There is great interest in imagining “life” on other worlds. This is one of the main applications of Planetary Biology theory. But the term, “life,” is very much a term linked to planet Earth. This interesting phenomenon is a product of and dependent upon Earth’s physical environments. But the environments on other worlds probably won’t match those on Earth. Other worlds may be very, very different from Earth and each other.
The main problem with the term, “life,” is that it is, by default, biased. It slants our perspective to consider only Earth-like “life” on other worlds. For example, we often think that a world must have liquid water on it in order to support “lifelike” operations. But could lifelike operations use other liquids besides water? What is needed is a more generic and more inclusive term.
As an alternative to the term, “life,” I am proposing the expression, “Self-Persisting Operational Complex,” or, SPOC. A SPOC would be a physical object with an identifiable set of interactive operations (operational complex) that, by virtue of their interactions with energy and matter, produce actions and transformations that result in the continuation of those interactive operations (self-persisting).
All living things on Earth satisfy the basic definition embodied in SPOC. Living things on Earth are complex operational systems that, by their behavior, result in persistence of the systems that compose them.
Using SPOC instead of “life” discards many of the biases associated with “life” on planet Earth. It widens our search bandwidth and might help us discover interesting phenomena on other worlds that we might otherwise overlook.
The only thing that matters is “persistence”
On Earth, most living systems are not goal oriented. Your heart is not “trying” to pump blood to your brain. A leaf is not “trying” to track the sun. A monarch butterfly is not “trying” to migrate to Canada. Operations occur in living things because:
- Operations are based on copies of operation-influencing DNA inherited from predecessors.
- Predecessors that expressed those operations persisted and matured to a state whereby they could pass on copies of operations and their underlying DNA codebase to offspring. On Earth, those operational copies are encapsulated in cells, such as eggs and sperm.
The focus on “persistence” tries to simplify and flatten the essence of what living things do on Earth and what SPOCs would do on other worlds. Living things and SPOCs exist as dynamic objects to the extent that their associated operational complexes continue to operate. For living things on Earth, we think of “life” or “death.” For SPOCs beyond Earth, we can think of “continuing operations,” or “halted operations.”
Considering SPOCs on other worlds
I am proposing that when assessing other worlds, we set aside our Earth-bound paradigm of “life,” and employ the SPOC perspective instead. With practice, and discipline we may discover truly astonishing alternatives on other worlds – in our own planetary system and beyond.
One final comment. Given that the term "habitable zone" is based on the chemistry of life on Earth -- with its dependency on liquid water and solar access -- how would we define "habitable zone" for SPOCs with entirely different compositional and operational setups?