One of the transfiguration safety rules: Never transfigure something into anything that might be eaten or breathed. Is it possible to demonstrate partial transfiguration (on, for example, his father's rock) while transforming much of its substance very temporarily into a breathable gas?
I think those are just safety rules, rather than laws of transfiguration magic, so it should be possible.
(in any case, I don't really think partial transfiguration is actually the solution, since anything which involves combat is necessarily a long shot with too many magical unknown unknowns to count).
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 113.
There is 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.)
IMPORTANT -- From the end of chapter 113: