Field of Science

The Higgs boson and the future of science

My latest post on the Scientific American blog network ties together several threads about reductionism, emergence and the nature of scientific problems which I have explored on this blog.

Philip Anderson: Anderson first described the so-called Higgs mechanism and also fired the first modern salvo against strong reductionism (Image: Celeblist)
The discovery of the Higgs boson (or the "Higgs-like particle" if you prefer) is without a doubt one of the signal scientific achievements of our time. It illustrates what sheer thought - aided by data of course - can reveal about the workings of the universe and it continues a trend that lists Descartes, Hume, Galileo and Newton among its illustrious forebears. From sliding objects down an incline to smashing atoms at almost the speed of light in a 27 kilometer tunnel, we have come a long way. Dissecting our origins and the universe around us scarcely gets any better than this.

Yet even as the exciting discovery was being announced, I could not help but think about what the Higgs does not do for us. It does not speed up the time needed to discover a new cancer drug. It does not help us understand consciousness. It does not tell us how life began or whether it exists elsewhere in the universe. It does not explain romantic love, how to design the best solar cell, why people have certain political preferences and how exactly to predict the effects of climate change. In fact we can safely predict that the discovery of the Higgs boson, as consciousness-elevating as it is, does not impact the daily work of 99% of all pure and applied scientists in the world.

I do not say all this to downplay the discovery of the particle which is an unparalleled triumph of human thought, hard work and experimental ingenuity. I also do not say this to make the obvious point that a discovery in one field of science does not automatically solve problems in other fields. Rather, I say this to probe the deeper reality beyond that point, to highlight the multifaceted nature of science and the sheer diversity of problems and phenomena that it presents to us at every level of inquiry. And I say this with a suspicion that the Higgs boson may be the most fitting tribute to the limitations of what has been the most potent philosophical instrument of scientific discovery - reductionism.

In one sense the discovery of this fundamental component of matter can be seen as the culmination of reductionist thinking, accounting as it does for the very existence of mass. Reductionism is the great legacy of the twentieth century, a philosophy whose seeds were sown when Greek philosophers started mulling the nature of matter. The method is in fact quite intuitive; ever since they stepped down from the trees, human beings have tried to solve problems by breaking them down into simpler parts. In the twentieth century the fruits of reductionism have been nothing short of awe-inspiring. Reductionism is what told us that molecules are made of atoms, that the universe is expanding, that DNA is a double helix and that you can build lasers and computers. The reductionist ethic has given us quantum mechanics, relativity, quantum chemistry and molecular biology. Over the centuries it has been used by its countless practitioners as a fine scalpel which has laid bare the secrets of nature. In fact many of the questions answered using the reductionist method were construed as being amenable to this method even before their answers were provided; for instance, how do atoms combine to form molecules? What is the basic nature of the gene? What are atoms themselves made up of?

Yet as we enter the second decade of the twenty-first century, it is clear that reductionism as a principal weapon in our arsenal of discovery tools is no longer sufficient. Consider some of the most important questions facing modern science, almost all of which deal with complex, multifactorial systems. How did life on earth begin? How does biological matter evolve consciousness? What are dark matter and dark energy? How do societies cooperate to solve their most pressing problems? What are the properties of the global climate system? It is interesting to note at least one common feature among many of these problems; they result from the buildup rather than the breakdown of their operational entities. Their signature is collective emergence, the creation of attributes which are greater than the sum of their constituent parts. Whatever consciousness is for instance, it is definitely a result of neurons acting together in ways that are not obvious from their individual structures. Similarly, the origin of life can be traced back to molecular entities undergoing self-assembly and then replication and metabolism, a process that supersedes the chemical behavior of the isolated components. The puzzle of dark matter and dark energy also have as their salient feature the behavior of matter at large length and time scales. Studying cooperation in societies essentially involves studying group dynamics and evolutionary conflict. The key processes that operate in the existence of all these problems seem to almost intuitively involve the opposite of reduction; they all result from the agglomeration of molecules, matter, cells, bodies and human beings across a hierarchy of unique levels. In addition, and this is key, they involve the manifestation of unique principles emerging at every level that cannot be merely reduced to those at the underlying level.
The traditional picture of science asserts that X can be reduced to Y. Reality is more complicated (Image: P. W. Anderson, Science, 1972)
A classic example of emergence: The exact shape of a termite mound is not reducible to the actions of individual termites (Image: Wikipedia Commons)

