For control purposes, it was a good idea to test out the cloud chamber first by putting something inside that you knew, for a fact, would give off actual radiation. That way, you’d know if the cloud chamber worked. In the Scientific American article, they’d used the face from an old watch with uranium-based paint, just like his dad had talked about.

“Once we know from our test with the watch that conditions are right,” Nate told Naomi, “then we try to spot the other type of rays.”

“I don’t know if I get it yet,” she said. “I mean, the difference between what comes from the watch and these other rays. What is it we’d actually be seeing in this chamber that makes it such a big deal?”

“What you’d see,” he said, and his voice took on a hushed intensity, “are tiny energy particles from actual explosions that took place millions of years ago. Actual evidence of solar activity. Supernovae.”

“So what we’d see is kind of like fallout from space? Like if a car wreck happened, and a piece of someone’s windshield that shattered ended up in my yard?”

“Only the car wreck happened a few million years ago, and the windshield’s only just now reaching you. Let’s say a couple of galaxies collided, back in dinosaur times—or before the dinosaurs, even. What we’re talking about is a catastrophe. Something bigger than the worst disaster we could imagine happening on earth. Imagine the most violent event you could dream of. Something like that. Imagine all the energy that’s swirling around us, crashing into the atoms of our own bodies at this very moment,” he said.

“Like there’s all this stuff going on around us, all the time, that nobody can see,” Naomi added. “It’s like if you got to put on one of those special pairs of glasses they sell at the back of comic books that let you see the bones in your own hand or something. Only those are fake. What we’re doing is real.”

Hearing Naomi talk about the two of them as a “we” sounded strange to Nate, but there you had it. Like it or not, they were partners.

She looked at him more soberly then, with something like real respect. “How do you know all this stuff, anyway?”

“My dad. My dad was always talking about stuff like this. He knew everything there is to know about space.” It startled him to hear his own voice speak of his father as he did just then. As if he were dead.

“My dad and I are always planning out neat projects to do,” he said, changing it back.