How to Talk about Science to the Public – 2. Speak Honestly about Uncertainty

Don Howard

We are all Humeans, all of us who are trained in science, at least. We know that empirical evidence confers at most high probability, never certainty, on a scientific claim, and this no matter how sophisticated the inductive logic that we preach. Enumerative induction doesn’t do it. That the sun rose every day in recorded history and before does not imply that it will, of necessity, rise tomorrow. Inference to the best explanation doesn’t do it, for such inferences depend on a changing explanandum (that which is to be explained) and upon both an obscure quality metric (what determines the “better than” metric) and a never complete reference class of competing explanations. Bayes’s theorem can’t do it either.

No. All of us who are trained in science know that every theory, principle, law, and observation is open to challenge and that many once thought secure now populate the museum of dead theories. Sophisticated philosophers of science have invented the intimidating name, “the pessimistic meta-induction” for the thesis that, just as all theories in the past have turned out to be false or significantly limited in scope, so, too, most likely, will our current best and future science.

No. We all know that science is a matter of tentative hypotheses and best guesses. Some principles that have proven their mettle over the long haul, such as the conservation of energy, rightly earn our confidence that they can be reliable guides in the future. But more than one scientist has been willing to sacrifice even the conservation of energy if that were the price to solve another intractable riddle, as when Niels Bohr twice proposed theories that assumed violations of energy conservation.

That science does not deal in certainty is a major part of what makes it such a precious cultural achievement. Science is not dogma. Science admits its failings and learns from its mistakes. That it does so is key to how it achieved the dramatic expansion of scientific understanding that we have witnessed at least since the Renaissance.

Why, then, do we have so much trouble speaking honestly to the public about uncertainty? Why, when debating on the campaign trail, do we give in to the temptation to describe anthropogenic climate change as “proven fact.”? Why, when on the witness stand, do we feel the need to assert that a Darwinian story about human origins is established “beyond all reasonable doubt”? We have lots of good reasons for believing in human-caused climate change and Darwinian evolution. Few scientific claims are as well established as these. But about both we might be wrong in some as yet unforeseen or unforeseeable way. Why lie? Why not speak honestly?

There are at least two reasons why, when speaking to the public, we so often seek refuge in the rhetoric of proof and truth. The first is that we wrongly think that the scientific laity cannot understand uncertainty and probability. This is one of the most worrisome ways in which we insult the intelligence of our audience.

That lots of us – scientists and non-scientists alike – make lots of inductive and probabilistic mistakes is obvious. Casinos, state lotteries, and race tracks are all the evidence one needs. They profit only thanks to those mistakes. Nor are any of us rational utility maximizers, soundly weighing expected gains and losses against the probabilities of various outcomes. The stock market provides the relevant evidence here.

But the fact that lots of people make inductive errors doesn’t imply that the educated public can’t deal with uncertainty. We all deal with uncertainty all the time, and, in the main, we do a good job with it. Do I take I-294 or the Skyway, the Dan Ryan, and the Kennedy to O’Hare? What are the odds of congestion on each at this time of day? How much of a time cushion do I have? What are the consequences of being early or late? How likely am I to miss my flight if there is a ten-minute delay, a twenty-minute delay, or an hour-long delay? Chance of rain? Do I take the umbrella or also my overcoat? Much of life is like this. We make mistakes, but we get by, don’t we?

Naomi Oreskes and Erik Conway. Merchants of Doubt. Bloomsbury Press, 2010.

The second major reason why we retreat to the rhetoric of proof and truth is that we allow ourselves to be intimidated by the merchants of doubt.* The political exploitation of uncertainty to create the illusion of scientific dissensus and thereby stymie policy making on global warming, public health, energy, and other issues is now, itself, big business. There are lobbying firms, fictitious “think tanks,” corporate public relations offices, sham public interest groups, and members of congress who might as well be paid spokespersons. Much of the same kind of apparatus is encountered in the “debates” over evolution and intelligent design. Acknowledge uncertainty, and that becomes the wedge by means of which the illusion of scientific controversy can be created where there is, in fact, no controversy. What is to be done?

