This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 99, 100, and 101. The previous thread is at nearly 500 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically:
You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).
If there is evidence for X in MOR and/or canon then it’s fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that “Eliezer said X is true” unless you use rot13.
Harry can obliviate people well enough to make them "lose every single life memory involving the color blue". This is a Big Deal. It allows for things like:
O-
October
After walking Herminone to Broomstick class, Harry wandered alone about the upper hallways of Hogwartz pondering Neville's rememberal. He must have forgotten about something important, but w-
Ow!
A Green Elephant appeared out of nowhere and struck Harry's head. It was a stuffed animal, the type you might buy for a small child, if the child's favorite color were Eerily Glowing Green. Harry removed an index card pinned to the elephant's side.
Harry rubbed his temple. It was at times like these that Harry wished he had less affinity for cryptic clues and assaulting people with glowing megafauna.
Less than 5 minutes of search at the library Harry and found the next hint: a fluorescent green post-it labeled "Elephant" on the book Mind Magic: A Modern Approach.
Harry kicked himself. Well, that solved the mystery of the glowing rememberal. He had forgotten a task he had assigned himself his first day at Hogwarts:
Todo 1̶2: Research every kind of mind magic you can find. Mind is the foundation of our power as humans, any kind of magic that affects it is the most important sort of magic there is.
Harry opened the book at a green elephant-shaped bookmark and read.
...Or every life memory involving Green Elephants, Harry thought. So that's what he was up to with the elephant. Harry had ensured that every memory he made while learning obliviation would be tagged with a obvious marker. If Harry ever needed to plead ignorance of mind magic in the future, he could obliviate all his life green-elephant memories (be prepared!). Alright, new plan. He would study obliviation in secret, always thinking about a green elephant when doing so.
A grinning Harry wandered out of the library and into the Weasley twins.
"Harry! We got you a present." said Fred or George.
"You'll never guess what it is."
Harry put a finger on his cheek "Is it...A glowing green elephant?"
April 16th, 1992.
2:34 PM
Harry slowed the broomstick to a halt in midair of a hallway, his wand already coming into his hand, the driving will to protect Hermione Granger rising to the front of his mind like a sun of silver fire and flowing down his arm as he cried
"EXPECTO PATRONUM!"
and the blazing white humanoid burst into existence like a nova, the Weasley twins' voices crying aloud in shock.
"Tell Hermione Granger - that there's a troll loose in Hogwarts - it could be hunting for her - she needs to get into direct sunlight, now!"
The silver figure turned as though it was departing, and then -
A floating green elephant appeared
Harry's Patronus raced out of the room. It took forty agonizing seconds before the silvery figure returned, opened it's mouth and said .
An invisible voice shouted "EXPECTO PATRONUM!".
A second true Patronus appeared next to the floating green elephant.
The invisible voice instructed "Send the following message to me: 'Hermione Granger says,'" the invisible voice rose in pitch in a poor imitation of Hermione, "AHHHHHHHHH!"
The floating green elephant disappeared.
"Merlin's underpants," breathed Fred or George.
Battle with the troll:
One hand held a tremendous stone club as long and as wide as an adult human, and the other hand held a green elephant and
...
The troll snorted and spun around to face them, dropping a green elephant and
into the red pool that had spread out beneath its feet, raising its club high.
Aftermath:
Harry told Dumbldore about the , though he knew later he would be unable to process the memory later.
...
But Harry didn't see anything helpful he could do using spells in his lexicon, Dumbledore wasn't being very cooperative, and in any case this was several minutes after the critical location within Time and Harry's green elephant weilding, time-traveling double would be more chronologically equipped.
Dumbledore walked to Harry's side, George moved to keel next to his brother, and Fred lay supine.
Why had future Harry shown him the Green Elephant?
"Harry," the Headmaster whispered, laying his hand on Harry's shoulder. "Harry, you must go from this place"
Harry sat outside the infirmary storeroom clutching his time-turner. He could go back; he could save her. But not yet.
Think of a green elephant
He knew too much. He could't go back now -- the information carried in his mind would strech time too far.
Think of a green elephant
There was only one way left. Harry turned his wand on himself, his fingers forming the motion he had practiced all year.
Think of a green elephant
In a flash, his mind would race his memories of a Green Elephant and wipe them out forever.
Harry drew his breath.
-bliviate
I had the exact opposite interpretation of that line. I thought it meant that Harry still had so little control that if he was trying to get rid of a memory which involved the colour blue (presumably referring to the unicorn and its blood, which was "not white, but pale blue, or appearing so"), he would instead end up removing all such memories without meaning to.
That's rather like saying "he couldn't perform surgery unless he wanted somebody to lose every single organ in their abdomen". Not something you want to use as a tool - at most, it's a very blunt weapon where Harry has access to far better ones for most situations.