness is, as far as science is concerned, nothing more than the result of electrical and chemical flows in our brains. “There may be no end to space,” Lightman says. “That’s just something that we can’t fathom. And yet modern science has uncovered these really incredible facts about the universe and about existence and about ourselves.”

A collection of previously-published and new essays, Probable Impossibilities offers a primer on many of modern science’s most mind-blowing discoveries, incorporating profiles of scientists performing cutting-edge research—including one trying to create life from scratch. Lightman weaves his own story and voice though the book.

In an essay titled “Nothingness,” Lightman describes a profound experience he had at age nine. Standing in his bedroom, listening to a distant train, he suddenly felt he had left his body and was watching himself from the outside. In that moment, he felt a deep connection to the universe while also understanding himself as a brief blip in the vastness of time and space. “That experience gave me a much bigger view of science,” he says. “It was part of my philosophical exploration of the world, and it made me see science as part of a larger aspiration of who we are, and where we are, and where we fit in the cosmos.”

When Lightman was a postdoctoral fellow in astrophysics at Cornell, he began publishing poetry in literary magazines. During his tenure as a research scientist at the Harvard-Smithsonian Center for Astrophysics, he began publishing essays about the human side of science in Smithsonian Magazine and the New Yorker, and he later wrote for the Atlantic and Harpers.

Lightman published his breakout first novel, the modern classic Einstein’s Dreams, in 1993, and during that period transitioned from being a scientist who writes to a writer who applies his knowledge of science to deeper questions of human existence. “As I’ve gotten older, I have thought about these issues more deeply, just as we all do as we get older,” he says. “At some point I’ll start getting Alzheimer’s or something and I’ll think about things less deeply.”

For all of Lightman’s enormous accomplishments, he knows what he is: a being composed of atoms, which are mainly composed of space. He explains that if an atom were the size of a baseball stadium, with its electrons orbiting in the outer bleachers, its nucleus would be the size of a mustard seed. “Most of the volume of our bodies is empty space. It gives new meaning to meeting somebody who’s a lot of hot air.”

It’s funny but also upsetting. Are we really just star debris and space? Surely the fact that we have consciousness, that we can understand and joke about these things, means that we are special somehow. But physical science says no. What we call consciousness is, as far as science is concerned, simply the electrochemical activity of the neurons in our brains.

Lightman agrees that this information is hard to take. “The experience of having a self—of I-ness—is so powerful. We have this feeling that there is something special about our consciousness in our minds—all of the delicate thoughts we have, the art that we’re able to compose, and all the emotions that we have. It seems almost impossible that that could be reducible to atoms and molecules sending electrical and chemical signals between themselves. It seems almost a desecration to say that we are nothing but atoms and molecules obeying the laws of physics. It seems like a desecration of the dignity and specialness of life.”

Raised in a secular Jewish household, Lightman places himself somewhere between agnosticism and atheism. “I don’t believe that there’s an intelligent purposeful creator who made the universe, and yet I do feel connected to something much larger than myself,” he says. And even physical science offers some solace. We may just be atoms, he notes, but those atoms will live on. After we die, they will disperse through the environment, mixing with the soil, wind, and water.

“Eventually some of those atoms will become part of new people,” Lightman says. “Through the food that they eat and the air that they breathe, they will incorporate some of your atoms.”

Lightman is also buoyed by the human desire to know. “We still have a curiosity about the world, even when we know that what we learn may disturb us psychologically and emotionally,” he says. “We still have this innate desire to learn what’s out there.”

As someone who has spent his life seeking information that can seem upsetting, has Lightman found a way to live with it? “I’ve learned to live with a tension in my gut,” he says. “It’s a tension that I associate with creativity. Often creative ideas come to me when I’m when I’m confused or disturbed about something. So I have come to accept that this disturbance is part of my creative enterprise.”

It’s also just... life. “In a larger sense, I think this dissonance is part of being human,” Lightman says. “It’s part of being alive and in the world. This is the best answer I can give.”

Sara Eckel is the author of It’s Not You: 27 (Wrong) Reasons You’re Single (TarcherPerigee).