Bees, Crabs and the Quest for Universal Computation: A Field Notes Talk on Bio Inspired Machines and Consciousness

Summary

The Rest Is Science examines whether computational power can arise in biological systems, from trained honeybees performing addition and subtraction in a Y shaped maze to soldier crabs forming basic logic gates. The hosts compare these results to the concept of a universal Turing machine and the von Neumann architecture, discuss the limits of animal-based computation, and explore profound questions about consciousness and panpsychism. They also touch on the Holocene calendar as a way to reframe time scales and end with reflections on life’s finite horizon. The episode blends laboratory findings, thought experiments, and philosophy to illustrate how simple rules, embodied in living systems, can illuminate fundamental ideas about computation and mind.

Introduction and Framing

The Rest Is Science opens with a light note about a scarf that cannot be cut in half and pivots to a deeper discussion of computation in nature. The central question is whether non-human, biological systems can perform computations and what that would imply for our understanding of universal computation. The host frames this as a conversation between simple rule-based behavior in living beings and the formal concepts of computation that were developed long before modern computers. The episode promises a blend of experiments, thought experiments, philosophy, and playful exploration of how life might implement computational tasks and what that reveals about mind and intelligence.

Bees as Computation Agents

The discussion then centers on bees, which are known for sophisticated pollination behavior and complex communication like the waggle dance. The hosts recount how bees can be trained to recognize simple shapes, colors, odors, and landmarks, and even follow instructions to perform basic arithmetic tasks in response to inputs. A key question arises: can bees simulate a universal Turing machine, the theoretical device that could compute anything that is computable given unlimited time and memory? This leads into a careful distinction between recognizing quantities and performing symbolic storage and manipulation, which are essential features of a universal computer.

The 2019 Bee Addition Subtraction Experiment

The episode reviews a landmark 2019 study conducted in Australia in which bees were taught to add and subtract using a color-coded scheme. The experimental setup involved a Y shaped maze where a bee enters and encounters a card or card-like display with a certain number of shapes. Colors are associated with the operation: yellow denotes subtraction, blue denotes addition. The bee must interpret the color cue and navigate a fork in the maze to choose the correct path that will yield the sugar reward at the gate with the right number of shapes. If the initial set shows three blue squares, and the deeper fork shows a choice between two and four squares, the bee chooses the 4-squares path when blue indicates addition. If the yellow cue is present and the task is subtraction, the bee would choose the 2-squares gate. This demonstrates the bee’s ability to count, compare quantities, and follow an operation-specific rule to reach a reward, all without explicit arithmetic understanding.

What These Experiments Tell Us About Computation

The hosts discuss the implications: the bees are performing a form of computation, but not necessarily doing math in the human sense. They can follow rules and manipulate inputs to produce correct outputs under training, suggesting that simple rule-based systems can perform computational tasks. However, a universal Turing machine requires the ability to write symbols, store them, retrieve them later, and perform conditional, memory-based computation. The bees can read a “penny” (interpreted as a unit in their task) and move it in one direction, but they cannot symbolically store information or return to a stored state later in a way that constitutes true memory storage. This distinction highlights the subtle boundary between rule-following behavior and the archetypal universal computation that can, given enough time and memory, compute anything that is computable.

Waggle Dance, Navigation, and Cognitive Limits

The waggle dance is discussed as a natural communication mechanism in which a bee’s dance conveys information about the location of a food source relative to the sun. Experiments where researchers patched the bee’s eyes or manipulated the sun-like cues demonstrated that the dance encodes directional information rather than a simple signal. These studies illustrate how insects coordinate complex collective behavior with relatively few neurons, sparking questions about how much of cognition is distributed across a population and how that scales with system size. The hosts emphasize that while bee brains are small, their network-level behavior can be astonishingly sophisticated, yet still distinct from the explicit symbolic computation required by Turing machines.

Crabs as Logic Gates and the Notion of Biotic Computation

The conversation then explores a 2011 study on soldier crabs, which live in dense swarms and can display collective behavior that resembles logical operations. The researchers designed mazes and mazes-like arrangements where crabs’ interactions create probabilistic gate-like outcomes. The host explains that a not gate or an AND gate can be implemented with swarm dynamics: the presence or absence of two crab groups passing through different channels can correspond to logical inputs and outputs. The crucial insight is that computation can emerge from the collective dynamics of simple agents, even if none of the crabs have an understanding of the computation. This raises philosophical questions about what counts as computation and whether emergent phenomena in biology can be considered computational devices in their own right.

Philosophical Implications: Consciousness and Panpsychism

Beyond the practical experiments, the episode delves into questions about consciousness. The hosts discuss whether human consciousness is an emergent property of complexity or if it has a more fundamental, perhaps panpsychist, basis. They debate whether experiences such as feeling and awareness could be intrinsic to matter itself or require a certain threshold of complexity for their emergence. They also acknowledge that this is a topic for future episodes but use it to frame the broader question of what computation means in living systems and whether a sufficiently large, complex swarm could possess a form of collective consciousness.

Von Neumann Architecture and Simple Rule Machines

To illustrate how universal computation is built, the hosts provide a simplified thought experiment: imagine a person with an eye mask and a line of plates, each plate either containing a penny or being empty. The rule set allows moving pennies to the right when encountered, placing a penny on empty plates, and then, after reaching the end, stepping back and removing a penny to signal the result. This toy model demonstrates the concept of an automaton operating on a tape and performing addition without the human understanding of arithmetic. It helps distinguish between following rules and performing stored-program computation, which is central to the idea of a universal Turing machine developed by Turing and later extended by von Neumann into the architecture underlying modern computers.

Animal-Based Logic Gates and Limitations

The episode notes that while bees might implement simple rule-based computations, they cannot store information in the symbolic sense necessary for a universal machine. The crab experiments show that even more complex collective dynamics can function as logical elements, but again without any understood symbolic storage by the crabs themselves. The discussion culminates in the idea that a true universal computer would require the capacity to write and later retrieve stored information, something bees and soldier crabs do not obviously demonstrate, though the implications for understanding computation in nature remain profound.

Holocene Calendar, Time Scales, and the Big Picture

The hosts turn to the Holocene calendar as a way to reframe our perspective on history and time scales, arguing that it helps place human achievements within a longer, more continuous timeline. They discuss how the calendar starts at the beginning of the Holocene epoch and adds 10,000 years to the current year, producing clearer year-zero conventions and easier comparisons across eras. A listener named Michael Rourke shares a visualization that maps notable events across the entire Holocene era, inviting readers to explore the exponential acceleration of technological progress and to reflect on how our sense of history shapes our understanding of science and civilization.

Field Notes on Time, Life, and the Book If

The episode closes with references to the children’s book If, which uses visualizations to convey time, life, and scale. The hosts discuss sections like life on Earth condensed into an hour and a pizza of life, which helps people contemplate the allocation of time across school, work, sleep, leisure, and other activities. They connect these ideas to thoughts on limited lifespans, the value of time, and the importance of placing individual lives within a broader arc of human history and scientific progress. The closing remarks invite listeners to return for future explorations of these themes and to send in questions for the next Field Notes episode.