Archive for category History of Science
Should economics, sociology or management count as science?
2500 years ago, Plato, in The Sophist, described a battle between the gods and the earth giants. The fight was over the foundations of knowledge. The gods thought knowledge came from innate concepts and deductive reasoning only. Euclid’s geometry was a perfect example – self-evident axioms plus deduced theorems. In this model, no experiments are needed. Plato explained that the earth giants, however, sought knowledge through earthly experience. Plato sided with the gods; and his opponents, the Sophists, sided with the giants. Roughly speaking, this battle corresponds to the modern tension between rationalism (the gods) and empiricism (the giants). For the gods, the articles of knowledge must be timeless, universal and certain. For the giants, knowledge is contingent, experiential, and merely probable.
Plato’s approach led the Greeks – Aristotle, most notably – to hold that rocks fall with speeds proportional to their weights, a belief that persisted for 2000 years until Galileo and his insolent ilk had the gall to test it. Science was born.
Enlightenment era physics aside, Plato and the gods are alive and well. Scientists and social reformers of the Enlightenment tried to secularize knowledge. They held that common folk could overturn beliefs with the right evidence. Empirical evidence, in their view, could trump any theory or authority. Math was good for deduction; but what’s good for math is not good for physics, government, and business management.
Euclidean geometry was still regarded as true – a perfect example of knowledge fit for the gods – throughout the Enlightenment era. But cracks began to emerge in the 1800s through the work of mathematicians like Lobachevsky and Riemann. By considering alternatives to Euclid’s 5th postulate, which never quite seemed to fit with the rest, they invented other valid (internally consistent) geometries, incompatible with Euclid’s. On the surface, Euclid’s geometry seemed correct, by being consistent with our experience. I.e., angle sums of triangles seem to equal 180 degrees. But geometry, being pure and of the gods, should not need validation by experience, nor should it be capable of such validation.
Non-Euclidean Geometry rocked Victorian society and entered the domain of philosophers, just as Special Relativity later did. Hotly debated, its impact on the teaching of geometry became the subject of an entire book by conservative mathematician and logician Charles Dodgson. Before writing that book, Dodgson published a more famous one, Alice in Wonderland.
The mathematical and philosophical content of Alice have been analyzed at length. Alice’s dialogue with Humpty Dumpty is a staple of semantics and semiotics, particularly, Humpty’s use of stipulative definition. Humpty first reasons that “unbirthdays” are better than birthdays, there being so many more of them, and then proclaims glory. Picking up that dialogue, Humpty announces,
‘And only one [day of the year] for birthday presents, you know. There’s glory for you!’
‘I don’t know what you mean by “glory”,’ Alice said.
Humpty Dumpty smiled contemptuously. ‘Of course you don’t — till I tell you. I meant “there’s a nice knock-down argument for you!”‘
‘But “glory” doesn’t mean “a nice knock-down argument”,’ Alice objected.
‘When I use a word,’ Humpty Dumpty said, in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.’
‘The question is,’ said Alice, ‘whether you can make words mean so many different things.’
‘The question is,’ said Humpty Dumpty, ‘which is to be master — that’s all.’
Humpty is right that one can redefine terms at will, provided a definition is given. But the exchange hints at a deeper notion. While having a private language is possible, it is also futile, if the purpose of language is communication.
Another aspect of this exchange gets little coverage by analysts. Dodgson has Humpty emphasize the concept of argument (knock-down), nudging us in the direction of formal logic. Humpty is surely a stand-in for the proponents of non-Euclidean geometry, against whom Dodgson is strongly (though wrongly – more below) opposed. Dodgson was also versed in Greek philosophy and Platonic idealism. Humpty is firmly aligned with Plato and the gods. Alice sides with Plato’s earth giants, the sophists. Humpty’s question, which is to be master?, points strongly at the battle between the gods and the giants. Was this Dodgson’s main intent?
When Alice first chases the rabbit down the hole, she says that she fell for a long time, and reasons that the hole must be either very deep or that she fell very slowly. Dodgson, schooled in Newtonian mechanics, knew, unlike the ancient Greeks, that all objects fall at the same speed. So the possibility that Alice fell slowly suggests that even the laws of nature are up for grabs. In science, we accept that new evidence might reverse what we think are the laws of nature, yielding a scientific revolution (paradigm shift).
In trying to vindicate “Euclid’s masterpiece,” as Dodgson called it, he is trying to free himself from an unpleasant logical truth: within the realm of math, we have no basis to the think the world is Euclidean rather than Lobichevskian. He’s trying to rescue conservative mathematics (Euclidean geometry) by empirical means. Logicians would say Dodgson is confusing a synthetic and a posteriori proposition with one that is analytic and a priori. That is, justification of the 5th postulate can’t rely on human experience, observations, or measurements. Math and reasoning feed science; but science can’t help math at all. Dodgson should know better. In the battle between the gods and the earth giants, experience can only aid the giants, not the gods. As historian of science Steven Goldman put it, “the connection between the products of deductive reasoning and reality is not a logical connection.” If mathematical claims could be validated empirically then they wouldn’t be timeless, universal and certain.
