Here's a bit more detail on what I mean when I talk about the "most important century for humanity."

There are two different senses in which I think this could be the "most important century," one higher-stakes and less likely than the other:

Meaning #1: Most important century of all time for humanity, due to the transition to a state in which humans as we know them are no longer the main force in world events.

Here the idea is that:

• During this century, civilization could either end entirely, or change so dramatically that "humans as we know them today" would either not exist anymore, or would at least be a very small part of the population.
  • I think the future I describe in Digital People Would Be An Even Bigger Deal would probably reach this level of unfamiliarity pretty quickly.
  • The possibility of AI systems' expanding across the galaxy based on their own objectives - with humans' becoming fairly irrelevant in comparison - would qualify as well.
• This century is our chance to shape just how this happens.
  • If we develop digital people, the initial set of digital people could quickly set about making many copies of themselves, multiplying and working at a far faster rate than normal humans would be able to track or keep up with. With these points in mind, the initial set of digital people - and the virtual conditions they're placed in - could be crucial in a lasting way.
  • If we instead develop AI systems that expand across the galaxy based on their own objectives, this could permanently lose the opportunity to have the main force in world events be anything like humans at all.

Based on these points, this would be the "most important century" for humans as we are now, in the sense that it's the best opportunity humans will have to influence a large, post-humans-as-they-are-now future.¹

This could be consistent with other centuries being "most important" for other "species."

• Some past century may have been the most important century for chimpanzees. (This may have been some century during which humans started to emerge.)
• Some future century might be the most important century for whatever "comes after humans." (Although this century might be most important for them too.)

I want to roughly say that if something like PASTA is developed this century, it has at least a 50/50 chance of being the "most important century" in the above sense.

Meaning #2: Most important century of all time for all intelligent life in our galaxy.

It's possible, for reasons outlined here, that whatever the main force in world events is (perhaps digital people, misaligned AI, or something else) will create highly stable civilizations with "locked in" values, which populate our entire galaxy for billions of years to come.

If enough of that "locking in" happens this century, that could make it the most important century of all time for all intelligent life in our galaxy.

I want to roughly say that if something like PASTA is developed this century, it has at least a 25% chance of being the "most important century" in the above sense. This is half as much as the probability for the previous version of "most important century." I don't mean to be precise here; I'm giving a rough indication of how likely I think such a development would be.

To put this possibility in perspective, it's worth noting that the world seems to have "sped up" - in the sense of changing more rapidly - over the course of history, and could continue to do so if something like PASTA is developed. With this in mind:

• If the first bacteria had been talking with each other, one of them might have claimed they were in the "most important 5-billion-year period," the one in which bacteria would evolve into complex animals.
• The first complex animals might have claimed that they were in the "most important eon," the one in which humans would emerge.
• Someone living through the Scientific Revolution might have claimed that they were in the "most important millennium," the one in which scientific and technological progress would take off.
• If transformative AI leads to a digital-people-run civilization around, say, 2080, some digital person in 2080 might claim that they're in the "most important decade." A decade might feel to them the way a century (or longer) feels to us.
• These digital people might create more advanced digital people who claim that they're in the "most important day," figuring that they will evolve into something even stranger during that vast-feeling period of time.
• And they could all be right!

Holistic intent of the "most important century" phrase. I have largely chosen the phrase "most important century" as a wake-up call about how high the stakes seem to be.

While I've tried to give it slightly more precise meaning above, my main intent is to call attention to the "Holy !@#$" feeling of possibly developing something like PASTA this century, which in turn could lead to a radically unfamiliar future, possibly involving a stable galaxy-wide civilization.

If I'm right about that picture but wrong about the "most important century" for some reason (for example, perhaps something even more remarkable happens 5 billion years from now, or perhaps it turns out that the simulation hypothesis is correct), I'd still think this series's general idea was importantly right.

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Footnotes