Entangled Truths, Contagious Lies
post by Eliezer Yudkowsky (Eliezer_Yudkowsky)
One of your very early philosophers came to the conclusion that a fully competent mind, from a study of one fact or artifact belonging to any given universe, could construct or visualize that universe, from the instant of its creation to its ultimate end . . .
If any one of you will concentrate upon one single fact, or small object, such as a pebble or the seed of a plant or other creature, for as short a period of time as one hundred of your years, you will begin to perceive its truth.
I am reasonably sure that a single pebble, taken from a beach of our own Earth, does not specify the continents and countries, politics and people of this Earth. Other planets in space and time, other Everett branches, would generate the same pebble.
On the other hand, the identity of a single pebble would seem to include our laws of physics. In that sense the entirety of our Universe—all the Everett branches—would be implied by the pebble.1
From the study of that single pebble you could see the laws of physics and all they imply. Thinking about those laws of physics, you can see that planets will form, and you can guess that the pebble came from such a planet. The internal crystals and molecular formations of the pebble developed under gravity, which tells you something about the planet’s mass; the mix of elements in the pebble tells you something about the planet’s formation.
I am not a geologist, so I don’t know to which mysteries geologists are privy. But I find it very easy to imagine showing a geologist a pebble, and saying, “This pebble came from a beach at Half Moon Bay,” and the geologist immediately says, “I’m confused,” or even, “You liar.” Maybe it’s the wrong kind of rock, or the pebble isn’t worn enough to be from a beach—I don’t know pebbles well enough to guess the linkages and signatures by which I might be caught, which is the point.
“Only God can tell a truly plausible lie.” I wonder if there was ever a religion that developed this as a proverb? I would (falsifiably) guess not: it’s a rationalist sentiment, even if you cast it in theological metaphor. Saying “everything is interconnected to everything else, because God made the whole world and sustains it” may generate some nice warm ’n’ fuzzy feelings during the sermon, but it doesn’t get you very far when it comes to assigning pebbles to beaches.
A penny on Earth exerts a gravitational acceleration on the Moon of around 4.5 × 10-31 m/s2, so in one sense it’s not too far wrong to say that every event is entangled with its whole past light cone. And since inferences can propagate backward and forward through causal networks, epistemic entanglements can easily cross the borders of light cones. But I wouldn’t want to be the forensic astronomer who had to look at the Moon and figure out whether the penny landed heads or tails—the influence is far less than quantum uncertainty and thermal noise.
If you said, “Everything is entangled with something else,” or, “Everything is inferentially entangled and some entanglements are much stronger than others,” you might be really wise instead of just Deeply Wise.
Physically, each event is in some sense the sum of its whole past light cone, without borders or boundaries. But the list of noticeable entanglements is much shorter, and it gives you something like a network. This high-level regularity is what I refer to when I talk about the Great Web of Causality.
I use these Capitalized Letters somewhat tongue-in-cheek, perhaps; but if anything at all is worth Capitalized Letters, surely the Great Web of Causality makes the list.
“Oh what a tangled web we weave, when first we practise to deceive,” said Sir Walter Scott. Not all lies spin out of control—we don’t live in so righteous a universe. But it does occasionally happen that someone lies about a fact, and then has to lie about an entangled fact, and then another fact entangled with that one:
“Where were you?”
“Oh, I was on a business trip.”
“What was the business trip about?”
“I can’t tell you that; it’s proprietary negotiations with a major client.”
“Oh—they’re letting you in on those? Good news! I should call your boss to thank him for adding you.”
“Sorry—he’s not in the office right now . . .”
Human beings, who are not gods, often fail to imagine all the facts they would need to distort to tell a truly plausible lie. “God made me pregnant” sounded a tad more likely in the old days before our models of the world contained (quotations of) Y chromosomes. Many similar lies, today, may blow up when genetic testing becomes more common. Rapists have been convicted, and false accusers exposed, years later, based on evidence they didn’t realize they could leave. A student of evolutionary biology can see the design signature of natural selection on every wolf that chases a rabbit; and every rabbit that runs away; and every bee that stings instead of broadcasting a polite warning—but the deceptions of creationists sound plausible to them, I’m sure.