What is not to be done is misrepresenting the contingency of science. It is a mistake to confront the merchants of doubt with the pretense of certainty and proof. The right response is to trust the public to understand the weighing of evidence and the adjustment of policy to the strength of the evidence. The right response is, simply and clearly, to present the evidence. To be sure, climate modeling and population genetics involve sophisticated statistical tools that cannot be explained in detail in a few sentences. But with only a bit effort one can usually explain the general issue in an accessible manner.

A good example of making probabilities accessible is the recent reporting on the hunt for the Higgs boson with the Large Hadron Collider at CERN. Any reader of the New York Times or the Wall Street Journal now knows the expressions “three-sigma” and “five-sigma.” A tutorial on calculating standard deviations was not needed to communicate the point that, when sorting through oceans of data, looking for truly exceptional events, one wants to be sure that what one is seeing is more than what would be expected from random fluctuations. People understand this. If the roulette ball lands on 36 twice in a row one is mildly surprised but doesn’t accuse the croupier of cheating. If it lands on 36 five times in a row, then it’s time to ask to see the manager.

No contentious policy questions turn on the results from CERN, so perhaps it is easier for us to speak about uncertainty in this context. But if we can educate the public about statistics in particle physics, surely we can do it as well when the topic is flu epidemics or vehicle safety or climate change. Here is the evidence for increased global temperatures over the last century. Here is what the models predict for increased sea levels. Here is our degree of confidence in these predictions. Now let’s talk about the costs and benefits of different courses of action. Be firm. Be clear. Don’t be afraid to call a lie a “lie” when others misrepresent the evidence or misdescribe the models. But trust the public to follow the logic of the science if we do a good enough job of explaining that logic.

There might be one final reason why we too often retreat to the rhetoric of proof and truth, a reason that I’ll just mention here, saving a fuller discussion for another occasion. It is that too many of us were, ourselves, badly trained in science. Too many textbooks too many courses, and far, far too many popular science writers still teach the science in ways that encourage the illusion of settled fact where there is none. Thomas Kuhn taught us that science teaching often looks more like indoctrination than we might be comfortable acknowledging. There are remedies for this, foremost among them a more thorough and sophisticated incorporation of history and philosophy of science into science pedagogy. But, again, that is a topic for another post.

*See the excellent book by this title: Naomi Oreskes and Eric Conway, Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming (Bloomsbury Press, 2010).

Science and Values – 1. The Challenge for the Philosopher

Don Howard

Science, by which I mean also the technologies that flow from and inform it, is a form of social practice. It has evolved distinct institutions and a distinct sociology. It has accumulated and refined an array of formal techniques and instrumental means for knowledge production and certification. That it is also socially embedded, affected by and affecting every aspect of human life, is a trivial truth. The only question, albeit a large one, is, “How?” By what means, in which respects, and to what extent does science change our world and does the world change science? Some changes are obvious, as with the accelerating transformation of material culture effected by science, and changes in our understanding of self, the worlds our selves inhabit, their relation to one another, and the relation of both to nature and spirit. Other changes, and the manner of the change, are less so, as with the content and modes of production of scientific knowledge. Does it make a difference when science is done in a democracy? Does it make a difference when research is funded by the private sector rather than the state? Is science neutral, objective, and above the fray? Understanding how science affects and is affected by its surround is necessary if we wish to effect intelligent control over science and the part of human life that it touches, which is well nigh the whole of the human experience.

Philosophers of science are supposed to understand the structure, methods, and interpretation of science. But apart from modest progress on the formal side and a few helpful insights in the foundations of some individual sciences, philosophy’s record from the early twentieth century has been, until late, rather spotty. In the main, when it comes to all but the more formal questions, philosophers of science have handed the task to their colleagues in history and sociology. History has given good service. Fans of technical history of science have been a tad disappointed in recent decades, but otherwise the history of science is a thriving field, with an expanding scope and a healthy plurality of approaches. Historians have taught us much about how science works and how it lives in its many contexts. But history remains, for the most part, a descriptive, narrative, or hermeneutic enterprise, deliberately eschewing critique and normativity. We may argue about how good a job the sociologists have done since the advent of the “strong programme” (“strong” = context shapes the content of science, not just its aims and institutions) some thirty plus years ago. Instead let’s thank them for forcing everyone to take the question of context seriously and for unsettling our lazy assumptions about the distinctive superiority of science among other social practices, its objectivity, and its social detachment. Subversion of prejudice is a form of critique, but sociology of science, like history of science, remains a largely descriptive, not critical enterprise.

Which brings us back to the challenge for the philosophers of science, my native tribe. Until late, we have struggled to say much that is helpful about the embedding of science in society because we were in thrall to an ideology of value neutrality and the social detachment of science, wrongly think these to be necessary conditions for scientific objectivity. We used to credit logical positivism for this deep insight into objectivity, citing Hans Reichenbach’s distinction between the “context of justification” and the “context of discovery,” the latter being the dustbin into which history, sociology, and all interesting questions about context were cast, the former being the sandbox in which elite philosophers of science alone were allowed to play. Now we regard such dogma not as insight, but as blindness, and the newer historiography explains it as not just the conclusion of a bad argument but as the discipline’s defensive response to political persecution before (Hitler) and after (Joe McCarthy) the Second World War. Weak inductive evidence for the new historiography is afforded by the fact that, curiously, philosophers of science began to overcome their fear of values talk at about the same time that the Berlin Wall came down.

Today, one is happy to report, everyone is eager to get on the science and values bandwagon. There are conferences, books, anthologies, special issues of journals, albeit, as yet, no prizes. Philosophers of science are eager to learn about science policy. They now invite historians and sociologists to their meetings, and they try hard to be respectful, even as they struggle to figure out exactly how empirical evidence bearing on the actual practice of science is supposed to inform their philosophers’ questions. But that is precisely the problem, for what the philosophy of science still lacks are tools for theorizing the manner and consequences of the social embedding of science.

This is not for want of trying. Our feminist colleagues have been at it for thirty or more years. They have taught us a lot about episodes where science has been more deeply affected by its social embedding – read now its “gendering” – than many of us had or wanted to think. Among them there is a proliferation of analytical frameworks, from feminist empiricism to standpoint theory, difference feminism, and postmodernist feminism, each of which has taught us new ways to query once-settled pieties. Phil Kitcher is probably the most prominent philosopher of science otherwise to have taken the plunge, borrowing ideas from John Rawls to think about the place of science in democracy while holding onto what some think are rather shopworn notions of truth and realism (perhaps also a shopworn notion of democracy). Most interesting to me are those projects that mine the past for fresh insights on science, values, and social embedding, as with Heather Douglas’s re-reading of Richard Rudner, Tom Uebel’s rehabilitation of Otto Neurath, and Matt Brown’s resuscitation of John Dewey (more on all of which anon). New theoretical ideas emerge, thus, from attentive history that is more than mere antiquarianism and rational reconstruction.

Lots of commotion. Still we lack, by my lights, the kinds of theoretical tools needed to answer the “How?” question posed above: “By what means, in which respects, and to what extent does science change our world and does the world change science?” We need a theory of science that integrates the history, philosophy, anthropology, psychology, sociology, and even biology of science and scientists into a comprehensive project. In its critical and reformist aspects this theory of science must learn to be normative not just after the fashion of the inductive logician but also in the way of the political theorist and the moral theorist. Promotion of the common good should be the guiding principle. And it would be fun it if could even be a bit utopian.

The next post will set us on our way with a more specific list of necessary conditions for the possibility of such a theory of science.

Physics as Theodicy

Don Howard

A few years ago I had the good fortune to participate in a great conference at the Vatican Observatory on “Scientific Perspectives on the Problem of Natural Evil.” The conference was organized by the Center for Theology and the Natural Sciences, at Berkeley, and co-convened by CTNS and the Vatican Observatory. The Observatory shares Castel Gandolfo with the Papal summer residence, and Pope Benedict was in residence during the entirety of the conference. Many fond memories, among them a state visit by Queen Noor of Jordan, and our being serenaded by Benedict one afternoon as he practiced a Beethoven sonata on the piano. But the really cool thing was being saluted by members of the Swiss Guard every morning as we entered and every evening as we left, snapping to attention with the greeting, “Buongiorno” or “Buonasera.”

Nancey Murphy, Robert John Russell, and William Stoeger, S.J., eds. Physics and Cosmology: Scientific Perspectives on Natural Evil. Vatican City: Vatican Observatory, 2007.

