Wednesday, September 16, 2015

Harry Potter MoR: The must-read book that isn’t in a library

Harry Potter and the
Methods of Rationality

by Eliezer Yudkowsky
(pen name: LessWrong). 

Reviewed by
William H. Calvin

No, it isn’t a J. K. Rowling sequel.  It comes from a genre known as fan fiction that exists out there in the cloud.

Recall Harry’s foster parents (Aunt Petunia, who married a businessman named Vernon Dursley)?  The basic pretense of Yudkowsky’s alternative Harry Potter universe is this:

PETUNIA EVANS married Michael Verres, a Professor of Biochemistry at Oxford. 

HARRY JAMES POTTER-EVANS-VERRES grew up in a house filled to the brim with books. He once bit a math teacher who didn’t know what a logarithm was. He’s read Godel, Escher, Bach and Judgment Under Uncertainty: Heuristics and Biases and volume one of The Feynman Lectures on Physics. And despite what everyone who’s met him seems to fear, he doesn’t want to become the next Dark Lord. He was raised better than that. He wants to discover the laws of magic and become a god.

This makes Harry’s first day at Hogwarts a little different:

After the boy had closed that [train] compartment door, Hermione said, “Can I help you with something?”  
   The scarfed face turned to look at her, and the voice said, “Not unless you can name the six quarks, or tell me where to find Hermione Granger.”
   “Up, down, strange, charm, truth, beauty, and why are you looking for her?”
  - - -
“Oh, good, very good, that. And if someone bumps into me, the Time-Turner will not break and will not trap the whole castle of Hogwarts in an endlessly repeating loop of Thursdays.”
 - - -
“Really,” Harry said [to Minerva]. “Ahahahaha.  Of course you wouldn’t give time machines to children if they were dangerous, what was I thinking? 
   So just to be clear, sneezing on this device will not send me into the Middle Ages where I will run over Gutenberg with a horse cart and prevent the Enlightenment?  Because, you know, I hate it when that happens to me.”

And what’s this about rationality’s methods in the title?  Briefly, it means the procedures for making your thoughts “less wrong” (as in the author’s pen name).

You know, said the part of him that refined his skills, didn’t you sort of ponder, once, how every different profession has a different way to be excellent, how an excellent teacher isn’t like an excellent plumber; but they all have in common certain methods of not being stupid; and that one of the most important such techniques is to face up to your little mistakes before they turn into BIG mistakes?
  - - -
 “You know, Draco, just as the fundamental question of rationality is ‘What do I think I know and how do I think I know it?’, there’s also a cardinal sin, a way of thinking that’s the opposite of that.
   Like the ancient Greek philosophers. They had no clue what was going on, so they’d go around saying things like ‘All is water’ or ‘All is fire’, and they never asked themselves, ‘Wait a minute, even if everything is water, how could I possibly know that?’
   They didn’t ask themselves if they had evidence which discriminated that possibility from all the other possibilities you could imagine ….”
  - - -
And standing amid the dusty desks in an unused classroom in the dungeons of Hogwarts, the green-lit silhouette of Harry Potter spread his arms dramatically and said, “This day shall mark the dawn of… the Bayesian Conspiracy.”
  - - -
It did occur to Minerva to wonder (now that she’d spent a few months around Mr. Potter) how anyone could possibly know that [about time travel]; but she also knew better than to ask Albus, in case Albus tried to tell her. Minerva firmly believed that you only ought to worry about Time if you were a clock.
  - - -
There is only one reality that generates all of the observations. If different observations seem to point in incompatible directions, it means the true hypothesis is one you haven’t thought of yet.
   And in those cases, when you finally think of the correct hypothesis, everything aligns behind it, beyond denial or horror, tearing away every doubt and every emotion that might stand in its path.
  - - -
Eliezer Yudkowsky
There was an upper-year spell Harry had run across whose literal incantation was ‘Arresto Momentum!’ and when Harry had asked if the momentum went anywhere else, he’d just gotten a puzzled look. Harry had kept an increasingly desperate eye out for some kind of conservation principle in magic….

This book is not merely rich in philosophy and physics thinking; there is no end of psychology, genetics, sociobiology, and cognitive science scattered throughout this remarkable book.  It is science made palatable, even literary.

