Cosmological CSI: Fine-Tuned for Life

The laws, constants, and initial conditions of the cosmos conform to a special set of requirements (specifications) that make life possible in our universe. Of the indefinite number of mathematical forms physical laws might take, those in a life-permitting cosmos must have certain forms. Such laws include a long-range attractive force like gravity that drops off with distance so that stars and planets can form, a very short-range strong nuclear force to bind protons and neutrons together stably in each atomic nucleus, and an electromagnetic force that drops off with distance to hold electrons in orbit around each atomic nucleus and transmit light energy from a host star to its planets.

The constants that calibrate natural laws, such as the gravitational constant that determines the strength of gravity and the initial conditions of the universe, are also coordinated to permit life. Some aspects of the fine-tuning of gravity are relative to yet other physical parameters. For example, gravity is fine-tuned relative to the initial condition of the density of matter in the early universe and factors controlling the Big Bang’s expansion rate. “Holding these other parameters constant,” Robin Collins (2009) explains, “if the strength of gravity were smaller or larger by an estimated one part in 10⁶⁰ of its current value, the universe would have either exploded too quickly for galaxies and stars to form, or collapsed back on itself too quickly” to support life.¹⁰ “The lesson here,” says Collins (2009, sec. 2.3.2), “is that a single parameter, such as gravity, participates in several different fine-tunings relative to other parameters.” Many scientists accept that the universe is fine-tuned for life in the way Collins summarizes. Making this point, Luke Barnes (2012, 7) cites work by an impressively wide range of cosmologists. “They differ, of course, on what conclusion we should draw from this fact,” Barnes notes.

An early study of cosmic fine-tuning, launched by Harvard biochemist Lawrence Henderson, argued that the peculiar properties of water and carbon dioxide—and the underlying laws governing carbon, hydrogen, and oxygen—are well suited for the only kind of life that appeared to him physically feasible, namely, carbon-based life. Henderson (1913, 312) concluded that “the biologist may now rightly regard the universe in its very essence as biocentric.” By this he primarily meant that the chemistry of the cosmos is functionally aimed at the support of life. As a pioneer of biochemistry and its use in biology, he identified a collectively improbable (probabilistically complex) arrangement of coordinated chemical regularities that satisfies the independently given specifications (tight constraints) of life-permitting chemistry. This constituted the preliminary development of the idea of cosmic CSI. Even if, contrary to Henderson (and many astrobiologists today), alternatives to carbon-based life are plausible, this does not undermine Richard Dawkins’s (1986, 9) point: “[H]owever many ways there may be of being alive, it is certain that there are vastly more ways of being dead, or rather not alive.” In the section “The Rarity of Value: A Consequence of Small Selection within Vast Possibility Space,” we explore this rarity feature of life’s CSI as evidence of its status as informational value.

Earlier we defined CSI as a probabilistically complex (improbable) arrangement of entities that satisfies independently given specifications (tight constraints), such that it has function. In this definition, “function” was used in the general sense of tightly structured capability within a probabilistically complex system. The fine-tuning of our cosmos, which constitutes CSI, renders it functional because it has the tightly constrained capability of supporting the possibility of life. These tight constraints render our fine-tuned-for-life cosmos rare in relation to other possible universes, the vast majority of which are incompatible with life.

It is important to emphasize that the complexity relevant to cosmological CSI lies not in the algorithmic length of the laws themselves, which may be quite short, but in the extraordinarily small region of the space of possible laws, constant-values, and initial conditions that jointly satisfy the independently specified functional requirement of permitting complex life. Even an algorithmically simple law—like Newton’s or Coulomb’s inverse square laws—could be one point in a possibility space whose life-permitting region is vanishingly small. The probabilistic complexity of cosmological fine-tuning therefore concerns the scarcity of life-consistent parameter combinations, not the compressibility of physical equations.

Even so, one way to connect CSI with algorithmic information theory (AIT) is to let AIT contribute to the recognition of a legitimate specification rather than characterize complexity. In many cases, the simplicity and non-gerrymandered character of a specification can be better recognized when it can be given a short description within the relevant mathematical or physical language (e.g., “life-permitting cosmos” in the case of cosmological fine-tuning). Such descriptions are algorithmically compressible even when the underlying microstate or parameter combination is highly complex. CSI can combine this AIT-bolstered treatment of specification with probabilistic complexity, assessing how difficult it is for stochastic processes to land within the life-permitting region defined by that specification. On this view, AIT (in many cases) can help explain how we recognize a non-ad hoc specification, while probabilistic CSI quantifies how hard it is to realize that tightly constrained specification by stochastic processes.