There were many fine presentations by a first-rate group of scholars. I measure the quality of a conference by how much I learn that is new and interesting to me. By those metrics, this meeting is among the very best I’ve ever attended. Take a look at the contents of the published volume, which came to fruition largely through the efforts of Nancey Murphy and her colleagues at Fuller Theological Seminary in Pasadena, and was co-published by CTNS and the Vatican Observatory:

Physics and Cosmology: Scientific Perspectives on the Problem of Natural Evil

My own presentation was entitled “Physics as Theodicy.” A “theodicy” is a solution to the problem of natural evil. Traditionally we distinguish “natural evil” from “moral evil.” Natural evil is suffering that is a consequence of the operation of natural law. Death and destruction wrought by earthquakes, hurricanes, and disease are classic examples. Moral evil concerns suffering in consequence of the moral failings of human beings. Murder, slavery, and too many other sins afford examples. The classic problem of natural evil, famously discussed by Leibniz in his Théodicée (1710) and Voltaire in Candide (1759), is how there can be natural evil in a world governed by an omnisicient, omnipotent, and benevolent God. Leibniz argued that ours is the best of all possible worlds, a view echoed by Alexander Pope in his “Essay on Man” (1734) and viciously mocked by Voltaire.

The traditional problem of evil interests me less than the question of where and how we draw the line between natural and moral evil. The main point of my talk was a simple one: With the progress of science, physics leading the way, we learn more about the laws of nature and so acquire an ever greater capacity to prevent or ameliorate the suffering caused by disease or natural catastrophes. We still cannot prevent an earthquake or a tsunami, but we can predict them, and we can build office towers and bridges that can survive an earthquake, sea walls that can control storm surges, and warning systems that can give people time to take refuge. But do we choose to exercise this power? If we could have prevented a catastrophe or lessened the suffering, but chose not to do so, then the evil is moral, not natural. Thus, with the progress of science, the boundary between natural and moral evil shifts. As science teaches us more about our world, we must accept the moral responsibility for making the world a better place. Even without global climate change, Hurricane Katrina would have been a terrible storm. But at the very least, we could have built stronger dikes. We could not have prevented the earthquake that caused the horrific Indian Ocean tsunami of 2004, but we could have put in place a tsunami warning system that would have saved many tens of thousands of lives. Those deaths are our fault, not nature’s or God’s.

Want to know more? You can download the full paper here:

“Physics as Theodicy”
(Made available here with the permission of the Vatican Observatory.)

And you can buy the book through the University of Notre Dame Press:

How to Talk about Science to the Public – 1. Don’t Insult the Intelligence of Your Audience

Don Howard

About ten years ago I wrote the Einstein article for the new edition of a major encyclopedia. It shall remain unnamed, but you would most definitely recognize it. I enjoyed the challenge and am proud of the product, both because such writing is important and because it is hard work. One must be engaging, intelligible, and concise. Academics must resist the urge to splurge on words.

Writing this article was, however, harder than it should have been, because my editor kept repeating the old journalist’s mantra about writing to the level of the typical fourteen-year-old. We fought. I resisted. He won. He demanded plainer language. He insisted on tediously pedantic explanations of what I thought the reader would see as simple, even if slightly technical concepts. He struck whole paragraphs that I thought were wonderful and he thought were too arcane. Time and again I said that the real fourteen-year-olds I knew could easily understand points that he thought beyond the reach of his imaginary, teen reader. I don’t think that I made a friend. I taunted him by noting that the reader confused about concept X could simply look up the article on X elsewhere in the same encyclopedia. Impolitic, yes, but I couldn’t stop myself. Naughty Don.

A few years later I was asked to do a series of lectures on Einstein for the company then called The Teaching Company and now re-branded as The Great Courses. This was a totally different and far more enjoyable experience, largely because the smart folks in charge at The Great Courses start with a very different assumption about the audience. They asked me to imagine an audience of college-educated professionals, people who loved their student experiences and were hungry for more. Of course, one still had to adjust one’s writing to the level and background of the audience, as one must do with any class one teaches. That is a trivial truth. But what I knew about those kinds of students in my classes was that they wanted to be pushed and challenged. They wanted to be taught new things. They didn’t run in fear of difficult concepts and ideas. Like athletes striving for a personal best, they enjoyed the hard work. The muscles ache, the brain needs a rest, but the achievement makes it worthwhile. Most important is that such students appreciate one’s flattering them with the assumption that they have brains, that they are smart, well-educated, and able to rise to the moment.

