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No One Knows What Science Doesn't Know

38 Post author: Eliezer_Yudkowsky 25 October 2007 11:47PM

At a family party some years ago, one of my uncles remarked on how little science really knows.  For example, we still have no idea how gravity works - why things fall down.

"Actually, we do know how gravity works," I said.  (My father, a Ph.D. physicist, was also present; but he wasn't even touching this one.)

"We do?" said my uncle.

"Yes," I said, "Gravity is the curvature of spacetime."  At this point I had still swallowed Feynman's line about being able to explain physics to one's grandmother, so I continued:  "You could say that the Earth goes around the Sun in a straight line.  Imagine a graph that shows both space and time, so that a straight line shows steady movement and a curved line shows acceleration.  Then curve the graph paper itself.  When you try to draw a straight line on the curved paper, you'll get what looks like acceleration -"

"I never heard about anything like that," said my uncle.

When was the last time, in history, when it was possible for a single human to know the knowledge of the most advanced civilization?  I've seen various estimates for this - usually in the form of polymaths nominated for the position of "last person to know everything".  One plausible candidate is Leonardo da Vinci, who died in 1519 - shortly after the printing press began to become popular, and shortly before Copernicus inaugurated the scientific revolution.

In the ancestral environment it was possible to know everything, and nearly everyone did.  In hunter-gatherer bands of less than 200 people, with no written literature, all background knowledge was universal knowledge.  If one person, in a world containing 200 people total, discovered how gravity worked, you could certainly expect to hear about it.

In a world of 6 billion people, there is not one person alive who can say with certainty that science does not know a thing.  There is too much science.  Our current lifetimes are too short to learn more than a tiny fraction of it, and more is being produced all the time.

Even if last week's technical journal doesn't contain the answer to a mystery, that doesn't mean that no one knows it.  Maybe someone out there is typing up the paper at this very moment.  You can't generalize over all 6 billion people in the world because you haven't talked to all of them - which is a non-ancestral condition!  For the vast majority of humanity's evolutionary history, it was possible to meet everyone in your little world.  Now there's 6 billion people who might know the answer to any question you care to ask, and you can't ask all of them.

No one knows anymore what no one knows.

My uncle is not an isolated phenomenon.  I've met people who think that science knows nothing about the brain, that thought is a complete mystery unto us.  (My favorite was the fellow who confidently asserted that neuroscience had been unable to assign any function "to the cerebral cortex".)  As Tom McCabe put it:  "Anyone who claims that the brain is a total mystery should be slapped upside the head with the MIT Encyclopedia of the Cognitive Sciences.  All one thousand ninety-six pages of it."

I haven't seen the movie What The Bleep Do We Know, but if the horror stories are true, it's one long celebration of imaginary ignorance.  Particularly the "mysterious effect of conscious observation" in quantum physics, which was explained away as ordinary decoherence in the 1950s, but let's not get into that again.

Ignorance should not be celebrated in the first place; I've made this point before.  It is a corruption of curiosity to prefer the question to its answer.  Yet people seem to get a tremendous emotional kick out of not knowing something.  Worse, they think that the mysteriousness of a mysterious phenomena indicates a special quality of the phenomenon itself, inferring that it is surely different-in-kind from phenomena labeled "understood".  If we are ignorant about a phenomenon, that is a fact about our state of mind, not a fact about the phenomenon itself.

In the ancestral environment, there was a certain permanence to the division between ignorance and knowledge.  If none of your fellow hunter-gatherers knew what made rain fall, it was likely that no one would ever find out in your grandchildren's lifetimes.  Today, the absence of knowledge is a fragile and temporary condition, like the darkness in a closet whose door happens to be shut.  A single thought can shatter the absence of thought.  Every scientific discovery ever made, destroyed an ancient absence-of-knowledge dating back to the dawn of time.  No one knows what 6 billion people don't know today, and still less does anyone know what 7 billion people will know tomorrow.

Comments (107)

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Comment author: Matthew2 26 October 2007 12:25:06AM 1 point [-]

So when a christian presuppositionalist claims we can only know anything because God exists, your answer would be? I mean to say their is clearly no epistemology which explains clearly and technically intelligence itself. What is the your answer to the assertion: you have no epistemology but God is the basis of epistemology? I don't agree at all, my question is simply how to respond since they assume one needs to justify logic itself.

Comment author: wedrifid 10 July 2009 07:58:02PM 9 points [-]

So when a christian presuppositionalist claims we can only know anything because God exists, your answer would be?

"You could be right! Hey, get this! The funniest thing happened to my friend Jake just the other day..."

Comment author: Solvent 18 October 2011 07:51:06AM 2 points [-]

I know this is about two years late, but I'm really curious as to what that means.

Comment author: wedrifid 18 October 2011 09:32:24AM *  4 points [-]

It means 'change the topic and talk about something fun'. The 'You could be right!' also constitutes 'fogging'. ie. It diffuses the argument and gives them nothing to attack and less incentive to take an aggressive stance on that issue.

Comment author: MarkusRamikin 18 October 2011 10:43:10AM *  9 points [-]

Fogging indeed. If Matthew by his question meant "how would you honestly address that argument", then you didn't answer Matthew any more than that hypotetical presuppositionalist.

Comment author: NDJS 14 August 2011 12:43:26AM 7 points [-]

They are making an unfounded assertion on top of an already unfounded assertion. Two wrongs don't make a right, especially in fields lacking any subjectivity.

Comment author: lessdazed 14 August 2011 12:50:51AM 1 point [-]
Comment author: Nick_Tarleton 26 October 2007 12:33:01AM 5 points [-]

Does anyone know how to build a Friendly AI?

It seems perfectly possible to know a particular field well enough that you can predict with high confidence that nobody currently knows the answer to some question. You can never be certain of this, but that's trivial.

Comment author: soreff 07 May 2011 01:01:47AM 1 point [-]

Agreed (albeit I also agree with Ken2's comment in response). One other point, though, is that there are some limitations one can know based on our current ability to do experiments. Perhaps one of the string theories is right about physics at Plank energies - but we currently have no access to particles at those energies, which severely limits how well we can currently test such theories. Given two theories which make different predictions in this regime, but which have nearly indistinguishable low energy limits, we have essentially no current way to tell which is more likely to be true.

Comment author: James_Smith 28 June 2011 12:33:01AM 0 points [-]

I agree with the original premise that there are too many people for one person to know everything or even everything that is known.

Something I read some years ago is that everyone knows something that you do not. In that regard, everyone is your master.

Comment author: Ken2 26 October 2007 01:12:24AM 3 points [-]

Nick that's an interesting thought, but it is possible that someone does know how to build a friendly AI, but may not know that he knows this. What I mean is that a person may be working on something unrelated to AI or is not interested in AI, but knows all the ingredients and technical things needed to make a friendly AI. Maybe he just doesn't know the implications of his own knowledge.

I think it's fair to say many scientists fall into this category, if only due to specialization. Maybe some inorganic chemist knows the cure to cancer. But simply due to his ignorance/uninterest in biochemistry or organic chemistry or whatever subject that's relevant is unaware of the implications of his own specialized knowledge on topics outside his area of expertise.

Comment author: Untrained_rationale 10 July 2015 11:53:37AM -1 points [-]

An interesting thought and to further that it is quite probable that the cure to cancer is locked up in a child's brain in Africa struggling to survive. Similarly, it is also quite probable that the many humans beings inhabiting our planet that do not receive education and thus remain blissfully ignorant could've solved the many problems of science, medicine etc that all the learned minds in the world are struggling with. To me this thought invited very mind boggling epiphanies about life and about our existence and most importantly about the nature of our world.

Comment author: Eliezer_Yudkowsky 26 October 2007 01:37:18AM 3 points [-]

Ken, logical ignorance is still ignorance; if this were not so, I would know a proof of the Riemann Hypothesis.

Nick, it's possible, though not at all probable, that someone among Earth's 6 billions is putting the finishing touches on their quiet project right now.

Comment author: J_Thomas 26 October 2007 03:21:02AM 0 points [-]

I've spent a little time looking over some crank physics, particularly surrounding Maxwell's equations. Particularly quaternions applied to maxwell's equations. Note that maxwell's equations are very good at describing charges and electromagnetic radiation in terms of quantities in volumes, though they say nothing about how electromagnetic radiation interacts with charged or uncharged masses. Special relativity was designed to "fix" a problem with maxwell's equations, and lasers were invented after a derivation of maxwell's equations implied that they should be possible.

After reviewing a fraction of the online literature on this topic, I can confidently say that there are a whole lot of things here that a few people know that most physicists do not know. And I can say with considerably less confidence that some of those things might actually be true.

If someone truly knows how to make an inexhaustible battery, or reliable working cold fusion, etc -- I can confidently say that it hasn't passed sufficient peer review to make a big splash. There may be such things that most people don't know about. Almost certainly there are. But when they actually get tested enough to be believable, they'll stop being secret -- unless some government manages to classify them.

Comment author: Ken2 26 October 2007 04:41:37AM 0 points [-]


"[L]ogical ignorance is still ignorance; if this were not so, I would know a proof of the Riemann Hypothesis." I understand what you mean by logical ignorance is still ignorance; as for the second part of your statement, I don't think that's necessarily true.

For example, if the RH were true you would need n statements in a particular order. Meaning that you have stated assumptions, then you proceed to S1->S2->...->Sn (where Si is the ith logical statement) and Sn is the conclusion of the proof. What you are saying is that you know all n statements, but not the order and you're trying to figure that out or possibly could if you thought about it. BUT, you may not know all n statements, which is what the second part of your statement claims. Your statement, also, assumes the RH is true, which is what the fuss is all about. No one really knows if it's true.

What I was trying to say is that you may know all n statements, even their order and have come up with them to solve some other problem. But you may never have heard of the RH, so don't know that you can solve it. I understand that this is still a form logical ignorance, but the second part of your statement (that you know a proof of the RH) doesn't follow from the first part.

Comment author: Jonathan_El-Bizri 26 October 2007 04:59:24AM 3 points [-]


Don't ever see 'what the bleep do we know'. The woo almost killed me.

Comment author: bjk2 26 October 2007 12:23:24PM 6 points [-]

Isn't "because of the curvature of space" just a curiosity stopper?

Comment author: Peter_de_Blanc 26 October 2007 01:34:55PM 1 point [-]
Comment author: Constant2 26 October 2007 01:41:12PM 0 points [-]

I guess General Relativity is a curiosity stopper, then. :) Actually, isn't one of the criticisms of science that it is a curiosity stopper? It takes the mystery out of the world. Lesson: we need to be careful about what we call a "curiosity stopper".

