Depends on what’s being written, and who the audience is. Anything of any length would be hard to simulate in a way that would fool an author - writing has a certain flow to it. A cadence. The editing and restructuring, deleting of words, typos you don’t catch until some random reread, rephrasing of sections because you want to use the original phrasing later in the piece.

Could you simulate something be typed? Trivially. Could you simulate something be drafted? Honestly, even if you wanted to put in all that time and effort, I’m not even sure LLMs are sophisticated enough to send the logical drafts, loops and edits that would pass a writers sniff test

I think you could simulate something that passes a sniff test. A writer would probably spot implausibilities in the simulation if they paid attention, but then we're back to square one, because you can spot that something was written by an LLM after you've wasted your time reading it and realize that you've been led around in circles with superficial information and no coherent train of thought, but by then your time has already been wasted.

To add to this, one can’t ignore the relationship between signal and receiver. I’d imagine most people on HN have enough pre-LLM reading experience to have a decent sense of what was written by an LLM versus a human.

And as LLMs get better at producing human-like text, that same pre-LLM reading experience, which helps people tell the two apart, will become less and less common.