The Thread in the Onion

The library had gone the kind of quiet where you could hear the vending machine humming three rooms away. The science club had packed up an hour ago. Maya and Soren stayed, because nobody had told them to leave, and because there was still an onion.

"Look at this," Maya said. She was reading the back of the extraction kit somebody had left behind. "It says you can pull DNA out of an onion with dish soap and salt and rubbing alcohol. That's it. That's the whole thing."

"Then it isn't the DNA," Soren said. "It's probably a trick. Some cloudy stuff that looks like DNA."

"So let's find out."

They mashed the onion in a plastic cup, added the soapy salt water, waited the way the card told them to wait. Maya tapped the table. Soren wrote down the times. When it was ready, Maya tilted the cold alcohol down the inside of the cup, slow, the way you pour something you don't want to disturb.

Where the two liquids met, a cloud gathered. Then the cloud pulled itself into threads. White, stringy, rising.

"That's mucus," Soren said. "Or protein. It can't be DNA. There's too much of it."

"Fish some out."

He hooked it on a wooden stick and lifted. The thread stretched, thin and glassy, clinging to itself, longer than the cup was deep.

"Okay," Soren said slowly. "That is a lot of thread from a little bit of onion."

"How much would one cell have?"

"One cell? You can't even see one cell."

"That's what I'm asking. If we can see this much thread, and one cell is invisible, how long is the thread inside one cell?"

Soren stopped winding. He pulled the extraction card back toward him and read the small print at the bottom, the part nobody reads.

"It says here," he said, "human cells have about two meters of DNA each."

"Two meters."

"Per cell. Two meters." He held his hands apart, then kept moving them until his arms were all the way open. "That's taller than my dad. In one cell."

Maya went to the microscope. There was already a prepared slide clipped under it, cheek cells, stained purple, left behind from the demonstration. She looked. She adjusted. She found one cell, and inside it the dark round dot that the club leader had called the nucleus.

"Soren. Come look. The whole cell is barely a speck. And the nucleus is a speck inside the speck."

He looked. "So where does two meters go?"

"It has to be in there. In the dot."

"It can't fit in the dot."

"It's already in the dot."

They both stood back from the microscope. Soren picked up the wooden stick again, with its ghost of onion thread, and looked at it, and looked at the purple dot he could barely see, and the size of the problem got into his chest.

"Do the math," Maya said. "How small is that dot, really."

Soren found the ruler markings on the slide box and the magnification number and worked it out on the back of the card, crossing out twice.

"The nucleus is about six micrometers across," he said. "Six millionths of a meter. And the thread is two meters. So the thread is about, um." He divided. He checked it. "Three hundred thousand times longer than the box it lives in."

"Say that as something real."

"It's like." He looked at the ceiling. "It's like taking a fishing line that reaches from here to the next town and folding it into a grain of rice. Without it tangling. Without it knotting up so you could never read it again."

"But you can read it," Maya said. "That's the whole point of it, right? The cell reads it. All the time. It has to reach in and find one exact spot and open just that part."

"In a two-meter thread crushed into a speck."

"Without cutting the wrong bit."

They were quiet. The vending machine hummed.

"That's not folding," Soren said finally. "When I fold my earbuds they come out of my pocket in a knot every time. Every single time. And that's one wire."

Maya laughed, and then stopped laughing "Every cell," she said. "Not one special cell. You said each one. So the thread in my thumb is doing it, and the thread behind my eye is doing it, and they're all folded so smart that the cell can still open the right page whenever it wants."

"Trillions of cells," Soren said. "All of them holding two meters. All of them keeping it from tangling."

"Right now."

"Right now, while we're just standing here."

Maya held her own hand up in front of her face, palm toward her, fingers spread, and looked at it like it belonged to somebody she had just met.

"I always thought the amazing stuff was far away," she said. "Like space. Big far-off things."

"This is the opposite direction," Soren said. "It goes down instead of up. It goes smaller and smaller and it never stops being huge."

He reached for his notebook. He wrote two meters, then six micrometers, then a slash between them, and then under it he wrote fold, and drew a line around the word, and drew another line around that.

"Nobody folded it for us," Maya said. "Nobody sat down and engineered it. It just does it. It taught itself before there were people to be impressed."

Soren looked at the onion thread on the stick, then wound it once more around the wood, careful now, like it mattered how he did it.

"We can see this thread because there's a spoonful of onion in that cup," he said. "Millions of cells' worth, all their threads together, that's the size of a cotton ball. One cell's worth we'll never see."

"But it's there."

"It's there."

Maya bent back to the microscope, to the single dot inside the single speck, and turned the focus knob one hair-width, chasing the edge of the smallest thing she had ever tried to look inside.