I am really proud of the lectures: Albert Einstein: Physicist, Philosopher, Humanitarian. The uniformly positive feedback confirms the point that the intelligent student, reader, and listener can and wants to understand more than journalistic mythology asserts.

Don Howard. Albert Einstein: Physicist, Philosopher, Humanitarian. The Great Courses.

My old encyclopedia editor friend will object, I’m sure: “What about all of the others, the ones who didn’t have a college education or weren’t even ‘B+’ students?” Well, yes indeed, what of them? They are a numerous lot. And if one has the crime “beat” at the local newspaper or writes the “Friends and Neighbors” column, then, yes, ok, I suppose that one must write down to the level of a poorly-educated, fourteen-year-old.

But is that the audience for those of us who write about science for a general public? I hope not. Is it elitist of me to say that I don’t want “Joe the Plumber” making science policy for the 21st century?

I like to think of the main target audience for good science writing as the educated, scientific laity or those (such as smart high school students) who are soon to become part of it. These are the neighbors and fellow citizens who must be involved in the national and global conversation about science and technology for the future. These are the people whose voices should count in debates about climate change, biotechnology, space exploration, and cyberconflict. These are the people for whom we must learn to write and speak.

They deserve our respect.

(Subsequent posts in this series will address more specific challenges in writing about science and technology for the general public.)

Where’s the Intelligence in Intelligent Design?

Don Howard

(Originally published in 2008 as part of a Reilly Center Reports issue on “Evolution and Intelligent Design” that contains excellent pieces by George Coyne, S.J., the former director of the Vatican Observatory, William E. Carroll, the Thomas Aquinas Fellow in Science and Religion at Blackfriars Hall, Oxford, Noah Efron, from Bar Ilan University, Israel, and Reilly Center Fellows Matthew Ashley, Christopher Hamlin, Gerald McKenny, and Phillip Sloan.)

Intelligent design is an idea with a history going back at least to the late seventeenth and early eighteenth centuries, when Deists, especially, were moved by the seeming clockwork precision of the universe as described by Newton to infer the existence of a clockmaker God with an intelligence equal to the cosmic task of creation and design. Just as old are critical philosophical commentaries on design arguments, the most famous from the eighteenth century being David Hume’s mocking attack in his posthumously-published Dialogues Concerning Natural Religion (London, 1779).

Two features of design arguments impressed Hume. The first was that, since design arguments are arguments by analogy, they are, like all analogical reasoning, inductive arguments. That means that, at best, they confer on their conclusions only a high probability and not the necessity that one finds in the rigorous deductive proofs of Euclid’s geometry. Does induction suffice as a demonstration of God’s existence through His works? The second feature that impressed Hume was the arbitrary and persuasive choice of analogies upon which design arguments are grounded. See the universe as being like a watch and the inference to an intelligent designer God is inviting. But why that analogy rather than another? In the Dialogues, Hume’s spokesperson, Philo replies to Cleanthes’ defense of the design argument by suggesting that one could just as well focus on features of the universe that make it like an animal body or a vegetable, from which one could then infer that, like an organism, the universe must be the product of generation or vegetation, rather than reason and design. Absent a prior and independent commitment to the existence of a designer God, one could, thus, with equal reason infer that the universe was the product of sexual union between a cosmic mother and father or of the kind of budding whereby various plants, yeasts, or viruses reproduce.

Other questions loom larger when considering the kinds of design arguments popular today. Consider first that while design inferences are perfectly sensible, indeed, essential in various mundane settings, as in ordinary detective work, their employment in a cosmological setting or in the context of discussions of human origins is a riskier business. The main reason is that, in these extramundane settings, the major premises of a design argument are drawn not from unvarnished observation of the world, as when Holmes noted the hound that did not bark, but from what are typically theoretically sophisticated scientific descriptions of the world, as in the cosmological fine tuning argument.

