When physicists realized most of the universe was missing, they suddenly knew they had a major problem on their hands—the biggest problem imaginable, actually.
Problem was, they hardly even know how to imagine it.
They started looking, using a series of ultra-sensitive experiments. One of them included a set of data-gathering devices buried deep beneath the bedrock of northern Minnesota in an abandoned iron mine. The devices fed their data into a computer system, and teams of scientists around the world gathered together to look at the results simultaneously.
“The time had come to look inside the box,” writes author Richard Panek.
The data revealed two dots. But those dots didn’t represent periods punctuating the conclusion of their scientific search. Indeed, each dot more accurately resembled the dot at the bottom of a question mark: Why can we only account for about four percent of the universe? Why can’t we find the rest of it?
“Figuring out the missing 96 percent of the universe is the most important problem in science,” says Panek, author of the new book The 4% Universe: Dark Matter, Dark Energy, and The Race to Discover the Rest of Reality. Panek’s book chronicles the search to solve this greatest of scientific mysteries.
“Until recently we hadn’t realized that our universe was almost entirely missing,” Panek says. “The questions that raises are so provocative and so profound. We don’t even know how to know about it.”
* * * * *
Astronomers noticed something was amiss in the 1970s, when the behavior of spinning galaxies didn’t match up to the math. At the rate galaxies spin, they should—theoretically—fling themselves apart. But they don’t.
“Galaxies are living fast but not dying young,” Panek writes in his book, “a fact that makes sense only if we say that there’s more matter out there, gravitationally holding galaxies and even clusters of galaxies together, than we can see.”
For lack of a better term, scientists began calling this mysterious mass “dark matter.” It makes up about 23 percent of the universe.
“Dark matter is some relic left over from the Big Bang,” Panek says. “It’s not ‘dark’ as in distant or invisible. It’s not a case of ‘look behind that planet and you’ll find it. This is ‘dark’ as in unknown, and possibly unknowable.”
To account for the “dark-matter deficit,” wrote Panek in a 2007 article for The New York Times, the matter would have to be “so massive and so numerous that we couldn’t possibly miss it.”
The alternative? Scientists just don’t know how to see it. “The tools we have for studying the universe might not be adequate for dark matter,” Panek says. “It’s a complete mystery. It’s off the wall. But there’s every reason to think it exists.”
More difficult to understand is dark energy, which makes up the remaining 73 percent of the universe. As with dark matter, scientists have no way of seeing it. The math suggests it’s there, though—somehow, somewhere.
Because, otherwise, the math suggests that the expansion of the universe in the wake of the Big Bang should be slowing down as it cools. Based on that, cosmologists debated for years whether the universe would die in a Big Chill, where the universe cooled to such a degree that it stopped expanding and basically froze in place, or a Big Crunch, where the expansion would reach an outer limit and then snap back in on itself like an overextended rubber band.
But in the 1990s, two competing teams of scientists discovered that the expansion of the universe was speeding up, not slowing down. Some mysterious force was defying the math by defying gravity itself.
Scientists called that force dark energy.
And it is, according to one researcher who spoke with Panek, “the most profound mystery in all of science.”
* * * * *
“The idea that 96 percent of the universe was made up of something we didn’t even know was such a wild idea,” Panek says.
He speaks from a small, Spartan office on the second floor of an old haybarn converted into academic space at a small private college in the woods of northern Vermont. He teaches creative nonfiction for the school’s low-residency program, so he only occupies the room about two weeks a year. It’s a quiet, contemplative setting—certainly low-tech—which might actually make it the perfect place to consider the nature of the cosmos.
It’s a story Panek can’t resist.
“I thought, ‘This is probably too wild to be true.’ This is really wild and people don’t know about it,” he says.