The words seemed to echo inside Harry’s head, sparking resonances that as quickly died away, broken patterns trying to complete themselves and failing. 
 - - -
The Defense Professor’s small office was silent, the sound-warded room quiet in a way the Headmaster’s office never could be. Sometimes the two of them both happened to finish exhaling or inhaling at the same time; and then there was an auditory emptiness that was almost a sound in itself.”
 - - -
When you walked through a park, the immersive world that surrounded you was something that existed inside your own brain as a pattern of neurons firing. The sensation of a bright blue sky wasn’t something high above you, it was something in your visual cortex, and your visual cortex was in the back of your brain.
 - - -
Human beings modeled the world using stratified levels of organization, they had separate thoughts about how countries worked, how people worked, how organs worked, how cells worked, how molecules worked, how quarks worked.
  - - -
   “Science is not a bag of technological tricks,” Harry said. “It’s not just the Muggle version of a wand. It’s not even knowledge, like memorizing the periodic table. It’s a different way of thinking.”

Novels are about people and why they do the things they do.

“They hurt when they see their friends hurting. Someone inside their circle of concern, a member of their own tribe. That feeling has an off-switch, an off-switch labeled ‘enemy’ or ‘foreigner’ or sometimes just ‘stranger’.
   That’s how people are, if they don’t learn otherwise. So, no, it does not indicate that Draco Malfoy was inhuman or even unusually evil, if he grew up believing that it was fun to hurt his enemies.”
  - - -
Harry Potter gave a little shrug. His spoon dropped back into his cereal, and went on stirring without a pause. “Why does any kind of cynicism appeal to people? Because it seems like a mark of maturity, of sophistication, like you’ve seen everything and know better. Or because putting something down feels like pushing yourself up…. Or because being cynical feels like knowing a secret truth that common people don’t know…”
 - - - 
And now even within Ravenclaw, his only remaining competitors [for high grades] were Padma Patil (whose parents came from a non-English-speaking culture and thus had raised her with an actual work ethic), Anthony Goldstein (out of a certain tiny ethnic group that won 25% of the Nobel Prizes), and of course, striding far above everyone like a Titan strolling through a pack of puppies, Hermione Granger.
  - - -
Dumbledore gazed out at the tables with a distant look. “In every city,” the old wizard quoted softly, “the population has been divided for a long time past into the Blue and the Green factions… And they fight against their opponents knowing not for what end they imperil themselves… So there grows up in them against their fellow men a hostility which has no cause, and at no time does it cease or disappear, for it gives place neither to the ties of marriage nor of relationship nor of friendship, and the case is the same even though those who differ with respect to these colours be brothers or any other kin. I, for my part, am unable to call this anything except a disease of the soul…“
   “I’m sorry,” said Minerva, “I don’t -”
   “Procopius,” said Dumbledore. “They took their chariot-racing very seriously, in the Roman Empire.
 - - -
“Yes,” said Harry Potter, “but the problem of acting together isn’t just for wars, it’s something we have to solve all our lives, every day. If everyone is coordinating using the same rules, and the rules are stupid, then if one person decides to do things differently, they’re breaking the rules. But if everyone decides to do things differently, they can. It’s exactly the same problem of everyone needing to act together. But for the first person who speaks out, it seems like they’re going against the crowd.
   And if you thought that the only important thing was that people should always be unified, then you could never change the game, no matter how stupid the rules.”
 - - -
It was very hard for Harry to control his breathing. “Professor Quirrell… your proposals are extremely alarming to anyone who has the slightest familiarity with Muggle history over the last century. The Italian fascists, some very nasty people, got their name from the fasces, a bundle of rods bound together to symbolize the idea that unity is strength.”
 - - -
It was a sad commentary on how little human beings understood each other…. But then human beings only understood each other in the first place by pretending. You didn’t make predictions about people by modeling the hundred trillion synapses in their brain as separate objects….You predicted people by telling your brain to act like theirs.
 - - -
   “It’s funny,” Dean Thomas said thoughtfully. “I didn’t believe the General [Potter] when he said that what we learned would change us forever, and we’d never be able to return to a normal life afterward. Once we knew. Once we saw what he could see.” 
   “I know!” said Seamus Finnigan. “I thought it was just a joke too! Like, you know, everything else General Chaos ever said ever.”  
  “But now -” Dean said sadly. “We can’t go back, can we?  It’d be like going back to a Muggle school after having been to Hogwarts.  We’ve just… we’ve just got to stay around each other.  That’s all we can do, or we’ll go crazy.”

