When cosmologists try to make sense of the universe and its origin, they look at entropy and the number of different ways a universe like ours could arise. It is usually thought that blackholes and dark energy make the most significant contribution to the entropy of the cosmos. But new work by Marina Cortês, Stuart Kauffman, Andrew Liddle and Lee Smolin has quantified the complexity of life and compared it to that of the cosmos for the first time. The results? There is more to life on Earth than you might think. 

Biology. Cosmology. Biology and cosmology. Two fields that are normally thought to have nothing in common and nothing to teach each other. We — Stuart Kauffman, Andrew Liddle, Lee Smolin and I — are putting an end to this. By reformulating cosmological physics to include biological systems, we have developed a common currency with which their respective systems can be counted and compared. This ‘currency’ allows us to quantify the value of biologicals systems when set against the character cast of cosmology: galaxies, dark energy and black holes. 

This synthesis of biology and cosmology required a shift away from reductionism and the belief that all systems can be understood by breaking them down into their constituent elements. Instead, the new way of thinking makes sense of complex systems and their evolution by considering the number of possible future states those systems could take.

In a technical sense, this synthesis uses the idea of a system’s expanding space of possible outcomes, which Stuart Kauffman established as the Theory of the Adjacent Possible (TAP). 

In a general sense, this theory may prove to have vital implications for understanding many aspects of our lives, notably economics, innovation, and catastrophic climate change.

So, what is the Earth’s biosphere worth in this new currency? Our attempt to answer this question has deep implications for what theoretical physics should be, where it can reach, and what it will become.

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Until about 20 years ago, it was thought that black holes, particularly the supermassive black holes found at the centres of galaxies, were the dominant contribution to the entropy and possible states of the universe.

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The possible states of the universe

When seeking to understand the origin of our Universe, cosmologists want to calculate how likely it was to have been as it was and not in some other form. According to simple thermodynamics, which says that disorder and entropy increase over time, the Universe should just be a huge featureless blob of lukewarm gas today. But instead, we see many different things: stars, planets, galaxies, black holes. To understand how probable or improbable our Universe is, we need to count the number of ways (in technical language the ‘microstates’) in which a universe like ours can arise.

Until about 20 years ago, it was thought that black holes, particularly the supermassive black holes found at the centres of galaxies, were the dominant contribution to the entropy and possible states of the universe. Using a formula discovered by Jakob Bekenstein and Stephen Hawking, Roger Penrose showed that they contribute a staggering 10^(10^101) possible states of the Universe. [The number 10^101 means a one followed by 101 zeros, and is already a number bigger than the number of particles within our entire observable Universe. But we are talking about a one followed by 10^101 zeroes!] But even that is dwarfed by the discovery of dark energy, the putative cause of the Universe’s present acceleration. This contributes 10^(10^124) to the count of possible states of the universe. This is the biggest number ever encountered in the natural world.

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Life innovates, creates new niches and possibilities, and interactions, in ways that cannot be predicted in advance. Unlike in physics, in biology, the space of possibilities is forever unpredictably expanding.

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The possible states of life

Up until now, physicists have ignored life when they have counted the number of ways in which a universe like ours could arise. Traditionally physicists, particularly those wedded to reductionism, would argue that life’s contribution is so obviously negligible that the question need not even be asked, far less answered. We’ve taken a different view.

A key distinction between physics and biology is that while physics contains a fundamental standard model encompassing its phenomena, there is no such thing in biology. Life innovates, creates new niches and possibilities, and interactions, in ways that cannot be predicted in advance. Unlike in physics, in biology, the space of possibilities is forever unpredictably expanding.

‘Combinatorial innovation’ is the new theoretical development that can account for this distinction and bring physics and biology together. Combinatorial innovation counts every new combination of a system’s elements as the creation of a new element. As a system evolves it creates new possibilities through these new combinations and becomes more complex. (A non-technical usage of “combinatorial innovation” describes how new ideas arise through the combination and testing of ideas that already exist.)

The Theory of the Adjacent Possible envisages this wave of creation expanding to create new states in a process described by the TAP equations. A generic prediction of the TAP equations is that the number of states of an evolving complex system usually follows a long slow plateau before suddenly increasing in number.

What does combinatorial innovation mean for the complexity and the number of possible states of life on Earth? The combinations of just six elements make up most biological molecules (Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulphur, usually known as CHNOPS). We took these chemical elements as the constituents of the complex system we were modelling. Then we used the TAP equations to simulate the number of possible configuration states of the biosphere as it evolved. By the time of the first RNA molecules, 3.5 billion years ago, the number of possible states that the biosphere could take was: 10^(10^237)

This is a staggering finding. Recall that the total number of possible states of the universe today is only 10^(10^124). This means that life already surpassed the universe in complexity already 3.5 billion years ago, in the RNA world. As cosmologists we could never, in a billion years, have anticipated that such a number would stem from the evolution of living organisms. It took us three years of calculations, endlessly revising and double-checking our mathematical models, before we can now support the numbers we present today.  

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A tiny, insignificant, barely there, corner of the Universe can create diversity and complexity that compares with that of everything else in the Universe.

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The future of biocosmology

What does this all mean? What is the significance of these large numbers of possible states?

We went from the commonly-held perspective that the cosmos has the biggest contribution to entropy and diversity, with our planet contributing effectively nothing, to instead seeing the entropy and diversity embedded in life on earth as dwarfing the contribution from cosmological entities.

We have a way to quantitatively put a value on life within the cosmos and its value to the Universe is enormous. A tiny, insignificant, barely there, corner of the Universe can create diversity and complexity that compares with that of everything else in the Universe. Through this, cosmology can contribute to the climate change debate by conveying an idea of what we are worth and are risking to lose. Namely, the most valuable contribution to the physical diversity in the Universe. Not even black holes can compete with life.

Read more about Biocosmology at https://www.biocosmology.earth/