Not all lies are uncovered, not all liars are punished; we don’t live in that righteous a universe. But not all lies are as safe as their liars believe. How many sins would become known to a Bayesian superintelligence, I wonder, if it did a (non-destructive?) nanotechnological scan of the Earth? At minimum, all the lies of which any evidence still exists in any brain. Some such lies may become known sooner than that, if the neuroscientists ever succeed in building a really good lie detector via neuroimaging. Paul Ekman (a pioneer in the study of tiny facial muscle movements) could probably read off a sizeable fraction of the world’s lies right now, given a chance.
Not all lies are uncovered, not all liars are punished. But the Great Web is very commonly underestimated. Just the knowledge that humans have already accumulated would take many human lifetimes to learn. Anyone who thinks that a non-God can tell a perfect lie, risk-free, is underestimating the tangledness of the Great Web.
Is honesty the best policy? I don’t know if I’d go that far: Even on my ethics, it’s sometimes okay to shut up. But compared to outright lies, either honesty or silence involves less exposure to recursively propagating risks you don’t know you’re taking.
Comments sorted by oldest first, as this post is from before comment nesting was available (around 2009-02-27).
comment by Nominull3 ·
2008-10-16T01:03:29.000Z · LW(p) · GW(p)
It's amazing how many lies go undetected because people simply don't care. I can't tell a lie to fool God, but I can certainly achieve my aims by telling even blatant, obvious lies to human beings, who rarely bother trying to sort out the lies and when they do aren't very good at it.
It sounds to me like you're overreaching for a pragmatic reason not to lie, when you either need to admit that honesty is an end in itself or admit that lies are useful.
comment by Jordan_Fisher ·
2008-10-16T02:40:53.000Z · LW(p) · GW(p)
I agree with Nominull, a good number of lies are undetectable without having access to some sort of lie detector or the agent's source code. If an AI wanted to lie "my recursive modification of my goal systems hasn't led me to accept a goal that involves eventually destroying all human life" I don't see any way we could bust that lie via the 'Web' until the AI was actively pursuing that goal. I value honesty not for the trouble it saves me but because I find (sometimes only hope) that the real world free of distortion is more interesting than any misrepresentation humans can conjure for selfish means.
comment by Tom_McCabe2 ·
2008-10-16T03:07:29.000Z · LW(p) · GW(p)
"Human beings, who are not gods, often fail to imagine all the facts they would need to distort to tell a truly plausible lie."
One of my pet hobbies is constructing metaphors for reality which are blatantly, factually wrong, but which share enough of the deep structure of reality to be internally consistent. Suppose that you have good evidence for facts A, B, and C. If you think about A, B, and C, you can deduce facts D, E, F, and so forth. But given how tangled reality is, it's effectively impossible to come up with a complete list of humanly-deducible facts in advance; there's always going to be some fact, Q, which you just didn't think of. Hence, if you map A, B, and C to A', B', and C', use A', B', and C' to deduce Q', and map Q' back to Q, how accurate Q is is a good check for how well you understand A, B, and C.
Replies from: AshwinV
↑ comment by AshwinV ·
2015-07-01T05:40:28.393Z · LW(p) · GW(p)
It's definitely a check, but not a very good check. There are too many in between facts in this case. It really depends on whether Q is solely dependent on Q' or whether it depends on a number of other things (Q'',Q'''......), provided of course that Q'' and Q''' are not in themselves dependent on A, B and C.
comment by Nate_Barna ·
2008-10-16T03:38:46.000Z · LW(p) · GW(p)
If a lie is defined as the avoidance of truthfully satisfying interrogative sentences (this includes remaining silent), then it wouldn't be honest, under request, to withhold details of a referent. But privacy depends on the existence of some unireferents, as opposed to none and to coreferents. If all privacy shouldn't be abolished, then it isn't clear that the benefits of honesty as an end in itself are underrated.
comment by Z._M._Davis ·
2008-10-16T04:06:15.000Z · LW(p) · GW(p)"[...] when I talk about the Great Web of Causality. I use these Capitalized Letters somewhat tongue-in-cheek [...]"
Personally, I prefer "Great Romance of Determinism."
comment by Thomas ·
2008-10-16T06:45:27.000Z · LW(p) · GW(p)
"Other planets in space and time, other Everett branches, would generate the same pebble."