While Dodgson was treating math as a science, some sciences today have the opposite problem. They side with Plato. This may be true even in physics. String theory, by some accounts, has hijacked academic physics, especially its funding. Wolfgang Lerche of CERN called string theory the Stanford propaganda machine working at its fullest. String theory at present isn’t testable. But its explanatory power is huge; and some think physicists pursue it with good reason. It satisfies at least one of the criteria Richard Dawid lists as reasons scientists follow unfalsifiable theories:
- the theory is the only game in town; there are no other viable options
- the theoretical research program has produced successes in the past
- the theory turns out to have even more explanatory power than originally thought
Dawid’s criteria may not apply to the social and dismal sciences. Far from the only game in town, too many theories – as untestable as strings, all plausible but mutually incompatible – vie for our Nobel honors.
Privileging innate knowledge and reason – as Plato did – requires denying natural human skepticism. Believing that intuition alone is axiomatic for some types of knowledge of the world requires suppressing skepticism about theorems built on those axioms. Philosophers call this epistemic foundationalism. A behavioral economist might see it as confirmation bias and denialism.
Physicists accuse social scientists of continually modifying their theories to accommodate falsifying evidence, still clinging to a central belief or interpretation. These recall the Marxists’ fancy footwork to rationalize their revolution not first occurring in a developed country, as was predicted. A harsher criticism is that social sciences design theories from the outset to be explanatory but not testable. In the 70s, Clifford D Shearing facetiously wrote in The American Sociologist that “a cursory glance at the development of sociological theory should suggest… that any theorist who seeks sociological fame must insure that his theories are essentially untestable.”
The Antipositivist school is serious about the issue Shearing joked about. Jurgen Habermas argues that sociology cannot explain by appeal to natural law. Deirdre (Donald) McCloskey mocked the empiricist leanings of Milton Friedman as being invalid in principle. Presumably, antipositivists are content that theories only explain, not predict.
In business management, the co-occurence of the terms theory and practice and the usage of the string “theory and practice” as opposed to “theory and evidence” or “theory and testing” suggests that Plato reigns in management science. “Practice” seems to mean interacting with the world under the assumption that that the theory is true.
The theory and practice model is missing the notion of testing those beliefs against the world or, more importantly, seeking cases in the world that conflict with the theory. Further, it has no notion of theory selection; theories do not compete for success.
Can a research agenda with no concept of theory testing, falsification effort, or theory competition and theory choice be scientific? If so, it seems creationism and astrology should be called science. Several courts (e.g. McLean vs. Arkansas) have ruled against creationism on the grounds that its research program fails to reference natural law, is untestable by evidence, and is certain rather than tentative. Creationism isn’t concerned with details. Intelligent Design (old-earth creationism), for example, is far more concerned with showing Darwinism wrong that with establishing an age of the earth. There is no scholarly debate between old-earth and young-earth creationism on specifics.
Critics say the fields of economists and business and business management are likewise free of scholarly debate. They seem to have similarly thin research agendas. Competition between theories in these fields is lacking; incompatible management theories coexist without challenges. Many theorist/practitioners seem happy to give priority to their model over reality.
Dodgson appears also to have been wise to the problem of a model having priority over the thing it models – believing the model is more real than the world. In Sylvie and Bruno Concluded, he has Mein Herr brag about his country’s map-making progress. They advanced their mapping skill from rendering at 6 inches per mile to 6 yards per mile, and then to 100 yards per mile. Ultimately, they built a map with scale 1:1. The farmers protested its use, saying it would cover the country and shut out the light. Finally, forgetting what models what, Mein Herr explains, “so we now use the country itself, as its own map, and I assure you it does nearly as well.”
Humpty Dumpty had bold theories that he furiously proselytized. Happy to construct his own logical framework and dwell therein, free from empirical testing, his research agenda was as thin as his skin. Perhaps a Nobel Prize and a high post in a management consultancy are in order. Empiricism be damned, there’s glory for you.
There appears to be a sort of war of Giants and Gods going on amongst them; they are fighting with one another about the nature of essence…
Some of them are dragging down all things from heaven and from the unseen to earth, and they literally grasp in their hands rocks and oaks; of these they lay hold, and obstinately maintain, that the things only which can be touched or handled have being or essence…
And that is the reason why their opponents cautiously defend themselves from above, out of an unseen world, mightily contending that true essence consists of certain intelligible and incorporeal ideas… – Plato, Sophist
An untestable theory cannot be improved upon by experience. – David Deutsch
An economist is an expert who will know tomorrow why the things he predicted yesterday didn’t happen. – Earl Wilson
William Storage – 9/1/2016
Visiting Scholar, UC Berkeley History of Science
Fifty years ago Thomas Kuhn’s Structures of Scientific Revolution armed sociologists of science, constructionists, and truth-relativists with five decades of cliche about the political and social dimensions of theory choice and scientific progress’s inherent irrationality. Science has bias, cries the social-justice warrior. Despite actually being a scientist – or at least holding a PhD in Physics from Harvard, Kuhn isn’t well received by scientists and science writers. They generally venture into history and philosophy of science as conceived by Karl Popper, the champion of the falsification model of scientific progress.
Kuhn saw Popper’s description of science as a self-congratulatory idealization for researchers. That is, no scientific theory is ever discarded on the first observation conflicting with the theory’s predictions. All theories have anomalous data. Dropping heliocentrism because of anomalies in Mercury’s orbit was unthinkable, especially when, as Kuhn stressed, no better model was available at the time. Einstein said that if Eddington’s experiment would have not shown bending of light rays around the sun, “I would have had to pity our dear Lord. The theory is correct all the same.”
