The end of knowledge

There's a great quote, sometimes attributed to Kelvin, but apparently fabricated from things said by one or more other people, that goes "There is nothing new to be discovered in physics now. All that remains is more and more precise measurement." Of course, this was in the late 1800s, just before the discovery of relativity, nuclear physics, quantum mechanics, subatomic particles, black holes and the big bang theory. So I guess you could say that turned out to be a bit short-sighted.

Though, when you think about it, what is the answer? Will we ever know everything? I think the instinctive answer is "no", because the universe is too big, and to an extent maybe we want it to be too big. But, if you follow that through for a second, how could it possibly be true? Purely from an information theory perspective, there's no way you can encode an infinite amount of information in a finite space, so, worst case, there must be a finite description of the observable universe.

That description could be as large as the universe itself, if the unverse was purely structureless and random. I'm not even sure if that's possible; if the universe used to be smaller and denser, the information now can't be greater than the information then unless we assume some external source injecting information in. Regardless, the universe seems to have structure – in fact, a lot of structure – so I can't see any reason it won't, eventually, be completely described. I think, at some point, we will know everything.

And where does that leave us? I mean, what do we do when the universe's mysteries are completely explained to us? Perhaps it will all seem pointless then. But on the other hand, there are a lot of domains where people effectively know everything now and it doesn't seem to bother them. It's possible to know everything about a given programming language, for example, or bicycle repair. I don't think people who use programming languages or repair bicycles are filled with existential dread. Or, at least, not because of the completeness of their knowledge. And many fields seem to just generate an infinite stream of new things.

In the end, I suppose I'm making an argument that essential complexity is finite, but I don't think the same is true of accidental complexity. I read an Iain Banks book where a super-advanced species lived only for a kind of futuristic Reddit karma. Maybe that's where we'll end up.