What if you could live forever—but only if you can afford it? This is the devious code source at the heart of the new Netflix series “Altered Carbon.” In the show’s future, human consciousness can be downloaded into chips called stacks and transferred from one body to another—the bodies are called “sleeves.” The process, called “re-sleeving,” is expensive, and only the truly wealthy can keep re-sleeving as each of their current bodies die. These impossibly wealthy people secretly run the world, and they are called “Meths,” derived from the biblical character Methusaleh, the oldest man in the Bible.