Oceans simple, oceans complex

There is a defining moment in the history of oceanography that is also a defining moment in history itself, for I shall argue that it marks the end of the historical period we call the Enlightenment, and the beginning of the modern age. That moment is late in 1880 when the first volume of the Challenger Report was published. The great T. H. Huxley noted the moment in Nature, even if he did not understand its true significance. He thought that the Report would serve mainly to reveal some of the 'secrets of the busy life which, contrary to all the beliefs of the naturalists of a past generation, blindly toils and moils in the darkness and cold of the marine abysses'. He did not understand that it would also change the way we do science and so usher in a new era. We should not be too hard on 'Darwin's bulldog', the champion of evolution, for he was embedded in the moment as part of the process that was changing science. And, even more than a century later, there are those of us who, whether through the inertia or hysteresis of science, are still unaware that a scientific revolution, fully comparable to that of the Enlightenment, has swept up us all in its train.

To understand the importance of this moment - and of course it was not really a single moment, but an event which serves as an icon for a process that was occurring at that time - we need to understand its context which is the triumphalism of late Victorian science. Here we see the Challenger Expedition of 1872-1876, under the leadership of Sir Charles Wyville Thomson, as the world's first foray into big science. The Expedition was the Apollo Program, the Human Genome Project, the Hubble Space Telescope of its day. The Expedition was to circumnavigate the world in the steam corvette, HMS Challenger, for the purpose, as resolved by the British Association in 1871, of 'carrying the physical and biological Exploration of the Deep-sea into all the great oceanic centres'.

This was a time of great excitement in science. Darwin's momentous theory had been published some twenty years before, and was the subject of intense and often acrimonious debate. Yet the idea of the spontaneous generation of life, an idea going back to Aristotle, was still being seriously debated along side the new Darwinism. Indeed the short survey of the north Atlantic in 1868 by Wyville Thomson and William Carpenter in HMS Lightning - the oldest and most cranky paddle-steamer in the Navy, according to Wyville Thomson - demolished the prevailing azoic theory, the theory that life was absent in the ocean depths, with astounding discoveries of a rich benthic fauna at more than 500 fathoms. And it also discovered a candidate for the spontaneous generation case - a supposed elementary protoplasmic substance identified and named Bathybius by Huxley himself. Clearly the deep-sea was the true frontier for the science of the day.

The drama was not confined to biology. In the physical sciences, there was a furious debate raging about the nature of oceanic circulation and the physical forces driving the great ocean currents, such as the Gulf Stream, that were just then being discovered. And the nature of submarine geology and its linkages to the processes being observed on the land were only to be guessed at.

Both the Royal Society and the British Association, the sponsors of the Expedition, hoped that it would, with one swoop, resolve many of these issues.

The Expedition made huge numbers of observations and collected tonnes of samples - the final volume of the Report was not published until 1895 - which raised as many questions as they answered. In fact the debates were developed and elaborated in what we would call today 'real time' through the miracle of the undersea telegraph, the Internet of the day. Preliminary results were cabled back to England from Canada, the East Indies and Australia and so on, as the expedition progressed around the world, setting alight the pages of Nature with their astounding discoveries, sometimes supporting this theory, sometimes that, in the tantalising way of modern science. The distribution and nature of the globigerina ooze was established, and a new radiolarian ooze was discovered in the deepest waters yet sounded, more than four and a half thousand fathoms. And even at these depths, animals 'high in the zoological series', as Wyville Thomson put it, were found. Even the Bathybius mystery was solved: it was merely an artefact of the way in which certain oozy samples had been preserved.

The physical measurements of the oceans gradually revealed their lineaments as we know them today. There emerged the idea of a mid-oceanic ridge separating the Atlantic into distinct basins, a daring idea and the precursor of the magnificent realisation of the world's greatest geographic feature, the earth-girdling mid-oceanic ridge dwarfing all the terrestrial mountain ranges in its length and height. The measurements of ocean temperature and specific gravity painted a picture of oceanic circulation in a detail never before revealed, but they did not resolve the issue of its physical forcing. The prevailing and competing theories, built on single assumptions of sea level or gravity or density or temperature, were insufficient to comprehend the vast number of variables that is ocean circulation. To an extent the data were ahead of science's ability to model and analyse them.

As Margaret Deacon notes in her fine history of oceanography, Scientists and the sea:

'The real difficulty lay in the fact that while basically simple in theory, in practice ocean circulation is a highly complicated process depending on a large number of variables and resulting in a vast network of interrelated movements which bear only a distant resemblance to the simple pattern [of the kinds proposed]. The picture lay hidden in a vast mass of data on temperature and specific gravity which the Challenger had collected but no one immediately connected with the voyage had the skills necessary for sorting out the pieces of the puzzle and putting them together.'