For the “cosmic fine-tuning as CSI” argument to succeed, one need not formulate it as a rigorous statistical inference. Similarly, the rock art at Altamira, Spain (depicting bison, etc.) clearly instantiates CSI, even though the probability of getting these images on rock by chance is not known with statistical rigor. However, in a step toward statistical rigor in fine-tuning argumentation, Jeffrey Koperski (2005) and Collins (2009) have proposed solutions to the normalizability problem that might have otherwise undermined demonstrating the improbability (complexity) of universal fine-tuned features. Barnes (2018) offers a Bayesian way to answer the normalizability objection. Regardless of how this debate in probability theory plays out, local fine-tuned features (our next topic) are immune to such universal fine-tuned worries. So, in many cases, cosmic fine-tuning for life is demonstrably probabilistically complex (improbable)—thus sufficiently establishing the “C” of CSI in such cases.

Cosmic fine-tuning, which includes the features reviewed here, exhibits CSI because the laws, constants, and initial conditions of the cosmos collectively constitute an improbable (probabilistically complex) arrangement of coordinated factors that satisfies the independently given specifications (tight constraints) of how to make a life-permitting cosmos¹¹ and has function in the sense of a tightly constrained capability: the capability of supporting life.

For a treatment of “functional information” suggestive of the functional status of cosmic fine-tuning, see Robert Hazen et al. (2007, 8574–75): “All complex systems alter their environments in one or more ways, which we refer to as functions.” They analyze the information that makes certain functions possible in alphabetic letter sequences, RNA aptamers (RNA structures that bind a target molecule), and the Avida computer program aimed at simulating evolving life forms. Their account of functional information is aimed at explaining complex emergent systems, in all of which “interactions among numerous components or ‘agents’ produce patterns or behaviors not obtainable by individual components” (Hazen et al. 2007, 8574). Such systems exist at “every scale of the physical universe,” which should reasonably include cosmic fine-tuning for life.

In addition to universal fine-tuning, local conditions must also meet certain requirements if a place is to be life-permitting. Since Guillermo Gonzalez, Donald Brownlee, and Peter Ward (2001) introduced the “galactic habitable zone” (GHZ), studies have largely confirmed this restricted life-friendly zone within a galaxy. Many astronomy textbooks now discuss the GHZ and acknowledge that a planet too near or too distant form a galaxy’s center would be uninhabitable owing to multiple factors.

The circumstellar habitable zone (CHZ), as defined since the 1950s, is a narrow ring around a host star where liquid water is sustainable on a planet’s surface. The prerequisites for planet habitability are numerous, and the list is growing: “The traditional definition of the CHZ, based on the radiant energy from the host star, is outdated and should be replaced with a definition that also includes such considerations as planetary impact rate, orbital dynamical stability and episodic reductions in the size of the astrosphere . . . Habitability factors are often interconnected in a complex web, and some factors can have multiple distinct effects on the habitability of a planetary system” (Gonzalez 2014, 56).

Local habitability requirements (especially for complex life) include having a planet of the right size and composition (appropriately orbiting the right kind of host star), the right kind of atmosphere, a global magnetic field, plate tectonics, a large appropriately distant moon, proper spatial relations to neighboring (and at times migrating) giant planets (like Jupiter), and much more.¹² Habitable environmental rarity is further increased by the many well-timed events (e.g., planet migration) that are preconditions for obtaining and maintaining many of the items listed here. Such local fine-tuned features collectively constitute a probabilistically complex (improbable) arrangement of entities that satisfies the independently given specifications of how to make and sustain a local habitable environment (within a given universe that has life-permitting physical–chemical laws).

Biological Complex Specified Information: Information that Guides the Maintenance and Reproduction of Life

Our characterization of CSI as a central feature of biological life, the point we will now support, is not an attempt to define life. Attempts at defining biological life have proved useful in certain fields, but there is no consensus on a definition. To proceed as a discipline, origin of life studies have had to grapple with what “life” minimally is. Fittingly, the notion of biological CSI made an early, but incompletely developed, appearance in that field.

