The Space Between the Dots

The argument started because Soren said the universe was mostly nothing.

"Not nothing," Maya said. "Empty is different from nothing."

They were lying on their backs on the observatory platform, which was really just a wooden deck bolted to the roof of the science camp's main building. The telescope was pointed at something else entirely. Ms. Aziz had left it aimed at a galaxy cluster before going to bed, telling them they could stay up another thirty minutes if they promised not to touch the tracking motor.

That had been forty-five minutes ago.

"Okay, mostly empty," Soren said. He had his notebook on his chest, but it was too dark to write. "The space between galaxies. Between stars. Between atoms, even. It's almost all gap."

"But the gap is doing something."

Soren turned his head on the wooden planks. "What do you mean, the gap is doing something?"

Maya didn't answer right away. She was looking at the Milky Way, which from here, sixty miles from the nearest real town, looked less like a band and more like a wound in the sky. Too bright. Almost violent with stars.

"Ms. Aziz said today that the expansion is accelerating. The galaxies aren't just moving apart, they're moving apart faster and faster. Right?"

"Right."

"So something is pushing. Or pulling. Or whatever. Something is making that happen."

"Dark energy," Soren said. "She talked about it. Sixty-eight percent of everything."

"Of everything," Maya repeated. She sat up. "Soren. Sixty-eight percent. More than two thirds. And nobody knows what it is."

"I know."

"No, I mean, nobody knows what it is. Not like, we haven't figured out the details. Like, there is no theory that works. There is no detection. There is nothing. It's the majority of the universe and it is completely unknown."

Soren sat up too. The notebook slid off his chest.

"She said that. I remember."

"But you wrote it down like it was a fact. Like it was the same kind of thing as the speed of light or the mass of an electron."

"It is a fact. We can measure the acceleration."

"The acceleration is a fact. What's causing it is a hole. A hole shaped like most of reality."

Soren picked up his notebook and held it in both hands, not to write, just to hold. He did this when something was too large for the inside of his head.

Below them, the camp was dark and quiet. Somewhere an owl was calling, two notes, over and over, like it was trying to confirm something.

"Okay," he said slowly. "So what are you saying? That we shouldn't have written it down?"

"No. I'm saying we wrote down the wrong sentence. We wrote 'dark energy is sixty-eight percent of the universe.' But the honest sentence is 'sixty-eight percent of the universe is something, and we called it dark energy because we needed to call it something, and we do not know what it is at all.'"

Soren was quiet for a while. Then he said, "Those are really different sentences."

"Yes."

"The first one sounds like we understand it."

"And we don't."

"No. We don't."

Maya lay back down. Soren stayed sitting, turning the notebook over in his hands.

"Here's what gets me," she said. "Every second, the space between galaxy clusters is getting bigger. Not because the galaxies are flying through space. Because space itself is stretching. New space, appearing between things. And the more space there is, the more of this unknown something there is in it, and the faster it stretches. It feeds itself."

"You're saying the universe is accelerating itself apart with something it can't identify."

"I'm saying we are inside something that is doing that. Right now. The platform we're lying on, the air, us. We're soaking in it and we can't feel it and we can't see it and we don't even have a wrong theory about what it actually is."

The owl called again. Two notes.

Soren opened his notebook. He couldn't see the lines but he didn't need lines. He wrote in the dark, pressing hard so he'd be able to feel the impressions later: SIXTY-EIGHT PERCENT UNKNOWN. Then, underneath, slowly: NAME IS NOT THE SAME AS UNDERSTANDING.

"Ms. Aziz said something today," he said while writing. "When DeShawn asked if dark energy was like dark matter. She said no, they just both have 'dark' in the name because dark means we can't see it. She said the dark in dark energy really means we are in the dark."

"We are in the dark," Maya repeated. "And the dark is sixty-eight percent of everything."

"More than that," Soren said. "Dark matter is another twenty-seven percent. Also never directly detected. Also unknown."

Maya made a sound, not quite a laugh. "So. Five percent. We understand five percent."

"We understand some of five percent."

They let that sit between them. Five percent. Some of five percent. The entire history of physics, every equation, every particle accelerator, every space telescope, every genius who ever lived, laboring to decode a sliver of a sliver, while ninety-five percent of reality sat there, unnamed, undetected, unexplained, doing whatever it was doing.

And the thing is, Maya thought, it's not hiding. It's everywhere. It's the main thing. We're the small part. We're the rounding error.

"This is the part where most people would feel small," Soren said.

"Do you?"

He thought about it honestly. "No. I feel like there's room."

Maya looked at him.

"Room for what?"

"I don't know. That's the point. If we understood ninety-five percent and were working on the last five, that would be almost finished. But we're at five percent. We are so near the beginning that almost everything is ahead of us. Some kid lying on a roof somewhere, right now, tonight, some kid is going to figure out what dark energy actually is. And when they do it won't be like adding one more fact to the list. It will be like. Like."

"Like seeing a new color," Maya said.

"Bigger. Like discovering that color exists."

The Milky Way turned above them, or they turned beneath it, which was the same thing. The space between every galaxy in every direction was growing at this exact moment. Growing faster. Full of something. Full of mostly something, and the something had no name that meant anything, and it was the majority of all that existed, and it was right here, passing through them like they were the ghost, not it.

"Soren."

"Yeah."

"That kid on that roof."

"Yeah."

She didn't finish the sentence. She didn't need to.

Above them the sky was full and the space between the stars was fuller, and the owl called its two notes into the dark like a question it was not finished asking.