Comment author: g 26 October 2007 03:08:47PM 6 points [-]

Longer version of PdB's answer: "because of the curvature of space" isn't "just a curiosity stopper" if you can actually say what that means, do the mathematics, and see how that leads to the phenomenon of gravitation. Of course when you do this you encounter other more fundamental things that you haven't explained yet. (See Eliezer's "Explain/Worship/Ignore" piece here some time back.) This is only curiosity-stopping if you then say "no point ever trying to go any deeper than this".

If the fact that there are not-yet-explained things underlying the curvature of space and how it produces gravity makes it improper to say "we do know how gravity works", then I think similar facts make it improper to say "we know how a windmill works" or "we know how a seesaw works", quod est absurdum.

Scientific explanations replace mysteries with smaller mysteries. You can call that "taking mystery out of the world" if you want to, but regarding that as a *criticism* is just preferring ignorance and stupidity over knowledge and understanding. If science took the *wonder* or the *curiosity* out of the world, that would be a criticism worth making, but oddly enough it's a criticism only ever made by people who don't know much science.

All of which seems to me to be merely repeating things Eliezer said -- and that were common knowledge before Eliezer said them, too -- so, bjk and/or Constant, maybe I'm misunderstanding you?

Comment author: Andrew22 26 October 2007 03:59:22PM 2 points [-]

The allure of the incompletely understood has something to do with wonder. The state of being curious gives me a nice warm fuzzy feeling inside that goes away when the curiosity eliminates itself. Assuming that others experience this as well, perhaps it is an evolutionary incentive to explore--to do some original seeing. This seems appropriate in the ancestral environment where, as you point out, going out and learning something new benefits the whole tribe.

In today's environment, however, most novel knowledge accessible to the average person is essentially trivial. If it were important and easy enough to learn, someone would already have found it. So people find ways to push their warm-fuzzy buttons by contemplating the implications of knowledge they don't really understand, such as quantum mechanics. This is then just a candy bar or a supermodel--a superstimulus.

Comment author: Eliezer_Yudkowsky 26 October 2007 04:04:50PM 9 points [-]

"Because of the curvature of space" is, indeed, not a good explanation - especially for someone who doesn't know automatically that a curved line on a spacetime graph equals acceleration - but I did not properly realize this at the time.

The point of this essay is that someone knows the answer, not that I successfully explained it to my uncle. Someone else knowing the answer should not cause you to be any less curious, once you realize that there are no "inherently mysterious" phenomena.

Matthew, if you haven't been raised in the Christian tradition, it's simply a non-sequitur, a random unsupported claim. Like saying that the Tooth Fairy exists and only the power of the Tooth Fairy lets you know things. There's no evidence that the Tooth Fairy exists and moreover someone understands perfectly well how this "knowing" business works (see What Is Evidence?) and that's not it. If you rename the Tooth Fairy to the Truth Fairy or God it's the same problem.

Comment author: Constant2 26 October 2007 04:20:58PM 0 points [-]

g - if you think I was endorsing the criticism of science for taking the mystery out of the world, then yes, you misunderstand me. I was holding up a particular criticism of science for ridicule. It went without saying that it deserves ridicule. I was using it as a reminder of how easily valid points can be badly applied.

Comment author: Matthew3 26 October 2007 06:58:07PM -1 points [-]

They would read 'what is evidence' and conclude you cannot trust your senses without justification through logic and since it takes logic to justify logic (which is circular) they would claim only God has that power (or the Truth Fairy). It simply feeds on ignorance of lower level processes - like how the brain uses logic or even how a modern computer chip uses logic. In the later case they could say, yes, computer chips are logical but their intelligence is very limited compared to man. Etc.

I've learned their is nothing you can teach a presuppositionalist in terms of a reductionist, materialist worldview. I've also learned its useless to have a debate between laymen. In addition, it's probably useless to have a debate between experts and non experts.

Comment author: MrHen 09 February 2010 11:21:06PM 0 points [-]

I've learned their is nothing you can teach a presuppositionalist in terms of a reductionist, materialist worldview.

You can teach it to them, but you will never convince them. There is actually a lot of room to work with a presuppositionalist's worldview. The conversations get tedious, though. If you know how to do it, you can find holes in their theories, but its more of an individual thing.

The easiest way into a Christian's head is to start comparing how they act with how they believe. It is hard to do this without making it personal, but with practice and a heaping dose of respect for how much it hurts to hear the charges you can do it.

Also, it may be possible to discuss materialism as a counter-theory without trigging the massive defense system people generally carry around with them. If they turtle up, just walk away or use them as practice for defending your own beliefs.

Comment author: sullyj3 27 September 2014 03:30:43AM *  3 points [-]

The easiest way into a Christian's head is to start comparing how they act with how they believe. It is hard to do this without making it personal, but with practice and a heaping dose of respect for how much it hurts to hear the charges you can do it.

I strongly disagree. The fact that people aren't perfect is a major component of Christian ideology. Christians are aware that they're hypocrites, and they try to do better. That doesn't invalidate their worldview. There are plenty of better arguments which do that on their own.

Comment author: cwillu 24 March 2017 02:53:35PM 0 points [-]

I think this might have been intended more in the purple dragon sense than anything: focus on how they know exactly what experimental results they'll need to explain, and what that implies about their gut-level beliefs.

Comment author: Jayson_Virissimo 27 September 2014 06:00:09AM *  2 points [-]

The easiest way into a Christian's head is to start comparing how they act with how they believe. It is hard to do this without making it personal, but with practice and a heaping dose of respect for how much it hurts to hear the charges you can do it.