Leslie Orgel expressed what origin-of-life researchers (like himself) would need to explain—namely, the origin of biological specified complexity. He noted that, in contrast to most nonliving things,

living organisms are distinguished by their specified complexity. Crystals are usually taken as the prototypes of simple, well-specified structures, because they consist of a very large number of identical molecules packed together in a uniform way. Lumps of granite or random mixtures of polymers are examples of structures which are complex but not specified. Crystals such as granite fail to qualify as living because they lack complexity; mixtures of random polymers fail to qualify because they lack specificity. (Orgel 1973, 189)

Orgel thought the “idea of information” could make “more precise” this joint occurrence of complexity and specificity in organisms. He stressed how “sequence information” in DNA “can serve to distinguish the contents of living cells from random mixtures of organic polymers” (Orgel 1973, 190–91).

Bernd Rosslenbroich (2016, 290) notes that “information processes are essential in all life functions.” He concludes: “Basically all structures of the organism must contain embodied information, whether it comes from the genotype or not.” In support of one of our major theses, biophysicist Bernd Küppers (like Rosslenbroich) concludes that information is the central unifying feature of life: “The fact that all phenomena of life are based upon information and communication is indeed the principal characteristic of living matter. Without the perpetual exchange of information at all levels of organization, no functional order in the living organism could be sustained. The processes of life would implode into a jumble of chaos if they were not perpetually stabilized by information and communication” (Küppers 2010, 170).

There is a range of opinion about the status of biological information, as Peter Godfrey-Smith (2007, 104) observes:

Some have hailed the employment of informational concepts here as a crucial advance . . . Others have seen almost every biological application of informational concepts as a serious error, one that distorts our understanding and contributes to lingering genetic determinism . . . Most of the possible options between these extreme views have also been defended. These include various arguments that some, though not all, of the popular uses of informational concepts in biology are legitimate.

Godfrey-Smith also notes (2007, 106): “The more contentious question then becomes whether or not biology needs another, richer concept of information as well as Shannon’s concept. Information in this richer sense is sometimes called ‘semantic’ or ‘intentional’ information.” He gives reasons to accept this richer sense of information in certain domains of biology. CSI accounts for this richer sense of information.

Similarly, John Maynard Smith (2000, 215) argues: “It does seem that there are today, in the living world, only two systems capable of unlimited heredity, that is, of transmitting an indefinitely large number of different messages: these are the genetic system based on nucleic acids, and human language.” Both of these systems involve symbolic sequence signals that contingently (not by necessity, as Smith emphasized) produce the targeted consequences of those transmitted signals. Smith notes that epigenetic mechanisms also play an important developmental role, for example, the “positional information” provided by the head–tail orientated gradient of the bicoid protein in a Drosophila egg.

More epigenetic types of biological information have recently surfaced. Some “systems approaches” to biology have emphasized the ubiquitous operation of “different regulatory levels such as genetic, epigenetic, and posttranscriptional gene regulation” (Rajewsky et al. 2018, vi). Such bioinformatic discoveries include many forms of “positional information.” For example, the three-dimensional organization of the genome within the cell nucleus “has an essential role in controlling genome function during normal growth, cellular differentiation, and stress response, showing that, overall, 3D reorganisation is tightly linked to changes in gene expression” (Fahmi, Sewitz, and Lipkow 2018, 1).

Philosophical reflection on systems biology has renewed efforts to understand what life is. Central to this ontological project is the systems biology study of “gene regulatory networks, rather than static DNA sequences as ‘codes’,” which “entails a different epistemology and ontology focused on the dynamic [informational] regulation of biological systems” (Green 2017, 5). Scholars also debate “whether systems biology explanations are mechanistic or not” (Green 2017, 5). This is understandable partly because systems biology increasingly relies on concepts like noise, filters, and amplifiers—which are derived from information theory and engineering (further supporting our CSI analysis of life).

Many biosemiotic practitioners have emphasized the importance of information theory to make sense of biological function. Wim Beekman and Henk Jochemsen (2023, 446) argue: “Biological regularity in protein biosynthesis appears dependent on normative symbolic information processing.” They think such biological information processing includes DNA as a carrier of “biological meaningful information.” Such biological information is “meaningful in the sense it delivers (eventually after some post-translational modification) a functional protein to a living cell. DNA contains functional information precisely in the context of the system of the living cell” (Beekman and Jochemsen 2023, 448). This approach contains some of the main features of our CSI account of biological information: CSI’s functionality (instructions for tightly structured capability within a probabilistically complex system) and normativity (maintaining conditions for correctness within an organism).

