note that it says:
On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity.
Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon. Videos of pratfalls or disasters, or cute animal pictures. If they'd cover it on TV news, it's probably off-topic.
This post doesn't fall clearly in the "Off-Topic" section, so it seems completely appropriate.
So basically, this is on the FP because enough people are interested in it.
Now if you're wondering why they're interested in this enough to up-vote it to FP even though it's not about start-ups, techs, or futurism, well that's more of a coincidence than anything else.
HN is ostensibly a forum for intellectual conversation, and that's it. This link tries to do just that, so it counts. In reality though HN is a business move. It's basically a niche forum geared towards the target customer base of YC and YC's affiliates and start-ups. That's how they advertise to them.
The real mystery here is why I'm not putting this kind of knowledge and insight to work toward making me a millionaire. I'm literally the same age as Sam Altman, yet I'm barely able to feed a family of 7. FFS.