What are the limits of life?
Can it exist on other planets or in a lab-created form on Earth?
These fascinating questions, often the stuff of science fiction, are now being explored through science itself.
A group of researchers, including several from the Santa Fe Institute, published an open-access paper in Interface Focus to examine what truly defines life.
By looking at life’s basic rules, they aimed to uncover whether certain forms of life are impossible—even on alien worlds or in laboratories.
The paper explored case studies across various scientific fields, including thermodynamics, genetics, cellular development, brain science, ecology, and evolution.
The findings show that life has some universal requirements and limitations.
One of the key requirements is entropy reduction, which means living things must have the ability to repair themselves and maintain order, even in chaotic environments.
Another essential rule is that life must be made up of closed-compartment cells, the tiny, self-contained units that protect and support life processes.
The researchers also highlighted the need for a system to process information and make decisions, like a brain. These systems rely on neuron-like units to gather, analyze, and respond to information from the environment. Without these fundamental elements, life—whether on Earth or elsewhere—cannot exist.
Interestingly, the authors looked back at historical predictions about life that turned out to be correct.
For example, in the 1940s, physicist Erwin Schrödinger predicted that life’s genetic information must be stored in molecules with a stable but flexible structure, calling them “aperiodic crystals.” This idea later paved the way for the discovery of DNA.
In another example, mid-20th-century simulations predicted that parasites would inevitably evolve in complex ecosystems. Modern biology has confirmed this prediction, showing how life’s evolution follows logical patterns.
These examples suggest that life everywhere might follow universal laws. The researchers propose that by understanding these laws, we can better predict how life might appear on other planets—or even how we might design artificial life in a lab.
While there’s still much to learn, this research provides a new perspective on one of humanity’s oldest questions: What makes life possible, and could it exist elsewhere in the universe?
Source: Santa Fe Institute.
