A New Law of Nature Explains Inevitable Complexity
For decades, physicists have wrestled with a puzzle that sits at the heart of our understanding of the universe. The second law of thermodynamics tells us that disorder, or entropy, should always increase. Yet everywhere we look, from the first living cells to the intricate structures of modern ecosystems, nature seems to be doing the opposite. It builds order from chaos, complexity from simplicity, and it does so relentlessly. This apparent contradiction between the arrow of time pointing toward disorder and the visible march toward organization has remained unresolved for generations.
Two scientists now argue that the resolution has been hiding in plain sight. Mineralogist Robert Hazen and planetary scientist Michael Wong propose that the natural world’s shift from humble beginnings to intricate order was not a lucky accident. [1] According to their view, this progression was inevitable, a fundamental feature of how our universe operates. They suggest that science has overlooked this obvious truth for too long, treating complexity as a remarkable exception rather than a rule waiting to be articulated.
The authors call for the establishment of guiding principles that can explain the complexity seen in all evolutionary systems, whether living or inert. This is a bold reframing. It suggests that the same underlying logic that drives biological evolution through natural selection also governs the formation of minerals, the structure of planets, and the organization of matter itself. What was once seen as separate domains—biology, geology, chemistry—becomes a single, unified story of how complexity emerges.
From Revolutionary Idea to Common Sense
History offers a useful parallel for understanding what Hazen and Wong are attempting. When the theory of evolution by natural selection first appeared, it was considered revolutionary, even dangerous. It challenged deeply held beliefs about the special place of humans in the natural order. Yet within a few generations, the core insight became so intuitive that it now seems almost banal to students learning biology for the first time. The idea that species change over time through differential survival is taught as basic fact, not as a shocking revelation.
Hazen and Wong must hope that their central idea follows a similar trajectory. They are betting that the concept of an inevitable progression toward complexity will one day be taught in classrooms as a fundamental principle of nature, as obvious as gravity or the conservation of energy. The timeline for such a shift in scientific thinking is rarely short. Major paradigm changes typically take decades to become fully absorbed into the mainstream of research and education, and even longer to reshape how textbooks are written and how new scientists are trained.
The book, titled Time’s Second Arrow: Evolution, Order, and a New Law of Nature, is scheduled for publication by W. W. Norton in 2026. [2] Its very existence signals that the authors believe the moment is right for this conversation. The scientific community has accumulated enough evidence across multiple disciplines to recognize patterns that were previously invisible. What was once a collection of separate observations about biological evolution, planetary formation, and mineral complexity can now be seen as expressions of a single underlying principle.
A Timeline Measured in Generations
The practical effects of this proposed framework will not be immediate. Scientific ideas do not transform the field overnight, even when they are compelling. The process typically begins with debate among specialists, followed by replication of key observations, then gradual incorporation into graduate curricula, and finally into undergraduate textbooks. Each step takes years, and resistance is common from researchers who have built their careers on the older, more fragmented view.
For the next decade, the most likely impact will be in how researchers frame their questions. If complexity is truly inevitable rather than accidental, then scientists studying the origins of life on Earth, or the formation of habitable planets elsewhere, will ask different questions. They will look for the conditions that enable complexity to emerge rather than asking why it emerged at all in a universe supposedly tending toward disorder. This shift in framing can open new avenues of research that were previously closed off by implicit assumptions about the improbability of organized structures.
The story of how life and our planet unfolded together is central to this new perspective. The authors are not merely proposing an abstract law; they are connecting it to the concrete history of Earth. The co-evolution of the biosphere and the geosphere—how living organisms shape the mineral composition of the planet, and how those minerals in turn create new niches for life—becomes a demonstration of the principle they describe. Each layer of complexity builds on the previous one, creating a staircase that ascends toward ever greater organization.
The Contradiction That Remains
Yet a fundamental tension persists at the heart of this proposal. The second law of thermodynamics is one of the most well-tested principles in all of physics. It states that entropy in a closed system never decreases. If complexity is inevitable, how does this square with the relentless increase of disorder that physicists have measured and confirmed in countless experiments? The authors acknowledge this tension implicitly by calling their concept a second arrow, suggesting that there are two distinct arrows of time operating simultaneously.
Even as complex organisms decompose and return to simpler components, entropy increases. The slime mould, a simple organism that nonetheless exhibits sophisticated behaviors, sits at the boundary between the living and the inert, demonstrating that the line between biological and non-biological complexity is not as sharp as once thought. Even as complex organisms decompose and return to simpler components, the overall system may be generating new forms of order elsewhere. The slime mould, a simple organism that nonetheless exhibits sophisticated behaviors, sits at the boundary between the living and the inert, demonstrating that the line between biological and non-biological complexity is not as sharp as once thought.
The unresolved question is whether these two arrows can be reconciled within a single framework. Hazen and Wong propose that they can, but the burden of proof lies with them and with the researchers who will test their ideas. Until a rigorous mathematical formulation is developed, and until predictions derived from that formulation are confirmed experimentally, the proposal remains a compelling hypothesis rather than an established law. The coming years will show whether the patterns of increasing complexity observed across so many domains reflect a genuine new principle or merely the local, temporary reversal of entropy that occurs within larger systems that are themselves tending toward disorder.
Sources
1. Carnegie Institution for Science
2. W. W. Norton