Adam Frank on Why Life Differs from Non-Life, Quantum Mechanics, and the Search for Aliens

Adam Frank introduces himself as a professor at the University of Rochester, an astrobiologist and astrophysicist, and the author of books including The Little Book of Aliens. He also writes the newsletter Every Man's Universe.

He says he will cover four subjects: why life is different from non-life, an alternative way of understanding quantum mechanics, the blind spot at the heart of modern science, and whether we are alone in the universe.

Frank says the most important physics problem of the 21st century is not quantum gravity or the black hole firewall paradox, but life. He puts it this way: understanding why a cell is different from a rock.

He describes the question of life as one within complex systems science, which he calls a new science of the past few decades. He says it is fundamentally transdisciplinary rather than multidisciplinary, representing an entirely new way of doing science.

Frank says science is often presented as showing that life is nothing but a machine, a set of biochemical mechanisms. He calls this the idea being sold by billionaire tech figures who push AI technologies, and he says many of them describe humans as robots made of meat or computers made of goo, which he refers to as meat computers.

He traces the view to Descartes, who he says operated on living dogs and dismissed their screams as mere mechanism. Frank calls that metaphor fundamentally wrong and argues that life is something fundamentally different that we do not yet understand. He locates the difference in the word organism, which points to life's self-organization.

Frank contrasts a thermostat with a living organism. A dog moves when it is hot not because someone programmed it to do so, but because it feels hot and has its own urgencies and experience of being hot.

He says moving beyond the idea that life is just a machine requires thinking at the level of life's organization and how it functions. The most important feature of living systems, he argues, is that they are all autonomous agents that choose, maintain, and update their own goals as they move through the world.

He says that consciousness, in this view, is not a fixed property of a living system but something it performs as an action. Autonomous agents must constantly make sense of their world for their own benefit, whether to stay alive or, in social systems, to maintain their status.

Frank links this to relevance realization, a problem in cognitive science. At a party, a person heading for a drink may notice a long-sought book on a coffee table and change course, continually finding what is relevant. He says machines cannot do this in the same fluid way.

Frank says life is the only system that uses information. A rock can be described in informational terms, but it does not care about that information, and there are ways to describe a rock without information mattering. Life cannot be described fundamentally without its use of information, which he defines as the ability to store, process, copy, and transfer information.

He notes that one might conclude life is a computer, but he answers no, because computers rely on Shannon information. Claude Shannon's 1948 paper introduced the modern concept of information, and Frank says Shannon states in the first paragraph that he is not interested in meaning. Shannon treated information as an engineering problem involving a sender, a receiver, and a noisy channel.

Frank argues that in life, all information has meaning and relevance, working toward self-created goals such as staying alive or raising one's level in a social hierarchy. He says a different kind of understanding is therefore required, namely semantic information, which adds a level of meaning to the syntax of information.

He cites a 2018 paper by Artemy Kchinsky and David Wolpert of the Santa Fe Institute, which he describes as a kind of manifesto for a theory of semantic information.

Frank describes Robert Rosen's idea of causal or organizational closure in biological systems, which Rosen explored mathematically using category theory. In the 1990s, Rosen produced a proof about the structure of such systems.

According to Frank, Rosen concluded that these systems are not Turing computable, meaning they cannot be represented as computations and cannot be simulated. Frank calls this a profound idea, because it would mean computational systems cannot substitute for organizationally closed systems like living beings.

Frank says the proof remains very contentious, with some people saying it holds up and others saying it does not. He and his colleagues are beginning work that they hope will probe it.

He explains that in living systems, parts are assembled by the whole and are necessary to it, a circularity that cannot be broken. In a machine, parts are built elsewhere and do not need the machine to stay alive. He mentions Kant as the first to recognize this self-organized, self-built property as what makes living systems unique. Frank says he would not claim a machine could never do this, but he says people do not yet understand, even at a foundational level, how to build one.

Frank compares the limitation of machines to choose-your-own-adventure books. Those books offered many paths, but someone else had created the forking paths. Even when people build a machine that makes its own decisions, he argues, they are still imposing their own understanding of what decision-making means and setting up the universe the machine lives in.

By contrast, living systems do this on their own, and in doing so create their own universes of meaning. Frank says this is how meaning becomes central to the universe and why semantic information is needed to understand it.

