The Pythagorean theorem hasn't been mentioned in HPMOR. Given this, would anyone bet me at 100-to-1 odds that future chapters will reveal that Harry rederived the Pythagorean theorem, in secret, while a student at Hogwarts, before April, and had fun?

I take it you mean bet against you? In present circumstances I shouldn't, but I'd most likely be willing to before the 15th (probably only at a scale of something like your $5 vs my $500, which may not be worth the effort).

5JoshuaZ5yIs there some reason to locate this hypothesis? Is there some reference I'm forgetting?

Harry Potter and the Methods of Rationality discussion thread, January 2015, chapter 103

by b_sen 1 min read29th Jan 2015174 comments


New chapter, and the end is now in sight!

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 103.

There is a site dedicated to the story at, 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

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Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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.