"Why do they break?"

"Entropy. They don't get enough of what they need to survive, something breaks a twig off from the rest of the branch, or the plant sheds things on its own. Or time, most things break if given long enough."

"What's entropy?"

"It's the - gradual decline into disorder. Or chaos. A system left alone for long enough, biological or political tends to break down into chaos."

"Why?"

"That is a... Complicated answer. I think the easiest way to explain it is that - things are not perfectly efficient, so the systems they make, when given long enough, eventually break down due to lack of resources, whether it's the more basic needs of energy and matter, or the more complex resources of creativity and drive."

"I don't get it."

"Things - run out of energy to do things," Lynn tries.

"Things get tired?"

"Can't they just sleep and then wake up again?"

"Would that they could," sighs Lynn. "There's obviously ways to keep things organized and fight entropy, but it's a hard thing to beat."

"Why?"

"... I think because it affects everything."

"Everything everything?"

"If there are any exceptions," says Lynn softly, "I don't know of them."

"How do things grow, then?"

"Things grow by harvesting resources around them, and then re-purposing things in them to what they need."

"But why are there any resources still around?"

"Well, because the re-purposed resources are resources themselves. For other things."

"But everything's getting less and less resource-y. Right? Why isn't it done yet?" asks Astrid, still floating in the water.

"Yes. And it - takes quite a long time. There are lots of resources in the universe, thankfully."

"How many?"

"I'm not sure. Too many to count, I'd say."

"So there will be enough for things to grow for a long time before the universe has to stop for gas?"