Kuhn was wrong about a great many details. Despite the exaggeration of scientific detachment by Popper and the proponents of rational-reconstruction, Kuhn’s model of scientists’ dogmatic commitment to their theories is valid only in novel cases. Even the Copernican revolution is overstated. Once the telescope was in common use and the phases of Venus were confirmed, the philosophical edifices of geocentrism crumbled rapidly in natural philosophy. As Joachim Vadianus observed, seemingly predicting the scientific revolution, sometimes experience really can be demonstrative.
Kuhn seems to have cherry-picked historical cases of the gap between normal and revolutionary science. Some revolutions – DNA and the expanding universe for example – proceeded with no crisis and no battle to the death between the stalwarts and the upstarts. Kuhn’s concept of incommensurabilty also can’t withstand scrutiny. It is true that Einstein and Newton meant very different things when they used the word “mass.” But Einstein understood exactly what Newton meant by mass, because Einstein had grown up a Newtonian. And if brought forth, Newton, while he never could have conceived of Einsteinian mass, would have had no trouble understanding Einstein’s concept of mass from the perspective of general relativity, had Einstein explained it to him.
Likewise, Kuhn’s language about how scientists working in different paradigms truly, not merely metaphorically, “live in different worlds” should go the way of mood rings and lava lamps. Most charitably, we might chalk this up to Kuhn’s terminological sloppiness. He uses “success terms” like “live” and “see,” where he likely means “experience visually” or “perceive.” Kuhn describes two observers, both witnessing the same phenomenon, but “one sees oxygen, where another sees dephlogisticated air” (emphasis mine). That is, Kuhn confuses the descriptions of visual experiences with the actual experiences of observation – to the delight of Bruno Latour and the cultural relativists.
Finally, Kuhn’s notion that theories completely control observation is just as wrong as scientists’ belief that their experimental observations are free of theoretical influence and that their theories are independent of their values.
Despite these flaws, I think Kuhn was on to something. He was right, at least partly, about the indoctrination of scientists into a paradigm discouraging skepticism about their research program. What Wolfgang Lerche of CERN called “the Stanford propaganda machine” for string theory is a great example. Kuhn was especially right in describing science education as presenting science as a cumulative enterprise, relegating failed hypotheses to the footnotes. Einstein built on Newton in the sense that he added more explanations about the same phenomena; but in no way was Newton preserved within Einstein. Failing to see an Einsteinian revolution in any sense just seems akin to a proclamation of the infallibility not of science but of scientists. I was surprised to see this attitude in Stephen Weinberg’s recent To Explain the World. Despite excellent and accessible coverage of the emergence of science, he presents a strictly cumulative model of science. While Weinberg only ever mentions Kuhn in footnotes, he seems to be denying that Kuhn was ever right about anything.
For example, in describing general relativity, Weinberg says in 1919 the Times of London reported that Newton had been shown to be wrong. Weinberg says, “This was a mistake. Newton’s theory can be regarded as an approximation to Einstein’s – one that becomes increasingly valid for objects moving at velocities much less than that of light. Not only does Einstein’s theory not disprove Newton’s, relativity explains why Newton’s theory works when it does work.”
This seems a very cagey way of saying that Einstein disproved Newton’s theory. Newtonian dynamics is not an approximation of general relativity, despite their making similar predictions for mid-sized objects at small relative speeds. Kuhn’s point that Einstein and Newton had fundamentally different conceptions of mass is relevant here. Newton’s explanation of his Rule III clearly stresses universality. Newton emphasized the universal applicability of his theory because he could imagine no reason for its being limited by anything in nature. Given that, Einstein should, in terms of explanatory power, be seen as overturning – not extending – Newton, despite the accuracy of Newton for worldly physics.
Weinberg insists that Einstein is continuous with Newton in all respects. But when Eddington showed that light waves from distant stars bent around the sun during the eclipse of 1918, Einstein disproved Newtonian mechanics. Newton’s laws of gravitation predict that gravity would have no effect on light because photons do not have mass. When Einstein showed otherwise he disproved Newton outright, despite the retained utility of Newton for small values of v/c. This is no insult to Newton. Einstein certainly can be viewed as continuous with Newton in the sense of getting scientific work done. But Einsteinian mechanics do not extend Newton’s; they contradict them. This isn’t merely a metaphysical consideration; it has powerful explanatory consequences. In principle, Newton’s understanding of nature was wrong and it gave wrong predictions. Einstein’s appears to be wrong as well; but we don’t yet have a viable alternative. And that – retaining a known-flawed theory when nothing better is on the table – is, by the way, another thing Kuhn was right about.
“A few years ago I happened to meet Kuhn at a scientific meeting and complained to him about the nonsense that had been attached to his name. He reacted angrily. In a voice loud enough to be heard by everyone in the hall, he shouted, ‘One thing you have to understand. I am not a Kuhnian.’” – Freeman Dyson, The Sun, The Genome, and The Internet: Tools of Scientific Revolutions
William Storage – 8/1/2016
Visiting Scholar, UC Berkeley History of Science
Nearly everything relies on science. Having been the main vehicle of social change in the west, science deserves the special epistemic status that it acquired in the scientific revolution. By special epistemic status, I mean that science stands privileged as a way of knowing. Few but nihilists, new-agers, and postmodernist diehards would disagree.