I've tried this when arguing with utilitarians. As far as I know, it hasn't persuaded anyone.

Also, it may be possible to discuss materialism as a counter-theory without trigging the massive defense system people generally carry around with them. If they turtle up, just walk away or use them as practice for defending your own beliefs.

Instead of "defending" your beliefs, you may want to try exposing those parts which seem weakest, so as to increase the probability that any errors in your web of belief will be be brought to your attention by your interlocutor.

Comment author: Jiro 28 September 2014 07:53:11AM 1 point [-]

Exposing your weaknesses increases the probability that your errors will be revealed as errors, but it also increases the probability that your correct beliefs will be falsely "revealed as errors". (In an area of weakness, your opponent could present flawed arguments whose flaws you would miss, leading you to believe them.)

Comment author: douglas 26 October 2007 07:08:20PM 0 points [-]

Ignorance is the basic foundation of science. Without things we are ignorant of there is no point to science. Mystery (and the desire solve it) is the motavation that drives most scientists to do the hard (often unrewarding) work that makes science. "Because God made it that way," can be the end of curiosity and therefore harmful to further discovery. "What has God wrought?" on the other hand has been the question that motavated men like Galileo, Newton, Maxwell, and Einstein. "Decoherence solved the observer problem in physics," is an example of an incorrect statement that hinders people from looking into and, hopefully, solving some of the greastest myseries of the universe. Ignorance of ignorance is the greatest problem for science of them all. (By the way, the phrase 'what science really knows' made me think this post was a parody at first)

Comment author: TGGP4 26 October 2007 07:33:50PM 0 points [-]

"Decoherence solved the observer problem in physics," is an example of an incorrect statement Care to support that?

Comment author: douglas 26 October 2007 08:12:09PM 0 points [-]

TGGP- there is a paper by Rosenblum and Kutter on arxiv.org that goes into this. I believe they make a convining case that no existent theory does away with the problem. I like this paper because it goes into the problems without too much jargon. You could google "observer problem decoherence" (or words to that effect) and you will find any number of papers written and a somewhat lively debate on the subject. The von Nuemann- Wigner interpretation of QM is often refered to as the "standard" interpretation, and it has as a basic that the observer injects a bit of information into the system with each subjective experience. The "quantum erasure" is an example of an experiment that might lead one to consider that the problem has not been solved. If you are technically minded, Stapp (you can just google stapp to get to his web page with its numerous papers) is a good source of information as to validity of various claims for various "interpretions" of QM. He's my personal favorite because he's been at it forever and knows the stuff cold. Need more?

Comment author: Dmitri 26 October 2007 09:11:56PM 2 points [-]


I'm not sure I follow your argument. It seems like you want to say, not that your uncle was wrong to claim that no one has any understanding of gravity because this claim is false, but rather that he was wrong to claim this because, in general, it is always wrong to claim that science doesn't know something. At this point, you seem to suggest that simply because it is always possible that someone has secretly or just recently explained a phenomena, that therefore, one is never justified in stating that a broad community of people lack such an explanation. On the face of it, this is simply an invalid argument.

Perhaps you are interpreting claims like "neuroscience has not yet explained subjective consciousness" as saying "Nobody on planet earth, as of the time of this utterance, has any understanding of subjective consciousness." Then, perhaps, you are claiming that no such person can make a claim like that, because they have not surveyed every living person. I don't think that claims like "neuroscience has not yet explained subjective consciousness" ought to be interpreted as referring to each and every thinker as of the moment of utterance - rather, they seem to be referring to the epistemic situation of a broad community of specialists. However, even if we take the above interpretation as correct, I don't think your argument holds water.

All of science procedes via inductive generalizations. We observe the behavior of an unimaginably small percentage of the electrons in the universe, and see that they have a certain charge, mass, etc., and then induce that all electrons have that charge, mass, etc. This is a justified conclusion. I would submit that surveying a large number of neuroscientists and discovering, not only that each of them have no understanding or explanation of subjective consciousness, but that each of them tells you that they have not heard of any neuroscientists who has an understanding or explanation, is sufficient to warrant the conclusion that no one has such an understanding. Of course this claim is defeasible, of course it could be false, but that does not mean that it is not justified.

It seems to me that your uncle had not even attempted to survey the scientific community (else he certainly would have discovered that he was incorrect). And it is for this reason that his presumptions were spurious, and not because one is always incorrect to claim that something is as-yet unexplained.

Comment author: g 26 October 2007 10:33:56PM 1 point [-]

Dmitri: As I read him, Eliezer is saying (1) that it's easy to be unaware of scientific progress even once it's made it into the literature, and (2) that at any given moment there's plenty going on that hasn't made it into the literature yet. #1 is sufficient to make his uncle wrong to say that no one knows how gravity works, and others wrong to say that no one's made any progress towards understanding consciousness. #2 isn't needed for those conclusions, but it's interesting in its own right.

Douglas: I had a look at the paper by Rosenblum and Kutter, and I don't see how it offers any reason to think that there's an "observer problem" that we need to worry about. The only "problem" is that it's difficult to reconcile some quantum phenomena with naive ideas about free will; but naive ideas about free will are notoriously difficult to make clear good sense of anyway, so this just looks like one more strike against those ideas. It sounds like Stapp instead wants to make some hand-wavy notion of consciousness fundamental to his model of the universe; if he manages to make this into an actual scientific theory with actual testable predictions, good luck to him, but it doesn't seem like that promising a project.