But not very likely! At least some of them not. What tells you something abut the Multiverse, if you buy it's idea.
comment by haig2 ·
2008-10-16T07:32:45.000Z · LW(p) · GW(p)
A new method of 'lie detection' is being perfected using functional near infrared imaging of the prefrontal cortex:
In this technique the device actually measures whether or not a certain memory is being recalled or is being generated on the spot. For example, if you are interrogating a criminal who denies ever being at a crime scene, and you show them a picture of the scene, you can deduce whether he/she has actually seen it or not by measuring if their brain is recalling some sensory data from memory or newly creating and storing it.
comment by Anatoly_Vorobey ·
2008-10-16T11:31:52.000Z · LW(p) · GW(p)
It seems doubtful to me that a pebble includes in it the law of gravity in the sense of determining it. The internal structure of the pebble, the reason it stays solid, locations of its atoms in relation to each other, are all due to electromagnetism (and strong/weak interactions inside the nucleus). Gravity is completely dominated by other forces, to such a degree that it seems plausible to me that an essentially indistinguishable pebble could exist in a universe with a very different gravity law (although in absence of planets it might be more difficult to explain its formation).
comment by JulianMorrison ·
2008-10-16T13:33:52.000Z · LW(p) · GW(p)
@Nominull: "I can certainly achieve my aims by telling even blatant, obvious lies to human beings"
You are leaving digital crumb trails that the technology of the present day can follow and the technology of 20 years hence will be able to fluidly integrate into a universal public panopticon / rewind button. I don't personally bank on keeping any secret at all in that sort of time-frame.
comment by Stuart_Armstrong ·
2008-10-16T15:15:57.000Z · LW(p) · GW(p)
So a single pebble probably does not imply our whole Earth. But a single pebble implies a very great deal. From the study of that single pebble you could see the laws of physics and all they imply. Thinking about those laws of physics, you can see that planets will form, and you can guess that the pebble came from such a planet. The internal crystals and molecular formations of the pebble formed under gravity, which tells you something about the planet's mass; the mix of elements in the pebble tells you something about the planet's formation.
Call me sceptical about this. We can deduce a lot from a pebble ourselves because we know a lot about our universe, and about our earth.
But are you sure that there are no exotic laws of physics, across all possible universes, that would give rise to the same structure? Or, more simply, with the powers of a god, could you not lie - change the laws of physics and the structure of the universe, until you produce exactly the same pebble in completely different circumstances?
comment by Abigail ·
2008-10-16T15:55:16.000Z · LW(p) · GW(p)
Oh what a tangled web we weave
when first we practice to deceive
But- practice makes perfect. Soon, fair youth,
Your lies will seem as pure as truth.
I thought quite hard before I came up with an answer to Sir Walter which rhymed and scanned. The hero of that poem, whose name I cannot remember at the moment, is fair haired. Perhaps it is not also true, but perhaps that is the point.
Replies from: johnlawrenceaspden
comment by Caledonian2 ·
2008-10-16T17:48:00.000Z · LW(p) · GW(p)
Gravity is completely dominated by other forces, to such a degree that it seems plausible to me that an essentially indistinguishable pebble could exist in a universe with a very different gravity law
Doesn't this depend heavily upon the sensitivity and discrimination of our observing phenomena, as well as whether we examine the pebble as a static, frozen moment or as a phenomenon occurring in time?
For the pebble to truly be completely identical, you might need for it to be embedded in a completely identical cosmos. How small does the difference have to be before it distinguishes one from the other, and do the effects of any one thing on the rest of the cosmos (and vice versa) ever drop to nothing?
comment by JulianMorrison ·
2008-10-16T22:21:58.000Z · LW(p) · GW(p)
No gravity - matter wouldn't have coalesced. It wouldn't have become stars, or fused or been caught up in supernovas, and so a pebble would be an unrealized theoretical possibility.
comment by Anatoly_Vorobey ·
2008-10-16T22:50:15.000Z · LW(p) · GW(p)
Caledonian, quantum mechanics may limit the sensitivity and discrimination of our observations. Also, if gravity's so weak on the atomic level in the pebble that its effects would cause a shift in the arrangement of the atoms smaller than the Planck length, it's not even clear that such a shift exists at all, or what meaning it has.
Julian, I suggested that a very different gravity law might be compatible with the existence of a pebble, not no gravity at all.
In fact, all kinds of things might be different about the laws of physics and the pebble could still exist. E.g. the second Newton's law could be wrong (look up MOND), which would change the story on galaxies in a big way, but not affect the pebble at all.