This kind of emergence has long since been seen as key to the continued unraveling of scientific mysteries. While emergence had been implicitly appreciated by scientists for a long time, its modern salvo was undoubtedly a 1972 paper in Science by the Nobel Prize winning physicist Philip Anderson titled "More is Different", a title that has turned into a kind of clarion call for emergence enthusiasts. In his paper Anderson (who incidentally first came up with the so-called Higgs mechanism) argued that emergence was nothing exotic; for instance, a lump of salt has properties very different from those of its highly reactive components sodium and chlorine. A lump of gold evidences properties like color that don't exist at the level of individual atoms. Anderson also appealed to the process of broken symmetry, invoked in all kinds of fundamental events - including the existence of the Higgs boson - as being instrumental for emergence. Since then, emergent phenomena have been invoked in hundreds of diverse cases, ranging from the construction of termite hills to the flight of birds. The development of chaos theory beginning in the 60s further illustrated how very simple systems could give rise to very complicated and counterintuitive patterns and behavior that are not obvious from the identities of the individual components.

Many scientists and philosophers have contributed to considered critiques of reductionism and an appreciation of emergence since Anderson wrote his paper. These thinkers make the point that not only does reductionism fail in practice (because of the sheer complexity of the systems it purports to explain), but it also fails in principle on a deeper level. In his book "The Fabric of Reality" for instance, the Oxford physicist David Deutsch has made the compelling point that reductionism can never explain purpose; to drive home this point he asks us if it can account for the existence of a particular atom of copper on the tip of the nose of a statue of Winston Churchill in London. Deutsch's answer is a clear no, since the fate of that atom was based on contingent, emergent phenomena, including war, leadership and adulation. Nothing about the structure of copper atoms allows us to directly predict that a particular atom will someday end up on the tip of that nose. Chance plays an outsized role in these developments and reductionism offers us little solace to understand such historical accidents.
Complexity theorist Stuart Kauffman who has written about the role of contingency as a powerful argument against strong reductionism (Image: Wikipedia Commons)

An even more forceful proponent of this contingency-based critique of reductionism is the complexity theorist Stuart Kauffman (supposedly an inspiration for the Jeff Goldblum character in "Jurassic Park") who has laid out his thoughts in two books. Just like Anderson, Kauffman does not deny the great value of reductionism in illuminating our world, but he also points out the factors that greatly limit its application. One of his favorite examples is the role of contingency in evolution and the object of his attention is the mammalian heart. Kauffman makes the case that no amount of reductionist analysis could explain tell you that the main function of the heart is to pump blood. Even in the unlikely case that you could predict the structure of hearts and the bodies that house them starting from the Higgs boson, such a deductive process could never tell you that of all the possible functions of the heart, the most important one is to pump blood. This is because the blood-pumping action of the heart is as much a result of historical contingency and the countless chance events that led to the evolution of the biosphere as it is of its bottom-up construction from atoms, molecules, cells and tissues. As another example, consider the alpha amino acids which make up all proteins on earth. These amino acids come in two potential varieties, left-handed and right-handed. With very few exceptions, all the functional amino acids that we know of are left handed, but there's no reason to think that right handed amino acids wouldn't have served life equally well. The question then is, why left-handed amino acids? Again, reductionism is silent on this question mainly because the original use of left-handed amino acids during the origin of life was to the best of our knowledge a matter of contingency. Now some form of reductionism may still explain the subsequent propagation of left-handed amino acids and their dominance in biological processes by resorting to molecular level arguments regarding chemical bonding and energetics, but this description will still leave the origins issue unresolved. Even something as fundamental as the structure and function of DNA - which by all accounts was a triumph of reductionism - is much better explained by principles of chemistry like electrostatic attraction and hydrogen bonding.

Life as we know it is based on left-handed amino acids. But there is no reason why right-handed amino acids could not sustain life (Image: Islamickorner)
Reductionism then falls woefully short when trying to explain two things; origins and purpose. And one can see that if it has problems even when dealing with left-handed amino acids and human hearts, it would be in much more dire straits when attempting to account for say kin selection or geopolitical conflict. The fact is that each of these phenomena are better explained by fundamental principles operating at their own levels. Chemistry has its covalent bonds and steric effects, geology has its weathering and tectonic shifts, neurology has its memory potentiation and plasticity and sociology has its conflict theory. And as far as we can tell, these sciences will continue to progress without needing the help of Higgs bosons and neutrinos. This also seems to make it unlikely that the discovery of a single elegant equation linking the four fundamental forces (the purported "theory of everything"), while undoubtedly representing one of the greatest intellectual achievements of humanity, will give sociologists and economists little pause for thought, even as they continue to study the stock market and democracies using their own special toolkit of bedrock principles.