Comment author: Jim 26 October 2007 10:42:55PM 0 points [-]


Whether or not something is non-sequitur doesn't depend on Matthew's upbringing.


Appealing to a materialist set of assumptions to argue against some view other than materialism (such as Christianity) is question begging. Of course you can reason your way from "Materialism is true" to "Christianity is false," but so what? This only shows that materialism and Christianity are incompatible which is not a matter of dispute at all.

Comment author: Matthew2 27 October 2007 12:42:40AM 0 points [-]

I could agree Jim about the question begging part if you haven't opened a neurology/neuroscience textbook.

You might as well have said: "Using materialist assumptions to explain chemistry is question begging. Of course christianity is incompatible with the laws of chemistry when one does not come from a materialist perspective."

Comment author: Mohamad 27 October 2007 07:13:30AM 0 points [-]

This is one of the best articles I've read in a long time. I agree with every statement. Thank you and please keep producing more. There are many people who enjoy this level of intellect.

Comment author: douglas 27 October 2007 09:04:24AM 0 points [-]

g- I think you've misread the article. There is nothing to worry about, of course, there are only possibilities to consider. The point the article makes is not dependant on any particular notion of free will. Stapp advocates the von Nuemann, Wigner formulation of QM, the only existing formulation that produces a rationally coherent idea of the reality that lies behind our experiences. IMHO Of course, one problem that people have with this formulation is that it agrees with with the experienced fact that our thoughts can influence our actions. Would anyone reading this post, or studying decision theory, or trying to overcome a bias, deny that?

Comment author: JIm2 27 October 2007 01:07:58PM 0 points [-]


Empricial findings in neuroscience or any other discipline don't change whether or not the structure of some argument presumes its conclusion. Neuroscience (which, by the way, brings materialism in as an assumption) or not, it's still question begging to draw on materialist assumptions to argue against Christianity. If you want to claim that drawing on Christianity to argue against materialism is also question begging, you'd be right, but that doesn't change the fact that the former is question begging also.

Comment author: g 27 October 2007 01:09:59PM 0 points [-]

Douglas, perhaps I have indeed misunderstood the article; I was reading it in the hope that it would give some indication of why you think there's a real "observer problem", and perhaps that was wrong. Since you've clearly read it with more attention than I have, perhaps you'd care to explain how the article justifies the statements you've been making about QM and the "observer problem"?

I think propositions like "our thoughts can influence our actions" are too vaguely defined to be any use in contexts like this.

Comment author: J_Thomas 27 October 2007 02:18:53PM 0 points [-]

"Knowing" is different for christians versus scientists. A christian can "know" that Jesus rose from the dead on the third day. A scientist who "knows" that gravity comes from the curvature of space is accepting a tentative hypothesis which he will discard when something better comes along. He's taken something that's compatible with the known facts and if he's active in that particular line of research then he's using what he "knows" to choose interesting things to look at.

At any given time some people will be behind the times about what science "knows". I met a mathematician who didn't believe me about molecular biology in 1982. She simply didn't know there was any such thing. She went off and researched it, and the next time we met she apologised for disbelieving me and she admitted that there was such a field. It's easy for scientists to be just as far behind as anybody else about things outside their own specialities.

This is related to people not keeping up with fashions and fads. The latest ideas in another field -- things you believe somebody "knows", the current default hypotheses -- often are just not very important to what you're doing.

Comment author: Matthew3 27 October 2007 10:36:30PM 0 points [-]

Jim, if modern science works, it isn't begging the question. There is nothing circular about results...except this conversation, which is predicated on your ignorance of the topic. But here I am violating my own principles. I promise not to reply to your reply.

Comment author: John4 28 October 2007 11:04:56PM 0 points [-]

The bit about Copernicus inaugurating the scientific revolution -- is that an error, or part of an example-from-argument that I should have been quick enough to catch?

My understanding is that De revolutionibus was ignored when it was published, and didn't start making waves until the 1600s. This fits with your point that no one knows what science knows -- except that in this case, Copernicus can't properly be said to have known what he knew, either.

As I understand it, the secular Saint Nicolaus thought he had found a neat trick for computing where planets would appear in the night sky, which was sometimes more accurate that the Ptolemaic model (ellipses > Fourier series epicycles > circles). He may have believed in a heliocentric universe, but given the evidence available to him at the time, his view could have been no more true than Newton's corpuscular theory of light.

It seems un-Bayesian to give much credit to Democritus.

Comment author: Benquo 29 October 2007 04:26:31AM 0 points [-]


My understanding of Copernicus's argument is that it doesn't stand out for its superior coincidence with observed facts -- Ptolemy's calculations (and observations) may actually have been slightly more accurate -- but rather that the geometry in Copernicus explains as necessary things that are merely notable coincidences in Ptolemy.

Ptolemy was aware of contemporary heliocentric theories, though. He admitted in Almagest that he had no knock-down argument against such theories, except that it's plainly ridiculous to think that the Earth moves -- after all, how would birds keep up with it while flying through the air? His astronomy is also justified by a quasi-Aristotelian metaphysics/theology, which he was probably aware was highly speculative. (There's a minority opinion among scholars of Ptolemy that he secretly was a heliocentrist.)

I think a lot of Copernicus's importance might be symbolic, showing that 1) empirical science can deny received truth, and 2) human life (and therefore life in general) is not the center of the universe. The second, especially, makes teleological physics much more difficult.