It seems plausible that a small familiar object like a pebble already has all the fundamental physical laws baked into it, so to speak, and that these laws could be deduced from its structure. But it isn't true. It's easy to overestimate how entangled the tangled web is, too.
comment by NancyLebovitz ·
2008-10-19T19:56:47.000Z · LW(p) · GW(p)
Nothing is lost; the universe is honest,
Time, like the sea, gives all back in the end,
But only in its own way, on its own conditions:
Empires as grains of sand, forests as coal,
Mountains as pebbles. Be still, be still, I say;
You were never the water, only a wave;
Not substance, but a form substance assumed.
Replies from: gwern
comment by djd ·
2008-10-20T21:04:45.000Z · LW(p) · GW(p)
FLOWER in the crannied wall,
I pluck you out of the crannies;—
Hold you here, root and all, in my hand,
Little flower—but if I could understand
What you are, root and all, and all in all, 5
I should know what God and man is.
I dare not confess that, lest I should compare with
him in excellence; but, to know a man well, were to
comment by LazyDave ·
2010-03-23T20:46:28.718Z · LW(p) · GW(p)
" 'God made me pregnant' sounded a tad more likely in the old days before our models of the world contained (quotations of) Y chromosomes. "
I don't know about that; the whole point about the "virgin birth" was that it was miraculous, i.e. physically impossible. Had they known about DNA, the story would have included God creating some DNA for "his" side of the deal. Saying that knowledge of DNA would have made the virgin birth less believable is like saying greater knowledge of classical physics would have made people more skeptical of Jesus walking on water. Impossible == Impossible.
Replies from: SilasBarta
↑ comment by SilasBarta ·
2010-03-23T20:51:51.744Z · LW(p) · GW(p)
Had they known about DNA, the story would have included God creating some DNA for "his" side of the deal.
"So wait, that means ... Samson the TallDarkHandsome Bard is God!" *worships*
comment by lockeandkeynes ·
2010-07-06T05:23:11.147Z · LW(p) · GW(p)
What's a light cone?
Replies from: Mass_Driver, elityre
↑ comment by Mass_Driver ·
2010-07-06T05:47:12.927Z · LW(p) · GW(p)
A future light cone is the part of space-time that can be affected by our actions in the present. Its boundaries are defined by the speed of light. If you imagine the Universe as having only two dimensions in space, then the area of space that you can affect 5 years in the future is a circle with a radius of 5 light-years; if you drew many such circles at different points in time, they would look like a cone. To affect a point in space outside your future light cone, you would have to send out some kind of order or projectile or information faster than the speed of light, and current physics says that this is impossible.
comment by Raw_Power ·
2011-09-04T15:13:28.453Z · LW(p) · GW(p)
There is a way to flawlessly lie, at least for the moment: to lie about what goes on in your minds. Specifically, lie about the motivations for past actions, especially when those motivations were nebulous in the first place and the lie is more plausible than the actual truth.
comment by kilobug ·
2011-09-15T08:31:32.311Z · LW(p) · GW(p)
Lies requiring new lies and having a risk of growing out of control is indeed a very fundamental reason for which "don't lie" is part of my ethics. But it's not an "absolute" ethical rule like "don't kill", "don't torture" or "don't use violence against someone you just disagree with". Because there are many situations in which lying is worth the risk and the "inehrent" badness of not following the truth.
When my grandmother hid Jews during Nazi occupation, and answered "no, there is on one here" to the Gestapo officer asking her, she lied, and she indeed took a great risk - she was risking her life. But she definitely right to do so. Sure, arguing by WW2 for general ethics is well... not the wisest. WW2 was an exceptional situation, which justified exceptional means.
But I've a similar example in my own personal life. During the Rwanda genocide (I was then a teenager), my family hid in my home (for a few weeks) a Hutu whose whole family was killed, and who was himself threatened, because his family was helping the Tutsi to avoid the genocide. This guy was an "illegal alien", and he could have been legally expelled from France, since, according to the legal authorities, he was a Hutu, and only Tutsi were endangered. To protect him I had to lie - like make excuses to not invite friends at home (since, well, teenagers tend to speak a lot, if the secret started to spread, it would quickly spread out of control, so even my friends were not allowed to know).