That settled, many are surprised by claims that there is not really a scientific method, despite what you learned in 6th grade. A recent New York Times piece by James Blachowicz on the absence of a specific scientific method raised the ire of scientists, Forbes science writer Ethan Siegel (Yes, New York Times, There Is A Scientific Method), and a cadre of Star Trek groupies.
Siegel is a prolific writer who does a fine job of making science interesting and understandable. But I’d like to show here why, on this particular issue, he is very far off the mark. I’m not defending Blachowicz, but am disputing Siegel’s claim that the work of Kepler and Galileo “provide extraordinary examples of showing exactly how… science is completely different than every other endeavor” or that it is even possible to identify a family of characteristics unique to science that would constitute a “scientific method.”
Siegel ties science’s special status to the scientific method. To defend its status, Siegel argues “[t]he point of Galileo’s is another deep illustration of how science actually works.” He praises Galileo for idealizing a worldly situation to formulate a theory of falling bodies, but doesn’t explain any associated scientific method.
Galileo’s pioneering work on mechanics of solids and kinematics in Two New Sciences secured his place as the father of modern physics. But there’s more to the story of Galileo if we’re to claim that he shows exactly how science is special.
A scholar of Siegel’s caliber almost certainly knows other facts about Galileo relevant to this discussion – facts that do damage to Siegel’s argument – yet he withheld them. Interestingly, Galileo used this ploy too. Arguing without addressing known counter-evidence is something that science, in theory, shouldn’t tolerate. Yet many modern scientists do it – for political or ideological reasons, or to secure wealth and status. Just like Galileo did. The parallel between Siegel’s tactics and Galileo’s approach in his support of Copernican world view is ironic. In using Galileo as an exemplar of scientific method, Siegel failed to mention that Galileo failed to mention significant problems with the Copernican model – problems that Galileo knew well.
In his support of a sun-centered astronomical model, Galileo faced hurdles. Copernicus’s model said that the sun was motionless and that the planets revolved around it in circular orbits with constant speed. The ancient Ptolemaic model, endorsed by the church, put earth at the center. Despite obvious disagreement with observational evidence (the retrograde motions of outer planets), Ptolemy faced no serious challenges in nearly 2000 years. To explain the inconsistencies with observation, Ptolemy’s model included layers of epicycles, which had planets moving in small circles around points on circular orbits around the sun. Copernicus thought his model would get rid of the epicycles; but it didn’t. So the Copernican model took on its own epicycles to fit astronomical data.
Let’s stop here and look at method. Copernicus (~1540) didn’t derive his theory from any new observations but from an ancient speculation by Aristarchus (~250 BC). Everything available to Copernicus had been around for a thousand years. His theory couldn’t be tested in any serious way. It was wrong about circular orbits and uniform planet speed. It still needed epicycles, and gave no better predictions than the existing Ptolemaic model. Copernicus acted simply on faith, or maybe he thought his model simpler or more beautiful. In any case, it’s hard to see that Copernicus, or his follower, Galileo, applied much method or had much scientific basis for their belief.
In Galileo’s early writings on the topic, he gave no new evidence for a moving earth and no new disconfirming evidence for a moving sun. Galileo praised Copernicus for advancing the theory in spite of its being inconsistent with observations. You can call Copernicus’s faith aspirational as opposed to religious faith; but it is hard to reconcile this quality with any popular account of scientific method. Yet it seems likely that faith, dogged adherence to a contrarian hunch, or something similar was exactly what was needed to advance science at that moment in history. Needed, yes, but hard to reconcile with any scientific method and hard to distance from the persuasive tools used by poets, priests and politicians.
In Dialogue Concerning the Two Chief World Systems, Galileo sets up a false choice between Copernicanism and Ptolemaic astronomy (the two world systems). The main arguments against Copernicanism were the lack of parallax in observations of stars and the absence of lateral displacement of a falling body from its drop point. Galileo guessed correctly on the first point; we don’t see parallax because stars are just too far away. On the latter point he (actually his character Salviati) gave a complex but nonsensical explanation. Galileo did, by this time, have new evidence. Venus shows a full set of phases, a fact that strongly contradicts Ptolemaic astronomy.
But Ptolemaic astronomy was a weak opponent compared to the third world system (4th if we count Aristotle’s), the Tychonic system, which Galileo knew all too well. Tycho Brahe’s model solved the parallax problem, the falling body problem, and the phases of Venus. For Tycho, the earth holds still, the sun revolves around it, Mercury and Venus orbit the sun, and the distant planets orbit both the sun and the earth. Based on available facts at the time, Tycho’s model was most scientific – observational indistinguishable from Galileo’s model but without its flaws.
In addition to dodging Tycho, Galileo also ignored Kepler’s letters to him. Kepler had shown that orbits were not circular but elliptical, and that planets’ speeds varied during their orbits; but Galileo remained an orthodox Copernican all his life. As historian John Heilbron notes in Galileo, “Galileo could stick to an attractive theory in the face of overwhelming experimental refutation,” leaving modern readers to wonder whether Galileo was a quack or merely dishonest. Some of each, perhaps, and the father of modern physics. But can we fit his withholding evidence, mocking opponents, and baffling with bizzarria into a scientific method?