Comment author: douglas 29 October 2007 10:58:40AM 0 points [-]

g- Perhaps a more rigorous paper would be appropriate. Try PCE Stamp (2006) It's on the web. After covering many new experiments and discussion of the current formulations the conclusion goes something like this: "Decoherence, according to the older ideas, is supposed to explain away the quantum measurement problem..." "There are many things we still do not understand about decoherence and what causes it, and it should now be clear this is a pressing problem." (Some people use the 'measurement problem', others the 'observer problem'-- it depends on their philosophical bent) The bigger and more important point is this: ignorance and mystery are what makes good science. They give us something to learn. Knowing and no mystery are comforting and give us religion. I don't have any problem with religion, as long as we don't turn science into one. I doubt that was the point of the original post-- but when I read 'science knows' I just getting a yucky feeling, and I was using this example of why it's not such a good phrase.

Comment author: g 29 October 2007 12:41:58PM 1 point [-]

Obviously science doesn't "know" anything in the sense of making it impossible or forbidden to question it. Eliezer wasn't saying it does, and the examples of saying "science doesn't know X" he quoted are ones where people are saying science *has no understanding of* X, when in fact it does. (Even though never a complete or unquestionable one.)

Stamp argues that the mechanisms underlying decoherence aren't fully understood and there's more decoherence going on than we have good models for, and that this might just turn out to indicate that QM needs some revision. OK, fine, I'll take his word for all that. None of it invalidates what Eliezer said, namely that we now know of ways in which almost any interaction with the environment (conscious or not) can produce just the sort of observations that were formerly described in terms of wavefunction collapse due to observation, and that there's therefore no longer any reason to suppose that conscious observation as such produces special effects.

The idea that "decoherence solves the observer problem" would be bad if it resulted in too little effort going into (say) looking at consciousness-centric views of QM. It seems to me (though evidently not to you) that the plausibility of such a view is so low that the small but nonzero amount of such effort we actually have isn't too little.

I've no idea why you say that "no mystery" leads to religion. (Even if you actually mean it the other way around.) The religion that's currently (and has been for ages) most popular is crammed full of mysteries. It might be true that the idea that everything needs an immediate explanation leads to religion (if you can't think why X happens, say "X happens because the gods made it so") but I don't think anyone is advocating such an idea.

In so far as religion (or anything else) gives us statements that we're supposed to believe in ways the evidence doesn't warrant, I *do* have a problem with it. If science, or some people's idea of science, starts doing that, something's wrong and needs fixing, but I don't see that what Eliezer says about "science knows X" has that problem.

Comment author: mnuez 03 November 2007 10:17:15AM -1 points [-]

Beautiful piece.

(Owing to blogs' unfortunate chronological set-up, there's a good chance no more than three or four people will ever read this comment and an even better chance that no one will follow up on something that I write here. This refrains my passion from expressing itself further on this subject in this particular cyber-location. May the future of blogging be kinder to the intellectual/literary output of who were yesterday.)

mnuez www.mnuez.blogspot.com

Comment author: Tim_Tyler 06 March 2008 11:49:00AM 0 points [-]

Curvature of spacetime was not present in the previous theory of gravitation. We can see that another paradigm-shift in the theory of gravity will likely be needed when gravity and quantum theory are combined. It is widely predicted that relativity will come off worse in this future tussle - it is the theory with the singularities in. I would not bet much on the longevity of the "curvature of spacetime" explanation - maybe it is an unfortunate example.

Comment author: Dave 17 May 2008 12:19:37PM -2 points [-]

Why is it that if you tell a lie over and over again that the majority of people will except it as fact?

Comment author: arbimote 12 January 2010 05:32:24AM 1 point [-]

I agree with the message of the article, but I do not think it is forever going to be impossible to query what science currently knows.

Improvements in search technology cause a decrease in the time taken to do a reasonable search for any existing knowledge on a topic. Before the internet you might have had to read dozens of journals to have a vague idea of whether a field had discovered something in particular. Now you can do an online search. Conceivably, a future search engine could be good enough that it could take some imprecise (non-jargon) search terms, and bring up the most relevant and up-to-date research on the topic.

This would be great for public perception of science. Consider your uncle typing "How does gravity work?", and being presented not only with a pop-science description (as you would today), but also with the latest peer-reviewed work and a list of prerequisite reading, should he want a more thorough understanding. It'd be harder for people to worship ignorance if there was less of a barrier between them and knowledge.

Comment author: Eliezer_Yudkowsky 11 February 2010 09:07:50PM 8 points [-]

Apparently the full quote from Richard Feynman is:

"I think I can safely say that nobody understands quantum mechanics."

This was in 1965. Everett's first paper was in 1957 IIRC. So not only was Feynman mistaken about nobody at that time understanding quantum mechanics, but he thought this could be said safely? When there are billions of people in the world, and all ignorance and confusion is a property of the map rather than the territory?

Feynman was one of the great Traditional Rationalists, but sometimes he really does manage to get it completely wrong. Einstein was much worse in the same department: "You do not really understand something unless you can explain it to your grandmother"!?

Comment author: Douglas_Knight 12 February 2010 05:37:42AM 8 points [-]

This was in 1965. Everett's first paper was in 1957 IIRC. So not only was Feynman mistaken about nobody at that time understanding quantum mechanics, but he thought this could be said safely?

Why are you so sure Feynman is ignorant of Everett, rather than talking about him?