Cultural Complex Specified Information: Signs of Intelligent Life

Recall Smith’s (2000) reference to the “two systems” (human language and the genetic–epigenetic system) capable of “transmitting an indefinitely large number of different messages.” Intelligent life is capable of generating CSI, which we call cultural CSI. Language plays a prominent role in the conception, instantiation, and transmission of cultural entities. Technological CSI includes robotic programs that direct automobile assembly. The owner’s manual (textual CSI) for an automobile includes a specifications section that documents the right sort of oil and other fluids one should use.

Such cultural artifacts embody CSI. We noted earlier how an airplane embodies CSI because it is a technologically functional complex arrangement of parts that satisfies the independently given specifications (tight constraints) of ways to be an airborne transportation machine. So, cultural CSI includes the prominent subcategories of technological CSI and textual CSI. All forms of cultural CSI share (with cosmic fine-tuned CSI and biological CSI) the common traits of probabilistic complexity and tightly constrained functional specificity.

Altogether: Life’s Complex Specified Information Operates at Three Interacting Levels

Life’s CSI, we have demonstrated, resides at three interacting levels: cosmic fine-tuning for a life-supportive environment, genetic–epigenetic information within organismic life, and the capacity of intelligent life to detect and create CSI. At the middle of these three tiers, biological life itself is only possible if it resides within and properly interacts with a fine-tuned environment. At the top tier of life, intelligent life, CSI figures into the picture in a yet additional unifying manner. Culture, in at least the case of humanity, includes impressive achievements in creative literature, technology, and science—all of which involve CSI. So, we have demonstrated that all three levels of life’s CSI interact with each other in ways that support an integrated theoretical framework for understanding life and its cosmic preconditions.

The relationship between the notions we have been employing can now be stated succinctly. AIT measures descriptive compressibility; Shannon theory measures uncertainty; CSI measures functional organization under probabilistic constraints. Because cosmological fine-tuning, biological regulation, and cultural artifacts all involve tightly specified functional requirements that must be met despite vast spaces of alternative possibilities, probabilistic complexity is their appropriate evaluative metric. CSI therefore captures the cross-domain unifying structure linking cosmological, biological, and cultural information.

Now we are ready to argue that life’s CSI is a kind of value, which is a new theory of significance for the foundations of value theory and for how to account for key aspects of biological function.

The Normativity of Value: Proper Function

The value trait of normativity means that entities ought to function properly (satisfy conditions of correctness). Persons ought to function in a proper manner epistemically, morally, and aesthetically. We rehearsed this in the previous two paragraphs. An account of normativity as proper function across the three classical values helps us identify life’s CSI as a kind of value because life’s CSI too exhibits this trait characterized in this way.

The Rarity of Value: A Consequence of Small Selection within Vast Possibility Space

Rarity is another common trait that life’s CSI shares with epistemic, moral, and aesthetic value. We argue that there are few ways to be reasonable, moral, beautiful, and alive—that is, in comparison to the many more ways to be unreasonable, evil, ugly, and dead (lacking sufficient life-functional CSI).

Rarity was staring us in the face in our earlier exploration of cosmic fine-tuning for life as well as the genetic and epigenetic information that makes possible the maintenance and reproduction of organisms. Remember that if the strength of gravity were smaller or larger by an estimated one part in 10⁶⁰ of its current value, the universe would have either quickly collapsed back on itself or expanded too rapidly for stars to form. In either case, such a cosmos could contain no life. Even within our fine-tuned cosmos, local conditions must meet many additional criteria to be habitable.

The extreme rarity of cosmological fine-tuning is echoed in molecular biology. Douglas Axe’s (2004) experimental work implies that “the overall prevalence of [amino acid] sequences performing a specific function by any domain-sized fold may be as low as 1 in 10⁷⁷, adding to the body of evidence that functional folds require highly extraordinary sequences.” A fold within a particular protein is an independent structural unit of that protein. Other studies have reinforced Axe’s conclusion.¹⁵ These studies collectively demonstrate empirically that the percentage of life-friendly amino acid sequences (ones that make useful proteins) out of the total possible sequences is extremely rare. Recall Dawkins’s (1986, 9) way of expressing this: “[H]owever many ways there may be of being alive, it is certain that there are vastly more ways of being dead, or rather not alive.”