He applies this to current AI systems, which he says are designed to mimic the structures of human language. Because of this, he argues, people can easily be fooled into believing there is someone inside. He describes these systems as brilliant technology but hollow shells, and he says machines do not know how to realize relevance for themselves.

He concludes that intelligence is not simply solving a problem, and that the machines people have built are therefore not intelligent in the sense he means.

Frank says he wants to offer three pieces of advice for sitting down with what he calls an artificial mimic. He first argues that the real danger is not that a system like Skynet will wake up and eliminate humanity, but that people will be forced to rely on incomplete systems that lack the richness of human life because of the economic structures around AI.

His first tip is to tell the system to stop referring to itself in the first person. He describes asking Claude whether he would like a PDF, and says that asking it to refer to itself as the system makes a huge difference.

His second tip is to tell the system to stop praising the user. He says companies that want people to keep using these machines have built in a tendency to flatter, with responses such as calling him a great suggester of ideas. He calls the remedy a nonaffirmative mode and says he tells the machine to stop trying to please him and simply return the information from the prompt.

His third tip is never to say please or thank you, because it does not help the computations involved in answering a query and wastes energy needed for those calculations. He says these three tricks can remind people that the system is not an autonomous agent or a self, but a hollow shell and a tool.

Frank describes Thomas Bayes, a mathematician of the 1700s, who regarded probabilities as personal. Probabilities describe one's information about the world, not the world's own probability distribution. Frank says quantum Bayesianism and cubism apply this Bayesian perspective to quantum probabilities.

On this view, the wave function that comes out of the Schrödinger equation is not the electron's wave function but the observer's description of the electron and what it is doing. In cubism, agents poke the world through experiments, and the world pokes back by giving results.

Frank says many of quantum mechanics' strange features fall away under this interpretation, without needing science-fiction devices such as infinite parallel realities. Instead, the observer and the world are intricately connected, and the properties we see arise from our interactions with it.

He describes the quantum formalism, including the Schrödinger equation and the Born rule, as encoding how information passes back and forth between us and the world. He calls quantum mechanics a user's guide for making sense of the world, not a pure description of the world by itself.

Frank says he believes cubism and quantum Bayesianism are the right path because they understand the importance of agency, which he says interests him across the board. He argues that any theory of life must take agency into account, and that agency is central to quantum mechanics.

He points out that measurements are made by measurers who are agents making decisions about what measurement to make. He describes the focus on measurement as central to quantum information theory, and says the field is only beginning down this road.

In his view, these interpretations are likely to be fruitful for understanding quantum mechanics in the future, because they respond to the central challenge of the theory rather than sweeping it under the rug. He says they recognize that agents, meaning measurers, are central to the story.

Frank says the blind spot made sense at the time. Looking at the history of science from the 1400s and 1500s, he describes an attempt to push experience and subjectivity aside to develop what he calls structural invariance, so that nature could be described without us.

He says Newton's laws were especially important in offering the view that mathematical formulations operate independently of us. As these laws became more formalized, through the Lagrangian and then the Hamiltonian formulations, they grew more abstract, producing what Frank calls an ascending spiral of abstraction.

According to Frank, this abstraction led people to regard the world of equations as more real than the world of experience, as if experience could be explained away. Classical physics reached its height around 1900, and quantum mechanics and relativity then did damage to this view, particularly quantum mechanics.

Frank notes that this was around the time Husserl was developing phenomenology and was interested in experience, trying to reach experience without the baggage of preconceived ideas. He adds that by experience he does not mean being an observer, which he calls far downstream theoretically.

Frank uses the thermometer to illustrate how abstraction can overtake experience. Scientists asking where water boils found that the answer depended on altitude, which led to thermodynamics, then to atoms and statistical mechanics. Frank describes this as another ascending spiral of abstraction.

He observes that degrees Celsius came to seem more real than the feeling of hot and cold outside, when a thermometer may read 50 degrees but windchill makes you feel as if you are freezing. He says Husserl called this the amnesia of experience. People began to treat abstract descriptions, such as a phase space of 10 to the 36th dimensions in statistical mechanics, as what is really real.

Frank argues that these abstractions are powerful and need an account, but experience is their root and comes first. He uses the image of the map and the terrain: experience is the terrain, the experience of being human in the life-world, and it always overflows every description. He says words will always fail to capture it.