Why is this problematic? It’s because of the contingency of those theoretical accounts. According to what philosophers of science call the “pessimistic meta-induction,” any current theory is likely to turn out, in future, to be false or at least seriously limited in scope. There is no reason to think that inflationary cosmology will be any exception to this rule, in spite of impressive and growing evidence in its favor. I’m old enough to remember a day when it had not occurred to anyone to think of the universe as having its origins in a cosmic explosion followed by expansion. When I was young, the steady-state model was the accepted wisdom. For two-hundred and fifty years, Newtonian mechanics could claim evidential warrant just as impressive as that attaching to the inflation model. But we now know that Newton was wrong. We don’t know, now, how inflationary cosmology will turn out to be wrong or of limited scope, but that it will seems to be the lesson of history. One might well be puzzled by a theology that dares to rest conclusions about fundamental aspects of religious doctrine on such a fragile, contingent, scientific foundation.

Even were it not for the contingent character of our theories, another question arises. If one is to take the major premises of a design argument from our current best science, is it not incumbent upon us to accept the whole of what that science tells us about such things as the place of intelligent human life in the cosmos? It is surely a striking fact about our current best cosmological models–if it is a fact about them–that intelligent life would have been impossible had the values of various cosmological parameters differed from their current values by a few thousandth’s of a decimal. But some of those same cosmological models also imply that the universe will develop in such a way as to become, in future, radically inhospitable to intelligent human life. If the fine tuning needed to make our corner of the universe home to intelligent life now is part of a cosmic design, then so too are all aspects of the cosmology in question. So was it the designer’s intention to create a universe in which for just the briefest tick of the cosmic clock intelligent human life could appear, only to be followed by cosmic aeons of emptiness? From such a more comprehensive point of view, the emergence of intelligent human life could hardly appear to have been the main goal of the enterprise.

Design arguments in the context of theories of human origins raise a similar question. First, as an aside, note the irony in the fact that the Darwinian story of human origins, a story introduced in part precisely to show how random variation with selection can imitate design, is now, instead, itself invoked as a premise in a design argument. Now it is not the individual human species that is the product of evolution that is held up as evidence of design, but the very evolutionary process that produced the human species that is taken as evidence of design. The natural process whose discovery Darwin thought obviated the need for assumptions of design is now said by the proponents of intelligent design itself to require the assumption of design.

But, as in the cosmological context, so too in the context of evolutionary stories of human origins one has to buy all of the science, not just some of it. Evolution has worked so as to produce intelligent human life. But the Darwinian story tells us that species fitness is always relative to an environment. When the environment changes, species adapted to it–if they cannot accommodate the changes–either evolve into new species or go extinct. From the Darwinian point of view, environmental change is largely a matter of external contingencies, not something implicated by the theory itself. Darwinian evolution does not predict mass extinctions consequent upon a giant meteoroid’s striking the earth at the end of the Cretaceous period, because it knows nothing of solar system dynamics. But it does predict that, if environmental change is drastic enough, extinction is possible or even likely. So, what if the environment to which the human species is adapted changes drastically, say as a result of another meteoroid impact, human-induced global climate change, or all-out nuclear war? Poof! No more human beings, the point being that, if one accepts the whole package, then, in this context too, it no longer appears as though the emergence of intelligent human life was a designer’s main goal.

I can see only one way around objections to design arguments based on the contingency of the theories providing the major premises. It would be to argue that, though theories come and theories go, any theoretical description of the universe that can claim the status of science must describe the universe in terms of some principles of order. What specific order is ascribed to nature might change as theories change, but order will be part of any scientific description of the universe, and so the conclusion still holds that from the order thereby described, design should be inferred. But am I alone in thinking that this maneuver trivializes the design argument, making it true by definition? Moreover, one would think that the specifics of the order described could make a difference to the conclusion one draws about causes. As Hume pointed out, if the order one discerns is like that of an artificial contrivance like a watch, then an intelligent designer as cause is suggested. But if the order is like that found in the plant and animal worlds, then sexual congress or vegetative reproduction is the cause suggested. And today one might add that, if the order described is like that of crystalline structure, then self-assembly in accord with fundamental structural principles (bonding angles, etc.) suggests itself as the cause.

