Harry Potter and the Methods of Rationality discussion thread, part 20, chapter 90

palladias

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 90. The previous thread has passed 750 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.

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Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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

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Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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

Here's how I would have saved Hermione if I were Harry.

In an accessible but seldom visited hallway of Hogwarts, a rail-way sign reads 6PM to 5PM Express.

At 5:00, a boy materializes under the sign. He is wearing a rail-way conductor's hat. He is holding a trunk. His name is Harry Potter.

Conductor Harry puts down the trunk. He opens the lid. Inside his Trunk of Holding are wooden seats numbered 1 through 1000. All seats appear to be empty.

Conductor Harry yells "Arriving at 5PM! Please add one tally to your forearm now".

Silently, hundreds of people draw a tally mark on their arms.

Conductor Harry steps away from the trunk and the hundreds invisible passengers of the 6PM to 5PM Express disembark.

At 5:10, Conductor Harry closes the trunk lid. He stashes the trunk [EDIT] and Time-Turner in the Great Hall.

At 5:12, Conductor Harry burns his conductor hat. He draws one tally mark on his previously blank arm, and puts on his invisibility cloak. He sighs. He has a long day ahead of him.

...

At 5:30 in the Astronomy Tower, a smelly and disheveled Harry Potter pulls off his invisibility cloak. He is covered with hundreds of tally marks, and looks like he hasn't slept in days. He yells "Screw this, I'm done!", collapses on the floor, and falls asleep.

...

At 5:40, the original Harry goes to his room. He has done no time traveling today, and has no tally marks on his arm.

Original Harry locates his trunk and his conductor's hat.

At 5:45, Original Harry brings his trunk and hat to the hallway with a 6PM to 5PM Express sign.

At 5:50, Original Harry puts on his conductor's hat. Harry -- now Conductor Harry -- opens the trunk, steps aside, and yells "All aboard the 6PM to 5PM Express!. Please go to your assigned seat."

Hundreds of invisible Harrys silently climb into the trunk. Each Harry counts the tallies on his arm and sits in the corresponding seat.

At 5:59, conductor Harry yells "Last Call for the 6PM to 5PM Express!"

At 6:00, conductor Harry closes his trunk. He picks up his trunk, and flips his time-turner.

Using this method, Harry can get as much time as he wants to study obliviation, transfigure large objects, or anything else, all with a single twist of his time turner. That's more than enough time to learn to obliviate yourself (and maybe the Weasley) and fake Hermione's death.

The method above might not work if we maintain a fixed past.

You see it can be compared to another similar situation.

Harry an hour (6 to 5 pm) in past and finds 4 time tuners with 4, 3, 2, 1 hours left.

Now harry has used all the five time tuners (but not all of their remaining hours) , done his work in the past and the time move to 5 again. here harry will have to leave 4 time tuners for another future harry to pick up. If we are preserving the past then the four time tuners should have the time left that the original time tuners had i.e.. 4, 3, 2, 1.

So you... (read more)

0shraiyance13y

The method above might not work if we maintain a fixed past. You see it can be compared to another similar situation. Harry an hour (6 to 5 pm) in past and finds there 4 time tuners with 4, 3, 2, 1 hours left. Now harry has used all the five time tuners (but not all of their remaining hours) , done his work in the past and the time move to 5 again. here harry will have to leave 4 time tuners for another future harry to pick up. If we are preserving the past then the four time tuners should have the time left that the original time tuners had i.e.. 4, 3, 2, 1. So you see even when harry uses these 4 extra time tuner he still will be unable to use it them to get back more than 6 hours in past. Now this can be scaled to 1000 time tuners or 1000 harries with time tuners it would make no difference in the amount of time that can be transversed in past by using time tuner. Summary :- Even if you find "n" more time turners once you go in the past, you would not be able to use them to go more then 6 hours in past because to preserve past you will have to leave "n" time tuners (after their use), thus have to leave as much time in them as you potentially gained earlier. Sorry for grammar, spelling mistake, complicated language etc. I am bad at languages.

1EternalStargazer13y

Well, he can get as much time as he wants in 40 minute intervals with no breaks in between. Smelly Harry must have been awake at least 1 hour per mark on his arm, unless he has at some point mastered Polyphasic sleep (which is completely contrary to his aberrant sleep cycles as mentioned previously) he is going to be significantly diminished in terms of mental acuity after a mere 24 or so cycles. He would need to spend a few cycles eating. After subjective days without sleep he should be moving into hallucination territory, barring some kind of magical aid. His "useful time" is only between 5:10-5:50 on each cycle, at other times he will be boarding or leaving the express. It's a moderately good hack, but it isn't of infinite versatility, barring the addition of a bit more cheating to get around the sleep/food problems.