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Semantic Stopsigns

54 Eliezer_Yudkowsky 24 August 2007 07:29PM

And the child asked:

Q:  Where did this rock come from?
A:  I chipped it off the big boulder, at the center of the village.
Q:  Where did the boulder come from?
A:  It probably rolled off the huge mountain that towers over our village.
Q:  Where did the mountain come from?
A:  The same place as all stone: it is the bones of Ymir, the primordial giant.
Q:  Where did the primordial giant, Ymir, come from?
A:  From the great abyss, Ginnungagap.
Q:  Where did the great abyss, Ginnungagap, come from?
A:  Never ask that question.

Consider the seeming paradox of the First Cause.  Science has traced events back to the Big Bang, but why did the Big Bang happen?  It's all well and good to say that the zero of time begins at the Big Bang—that there is nothing before the Big Bang in the ordinary flow of minutes and hours.  But saying this presumes our physical law, which itself appears highly structured; it calls out for explanation.  Where did the physical laws come from?  You could say that we're all a computer simulation, but then the computer simulation is running on some other world's laws of physics—where did those laws of physics come from?

At this point, some people say, "God!"

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Guessing the Teacher's Password

62 Eliezer_Yudkowsky 22 August 2007 03:40AM

Followup to:  Fake Explanations

When I was young, I read popular physics books such as Richard Feynman's QED: The Strange Theory of Light and Matter.  I knew that light was waves, sound was waves, matter was waves.  I took pride in my scientific literacy, when I was nine years old.

When I was older, and I began to read the Feynman Lectures on Physics, I ran across a gem called "the wave equation".  I could follow the equation's derivation, but, looking back, I couldn't see its truth at a glance.  So I thought about the wave equation for three days, on and off, until I saw that it was embarrassingly obvious.  And when I finally understood, I realized that the whole time I had accepted the honest assurance of physicists that light was waves, sound was waves, matter was waves, I had not had the vaguest idea of what the word "wave" meant to a physicist.

There is an instinctive tendency to think that if a physicist says "light is made of waves", and the teacher says "What is light made of?", and the student says "Waves!", the student has made a true statement.  That's only fair, right?  We accept "waves" as a correct answer from the physicist; wouldn't it be unfair to reject it from the student?  Surely, the answer "Waves!" is either true or false, right? 

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Your Strength as a Rationalist

69 Eliezer_Yudkowsky 11 August 2007 12:21AM

(The following happened to me in an IRC chatroom, long enough ago that I was still hanging around in IRC chatrooms.  Time has fuzzed the memory and my report may be imprecise.)

So there I was, in an IRC chatroom, when someone reports that a friend of his needs medical advice.  His friend says that he's been having sudden chest pains, so he called an ambulance, and the ambulance showed up, but the paramedics told him it was nothing, and left, and now the chest pains are getting worse.  What should his friend do?

I was confused by this story.  I remembered reading about homeless people in New York who would call ambulances just to be taken someplace warm, and how the paramedics always had to take them to the emergency room, even on the 27th iteration.  Because if they didn't, the ambulance company could be sued for lots and lots of money.  Likewise, emergency rooms are legally obligated to treat anyone, regardless of ability to pay.  (And the hospital absorbs the costs, which are enormous, so hospitals are closing their emergency rooms...  It makes you wonder what's the point of having economists if we're just going to ignore them.)  So I didn't quite understand how the described events could have happened.  Anyone reporting sudden chest pains should have been hauled off by an ambulance instantly.

And this is where I fell down as a rationalist.  I remembered several occasions where my doctor would completely fail to panic at the report of symptoms that seemed, to me, very alarming.  And the Medical Establishment was always right.  Every single time.  I had chest pains myself, at one point, and the doctor patiently explained to me that I was describing chest muscle pain, not a heart attack.  So I said into the IRC channel, "Well, if the paramedics told your friend it was nothing, it must really be nothing—they'd have hauled him off if there was the tiniest chance of serious trouble."

Thus I managed to explain the story within my existing model, though the fit still felt a little forced...

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The Virtue of Narrowness

56 Eliezer_Yudkowsky 07 August 2007 05:57PM

What is true of one apple may not be true of another apple; thus more can be said about a single apple than about all the apples in the world.
       —Twelve Virtues of Rationality 

Within their own professions, people grasp the importance of narrowness; a car mechanic knows the difference between a carburetor and a radiator, and would not think of them both as "car parts".  A hunter-gatherer knows the difference between a lion and a panther.  A janitor does not wipe the floor with window cleaner, even if the bottles look similar to one who has not mastered the art.

Outside their own professions, people often commit the misstep of trying to broaden a word as widely as possible, to cover as much territory as possible.  Is it not more glorious, more wise, more impressive, to talk about all the apples in the world?  How much loftier it must be to explain human thought in general, without being distracted by smaller questions, such as how humans invent techniques for solving a Rubik's Cube.  Indeed, it scarcely seems necessary to consider specific questions at all; isn't a general theory a worthy enough accomplishment on its own?

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Focus Your Uncertainty

33 Eliezer_Yudkowsky 05 August 2007 08:49PM

Will bond yields go up, or down, or remain the same? If you're a TV pundit and your job is to explain the outcome after the fact, then there's no reason to worry. No matter which of the three possibilities comes true, you'll be able to explain why the outcome perfectly fits your pet market theory . There's no reason to think of these three possibilities as somehow opposed to one another, as exclusive, because you'll get full marks for punditry no matter which outcome occurs.

