And entropy causes all sorts of nasty things. Such as death.
"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."
"Things grow by harvesting resources around them, and then re-purposing things in them to what they need."
"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."
"So there will be enough for things to grow for a long time before the universe has to stop for gas?"
"Yes. Longer than any of our lifetimes, I'd say. Unless yours happens to be measured in trillions of years."
"There probably is," she muses. "We should check that. That... Is a very important thing to figure out."