This rather gloomy view of reductionism may sound like science is at a dead end or at the very least has started collapsing under the weight of its own success. But such a view would be as misplaced as announcements about the "end of science" which have surfaced every couple of years for the last two hundred years. Every time the end of science has been announced, science itself proved that claims of its demise were vastly exaggerated. Firstly, reductionism will always be alive and kicking since the general approach of studying anything by breaking it down into its constituents will continue to be enormously fruitful. But more importantly, it's not so much the end of reductionism as the beginning of a more general paradigm that combines reductionism with new ways of thinking. The limitations of reductionism should be seen as a cause not for despair but for celebration since it means that we are now entering new, uncharted territory. There are still an untold number of deep mysteries that science has to solve, ranging from dark energy, consciousness and the origin of life to more supposedly pedestrian concerns like superconductivity, cancer drug discovery and the behavior of glasses. Many of these questions require interdisciplinary approaches which result in the crafting of fundamental principles that are unique to the problem statement. Such a meld will inherently involve reductionism only as one component.

Now there are some who may not consider these problems as "fundamental" enough but that is because they would be peering through the lens of traditional twentieth century science. One of the sad casualties of the reductionist undertaking is a small group of people who think that cosmology and particle physics constitute the only things truly worth doing and the epitome of fundamental science; the rest is all detail that can be filled in by second-rate minds. This is in spite of the inconvenient fact that perhaps 80% of physicists are not concerned at all with fundamental questions. But you would be deluding yourself if you are thinking that turbulence in fluids is a second-rate problem (still unsolved) for second-rate minds, especially if you remember that Heisenberg thought that God would will be able to provide an explanation for quantum mechanics but not for turbulence. The fact is that "pedestrian" concerns like superconductivity have engaged some of the best minds of the last fifty years without fully succumbing to them, and at their own levels they are as hard as the discovery of the Higgs boson or the accelerating universe. Exploring these worthy conundrums is every bit as exciting, deep and satisfying as any other endeavor in science. Those who are wondering what's next should not worry; a sparkling journey lies ahead.

To guide us on this journey all we have to remember are the words of one of the twentieth century's great reductionists and one of Peter Higgs's heroes. Paul Dirac closed his famous text on quantum theory with stirrings that will hopefully be as great a portent for the emergent twenty-first century as they were for the reductionist twentieth: "Some new principles are here needed".

1. P. W. Anderson, More is Different, Science, 1972177, 393
2. David Deutsch, "The Fabric of Reality", 2004
3. Stuart Kauffman, "Reinventing the Sacred", 2009; "At Home in the Universe", 1996
Other reading:
1. Terrence Deacon, "Incomplete Nature", 2011
2. John Horgan, "The End of Science", 1997
3. Robert Laughlin, "A Different Universe", 2006


  1. The text is great. However, it implies that there exists people who think "social conflicts" or the "origin of life" can be explained in terms of particle physics, or that every possible problem must be reduced to atoms in order to be understood. While my disbelief is high in what regards humanity and even most scientists, and therefore, I wouldn't be surprised if there are people who says these kinds of things, I have never read anything that claimed those even implicitly, quite simply because you need to be extremely naive and irrational to believe that reductionism is going to answer every single problem. Even in the classical case of Dirac's quote about problems in chemistry being a matter of solving complex equations, it is of course that he was referring to something that has no way of ever becoming practical. People need to give Dirac more credit, he was smart enough to know that macroscopic systems are too complex to be handled exactly with quantum and statistical mechanics.

    In any case, the reductionist approach is admirable, and even in molecular biology, or in the social sciences, the understanding of the simplest aspects in terms of deeper layers (which could come for example from interdisciplinary approaches as wells as from mild reductionism) is something that provides much more power and control over a problem than remaining stagnant with principles that are unique to your problem. If you can't provide any sort of generalization or unification than your science has become completely empirical. If you have no clue about any deeper aspects of the factors that determine a certain behavior, then you didn't understand it.

    Unfortunately that's what most of theoretical chemistry is now; problems are disconnected, interpretations abound, parameters fly, calculations are done to confirm pre-conceived notions, and no one has much control over anything. I am not a proponent of reducing chemistry to quantum electrodynamics, but much more effort should be made in searching different ways to understand problems from unifying perspectives. Even Ahmed Zewail wrote about this a few years ago, and in a way, the whole idea makes it understandable why several theoretical/condensed matter physics (including P.W. Anderson) despise theoretical chemistry.

    My thesis is that reductionism still needs to be a major factor in any research topic. Not "just another element", but then of course, reductionism shouldn't imply reduction to string theory; it could mean the investigation of deeper layers, search for unifying principles, rational generalizations, and so on.

