Just the other day I was having a nice little discussion with a stranger about drive exhaust in The Expanse universe. And it turns out that my initial position was likely very wrong. While there might be other SF boards where this kind of discussion is possible, it is much more convenient for me to join a few smaller communities of interest on reddit instead. I also like hearing about the latest developments on the RISC-V processor architecture. There actually is some discussion of this here on HN, but there's more over on /r/riscv.