"It's in the Mirror of Atlantis," Harry said.
"We need Gillyweed," said Luna, "Lots of Gillyweed."
"The Mirror of Atlantis is located at the end of the third-floor corridor on the right-hand side," said Harry.
"What are you waiting for?" said Luna.
"You're not going to ask me how I know these things?" said Harry.
"Why would I do that?" said Luna.
"Because…because…" Harry searched for words to express the magnitude of the epistemic hole.
"You talk like a Muggle," said Luna, "You think like one too."
Harry puzzled over whether he had just been insulted. Luna skipped ahead to the third floor.
Harry and Luna flew a double-seated broomstick over the dieffenbachia and other unmaintained obstacles to the Mirror.
"You're a really good flier," said Luna, "I bet you're on the Quidditch team. What position do you play? No. Wait. Don't tell me. I bet you play Seeker."
"This Mirror lets you store an object until someone with the right intentions arrives," said Harry testily.
"I seek entry to the Ravenclaw Common Room," said Luna to the Mirror, "I want to sleep in a bed."
"In Gödel's name, what monstrously difficult riddle did the bronze eagle ask of you?" asked Harry.
"'Where is my diadem?'" said Luna.
"You're supposed to say 'lost' or 'hidden'," said Harry, "You're not expected to rediscover the Lost Diadem of Ravenclaw."
"Oh," said Luna.
"Since we're already here, let's give it a modicum of effort," Harry withdrew a mechanical stopwatch from his pouch and set it to five minutes.
"I want the diadem to save the world," Harry said.
"I aim to save the lives of all sentient beings," Harry said.
"I promise to bring you, Rowena Ravenclaw, back to life," Harry said.
"I seek to disassemble stars," Harry said.
Luna ignored him. Rowena Ravenclaw was not a jealous witch. If she concealed knowledge then it was not because the knowledge could be used for evil. It was because the knowledge itself was intrinsically dangerous. A cascade of logic began to self-assemble.
Rowena's basilisk attacks those who know it exists.
Luna forced her thoughts back into disarray.
"BRIIIIIING!" the mechanical alarm went off.
"I'm hunting nargles," Luna said.
The Luna in the Mirror held the Diadem of Ravenclaw in her left hand. The real Luna held it in her right.
"What is a nargle?" said Harry.
"You don't want to know," said Luna.
"What do you plan to do with this magical artifact of incredible power?" asked Harry.
"I'm going to get a comfy night's sleep in the Ravenclaw dormitory," said Luna.
"Can I, uh, try it on first?" Harry asked.
"Sure," said Luna. They were friends, after all.
Harry Potter thrust the diadem onto his head.
Then he had a seizure.
Harry's arms locked into place as if a powerful electric current flowed through them. Luna failed to pry the diadem loose. Luna dug through her satchel for the Comed-Tea can. She released Wanda.
"Help him," Luna said.
Harry's convulsions stopped. Luna wrestled the diadem off Harry's head and out of his hands.
A cascade of logic began to self-assemble.[...]Luna forced her thoughts back into disarray.
This feels like a crossover between HPMoR and the Antimemetics Division of the SCP Foundation.
This doesn't seem to exist, otherwise. (Although I'm still looking.)
"You're not going to ask me how I know these things?" said Harry."Why would I do that?" said Luna.
But, chapter 1:
"How do you know?" Luna asked.
Is it only some knowledge that cannot be gained from nothing? Such as that a thing does not exist?
I think Luna is tuned into the difference between Harry's epistemology and Hermione's, and so thinks the question is worth asking in the one case and not the other; alternatively, she is tuned into how they respond to questions of that sort, and Hermione invites them whereas Harry does not.
"Why would I do that?" and "You think like a muggle" sound like she thinks Harry is making an epistemological error.
If she were as tuned in as you say, she should see that Harry asks because he doesn't see how tuned in Luna is.
One is a response to a statement which is positive (not 'it exists' but 'it is (there)), while the other is a statement which is negative (it does not exist, or specifically:
"There is no Platform Nine and One-Half," the unicorn replied.
For completeness, here is the other one:
There are other differences between surrounding contexts, but that difference really pops out - they're different responses to different types of claims. (Also, arguably one is magical, one is mundane/numeric.)
The spoiler doesn't logically follow from what comes before, right? She merely saw the possibility.
And if she's right, that's why it didn't attack her.
Given HJPEV's thoughts about intelligence explosions last chapter, I'm surprised he'd try to use the diadem. If nothing else, I figured his Vow would stop him. Or does he conversely feel safe to use it, precisely because he knows his Vow should counteract the value drift that could be induced in an intelligence explosion?
I thought maybe the seizure was the result of the Vow? But... I am generally quite confused, so don't listen to me.
I don't think so - the Vow is not an electric collar that shocks Harry every time he tries to destroy the world. This would invite ways to try and outsmart the Vow. Remember - the allegory here is to AI alignment. The Vow is not just giving Harry deterrents - it modifies his internal reasoning and values so that he would avoid world destruction.
But what if there was something Harry did that he was not smart enough to realize would likely end the world... And doing that thing made him smart enough to realize that. But he could only work through that with the intelligence from the world ending things. Seems like the sort of thing that could short out the enchantment.
Not sure what you mean.
If some action is a risk to the world but Harry doesn't know vow doesn't prevent him from doing it.
If afer taking some action Harry realizes it risked the world nothing happens except maybe him not being unable to repeat the decision if it comes up again.
If not taking some action (Example defeating someone about to obliviate him) would cause him to forget about a risk to the world vow doesn't actually force him to do it.
And if Harry is forced to decide between ignorance and a risk to the world he will choose whichever he thinks is least likely to destroy the world.
The thing about ignorance seems to also aply to abandoning intelligence buffs.
Perhaps: Harry will destroy the world eventually. And wearing the Diadem "normally" finds a more certain/swift result to the same outcome? If so, then he should take it off... but taking it off would perhaps leave him too dumb to work out why he should have taken it off ("it made sense at the time, maybe I should put it back on"), and also unable to see how his default plans eventually do so ("it seemed like a bad idea, but now the logic is fuzzy, let's keep going but more slowly") so taking it off would ALSO destroy the world.However, if he convulses forever back and forth between removing and not removing the diadem he kind of fulfills both impulses, and won't thus destroy the world either way, so that's the result?Kind of like a Garrabrant Inductor thinking about one of its own Goedel Statements?
1. Why would value drift be induced?
2. Maybe to find and stop someone else who used it? Who hasn't taken such a vow. (There's some stuff about inaction in the vow - it's long.)