Thin and hawkish, with a thin beard and a high, peaked hairline, Panek needs only a white lab coat and a clipboard and he’d look every bit the determined scientist. Yet he came to science writing in the mid-90s with no actual science background. Instead, he hoped that by approaching scientific material as a layman, he would be able to capture the essence of it in a way that would make it interesting for a general readership. “As it begins to make sense to me, it begins to make sense to the reader,” he explains.
His books include The Invisible Century: Einstein, Freud, and the Search for Hidden Universes and Seeing and Believing: How the Telescope Opened Our Eyes and Our Minds to the Heavens, and his articles have appeared in Discover, Smithsonian, Outside, and Natural History.
“When I come to these topics, I come to them with the general interest reader in mind,” Panek says. “I like to show readers exactly how science works.”
In 2007, he wrote an article about dark matter and dark energy for The New York Times. “I knew I had something more there,” he says. So he dove in further, ready to parlay his material into his next book.
“It’s kind of like going back to college but without the student loans,” he laughs.
He attended conferences. He watched experiments. He interviewed experts. He read, read, read. He immersed himself the story with the same gusto he advises his students to embrace: “Just throw yourself at a subject. Indulge yourself.”
“I’m finally ready for this material,” he said.
The trick, then, was taking that mass of material and giving it structure.
“Nobody had really taken the approach to look at this as a distinct moment in history,” he says. “That’s a very ‘fiction writer’ way of looking at things.”
To build his narrative, Panek employs many of the conventions of fiction—scenes, characters, dialogue, plot, suspense, pacing. “The story is grounded in character and details,” Panek says. “You don’t want to dump the exposition too soon. It has to rise out of the narrative organically.”
“The story is framed in a narrative way based on my own coming to understanding about the material,” Panek says. As he understands things, he helps readers understand things, too, so audience and author get to take the journey of discovery together.
“I use a narrative strategy that allows readers to enter into the story,” he says. “They get to stand shoulder to shoulder with the scientists as they ask these questions.”
In that way, Panek makes the biggest questions in the universe small enough to relate to. Amid all the science, amid all the mystery, he never loses sight of the story.
And what a story. An oft-quoted description of The 4% Universe calls it a “Wild West of the mind, where resources were scares, competition was fierce, and survival depended on small alliances of convenience….”
Giddy up, space cowboys. Things are getting wild.
* * * * *
The search for dark matter and dark energy is reframing the rules of scientific inquiry.
The rule for inquiry, as Panek writes in his book, has generally been, “The more we could observe, the more we would know.”
“But,” he then asks, “what about the less we could observe?”
That’s what the search for dark matter and dark energy require: a way of knowing more by observing less. It’s a game-changer on a grand, cosmological scale.
Panek devotes considerable ink to the game-changing nature of the search. “The book contains meditations on the history and philosophy of science, of how we relate to the universe,” he says.
“The way we think about the universe has become a science,” Panek explains. But it wasn’t always like that. “The first ‘scientists’ in the post-Renaissance age considered themselves to be ‘new philosophers’—philosophers who dealt with nature. Their thinking wasn’t objective science; it was hands-on, subjective engagement.”
As the Enlightenment continued to unfold, though, science became more formalized. “Taking this ancient quest and making it a science, making it predictable—‘Can you design an experiment, do the experiment, repeat the experiment?’ That process of scientific inquiry—that’s really remarkable,” Panek says.
“They’ve refined the questions. They’ve developed new ways to study the phenomenon.”
And yet mysteries endure.
“It’s a very human story,” Panek says. “We’re going to go out and solve this problem, but in solving the problem, you find a whole complete different aspect of something.”
But the quest for dark matter and dark energy—the search to know what’s unknown and, right now, unknowable—won’t just give us more knowledge and a greater understanding of our origins. Panek suggests there will be unintended, gestalt-shifting consequences that will come from the search, too. “No one could’ve predicted that the Enlightenment would lead to democracy, for instance. You couldn’t anticipate any of that at the beginning,” he says.
“We’re at the beginning of a new way of looking at the universe, and there’s no way of knowing what will happen.”
That is part of the dark, too.