But wait! Suppose you're a novice TV pundit, and you aren't experienced enough to make up plausible explanations on the spot. You need to prepare remarks in advance for tomorrow's broadcast, and you have limited time to prepare. In this case, it would be helpful to know which outcome will actually occur—whether bond yields will go up, down, or remain the same—because then you would only need to prepare one set of excuses.

Alas, no one can possibly foresee the future. What are you to do? You certainly can't use "probabilities". We all know from school that "probabilities" are little numbers that appear next to a word problem, and there aren't any little numbers here. Worse, you feel uncertain. You don't remember feeling uncertain while you were manipulating the little numbers in word problems. College classes teaching math are nice clean places, therefore math itself can't apply to life situations that aren't nice and clean.  You wouldn't want to inappropriately transfer thinking skills from one context to another.  Clearly, this is not a matter for "probabilities".

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Belief as Attire

40 Eliezer_Yudkowsky 02 August 2007 05:13PM

I have so far distinguished between belief as anticipation-controller, belief in belief, professing and cheering.  Of these, we might call anticipation-controlling beliefs "proper beliefs" and the other forms "improper belief".  A proper belief can be wrong or irrational, e.g., someone who genuinely anticipates that prayer will cure her sick baby, but the other forms are arguably "not belief at all".

Yet another form of improper belief is belief as group-identification—as a way of belonging.  Robin Hanson uses the excellent metaphor of wearing unusual clothing, a group uniform like a priest's vestments or a Jewish skullcap, and so I will call this "belief as attire".

In terms of humanly realistic psychology, the Muslims who flew planes into the World Trade Center undoubtedly saw themselves as heroes defending truth, justice, and the Islamic Way from hideous alien monsters a la the movie Independence Day.  Only a very inexperienced nerd, the sort of nerd who has no idea how non-nerds see the world, would say this out loud in an Alabama bar.  It is not an American thing to say.  The American thing to say is that the terrorists "hate our freedom" and that flying a plane into a building is a "cowardly act".  You cannot say the phrases "heroic self-sacrifice" and "suicide bomber" in the same sentence, even for the sake of accurately describing how the Enemy sees the world.   The very concept of the courage and altruism of a suicide bomber is Enemy attire—you can tell, because the Enemy talks about it.  The cowardice and sociopathy of a suicide bomber is American attire.  There are no quote marks you can use to talk about how the Enemy sees the world; it would be like dressing up as a Nazi for Halloween.

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Professing and Cheering

39 Eliezer_Yudkowsky 02 August 2007 07:20AM

I once attended a panel on the topic, "Are science and religion compatible?" One of the women on the panel, a pagan, held forth interminably upon how she believed that the Earth had been created when a giant primordial cow was born into the primordial abyss, who licked a primordial god into existence, whose descendants killed a primordial giant and used its corpse to create the Earth, etc. The tale was long, and detailed, and more absurd than the Earth being supported on the back of a giant turtle. And the speaker clearly knew enough science to know this.

I still find myself struggling for words to describe what I saw as this woman spoke. She spoke with... pride? Self-satisfaction? A deliberate flaunting of herself?

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Bayesian Judo

71 Eliezer_Yudkowsky 31 July 2007 05:53AM

You can have some fun with people whose anticipations get out of sync with what they believe they believe.

I was once at a dinner party, trying to explain to a man what I did for a living, when he said: "I don't believe Artificial Intelligence is possible because only God can make a soul."

At this point I must have been divinely inspired, because I instantly responded: "You mean if I can make an Artificial Intelligence, it proves your religion is false?"

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Belief in Belief

66 Eliezer_Yudkowsky 29 July 2007 05:49PM

Followup to: Making Beliefs Pay Rent (in Anticipated Experiences)

Carl Sagan once told a parable of a man who comes to us and claims: "There is a dragon in my garage." Fascinating! We reply that we wish to see this dragon—let us set out at once for the garage! "But wait," the claimant says to us, "it is an invisible dragon."

Now as Sagan points out, this doesn't make the hypothesis unfalsifiable. Perhaps we go to the claimant's garage, and although we see no dragon, we hear heavy breathing from no visible source; footprints mysteriously appear on the ground; and instruments show that something in the garage is consuming oxygen and breathing out carbon dioxide.

But now suppose that we say to the claimant, "Okay, we'll visit the garage and see if we can hear heavy breathing," and the claimant quickly says no, it's an inaudible dragon. We propose to measure carbon dioxide in the air, and the claimant says the dragon does not breathe. We propose to toss a bag of flour into the air to see if it outlines an invisible dragon, and the claimant immediately says, "The dragon is permeable to flour."

Carl Sagan used this parable to illustrate the classic moral that poor hypotheses need to do fast footwork to avoid falsification. But I tell this parable to make a different point: The claimant must have an accurate model of the situation somewhere in his mind, because he can anticipate, in advance, exactly which experimental results he'll need to excuse.

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Making Beliefs Pay Rent (in Anticipated Experiences)

111 Eliezer_Yudkowsky 28 July 2007 10:59PM

Thus begins the ancient parable:

If a tree falls in a forest and no one hears it, does it make a sound? One says, "Yes it does, for it makes vibrations in the air." Another says, "No it does not, for there is no auditory processing in any brain."

Suppose that, after the tree falls, the two walk into the forest together. Will one expect to see the tree fallen to the right, and the other expect to see the tree fallen to the left? Suppose that before the tree falls, the two leave a sound recorder next to the tree. Would one, playing back the recorder, expect to hear something different from the other? Suppose they attach an electroencephalograph to any brain in the world; would one expect to see a different trace than the other? Though the two argue, one saying "No," and the other saying "Yes," they do not anticipate any different experiences.  The two think they have different models of the world, but they have no difference with respect to what they expect will happen to them.

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