Epistemic value also exhibits the trait of rarity. Given that there are many possibly ways for beliefs or our belief-forming mechanisms to go wrong, knowledge is rare when compared to all the possible ways a person could hold unwarranted beliefs. Analysis of theoretical virtues also points to the rarity of epistemic value. Theoretical virtues are the traits of a theory that show it warrants acceptance. Such virtues include evidential accuracy, explanatory depth, and fruitfulness (Keas 2018). Although the characterization and epistemic status of the theoretical virtues are contested, many scholars affirm that these virtues help us infer which rival theory is the best explanation. Studies of prominent theories, especially in the natural sciences, have helped us recognize just how rare virtuous theories are compared to the vast number of possible ideas that would (rightly) be judged theoretically less virtuous (e.g., theories that are evidentially inaccurate, explanatorily shallow, fruitless, and ad hoc).

Similar considerations hold for aesthetic and moral value. Beauty requires a kind of harmony and order (among musical notes, words on a page, or pastels on a canvas) that is rare compared to the vast number of possibilities for disharmony and disunity. This point holds even if, as many have argued, our universe contains much beauty. With respect to possibility space, such beauty is rare and unexpected. The frequency of beauty (or any other classical value) in the actual world is not at the heart of our argument. Rather, we have focused on rarity as a consequence of tight constraint gauged in reference to comparable conceivable possibilities (i.e., the space of possibilities), not actual frequencies in the world.

For example, consider some of the aesthetic traits of a good story. A good story will exhibit beautiful traits such as wittiness, irony, simplicity, and unity. There are many more ways to write stories that score low (rather than high) in such aesthetic traits. The last two aesthetic qualities deserve special attention in this regard. Simplicity refers to a story that is not more complicated than what is needed to fully develop the plot. There are far more ways to gratuitously complicate a story than to tell a story with graceful simplicity. How about the trait of unity (or unification)? A story will exhibit a pleasing unity if it illuminates very different kinds of human experience by showing how these experiential components belong to a larger whole. There are many more ways for a story to exhibit disunity rather than unity. It takes more effort and more artistic skill to craft a story with high degrees of these aesthetic properties.

There is a similar principle of moral rarity. Highly exemplary moral people are rare, and it is for this reason that we honor and seek to emulate such persons. Part of the reason for the rarity of highly moral people is that for any given highly prized moral act in a certain circumstance, there are a vast number of ways to act that would fall short of the moral ideal. For example, consider the highly prized moral action of assisting a stranger in a way that best matches the stranger’s short-range and long-range needs, and that does so within the domain of the helper’s capabilities at that time (with due consideration for appropriately maintaining financial resources for helping other people in the future, etc.). There are a vast number of ways to act in this situation that would fall short (to one degree or another) of the moral ideal. For example, you could do less than what you are capable of doing, or you could act without the appropriate amount of effort to become acquainted with the precise nature of the stranger’s needs, and so on. The moral ideal occupies a tiny region within the space of such possibilities for action and motivation in that situation.

Let us probe deeper into the motivational reasons for the rarity of highly moral acts. Even in cases where someone acts publicly in an ostensibly moral manner, research shows that very frequently, the motivation for such acts is selfish (or a mixture of selfish and unselfish motives). For example, “the most investigated form of moral hypocrisy is pragmatic hypocrisy in which people fake moral commitment for their own advantage” (Lindenberg et al. 2018, 393). Furthermore, there is “a different form of hypocrisy in which people take a moral stance with regard to norms they endorse without thereby also expressing a commitment to act morally. Rather they do it in order to feel good” (Lindenberg et al., 2018, 393). This is hedonic moral hypocrisy. The rarity principle of morality is widely acknowledged among scholars.

The Gradedness of Value: Weighing Worth on a Scale

Philosophers have long recognized that value comes in degrees, including different grades of epistemic, moral, and aesthetic value. On the epistemic scale of value, persons form beliefs with varying degrees of justification (some beliefs are more rational to hold than others) and hold beliefs with varying degrees of confidence or credence. On the moral scale of value, persons embody different levels of goodness (and evil), and various actions can be more or less praiseworthy or blameworthy. On the aesthetic scale of value, persons, things, and events embody or instantiate various degrees of beauty, from aesthetic excellence (e.g., sublimity and sophisticated elegance) to mundane aesthetic goodness (e.g., cuteness and neatness). For example, a very low degree of neatness might be barely above the threshold of junky clutter. Regarding epistemic, moral, and aesthetic value, it is difficult to precisely quantify degrees of value, although we generally think our comparative value judgments reliable.

By contrast, life’s CSI is not only graded but is often more readily quantifiable. The amount of CSI present in a given case sometimes can be determined by a precise calculation. For example, the amount of information encoded in DNA can be measured in bits.