I'd expect that Wheeler, who liked Everett's work enough to write a companion piece, would have told his other students about it. Steve Hsu points to a 1957 conference where Wheeler talked about Everett and Feynman made it clear he was interested in this stuff.

Comment author: Kutta 12 February 2010 12:23:09PM *  2 points [-]

I think it's likely that both quotes were unrepresentative passages or insignificant slips of tongue that only got magnified and entrenched in people's minds after years of memetic selection. It's obvious that Einstein couldn't have meant the grandmother quote seriously, also, Einstein is known to be very prone to rampant misquotation. The grandmother quote is quite comforting to the layman, even if untrue, and sounds "deep" enough, likewise the Feynman quote raises the status of confused non-physicists and physicists alike, because "not even the pros get it, and it's allowed to not get it."

Comment author: Tyrrell_McAllister 12 February 2010 08:52:45PM *  6 points [-]

"I think I can safely say that nobody understands quantum mechanics."

This was in 1965. Everett's first paper was in 1957 IIRC. So not only was Feynman mistaken about nobody at that time understanding quantum mechanics

So long as the key link between the QM formalism and empirical observations is a mystery, I think it's fair to say that no one understands QM completely. In context, is it too charitable to read Feynman as referring to still-outstanding mysteries such as that?

Comment author: ata 07 May 2010 05:31:56AM *  10 points [-]

Einstein was much worse in the same department: "You do not really understand something unless you can explain it to your grandmother"!?

That's probably a misquote, it turns out. I can't find any source for it and Wikiquote agrees. The closest they could find was Ronald W. Clark claiming that Louis de Broglie claimed that Einstein believed "that all physical theories, their mathematical expressions apart, ought to lend themselves to so simple a description 'that even a child could understand them.'" (I'm interpreting this to mean that Clark attributed the outer quote to de Broglie, who attributed the inner quote to Einstein while giving his own explanation of the context.) Could be true, but our knowledge of it is a few degrees away from the primary source, so there's room for it to get corrupted or taken out of context along the way. And even if it is correctly attributed and interpreted, the "their mathematical expressions apart" bit redeems it somewhat (not completely). Though that does dilute the meaning of "understand[ing]" as used, or it identifies it with (as you've termed them) verbal understanding rather than technical understanding.

I'm going to tentatively reject the belief that the "...unless you can explain it to your grandmother"/"that even a child could understand them" quotes accurately describe Einstein's belief. He may have been a Traditional Rationalist, but he wasn't stupid, and I imagine he had a great deal of experience explaining things as well as he could but not having everyone (let alone children or stereotypical grandmothers) understand him.

(And I'm going to give myself a rationalist experience point for finding the original "grandmother" quote surprising enough that I thought to look it up.)

Comment author: JoshuaZ 07 May 2010 05:46:03AM 0 points [-]

Hmm, so how many xp do you get per a level?

Comment author: byrnema 07 May 2010 12:57:31PM *  1 point [-]

"You do not really understand something unless you can explain it to your grandmother"!?

This was probably said by Feynman. I'm pretty sure because I have an auditory memory of him saying it in a video ... but I can't remember which one, and wonder if perhaps I read it after all in his Lectures.

Comment author: [deleted] 19 November 2011 08:18:52PM 2 points [-]

IIRC, in the Lectures he says “to a freshman” not “to your grandmother”. It allegedly was Einstein who said “to your grandmother” (and Rutherford said “to a bartender”, and [someone else] said “to [someone else]” and so on).

Comment author: byrnema 11 February 2010 09:18:36PM 0 points [-]

I don't think you understand something until you understand the mechanism. This is what empiricism is about: if something is the result of an interaction, how does that interaction work? We don't know yet how gravity is the result of an interaction. We can only describe the result of this interaction.

Comment author: arundelo 12 February 2010 01:31:31AM *  4 points [-]

I don't think you understand something until you understand the mechanism.

How do you know when you've "hit the bottom" of a stack of explanations?

When I first learned about curved space and spacetime, I took some of the standard metaphors too literally. I remember speculating that space was a trampoline, but extending in three dimensions rather than two, infinitely thin in the fourth dimension, accelerating (forever!) in the fifth dimension, and of course not actually made of anything. (The acceleration was necessary to make the pieces of matter sitting on the trampoline stretch it.)

Years later I ran across the writings of a crank physicist (edit: I think I found him) whose big idea was that everything is constantly getting bigger (or maybe smaller), and that this explained gravity and maybe some of the other forces too.

Now I see both of these as taking a metaphor too literally because it seems to provide a mechanism. John Baez's Crackpot Index provides

10 points for arguing that while a current well-established theory predicts phenomena correctly, it doesn't explain "why" they occur, or fails to provide a "mechanism".

(This artice by Ronald Merrill, "Sufficient Reason and Causality", is related, though it's been a long time since I've read it.)

Comment author: dclayh 12 February 2010 02:37:36AM 6 points [-]

Scott Adams of Dilbert fame has also proposed the "everything is constantly getting bigger" theory of gravity.

Comment author: Jack 12 February 2010 02:50:37AM 0 points [-]

So I suppose asking how a crank physics theory is supposed to work is like asking Lewis Carroll for proof of concept but... what exactly is the the appeal of this? I don't even see the surface plausibility.

Comment author: byrnema 12 February 2010 03:03:34AM 1 point [-]

I liked Ali's review best. She wrote,

As for the "Expansion Theory", it cannot explain gravitation. This idea was tried before, and it fails. Maybe if McCutcheon learned some science, then he could do some science.