Lying is ethically bad, yes. But not near the level of endangering someone's life, or risking to have him exposed to torture. Sadly, we live in a world in which sometimes have to lie to protect.
comment by AndyCossyleon ·
2012-07-11T16:46:21.006Z · LW(p) · GW(p)
I find it much more convenient to, instead of lying, simply using ambiguous phrases to plant the false idea into someone else's mind. The important part is to make the phrase ambiguous in such a way that it can be plausibly interpreted truthfully. Say you don't want someone to know you went up the stairs, then you say "I didn't walk up the stairs" because you in fact ran up the stairs. Even if your lie is found out, this reduces the social cost since, if you are political enough, you can convince others that you didn't actually lie. And if you are very good at it, you can tailor the deception so that only a minority of people (which includes the addressee) would interpret it falsely; and you can then let the majority construe it as misunderstanding on behalf of the deceived.
comment by Decius ·
2012-07-14T12:43:59.215Z · LW(p) · GW(p)
So, where do you provide a manner to select the ethical premises which create the moral system in which honesty and lies are meaningful distinctions?
comment by ialdabaoth ·
2012-11-05T18:31:16.351Z · LW(p) · GW(p)
"Oh what a tangled web we weave, when first we practise to deceive," said Sir Walter Scott. Not all lies spin out of control—we don't live in so righteous a universe. But it does occasionally happen, that someone lies about a fact, and then has to lie about an entangled fact, and then another fact entangled with that one:
"Where were you?"
"Oh, I was on a business trip."
"What was the business trip about?"
"I can't tell you that; it's proprietary negotiations with a major client."
"Oh—they're letting you in on those? Good news! I should call your boss to thank him for adding you."
"Sorry—he's not in the office right now..."
The truth can just as easily "spin out of control" as a lie, if people are sufficiently powerful to create the appearance of a lie. It may sound absurd for a boss to go out of their way to cause an employee to appear to be lying to their spouse, but it does happen, and frighteningly regularly. Humans are masters of perception-manipulation for social gain; it's been part of the evolutionary landscape we developed in for at least O(million years), and is theorized as one of the reasons for our big brains. A sufficiently constructed lie will make all truth-speakers that disagree with it sound like liars. The assertion that the probability for the truth to spin out of control is greater than the probability for any given lie to spin out of control in any given situation is amenable to evidence - is there some way that we could categorize situations, and then examine their tendencies to spin out of control when told the truth vs. told a lie, such that more specifically accurate theories could be developed?
My own meager evidence has suggested that the truth is more likely to spin out of control than a lie when the truth conflicts with a sufficiently-prepared lie told by a social superior, for example.
comment by ChristianKl ·
2014-07-02T12:48:26.660Z · LW(p) · GW(p)
I am reasonably sure that a single pebble, taken from a beach of our own Earth, does not specify the continents and countries, politics and people of this Earth.
A single pebble contains a lot of atoms an those atoms interact via gravitational forces with the world around them. Heisenberg's uncertainty principle might prevent you from knowing everything about earth from a single pebble but otherwise you just would have to measure the movement of the atoms in the pebble closely enough.
Replies from: PetjaY
↑ comment by PetjaY ·
2015-01-24T18:02:55.866Z · LW(p) · GW(p)
Many different things can cause similar movements, you could detect something pulling those atoms in 1 direction, and something else pushing them back at the edge of the pebble which is closest to earths center of gravity. But you would not know what is causing that pull, only from where it is coming and how strong it is.
comment by Thomas Eisen (thomas-eisen) ·
2019-10-06T20:12:54.434Z · LW(p) · GW(p)
I don‘t understand the meaning of the sentence „And since inferences can propagate backward and forward through causal networks, epistemic entanglements can easily cross the borders of light cones. “
Replies from: Vaniver
↑ comment by Vaniver ·
2019-10-06T19:27:44.729Z · LW(p) · GW(p)
Suppose I have two cards, A and B, that I shuffle and then blindly place in two spaceships, pointed at opposite ends of the galaxy. If they go quickly enough, it can be the case that they get far enough apart that they will never be able to meet again. But if you're in one of the spaceships, and turn the card over to learn that it's card A, then you learn something about the world on the other side of the light cone boundary.
comment by jeronimo196 ·
2020-03-08T14:32:42.918Z · LW(p) · GW(p)
But compared to outright lies, either honesty or silence involves less exposure to recursively propagating risks you don’t know you’re taking.
Only if you value unblemished reputation over the short term gain provided by the lie.
Fooling some of the people some of the time might be sufficient for an unscrupulous agent.