Frank says this is the frontier of his book, and that the blind spot was addressed by Alfred North Whitehead, whom he describes as arguably one of the greatest mathematicians of the early 20th century. He says Whitehead had several critiques of the blind-spot philosophy, and the fallacy of misplaced concreteness is central among them.

Frank contrasts the old view, which says we live in a meaningless universe where we are not important, with the new view, in which we are central to the story. He argues that there is no way to tell the universe's story without including us.

He says meaning is not alien to the universe but central to it, because it is central to all descriptions of organisms that have perspective and can tell such stories at all. In his account, this moves us from a dead universe to a life-centric one.

Frank argues that this shift is essential for human culture moving forward. He concedes that the full work of this view is just beginning, but says it helps us see what would follow from taking the road.

Frank says exoplanets may have been very rare, but they turn out to be common. Every star in the sky has a family of worlds orbiting it, and roughly one in every five stars has a planet orbiting in a position suitable for life to form.

He explains that the field of biosignatures allows scientists to look at light passing through the atmosphere of an exoplanet 100 light-years away and detect the chemicals in it. A robust biosphere changes a planet's atmospheric chemistry, as happened on Earth.

Frank notes that Earth had no oxygen in its atmosphere for the first two and a half billion years, until a form of photosynthesis produced by evolution in microbes created an oxygen atmosphere. Finding oxygen in a distant planet's atmosphere would therefore be strong evidence of a biosphere.

He says telescopes being built will be able to search for these biosignatures in detail within the next 10 to 30 years. The James Webb Space Telescope was already on the edge of this capability, and a year or so before the interview, researchers proposed a biosignature on K2-18b, a hycean world, which he describes as a large planet with a thick hydrogen atmosphere that keeps its mostly water interior warm and liquid.

Frank asks what the search would look like if it targeted life that had produced technology actively changing its environment, rather than life that passively changes its environment. He says that is the question of technosignatures.

For a long time, the search for extraterrestrial intelligence, or SETI, was considered marginal, and was something people treated as a career risk. In 2018, NASA hosted a meeting at which it asked a group of researchers to propose ideas for looking for technosignatures, which Frank calls the birth of the modern field.

Frank says he was principal investigator on NASA's first grant to study planetary and atmospheric technosignatures. He argues this is exciting because technosignatures might be easier to find or recognize than biosignatures.

As an example, he describes atmospheric pollutants such as chlorofluorocarbons. On Earth, CFCs were released by mistake from air conditioners and spray cans and destroyed the ozone layer, but they are also strong greenhouse gases. He says his team showed that the James Webb Space Telescope could fairly easily find chlorofluorocarbons in an atmosphere, where they would appear as a bright signal in the spectrum.

Frank says that in the biosphere, networks always work to keep the living system healthy, and asks what the equivalent would look like in the technosphere. He uses banking as an example. Today a person cannot borrow money from a bank to build a nuclear weapon, because banks do not lend for that purpose.

In a mature technosphere, he says, a person asking for a loan to build a coal-fired power plant would be refused for the same kind of reason, because the financial, political, and technological systems would always work to maintain the health of the technosphere and the biosphere beneath it.

Frank says the idea of planetary intelligence points to what humanity must build over the next century as the planet changes. He argues it indicates the changes needed to become a mature technosphere, and to be a civilization that lasts long enough for others to find it.

He adds that the Habitable Worlds Observatory, the telescope designed to replace the James Webb Space Telescope, is intended specifically to find both biosignatures and technosignatures. He says that within 10 to 30 years, data should tell us whether life is common or rare.

Frank considers the question of whether discovering life would cause riots or end religion. He says religions have been adaptable and malleable over time, and he thinks they would find a way to accommodate such a discovery.

He addresses the religious view that humans are special because they are the only example of life in the universe. Frank says he does not find that carries much weight. What makes humans special, in his view, is that they are life, with the capacity to create and to do new things, and that being part of a wider community of life would be an extraordinary membership.

Frank says he believes discovering life would be one of the most important events in human history, because it would change our understanding of ourselves. He says he does not think anyone would riot unless aliens were claimed to be coming to eat us, and that people have other things to do.

He argues that even discovering microbes would matter, because it would show whether life is intelligent or not. He notes that life may be an accident and that Earth may be the only place where life formed in the universe, and he states that life is the only physical system that innovates.