Harry Potter and the Methods of Rationality

If you wanted to be specific, 3:32pm on Thursday afternoon.

Harry and all the other boys in the first year were outside on a grassy field with Madam Hooch, standing next to the Hogwarts supply of broomsticks. The girls would be learning to fly separately. Apparently, for some reason, girls didn't want to learn how to fly on broomsticks in the presence of boys.

Harry had been a little wobbly all day long. He just couldn't seem to stop wondering how that particular stable time loop had been selected out of what was, in retrospect, a rather large space of possibilities.

Also: seriously, broomsticks? He was going to fly on, basically, a line segment? Wasn't that pretty much the single most unstable shape you could possibly find, short of attempting to hold on to a point marble? Who'd selected that design for a flying device, out of all the possibilities? Harry had been hoping that it was just a figure of speech, but no, they were standing in front of what looked for all the world like ordinary wooden kitchen broomsticks. Had someone just gotten stuck on the idea of broomsticks and failed to consider anything else? It had to be. There was no way that the optimal designs for cleaning kitchens and flying would happen to coincide if you worked them out from scratch.

It was a clear day with a bright blue sky and a brilliant sun that was just begging to get in your eyes and make it impossible to see, if you were trying to fly around the sky. The ground was nice and dry, smelling positively baked, and somehow felt very, very hard under Harry's shoes.

Harry kept reminding himself that the lowest common denominator of eleven-year-olds was expected to learn this and it couldn't be that hard.

"Stick out your right hand over the broom, or left hand if you're left-handed," called Madam Hooch. "And say, UP!"

"UP!" everyone shouted.

The broomstick leapt eagerly into Harry's hand.

Which put him at the head of the class, for once. Apparently saying "UP!" was a lot more difficult than it looked, and most of the broomsticks were rolling around on the ground or trying to inch away from their would-be riders.

(Of course Harry would have bet money that Hermione had done at least as well when it came her own turn to try, earlier in the day. There couldn't possibly be anything he could master on the first try which would baffle Hermione, and if there was and it turned out to be broomstick riding instead of anything intellectual, Harry would just die.)

It took a while for everyone to get a broomstick in front of them. Madam Hooch showed them how to mount and then walked around the field, correcting grips and stances. Apparently even among the few children who'd been allowed to fly at home, they hadn't been taught to do it correctly.

Madam Hooch surveyed the field of boys, and nodded. "Now, when I blow my whistle, you kick off from the ground, hard."

Harry swallowed hard, trying to quell the queasy feeling in his stomach.

"Keep your brooms steady, rise a few feet, and then come straight back down by leaning forwards slightly. On my whistle - three - two -"

One of the brooms shot skyward, accompanied by a young boy's screams - of horror, not delight. The boy was spinning at an awful rate as he ascended, they only got glimpses of his white face -

As though in slow motion, Harry was leaping back off his own broomstick and scrabbling for his wand, though he didn't really know what he planned to do with it, he'd had exactly two sessions of Charms and the last one had been the Hover Charm but Harry had only been able to cast the spell successfully one time out of three and he certainly couldn't levitate whole people -

If there is any hidden power in me, let it reveal itself NOW!

"Come back, boy!" shouted Madam Hooch (which had to be the most unhelpful instruction imaginable for dealing with an out-of-control broomstick, from a flying instructor, and a fully automatic section of Harry's brain added Madam Hooch to his tally of fools).

And the boy was thrown off the broomstick.

He seemed to move very slowly through the air, at first.

"Wingardium Leviosa!" screamed Harry.

The spell failed. He could feel it fail.

There was a THUD and a distant cracking sound, and the boy lay facedown on the grass in a heap.

Harry sheathed his wand and raced forwards at full speed. He arrived at the boy's side at the same time as Madam Hooch, and Harry reached into his pouch and tried to recall oh god what was the name never mind he'd just try "Healer's Pack!" and it popped up into his hand and -

"Broken wrist," Madam Hooch said. "Calm down, boy, he just has a broken wrist!"

There was a sort of mental lurch as Harry's mind snapped out of Panic Mode.

The Emergency Healing Pack Plus lay open in front of him, and there was a syringe of liquid fire in Harry's hand, which would have kept the boy's brain oxygenated if he'd managed to snap his neck.

"Ah..." Harry said in a rather wavering sort of voice. His heart was pounding so loudly that he almost couldn't hear himself panting for breath. "Broken bone... right... Setting String?"

"That's for emergencies only," snapped Madam Hooch. "Put it away, he's fine." She leaned over the boy, offering him a hand. "Come on, boy, it's all right, up you get!"

"You're not seriously going to make him ride the broomstick again?" Harry said in horror.

Madam Hooch sent Harry a glare. "Of course not!" She pulled the boy to his feet using his good arm - Harry saw with a shock that it was Neville Longbottom again, what was