If he can make a model rocket, he can make a uranium gun design. It's one slightly sub-critical mass of uranium with a suitable hole for the second piece, which is shaped like a bullet and fired at it using a single unsynchronised electronic trigger down a barrel long enough to get up a decent speed. Edit: And then he or a friendly 7th year casts a charm of flawless function on it.
That was a lot more than a model rocket.... probably weighed at least 5kg. Also, the fact that either he OR Quirrel could make a working large rocket engine without knowing the exact composition of propellant, precise geometry of nozzle, etc indicates that Transfiguration can work at a really high level of abstraction. He probably would have no trouble at all transfiguring a nuclear weapon with a mechanical timer trigger.
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 98. 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.
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: