Hogwarts interferes with electrical devices, but brains still work.
There certainly seems to be a common thread in many magic worlds that "physics doesn't work, but all the stuff physics causes that most people intuitively EXPECT to happen, still happen"
And it doesn't simply degrade into bullshit because you think that you can explain why things work as expected for some physical reasons. You may have a certain level of reductionistic insight, you may expect things to stop behaving as usual, but magic is lawful, and so it continues working according to naïve physics, according to expectations of somebody who does not even pretend to understand world in physical terms.
Technology is (bastardized ancient) Greek for trickery. Electricity works, gravity works, macroscopic thermodynamic works. Counterintuitive trickery without Atlantis-issued license doesn't.
- This thread has run its course. You will find newer threads in the discussion section.
Another discussion thread - the fourth - has reached the (arbitrary?) 500 comments threshold, so it's time for a new thread for Eliezer Yudkowsky's widely-praised Harry Potter fanfic.
Most of the paratext and fan-made resources are listed on Mr. LessWrong's author page. There is also AdeleneDawner's collection of most of the previously-published Author's Notes.
Older threads: one, two, three, four. By tag.
Newer threads are in the Discussion section, starting from Part 6.
Spoiler policy as suggested by Unnamed and approved by Eliezer, me, and at least three other upmodders:
It would also be quite sensible and welcome to continue the practice of declaring at the top of your post which chapters you are about to discuss, especially for newly-published ones, so that people who haven't yet seen them can stop reading in time.