Forget the habitable zone – we need to find the computational zone

Astronomers are currently looking for signs of life in the “habitable zones” of nearby stars, which are defined as the band around a star where liquid water could exist. But recent research argues that we need to take a more careful and careful approach, based not on life potential, but on computational potential.

One way to define life itself is as a set of computations that operate on information. The information is stored in DNA and the calculations are done by various proteins. The ability to store information and act according to its environment allows life to undergo natural selection, which finds ever more complex arrangements.

Traditional searches for life look at how we understand it from an earthly context. They are organisms that live on the surface of the world at an appropriate distance from the parent star and use liquid water as a solvent for chemical reactions. But it is easy to imagine more complex and diverse forms of life in the universe. Life could use other solvents.

Underground life could be buried in the icy outer moons. Life may not even require a star. Biological systems can give rise to technological systems that do not fit our current definition of life but that may be alive in their own way.

So a pair of researchers wants to reconstruct the concept of the habitable zone using a more fundamental concept of computation. They argue that the best chances of finding signs of life are where there is easier access to the account. The researchers argue that these so-called “computational regions” require three properties. Firstly, there must be the ability to calculate, which means that there is a rich set of chemistry available. Second, there must be a raw form of energy, such as sunlight or hydrothermal vents. Finally, computation requires a substrate—something on which computations can take place.

The traditional view of habitable zones can now be seen as a subset of the much larger concept of computational zones. Wherever there is life as we currently understand it here on Earth, it does math. But this framework allows us to develop search strategies for concepts of extended life beyond that. For example, if we study individual systems through the lens of computational power, we may find systems that may be as amenable to artificial energy harvesting as Dyson spheres.

Or we can examine how clouds of gas around substellar structures can satisfy all the conditions necessary for computation, and thus the conditions necessary for an expanded definition of life.

The scientific search for life in our universe has just begun. And it’s important, the authors stress, to keep an open mind.

The paper has been published on arXiv Prepress server.