  - - -
“I was going to give you more space,” said Harry Potter [to the traumatized Hermione], “only I was reading up on Critch’s theories about hedonics and how to train your inner pigeon and how small immediate positive and negative feedbacks secretly control most of what we actually do, and it occurred to me that you might be avoiding me because seeing me made you think of things that felt like negative associations, and I really didn’t want to let that run any longer without doing something about it, so I got ahold of a bag of chocolates from the Weasley twins and I’m just going to give you one every time you see me, as a positive reinforcement, if that’s all right with you....”
   “Breathe, Harry,” Hermione said without thinking about it.

Yudkowsky, an AI theorist, has an enormous command of his topics.  He even gets my favorite subject right:

A natural guess, but wrong. Before people had quite understood how [human] evolution worked, they’d gone around thinking crazy ideas like the climate changed, and tribes had to migrate, and people had to become smarter in order to solve all the novel problems.
   But human beings had four times the brain size of a chimpanzee. 20% of a human’s metabolic energy went into feeding the brain. Humans were ridiculously smarter than any other species. That sort of thing didn’t happen because the environment stepped up the difficulty of its problems a little. Then the organisms would just get a little smarter to solve them. Ending up with that gigantic outsized brain must have taken some sort of runaway evolutionary process, something that would push and push without limits.

That is indeed the Big Question for understanding human evolution (I addressed it in A Brief History of the Mind).  And I love his version of the Big Picture:

The young boy stood very straight, his chin raised high and proud, and said: “There is no justice in the laws of Nature, Headmaster, no term for fairness in the equations of motion.  The universe is neither evil, nor good, it simply does not care.  The stars don’t care, or the Sun, or the sky.
   But they don’t have to!  We care!  There is light in the world, and it is us!”

William H. Calvin is the author of A Brief History of the Mind (Oxford University Press).  UCSD/Salk Center for Academic Research and Training in Anthropogeny, LaJolla CA, and Department of Psychiatry and Behavioral Sciences, University of Washington, 725 9th Avenue, Box 2605, Seattle WA 98104-2086 USA.  Email:

J. K. Rowling has not objected to this borrowing of the characters she created, given that no one is making money.  But without a profit motive, you currently cannot buy a copy of this must-read book, nor reserve a copy at your local library. Nor will you ever see it on a bestseller list.  
So you must get it in the same way as its many fans have used over the last five years as it appeared in serial form.  You can view it on the web at (all 122 chapters, one by one) or you can download it as one long file in MOBI (for Kindles and the Kindle web reader) or EPUB (for most other ebook readers).  This will leave, for example, the file in your download folder. 
Then you need to email this file as an attachment; for a Kindle, one looks up its email address on under Managing Your Content and Devices.  Send it off and the file will show up in the Cloud repository of your Kindle titles, which also makes it accessible from Amazon’s web readers.

When successful, reward yourself with some chocolate (not included).  Help yourself to an extra square for each potential science student to whom you forward this review. This book is the best thing 
in decades for popularizing science.

Sunday, November 23, 2014

Brain size in the Homo lineage, leaving out the side branches

How fast did brain size increase in our lineage? To answer that, one has to make some judgments as to who was not an ancestor. I've been working my way through Ralph Holloway's xls file of hominid skulls and their dating, removing all of the side branches such as the Neandertals and the more recent Homo erectus skulls.

So it is 2.5 myr of adding about 427 cc every million years, atop the 400 cc seen in the great apes and the bipedal woodland apes (those data points older than 2.5 myr).

That dashed gap from 2.5 to 1.9 myr?. There are bones enough to say there are Homo species in the gap, just not skulls good enough to reconstruct for a cranial capacity estimate.

And that last column of dots on the right stops before agriculture starts to confuse the issues. So they are not the modern human brain range, nor the stunted vegetarians of early irrigation agriculture with all the deficiency diseases seen in paleopathology.

And what, you may ask, happened 2.5 million years ago? The ice ages began and, with them, lots of fluctuations to cause more droughts.