    1. R - Unfortunately, there are scientists who think that everything can, at least in principle, be explained by particle physics - the "most fundamental science". Take Steven Weinberg for example. He is a very famous theoretical physicist (a Nobel Laureate as well), who has been very open about his views on reductionism. He argues that although the level of analysis is important for advances in everyday science, ultimately everything is explicable by more and more fundamental sciences - with particle physics being the most fundamental. Take a few quotes from his 1987 Nature paper ( which transcribes a talk he gave at Cambridge, and incidentally is somewhat in direct response to the ideas of Anderson's Science paper referenced in the post above:

      "No one thinks that the phenomena of phase transitions and chaos...could have been understood on the basis of atomic physics without creative new scientific ideas, but does anyone doubt that real materials exhibit these phenomena because of the properties of the particles of which the materials are composed?"

      He then goes on to say that even in chemistry, although we know the properties of molecules are in principle reducible, we are simply unable to reduce them with the tools available to us at this time (computer power, etc.).

      Another good quote from this paper is, "no biologist today would be content with an axiom about biological behavior that could not be imagined to have an explanation at a more fundamental level. That more fundamental level would have to be the level of physics and chemistry, and the contingency that the Earth is billions of years old. In this sense, we are all reductionists today."

      Anyways, although Weinberg claims, even within that paper, to not be an uncompromising reductionist, his writing in fact tells a different story. So, although many scientists I believe would say that they are not so absolute, it is rather ingrained in us that there is a natural hierarchy to science - and within that hierarchy, each level is at least in principle reducible to the one more fundamental to it (i.e. biology reduces to chemistry, chemistry to physics). Not saying this is my view - in fact it is not - but there are those that do hold this staunch view.

    2. Well, if we believe that quantum mechanics is the theory of atomic and molecular phenomena, then it is coherent to think that, in principle, biology and chemistry can be reduced to the study of the quantum mechanics of large systems. Every 'emergent' feature of a complex system should have its roots on the behavior of the particles that compose the system. And it is true that the only reason most studies of complex systems are not entirely understood in terms of quantum mechanics is lack of computational power or lack of understanding of the theory itself, and perhaps even if we had those, then we would probably suffer from lack of interpretive power because our intelligence is limited. Thus, the problem is really that we - humans - cannot use the fundamental theory to explain everything, but that's our problem.

      I saw nothing wrong with Weinberg's quote about biology, it is actually a very nice way to illustrate what I posted before: "If you can't provide any sort of generalization or unification than your science has become completely empirical. If you have no clue about any deeper aspects of the factors that determine a certain behavior, then you didn't understand it."

      I do not think Weinberg's views are as extreme as they seem to several people. I also cannot see why people take offense when theoretical physicists claim that cosmology or particle physics are more fundamental than biology or whatever, after all, these are classifications that humans created, and everyone is entitled to their own opinion. Unfortunately, this is an aspect of human nature that we have to deal with (vanity), but it should be isolated from this kind of discussion, which in the end is about productive approaches to scientific research.

  2. "the _signal_ scientific achievements of our time"

  3. This article was very illuminating but definitely misunderstands something very important. Reductionism does not entail that things at different levels of scale and organization should not be looked at differently, only that from the fundamental ingredients and their interactions everything can emerge, including collectively new behaviors of different systems. Sean Carroll puts it best in an article of his at Cosmic Variance, when speaking about the 'reality' of free will. Baseball exists, he says, as an organized event that is carried out by human beings.

    Despite this, it is not at all fundamental to the world. It wouldn't do much good to characterize baseball in terms of the interactions of quarks and gluons of every object from the pitcher to grass in the outfield, but that does not mean something spooky has occurred and a new thing now exists in the universe. Baseball is still made of those fundamental entities and the interactions between them. It is simply the fact that it is impractical and doesn't add any valuable information to someone who might carry out such a simulation on an extremely powerful supercomputer. I will say this, if, as I suspect most scientists agree, the universe obeys natural laws and is causally deterministic (don't come back at me with the stochastic nature of QM, there are many interpretations that are fully deterministic and recent evidence suggests the wavefunction is real), then in theory a simulation that starts with a massive amount of initial particles and evolves from that point will form galaxies, planets, life, humans, and cultures.

    This does not make life less beautiful, in fact its unifying nature is amazing to the point of a religious feeling. Emergence does exist, and obviously, if we start with a large group of particles we would be hard pressed to find out what things will exist later in its evolution, but thats where the (fully causal and deterministic) simulation comes in. We cant predict everything about a system without carrying out a large number of computations, but that in no way suggests reductionism is incomplete.

    Emergence is a bottom up process, and to suggest otherwise would be to bring magical forces into the arena of science that have no place in it. Yes, reductionism, cant answer origin questions; then again, nothing can. If you want to believe in God or pre-existing matter, pick whatever, but origins will always likely be beyond our grasp. We can, however, understand how the universe operates in a reductionist sense.


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