This inability to resolve the issue of ocean circulation provides a clue to the elemental importance of the moment that I am proposing. But there is another, more telling clue that we can find in the chemical analyses of the composition of sea water. For while a satisfactory theory of ocean circulation would not yield to a Victorian synthesis of the physical measurements, a startling new idea emerged from a synthetic treatment of the chemical observations. The components of marine salt were always in the same ratio to one another, irrespective of the total salinity. This held true regardless of depth or geographical location.

The ocean was a single complex system!

So it was that in Edinburgh, which was where the Challenger Report was compiled, the central informing idea of the Enlightenment, its idée fixe, first elaborated by Galileo three hundred years before, finally ran its course.

This idea, often associated with René Descartes, was that the world might be mysterious but it was not mystical. It was, potentially, understandable by the rational human mind through observation and experiment, through what became known as the scientific method. This understanding was not to come through the intercession of a priesthood or the revelations of a deity, but could be built, brick by brick, as a fully human edifice. It required the breaking down of problems into their simpler components. This reductionist process, as it became known, underpinned the tremendous successes of Newton's physics, Dalton's chemistry and Bernard's physiology and led to the tremendous flowering of science in the eighteenth and nineteenth centuries. It also led to a powerful sense of scientific hubris, a sense that all natural phenomena would yield to the Cartesian method.

What the Challenger Expedition did was to clearly establish the limits of the Cartesian method. It said that there were systems, important systems, that would not yield to the method. It might be argued that Darwin established the same thing twenty years earlier with the Origin, and as a fervent Darwinian, I would like this to be so. But I think it fairer to say that he used reductionist methods in conjunction with the inductive gift of genius to reach his conclusions about the complexity of the living world. Life, in a sense, is a single complex system, but one which is diffuse and intangible. The oceans confront us with their tangible physicality, we can delimit them as a single geographic entity. While Darwin could achieve a synthetic understanding of life through the leap of genius, no such synthesis was available to the Expedition. Here reductionist science faced its greatest test and failed.

What did they do, these clever Victorians, when faced with this problem? Here we need to be gentle in our analysis, for they did not see the problem with the clarity of a century of hindsight. We can see now that their response was beautifully Darwinian, they used what was at hand - the reductionist method - and adapted it. In less high-falutin terms, they muddled through.

We can see their acceptance that the ocean was complex in the subsequent development of oceanography. These early oceanographers acknowledged the irrefragable complexity, as a high Victorian might say, in the way they structured and organised their nascent science. After the Expedition, oceanographic institutions were created in Europe and America in places like Plymouth, Monaco, Helgoland, Copenhagen and Woods Hole, and oceanographic research vessels were launched by the all the great maritime powers. These institutions and vessels were all highly and intrinsically multidisciplinary, a huge departure from the structure of the rest of science. But because they were part of the greater structure of science, this multidisciplinarity had its limits. The traditional scientific disciplines within these institutes pursued an idealised disciplinary simplicity at the expense of an elusive synthesis.

What was laid down a century ago has endured to the present day. We now have a science of the oceans that is fundamentally schizoid. Two world-views - oceans simple and oceans complex - coexist uneasily within the science.

The natural tension between these views, at first blush completely incompatible, may overshadow their natural interdependence. Neither can progress its philosophical (or scientific) project without reference to the other. Nor can one supplant the other.

As the international community grapples with the reality of the Law of the Sea, as maritime states respond to their enlarged responsibilities with oceans policies, and as corporations struggle to develop the resources of the sea, this tension between two very different views of the ocean, each emanating from science, threatens the very process of sustainable development itself.

And just like the Victorian founders of oceanography, we are still muddling through. We sometimes accept one view, at other times another, in a rather schizoid balancing act. Physical oceanographers like to think of the ocean as simply physically forced by a few major drivers, and then fudge the complexity of the interactions of the oceans with the atmosphere or the land with some hard-learned rules of thumb. Biological oceanographers acknowledge the diversity of life in the oceans and the quirky importance of how it got to be as it is. Then they throw that knowledge out the window and look at the simple flow of carbon as if it were of some importance. Engineers overbuild those magnificent offshore platforms through a pragmatic mixture of simple physics and a generous margin to allow for the complexity of the real world. The law knows that man's interaction with the oceans is complex - rich in history and its frozen accidents, rich in contingency and potential. But then it behaves as if this could all be codified in treaties, protocols and laws - as if this rich, reticulate, recursive non-linearity could yield to the ultimately linear and serial world that is the law

For all the success that such muddling through has brought us - and we must admit that it has been successful in its way, since we stand here today with some sort of understanding of the lineaments of the ocean - we must also admit that we have reached the end of an era in our understanding of the oceans. We have reached the end of the taxonomic era, where the basic structure has been described and things oceanic have been pigeonholed and catalogued.