The believer may rightly be enjoined to seek and find in nature the traces of a divine intelligence’s creative activity. If there is a designer God, then at least the main features of his blueprint should be inferable from the nature built according to that plan. By his fruits ye shall know him. But design arguments wrongly turn the arrow of implication in the opposite direction, holding that, if there is order in nature, then a designer God must be responsible for that order. Such might well be the origin of order, but it is a plain fact that order arises in other ways too. Some order is the product of other order, as in crystal formation. Some order is biological in origin, as with the magnetite in Mars rocks that some think was produced by magnetotactic bacteria. And some order is, like it or not, the product of chance, as when, on average, one roll of the dice in every thirty-six yields a perfect pair of snake eyes.

Physics and Humility

Don Howard

(Orignally written a few years ago as sort of an op-ed after an interesting meeting on fundamental physics in the gorgeous resort town of Lake Bled in Slovenia, “Time and Matter 2007.”)

As the sun sets over the Julian Alps, as evening embraces the Assumption of Mary Pilgrimage Church in the middle of Lake Bled in Slovenia and church bells herald day’s end, we come to the conclusion of Time & Matter 2007, an unusually diverse gathering of physicists and philosophers, assembled here to bring their different perspectives to bear on the deep, unsolved problems of contemporary physics.

Assumption of Mary Pilgrimage Church Lake Bled Slovenia (Slovenian: Cerkev Marijinega vnebovzetja)

In the one hundred years since the quantum and relativity revolutions, advances in fundamental physics have completely transformed our understanding of nature. Powerful particle accelerators allow us to probe the structure of the tiniest subatomic particles, while orbiting observatories let us look out to the edge of the universe and back in time to its beginnings. No century produced an expansion of physical knowledge such as we saw in the twentieth century.

But where do we stand now? Modern physics is built on two foundations. Einstein’s theory of general relativity explains gravitation and the large-scale structure of the universe. Quantum mechanics–the work of Einstein, Max Planck, Niels Bohr, Werner Heisenberg, Erwin Schrödinger, and others–is the framework for explaining the other three fundamental forces–electromagnetism, and the strong and weak nuclear forces. With quantum field theory and the so-called “standard model” of particle physics–the quark model–quantum mechanics explains the microstructure of the universe. Part of what’s remarkable about twentieth-century physics is that each of these theories has been confirmed with extraordinary precision. One could be forgiven for thinking that we are on the verge of achieving a complete and final understanding of nature.

And yet the presentations and conversations here at Lake Bled have been dominated by talk of theoretical analyses and experimental tests that could very well refute every one of these theories. Tests of what are known as Einstein-Podolsky-Rosen correlations in neutral kaon decay could refute quantum mechanics. The still unresolved black-hole information loss paradox could point to a fundamental contradiction between quantum mechanics and general relativity. When CERN’s large hadron collider begins operation in 2008 the standard model might be refuted if the Higgs boson is not detected. More than one talk at Time & Matter 2007 used the acronyms, “BSM” and “NP” for “beyond the standard model” and “new physics.”

But more than anything else, the question looming over the meeting–in conversation at the opening reception and in talks on the closing day–are the problems of dark matter and dark energy. Within just the past ten years, observation has shown that the universe is populated with a strange form of matter, “dark matter,” that interacts gravitationally with ordinary, “baryonic” matter but is otherwise invisible, so far, to our current physics. Other observations have shown that the expansion of the universe is accelerating in a way seemingly explainable only if it is filled with a still stranger stuff, “dark energy,” that is completely invisible to current physics. Moreover, we now think that 96% of the universe consists of this strange new stuff. According to our best estimates, 22% of the universe is dark matter, and 74% is dark energy. That means that only 4% of the universe is made up of the kind of stuff–baryonic matter–that is explained by all of the revolutionary, new, physical knowledge that we accumulated in the twentieth century. That’s right. After all that hard work, our current best physics explains, at most, 4% of what’s in the universe.

There is irony in the fact that it was the very physics whose dramatic shortcomings are now revealed that made possible the discovery of those limitations. And physicists are to be admired for the fact that, proud as they are of what they’ve done, they turn right around and subject it all to tough, critical examination. No dogma here, just the patient, steady, self-critical effort to know more. But perhaps most important is the lesson of that 4% figure. The discovery of dark matter and dark energy provide the clearest proof known to me of the basic insight of Socrates, that wisdom lies in knowing what it is that we don’t know, that intellectual humility is the mark of true wisdom.

These are very exciting times in physics.

Bled, Slovenia
August 31, 2007