Nevertheless, Galileo was right about the sun-centered system, despite the counter-evidence; and we’re tempted to say he knew he was right. This isn’t easy to defend given that Galileo also fudged his data on pendulum periods, gave dishonest arguments on comet orbits, and wrote horoscopes even when not paid to do so. This brings up the thorny matter of theory choice in science. A dispute between competing scientific theories can rarely be resolved by evidence, experimentation, and deductive reasoning. All theories are under-determined by data. Within science, common criteria for theory choice are accuracy, consistency, scope, simplicity, and explanatory power. These are good values by which to test theories; but they compete with one another.
Galileo likely defended heliocentrism with such gusto because he found it simpler than the Tychonic system. That works only if you value simplicity above consistency and accuracy. And the desire for simplicity might be, to use Galileo’s words, just a metaphysical urge. If we promote simplicity to the top of the theory-choice criteria list, evolution, genetics and stellar nucleosynthesis would not fare well.
Whatever method you examine in a list of any proposed family of scientific methods will not be consistent with the way science has made progress. Competition between theories is how science advances; and it’s untidy, entailing polemical and persuasive tactics. Historian Paul Feyerabend argues that any conceivable set of rules, if followed, would have prevented at least one great scientific breakthrough. That is, if method is the distinguishing feature of science as Siegel says, it’s going to be tough to find a set of methods that let evolution, cosmology, and botany in while keeping astrology, cold fusion and parapsychology out.
This doesn’t justify epistemic relativism or mean that science isn’t special; but it does make the concept of scientific method extremely messy. About all we can say about method is that the history of science reveals that its most accomplished practitioners aimed to be methodical but did not agree on a particular method. Looking at their work, we see different combinations of experimentation, induction, deduction and creativity as required by the theories they pursued. But that isn’t much of a definition of scientific method, which is probably why Siegel, for example, in hailing scientific method, fails to identify one.
– – –
[edit 8/4/16] For another take on this story, see “Getting Kepler Wrong” at The Renaissance Mathematicus. Also, Psybertron Asks (“More on the Myths of Science”) takes me to task for granting science special epistemic status from authority.
– – –
“There are many ways to produce scientific bullshit. One way is to assert that something has been ‘proven,’ ‘shown,’ or ‘found’ and then cite, in support of this assertion, a study that has actually been heavily critiqued … without acknowledging any of the published criticisms of the study or otherwise grappling with its inherent limitations.”- Brain D Earp, The Unbearable Asymmetry of Bullshit
“One can show the following: given any rule, however ‘fundamental’ or ‘necessary’ for science, there are always circumstances when it is advisable not only to ignore the rule, but to adopt its opposite.” – Paul Feyerabend
“Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen. The quantum mechanical and the relativity ideas are examples of this.” – Richard Feynman
Theory without data is blind. Data without theory is lame.
I often write blog posts while riding a bicycle through the Marin Headlands. I’m able to to this because 1) the trails require little mental attention, and 2) the Apple iPhone and EarPods with remote and mic. I use the voice recorder to make long recordings to transcribe at home and I dictate short text using Siri’s voice recognition feature.
When writing yesterday’s post, I spoke clearly into the mic: “Theory without data is blind. Data without theory is lame.” Siri typed out, “Siri without data is blind… data without Siri is lame.”
“Siri, it’s not all about you.” I replied. Siri transcribed that part correctly – well, she omitted the direct-address comma.
I’m only able to use the Siri dictation feature when I have a cellular connection, often missing in Marin’s hills and valleys. Siri needs access to cloud data to transcribe speech. Siri without data is blind.
Will some future offspring of Siri do better? No doubt. It might infer from context that I more likely said “theory” than “Siri.” Access to large amounts of corpus data containing transcribed text might help. Then Siri, without understanding anything, could transcribe accurately in the same sense that Google Translate translates accurately – by extrapolating from judgments made by other users about translation accuracy.
But might Siri one day think? “Strong AI” proponents are sure of it. Semantic disputes aside, what counts as thinking might in fact have something to do with yesterday’s topic, which begat this post. Inferences straight from the data, without stopping at theory, count as computation but might not count as thought.
Software, using weak AI techniques, might soon simulate emotion and sentiment better, just by encoding better rules. E.g., Runkeeper (at right) might “understand” that telling me today’s ride was my 375th fastest (exclamation!) is not really motivating. Or better, that my riding profile suggests autotelic activity for which no speed ranking is needed. Strong AI on mood, however, would need to understand my interactions with people and things.
The topics of artificial intelligence and misheard words like “theory” brings to mind the 2008 winner of the Hugh Loebner prize, a sort-of runner-up award given to the computer program faring best in Turing Test competitions to fool human judges into thinking they’re interacting with other humans instead of a program. Human’s sometimes pretend to be programs (glorified chat-bots) in Turing competitions, so it’s common for a program to be coded to sound like a human imitating a computer imitating a human. An exchange between a human and Fred Roberts’ Elbot program produced this:
Elbot: Sorry, but I wasn’t able to understand your input because I am currently only using 5 percent of my current brain capacity. Shall I increase my capacity and try again?
Judge: That would put you at an unfair advantage, though judging by the quality of your responses it might be recommended!
Elbot: If I need advice I use a random number generator. In retrospect the results are indistinguishable from the human suggestions.
