The Physics of Agency, Part 4: The Law of Control Work — Agency Costs Energy
Understanding the Thermodynamic Cost of Intentional Control
The Law of Control Work
In the previous post, we introduced the kybit, a fundamental measure of intentional control over future outcomes. Now we formally establish the physical principle governing the energetic cost of exercising such control—the Law of Control Work:
Exercising intentional control over future outcomes requires physical work proportional to the kybits of control exerted.
Formal Statement
If an agent exercises a given number of kybits of control, the minimum energy cost required to perform this action is expressed as follows:
Where:
C is the number of kybits exerted,
k is Boltzmann's constant,
T is the temperature of the agent's environment,
ln(2) is the natural logarithm of 2, reflecting the binary nature of kybits.
Significance of This Law
Just as erasing information has a known thermodynamic cost (Landauer's Principle), intentionally shaping future outcomes—exercising agency—also incurs a measurable thermodynamic cost.
Agency, therefore, is never free.
Each deliberate action undertaken to influence future possibilities involves consuming real physical resources, fundamentally embedding agency within physical reality.
Drift vs. Control: Energy Landscapes
Drift represents the spontaneous, entropic evolution of systems toward disorder, which occurs without intentional effort.
Control requires intentional energy investment to move against entropy and selectively amplify specific futures.
The greater the degree of intentional control (the more kybits exerted), the greater the thermodynamic cost.
Real-World Illustrations
Clear examples of genuine agency include:
An AI-controlled drone adjusting its flight path in real-time based on predictive simulations to avoid obstacles.
An investment portfolio managed by a predictive algorithm continuously adjusting holdings to maximize future returns.
An animal storing food based on environmental cues predicting future scarcity.
In each of these scenarios, agents utilize predictive internal models and expend physical energy to intentionally shape future outcomes, clearly exemplifying the principles of agency.
Next Steps
In the following post, we'll examine the Law of Agency Decay:
Without continuous energy input, an agent’s capacity for control inevitably diminishes.
This principle highlights the inevitable thermodynamic constraints faced by all agents.
Reflective Question
Just as the First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed—how might recognizing agency as a transformation of physical energy reshape our understanding of decision-making, responsibility, and resource allocation?
(Share your reflections in the comments!)
Next post: "The Law of Agency Decay: Drift Always Waits"