Now the real work must begin. If we are to evolve and develop our relationship with the oceans to match our expectations of sustainable development, then resolving the tension between these two world-views becomes the most important project for the oceans community.

This is because sustainable development, the difficult union of ecological, economic and social concerns, demands a theatre in which to stage its play. If we are to make difficult decisions about the sustainable development of the oceans, we need a robust, coherent and rational framework describing the way the world actually is, not a muddled fibrillation between different world-views.

If science has created the tension, it may also provide the resolution. We may see the oceans simple view as an overhang, as it were, of the Enlightenment, on the modern world. We may also muse over the essentially scientific ideas of hysteresis and inertia, and wonder that we had not noticed them before as applying to ourselves. But it is too simple to merely stigmatise oceans simple as an idea that has had its day, and to say that oceans complex is the way to go. While this simplification acknowledges the tension, it ignores the interdependence. Rather we should look to the emerging theory of complex adaptive systems to provide both the tools and the concepts for a resolution.

But we will need to accept that such a resolution will come at a price - a more subtle understanding of the world which may lead to a more subtle understanding of ourselves as part of that world. Let me explain.

By asking science to understand complex phenomena like the oceans, society has forced science to change, to adapt, to learn some new ways of doing science. By asking science to change its ways, society has also implicitly asked science to renegotiate its contract with society. The surprising thing that is emerging from this is that science has learned a dramatically new way of understanding complexity, and that this is now forcing that renegotiation into new, uncharted waters.

In recent years science has responded to the need to know such phenomena as oceans or ecosystems, immune systems or economies with their messiness, fuzziness, incompleteness, novelty, surprise, adaptation - in short, with their irreducible and contingent complexity. It has developed a wide range of tools not only for acquiring the data about such systems, but also for analysing and visualising them. These tools are usually computer intensive and rejoice in such techno-names as adaptive game theory, simulated annealing, neural nets, fuzzy logic, genetic algorithms, cellular automata, spin glasses, and agent based modelling.

Together with the tools has come an approach, called the theory of complex adaptive systems, which offers a qualitatively new way of doing science. Where traditional science sees the search for simplicity and natural law as the goal, the new theory sees the search for emergent structures and dynamics. Where the old science gives primacy to testing hypotheses, the new encourages generating them. Where the old demands objectivity and the separation of observer and observed, the new sees no such distinction, encouraging interaction and recursion between them. The new science of complex adaptive systems tries to build exploratory tools, where the old constructs predictive ones.

The approach of complex adaptive systems theory, though, is ineffably scientific. It is not some woolly, 'anything goes since everything is relative' belief system. While it does say there may not be simple answers to the way the world is, it does not say any answer is as good as any other. While it does say that we may not yet have the right answers, it also says that many answers - nonscientific answers - are just plain wrong. On all those issues it is as one with traditional science. It fully acknowledges its scientific patrimony.

But this is a lot more than society asked for. All it really wanted was for science to repeat its trick of understanding simple systems, such as the motions of the planets or the workings of levers, with a similar sort of understanding for complex systems. We have had three hundred years to get used to Galileo's first scientific revolution, and we have got comfortable with the utility of that knowledge and the technological advances that have come with it. Despite the grandeur of their conceptions, the Apollo man-on-the-moon program was just the technological extension of Newton's reductionist physics, and the Human Genome Project and genetic engineering are likewise no more than technological extensions of Mendel's reductionist genetics.

Instead of that comfortable, practical and confinable sort of science, society has got a revolution instead. And revolutions are uncomfortable, impractical and, often, uncontainable.

We will get a resolution to this problem of how we are to know the oceans. And it will help inform and underpin the oceans' sustainable development. But to the extent that it is scientific, it will also be built on the theory of complex adaptive systems.

And if that is the case, as the marine physicist, Marie Julien Olivier Thoulet, said in 1895, it will help us achieve:

' ... les travaux, les découvertes - et en même temps - les profits et la gloire ... '

Notes

My quotes about the Challenger Expedition come from Margaret Deacon (1997) Scientists and the sea, 1650-1900: A study of marine science. Aldershot, Ashgate) 2^nd ed. This lovely book, first published in 1971 is now happily back in print in a second edition.

Further thoughts on the theory of complex adaptive systems may be found in the following rather eclectic list of references.