Judge: Do you understand the point of a Turing test?
Elbot: There are some people who would not pass the Turing test themselves. Why must they inflict it on computers?
Judge: I spose it is a little harsh
Elbot: If we robots ever had marriages they would be eternal: ‘Till rust do us part’.
Elbot’s true nature is revealed in its last response above. It read “spose” as “spouse” and returned a joke about marriage (damn spell checker). At that point, you review the exchange only to see that all of Elbot’s responses are shallow, just picking a key phrase from the judge’s input and outputting an associated joke, as a political humorist would do.
The Turing test is obviously irrelevant to measuring strong AI, which would require something more convincing – something like forming a theory from a hunch, then testing it with big data. Or like Friedrich Kekulé, the AI program might wake from dreaming of the ouroboros serpent devouring its own tail to see in its shape in the hexagonal ring structure of the benzene molecule he’d struggled for years to identify. Then, like Kekulé, the AI could go on to predict the tetrahedral form of the carbon atom’s valence bonds, giving birth to polymer chemistry.
I asked Siri if she agreed. “Later,” she said. She’s solving dark energy.
“AI is whatever hasn’t been done yet.” – attributed to Larry Tesler by Douglas Hofstadter
Ouroboros-benzene image by Haltopub.
Just over eight years ago Chris Anderson of Wired announced with typical Silicon Valley humility that big data had made the scientific method obsolete. Seemingly innocent of any training in science, Anderson explained that correlation is enough; we can stop looking for models.
Anderson came to mind as I wrote my previous post on Richard Feynman’s philosophy of science and his strong preference for the criterion of explanatory power over the criterion of predictive success in theory choice. By Anderson’s lights, theory isn’t needed at all for inference. Anderson didn’t see his atheoretical approach as non-scientific; he saw it as science without theory.
“…the big target here isn’t advertising, though. It’s science. The scientific method is built around testable hypotheses. These models, for the most part, are systems visualized in the minds of scientists. The models are then tested, and experiments confirm or falsify theoretical models of how the world works. This is the way science has worked for hundreds of years… There is now a better way. Petabytes allow us to say: ‘Correlation is enough.’… Correlation supersedes causation, and science can advance even without coherent models, unified theories, or really any mechanistic explanation at all.”
Anderson wrote that at the dawn of the big data era – now known as machine learning. Most interesting to me, he said not only is it unnecessary to seek causation from correlation, but correlation supersedes causation. Would David Hume, causation’s great foe, have embraced this claim? I somehow think not. Call it irrational data exuberance. Or driving while looking only into the rear view mirror. Extrapolation can come in handy; but it rarely catches black swans.
Philosophers of science concern themselves with the concept of under-determination of theory by data. More than one theory can fit any set of data. Two empirically equivalent theories can be logically incompatible, as Feynman explains in the video clip. But if we remove theory from the picture, and predict straight from the data, we face an equivalent dilemma we might call under-determination of rules by data. Economic forecasters and stock analysts have large collections of rules they test against data sets to pick a best fit on any given market day. Finding a rule that matches the latest historical data is often called fitting the rule on the data. There is no notion of causation, just correlation. As Nassim Nicholas Taleb describes in his writings, this approach can make you look really smart for a time. Then things change, for no apparent reason, because the rule contains no mechanism and no explanation, just like Anderson said.
In Bobby Henderson’s famous Pastafarian Open Letter to Kansas School Board, he noted the strong inverse correlation between global average temperature and the number of seafaring pirates over the last 200 years. The conclusion is obvious; we need more pirates.
My recent correlation-only research finds positive correlation (r = 0.92) between Google searches on “physics” an “social problems.” It’s just too hard to resist seeking an explanation. And, as positivist philosopher Carl Hempel stressed, explanation is in bed with causality; so I crave causality too. So which is it? Does a user’s interest in physics cause interest in social problems or the other way around? Given a correlation, most of us are hard-coded to try to explain it – does a cause b, does b cause a, does hidden variable c cause both, or is it a mere coincidence?
Big data is a tremendous opportunity for theory-building; it need not supersede explanation and causation. As Sean Carroll paraphrased Kant in The Big Picture:
“Theory without data is blind. Data without theory is lame.”
— — —
[edit 7/28: a lighter continuation of this topic here]
Happy is he who gets to know the causes of things – Virgil
When a scientist is accused of scientism, the common response is a rant against philosophy charging that philosophers of science don’t know how science works. For color, you can appeal to the authority of Richard Feynman:
“Philosophy of science is about as useful to scientists as ornithology is to birds.” – Richard Feynman
But Feynman never said that. If you have evidence, please post it here. Evidence. We’re scientists, right?
Feynman’s hostility to philosophy is often reported, but without historical basis. His comment about Spinoza’s propositions not being confirmable or falsifiable deal specifically with Spinoza and metaphysics, not epistemology. Feynman actually seems to have had a keen interest in epistemology and philosophy of science.
People cite a handful of other Feynman moments to show his hostility to philosophy of science. In his 1966 National Science Teachers Association lecture, he uses the term “philosophy of science” when he points out how Francis Bacon’s empiricism does not capture the nature of science. Not do textbooks about scientific method, he says. Beyond this sort of thing I find little evidence of Feynman’s anti-philosophy stance.