Comment author: dclayh 12 February 2010 03:06:03AM 9 points [-]

You jump into the air -> Earth expands -> voila, now you're touching the Earth again.

Comment author: Jack 12 February 2010 03:22:04AM 0 points [-]

Bwahahahaha. Alright. I see it. Thanks. :-)

Comment author: JGWeissman 12 February 2010 03:22:58AM 1 point [-]

But what does this theory say about orbits? or escape velocity?

Comment author: Eliezer_Yudkowsky 12 February 2010 06:42:35AM 3 points [-]

"Shut up"

I think a better question would be, what does this theory say about mass? As opposed to volume and distance? How can an object be equidistant between two other equally-sized objects and be attracted to one of them more than the other?

It fails even as a crank theory.

Comment author: Polymeron 01 May 2011 10:15:21AM 0 points [-]

I too have stumbled on "The Final Theory", and was wondering what it was all about - though not enough to actually spend money on the book. Thanks for digging this up!

Comment author: wnoise 12 February 2010 05:02:39AM 0 points [-]

Ah, yes. Another one for the "engineers are more likely to become cranks" files.

Comment author: Jack 12 February 2010 05:31:37AM 0 points [-]

"engineers are more likely to become cranks"

Why is this anyway? Are engineering degrees just easy to get? Maybe they don't have to internalize the scientific method? Not enough experimentalism?

Comment author: wnoise 12 February 2010 05:42:01AM 6 points [-]

My personal belief is that they learn simplified models that aren't quite correct, without enough explicit warnings that they aren't fully correct. Then, later on, they're smart enough to figure out that the models aren't good enough, so start building their own, without the requisite background of what the physicists' actual model are, and why certain approaches have and haven't been taken, and how counter-intuitive experiments have forced certain choices.

Comment author: bigjeff5 24 February 2011 11:55:43PM 1 point [-]

It's like the artillery officer who thinks you can't use GR to calculate the trajectory of an artillery shell - you have to use Newtonian mechanics to do it. Not that it wouldn't be practical go use GR, but that it could not be done. He doesn't realize that not only can you calculate it with GR, but that it would be far more accurate, too (it would, of course, be horribly impractical, however).

Comment author: JGWeissman 12 February 2010 05:45:57AM 0 points [-]

Scott Adams is not an engineer. He is a cartoonist who writes about engineers.

Comment author: Nick_Tarleton 12 February 2010 06:07:30AM *  2 points [-]
Comment author: JGWeissman 12 February 2010 06:27:43AM 3 points [-]

Yes, he worked with engineers, but he would be the first to tell you he is not an engineer himself. From his book The Dilbert Principle (page 171):

For the record, I am not an engineer by training. But I spent ten years working with engineers and programmers in a variety of jobs. I learned their customs and mannerisms by observing them, much the way Jane Goodall learned about the great apes, but without the hassle of grooming.

Comment author: wnoise 12 February 2010 08:50:42PM 2 points [-]

I stand corrected. (But I do think he has absorbed enough of the engineer's viewpoint to make it noticeable.)

Comment author: Douglas_Knight 12 February 2010 06:39:37AM 5 points [-]

I'm pretty sure that Scott Adams is not a crank, but a troll.

Comment author: arundelo 07 May 2011 12:24:57AM 0 points [-]
Comment author: SeanMCoincon 12 September 2014 10:10:07PM 0 points [-]

"... people seem to get a tremendous emotional kick out of not knowing something. " Could be simple schadenfreude: asserting that "no one" knows a thing, even those demonstrably more intelligent than yourself, has the emotional effect of knocking them down into the same mud in which you already believe yourself to be mired. Not productive, but good solace for those unwilling to be productive.

Comment author: Kevin92 07 June 2015 12:12:17AM 0 points [-]

Can this article be used to defend to idea that one day we may do things we currently believe are "physically impossible" such as build perpetual motion machines or alter physical constants?

Comment author: g_pepper 07 June 2015 12:31:07AM 0 points [-]

No, I don't think so. Perpetual motion machines are not "impossible" because we simply do not know how to create them; in fact we know that they are impossible because they would violate the laws of thermodynamics.

Comment author: Kevin92 07 June 2015 03:37:20AM 0 points [-]

Yes I get the difference, but the deal with "no one knows what science doesn't know" is that someone could say there are exceptions we don't know about or things we overlooked, just like Newton overlooked things that Einstein discovered.

Comment author: HarryHitherto 28 March 2017 04:17:52AM 0 points [-]

New here. Trying to sort out the jargon and what not, but have immensely enjoyed reading through the posts. Stumbled upon this one and, I realize it's ten years old, but I have criticism: In the initial example, the example upon which the rest of the post was built, the Uncle was actually correct. We do NOT know how gravity works. We know how it acts upon the physical world, but as we've never discovered gravitational force carriers, we've zero knowledge of the mechanism through which it manifests.

Also, this certainly depends on how extreme you care to be, but you can certainly say with certainty whether or not science knows a thing. Example: no scientist on earth knows with any degree of scientific certainty whether or not God exists.

Comment author: FourFire 30 March 2017 11:10:38AM *  0 points [-]

Enjoy your stay!

I think most of the people who were around ten, or even six years ago now consider this place a mostly static repository of articles which are useful to refer to, rather than a dynamic community forum capable of generating more of said articles.