Best of 2025

The blog posts Hacker News loved most in 2025. 202 posts.

Science & Space
35

LLMs aren't world models

I believe that language models aren’t world models. It’s a weak claim — I’m not saying they’re useless, or that we’re done milking them. It’s also a fuzzy-sounding claim — with its trillion weights, who can prove that there’s something an LLM isn't a model of? But I hope to make my claim clear and persuasive enough…

54

What Is Entropy?

People say many things about entropy: entropy increases with time, entropy is disorder, entropy increases with energy, entropy determines the arrow of time, etc.. But I have no idea what entropy is, and from what I find, neither do most other people. This is the introduction I wish I had when first told about entropy…

60

Air Traffic Control

Air traffic control has been in the news lately, on account of my country's declining ability to do it. Well, that's a long-term trend, resulting from decades of under-investment, severe capture by our increasingly incompetent defense-industrial complex, no small degree of management incompetence in the FAA, and…