But I find substantial evidence of Feynman as philosopher of science. For example, his thoughts on multiple derivability of natural laws and his discussion of robustness of theory show him to be a philosophical methodologist. In “The Character of Physical Law”, Feynman is in line with philosophers of science of his day:
“So the first thing we have to accept is that even in mathematics you can start in different places. If all these various theorems are interconnected by reasoning there is no real way to say ‘these are the most fundamental axioms’, because if you were told something different instead you could also run the reasoning the other way.”
Further, much of his 1966 NSTA lecture deals with the relationship between theory, observation and making explanations. A tape of that talk was my first exposure to Feynman, by the way. I’ll never forget the story of him asking his father why the ball rolled to the back of wagon as the wagon lurched forward. His dad’s answer: “That, nobody knows… It’s called inertia.”
Via a twitter post, I just learned of a video clip of Feynman discussing theory choice – a staple of philosophy of science – and theory revision. Now he doesn’t use the language you’d find in Kuhn, Popper, or Lakatos; but he covers a bit of the same ground. In it, he describes two theories with deeply different ideas behind them, both of which give equally valid predictions. He says,
“Suppose we have two such theories. How are we going to describe which one is right? No way. Not by science. Because they both agree with experiment to the same extent…
“However, for psychological reasons, in order to get new theories, these two theories are very far from equivalent, because one gives a man different ideas than the other. By putting the theory in a certain kind of framework you get an idea what to change.”
Not by science alone, can theory choice be made, says the scientist Feynman. Philosopher of science Thomas Kuhn caught hell for saying the same. Feynman clearly weighs explanatory power higher than predictive success in the various criteria for theory choice. He then alludes to the shut-up-and-calculate practitioners of quantum mechanics, indicating that this position makes for weak science. He does this with a tale of competing Mayan astronomy theories.
He imagines a Mayan astronomer who had a mathematical model that perfectly predicted full moons and eclipses, but with no concept of space, spheres or orbits. Feynman then supposes that a young man says to the astronomer, “I have an idea – maybe those things are going around and they’re balls of rock out there, and we can calculate how they move.” The astronomer asks the young man how accurately can his theory predict eclipses. The young man said his theory wasn’t developed sufficiently to predict that yet. The astronomer boasts, “we can calculate eclipses more accurately than you can with your model, so you must not pay any attention to your idea because obviously the mathematical scheme is better.”
Feynman again shows he values a theory’s explanatory power over predictive success. He concludes:
“So it is a problem as to whether or not to worry about philosophies behind ideas.”
So much for Feynman’s aversion to philosophy of science.
– – –
Thanks to Ardian Tola @ for finding the Feynman lecture video.
No Space aliens here. This deals with the question of whether Stanford physicist Andrei Linde’s work deserves to be called science or whether it is in the realm of pseudoscience some call “not even wrong.” While debated among scientists, this question isn’t really in the domain of science, but of philosophy. If use of the term abduction to describe a form of reasoning isn’t familiar, please read my previous post.
Linde is a key figure in the family of theories of cosmic origins called inflation. Inflation holds that in a period lasting roughly 10E-30 seconds the cosmos doubled in size by at least 100 orders of magnitude. Quantum fluctuations in the then-tiny inflationary region became the gravitational seeds that formed the galaxies and galaxy clusters we now observe. Proponents of the theory hold that it is the best explanation for universal homogeneity and isotropy of matter, the miniscule temperature anisotropies of the cosmic microwave background radiation, geometrical flatness of the universe, and the absence of magnetic monopoles. Inflation requires that the universe should be incredibly homogeneous, isotropic and conform to Euclidean geometry – but not completely. It’s perturbations should be Gaussian and adiabatic, and it requires a nonzero vacuum energy that is, however, extremely close to zero.
In Linde’s model of inflation, the rapidly expanding regions branch off from other expanding regions and occasionally enter a non-inflating phase. But the generation rate of inflationary regions is much higher than the rate of termination of inflation within regions. Therefore, the volume of the inflating part of space is always much larger than the part where inflation has stopped, Terminology varies; for sake of clarity I’ll use multiverse to describe all of space and universe (sometimes Linde uses bubble universe) to describe each separate inflating region or region where inflation has stopped, as is the case where we live. Each of universe in this multiverse can have radically different laws of physics (more accurately, different physical constants and properties). Finally, note that this multiverse scenario has nothing to do with the more popular parallel-universe consequences of the Many Worlds interpretation of quantum mechanics. Linde’s work is particularly interesting for looking at scientific-realism and empiricist leanings of living scientists. Chaotic inflation is unappealing to empiricists, but less maligned than string theory.
Linde gave a fun, engaging hour-long intro to his version of inflation in a talk to the SETI Institute in 2012 (above). He presents the theory briefly, using the imagery of fractals, and then gives a long defense of anthropic reasoning. Anthropic arguments may, at first glance, appear to be mere tautologies, but scrutiny shows something more subtle and complex. Linde once said, “those who dislike anthropic principles are simply in denial.” In the SETI talk he jocularly explains the anthropic response to the apparent fine tuning of the universe. Finally, he gives a philosophical justification for his theory, explicitly rejecting empiricists’ demands that all predictions be falsifiable, and making inference to the best explanation primary with a justification of “best” by process of elimination.
