Biometrics are measurements of the body. These measurements can be used as inputs to a modification or control signal. Fingerprinting, voice recognition, DNA, or retinal scans can be used for access control in security systems. Yet more to the point, biometrics for my heart rate, oxygenation, temperature, nutrient vectors, BMI, brain waves, microbiomes, and cultures are the inputs to a transfer function for the alignment of health and nutrition.

Feedback does not mean gathering advice or results of a poll. Feedback is specifically a modification and control signal. Feedback uses a quantitative representation of resulting output for some input. That quantitative representation, that number, is then fed-back into the system through a transfer function that modifies new input.

Spaceship Earth is a trope that has encouraged me to apply a design criteria to the metaphorical concept of earth imagined as a spaceship. This is not, denotationaly a spaceship, but cannotationaly a kind of design principle inspired by spaceships. Extending this concept recursively I see that my home can also be likened to a spaceship, an "earth-ship" perhaps. Go another level deeper into the recursion and I am a spaceship. My mind and body, my vehicle through the universe. Imagine a starship for a moment. It's primary functions being life support and propulsion. To sustain its inhabitants and to move them to a destination. In science fiction, these systems require an enormous amount of energy, an energy that is often dangerous to produce. This is why it is imagined that many sensors, actuators and many layers of redundant failsafes are operating at high framerates. The signals produced by these sensors travel with low latency and high bandwidth are aggregated and analysed to drive the actuators and keep the many subsystems stable. These signals measure oscillation, and feedback is applied to dampen the oscillations because runaway processes would be fatal to the starship and its inhabitants. This network of sensors and actuators is an algedonic system.

From the ancient greek álgos meaning pain and hēdonḗ meaning pleasure the modern word algedonic was constructed. Literally, it means pleasure and pain and in the sense of a system it is used to describe a network of interacting sensors and actuators involved in the autonomic response to pain and pleasure.

I have built-in instruments in my body that provide feedback through biometrics. For example, I know when I am tired. I know when I’m hungry. I know when nature calls. I can tell when I’m getting sick. For the most part, I know when things are going bad, and I know when things are going good. There are things that are obvious, that I become suddenly aware of that control what actions I take next. There are things that are more subtle, that require a mindfulness, or a probing of my own body to identify. Still, there are other actions that are taken by my autonomic nervous system that are beyond my conscious control. When I feel pain the automatic response of my body is to recoil, the response of my mind is a hyper vigilance scanning the environment for threats to my body. When I feel pleasure the Autonomous Sensory Meridian Response precipitates relaxation in my body and mind.

Beyond my built-in faculties for self awareness, there are instruments that have been built that I can access. Becoming comfortable using these instruments is important for shifting the locus of control. I need to extend my algedonic system with technology.

I need it for health. To create an alignment between my mind and body, I need to align intention, action and result. I intend to be healthy, and I take healthy actions. What are the results? I don't know. Everything appears to be fine, but subtle cumulative effects build up over time and suddenly everything's not fine. And I could be in a situation I cannot go back from.

I need it for mental health. I know that nutrition, diet, and the microbiology of my body plays a role in mental health. What is not certain is the extent to which that role is played. Without the tools to make measurements and the historical data to impart trend and correlation I will remain in the dark.

I need to move beyond guesswork. Get the real data to guide and motivate intelligent efforts, to align intention, action and result. Changes in my mind and body are occurring without conscious knowledge of it. When something negative happens, I can sit and introspect the cause but without data — without the measurements of inputs and outputs to create feedback — my algedonic signals don't extend beyond my nerve endings. Data quantifies reality, it quantifies how that reality changes in time. It exposes trends so I can make predictions.

Like matter and antimatter in a starship, the internal experience and the outward experience of my mind and body are constantly colliding and creating chemical energy. The chemical energy powers the functioning of my body as well as the qualities of thought and emotion. Whether I’m inclined to think metaphysically or in a more reductionist way, there is no denying that energy is conserved. Thoughts are a creation of energy, it has to go somewhere. What happens inside my body flows outward into the universe and what happens outside in the universe flows inward into my body. I am apart of the universe internally as much as externally.