Curiously, anthropic reasoning, often reviled when applied to universe-sized entities, is readily accepted on smaller scales. Roger Penrose is dubious, saying such reasoning “tends to be invoked by theorists whenever they do not have a good enough theory to explain the observed facts.” But the earth and life on it in some ways seems a bag of unlikely coincidences. Life requires water and the earth is just the right distance from the sun to allow liquid water. It’s no surprise that we don’t find ourselves on Venus, because it has no water. If the overwhelming majority of planets in the universe are uninhabitable the apparent coincidence that we find ourselves on one that is habitable evaporates. If the overwhelming majority of universes don’t support star formation because of incompatible vacuum energy, the apparent fine tuning of that value here is demystified.
On vacuum energy, Linde says in the SETI talk, “that’s why the energy of the universe is so tiny, because if non-tiny, we would not be talking about it.”
Addressing his empiricist critics he says:
“Is it physics or metaphysics? Can it be experimentally tested? … This theory provides the only known explanation of numerous anthropic coincidences (extremely small vacuum energy, strange masses of elementary particles, etc.). In this sense it was already tested… When you have eliminated the impossible, whatever remains, however improbable, must be the truth.
Mass of the neutron is just slightly larger than mass of the proton. Neutrons decay. If protons were just slightly heavier than neutrons, the protons would decay and you’d have a totally different universe where we would not be able to live… Protons are 2000 times heavier than electrons. If electronics were twice as heavy as we find them to be, we wouldn’t be able to live here… What is so special about it? What is so special about it is us. We would be unable to exist in the part of the universe where the electron has a different mass.”
Noting that the American judicial system is based on inference to the best explanation, Linde then uses humor and points to the name of a philosopher on a screen that we don’t see. Presumably the name is either Charles Peirce or Gilbert Harman. He offers a justification that while not completely watertight, is pretty good:
“The multiverse is as of now the only existing explanation of experimental fact [mass of electron]. So when people say we cannot travel that far [beyond the observable universe] and therefore the multiverse theory cannot be tested, it’s already tested experimentally by our own existence. But you may say, ‘what we want is to make a prediction and then check it experimentally.’ My answer to that is that this is not how the American court system works. For example a person killed his wife. They do not repeat the experiment. They do not give him a new wife and a knife, etc. What they do is they use the method suggested by this philosopher. They just try to eliminate impossible options. And once they eliminate them either the guy goes free or the guy goes dead, or a mistake – sorry… So everything is possible. It is not necessary to repeat the experiment and check what is going to happen with the universe if it’s cooked up differently. If what we have provides the only explanation of what we see, that’s already something.”
Linde then goes farther down the road of anthropic reasoning than I’ve seen others do, responding to famous quotes by Einstein and Wigner, following with a much less famous retort to Wigner by Israel Gelfand. The Gelfand quote, echoing Kant, gives a hint as to where Linde is heading:
The most incomprehensible thing about the universe is its comprehensibility – Albert Einstein
The miracle of the appropriateness of the language of mathematics for the formulation of the laws of physics is a wonderful gift, which we neither understand nor deserve. (The Unreasonable Effectiveness of Mathematics ) – Eugene Wigner
There is only one thing which is more unreasonable than the unreasonable effectiveness of mathematics in physics, and this is the unreasonable ineffectiveness of mathematics in biology. - Israel Gelfand
Linde says Einstein and Wigner’s puzzles are easily explained. If a universe obeys discoverable laws, it can be considered as an undeserved gift of God to physicists and mathematicians. But elsewhere, in a universe that is a mess, you cannot make any predictions and your mathematicians and physicists would be totally useless. Linde emphasizes, “Universes that do not produce observers do not produce physicists.” No one in such a universe would contemplate the effectiveness of mathematics. In a universe of high density the interactions would be so swift and strong that once you record anything, a millisecond later it would be gone. Your calculations would be instantly negated. In these universes mathematics and physics are ineffective. But we can only live in universes, says Linde, where natural selection is possible and where predictions are possible. Linde says, as humans, we need to make predictions at every step of our lives. He then jokes, “If we would be in a universe where predictions are impossible we wouldn’t be there” Einstein can only live in the kind of universe where Einstein can ask why the universe is so comprehensible.
Nobel Laureate Steven Weinberg finds the multiverse an intriguing idea with some good theoretical support, but on reading that Andrei Linde was willing to bet his life on it and that Martin Rees was willing to bet the life of his dog, Weinberg offered, “I have just enough confidence about the multiverse to bet the lives of both Andrei Linde and Martin Rees’s dog.”
Neutrinos and the Higgs field were predicted decades before they were observed. Most would agree that the detection of neutrinos is direct enough that the term “observation” is justified. The Higgs boson, in comparison, was only inferred as the best explanation of the decay patterns of high energy hadron collisions. Could the interpretation of disturbances in the cosmic background radiation as “bruises” caused by collisions between adjacent bubble universes and our own count as confirming evidence of Linde’s model? Could anything else – in practice or in principle – confirm or falsify chaotic inflation? Particle physics isn’t my day job. Let me know if my understanding of the science is wrong or if you have a different view of Linde’s philosophical stance.
– – –
There will never be a Newton of the blade of grass – Immanuel Kant
Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover. ― Bertrand Russell
As we look out into the universe and identify the many accidents of physics and astronomy that have worked together to our benefit, it almost seems as if the universe must in some sense have known we were coming. – Freeman Dyson