Home Forums Deep Time Journey Forum Is the universe a "living system"? Reply To: Is the universe a "living system"?

Stephan Martin

Hi Duane,
Glad to be joining the conversation at this point. A helpful approach to understanding whether the term metabolism applies to the universe might be to apply it to nested and emergent biological systems and see at what point (if any) the term breaks down as we apply it to larger scales. I think biologists would all agree that cells and organisms all metabolize by exchanging energy with the environment, and they might feel comfortable applying the term to collections of biological entities such as nests, colonies, or even ecosystems. At ecosystems, it begins to push the boundary between traditionally defined living and non-living entities. For example, the largest ecosystem on Earth could be considered to be the biosphere itself, which metabolizes sunlight as it’s primary energy source. This extends the ecosystem to at least the Sun-Earth system. At this point I think most astronomers would be uncomfortable using the term metabolism to describe the energy dynamics of the system, and would see it as a biological metaphor applied to a physical system. But I’m not sure it doesn’t apply here as well, if we’re using David Christian’s definition as a starting point. Astronomers also talk about galactic ecology, the exchange of energy between various parts of the galaxy and the enrichment of the interstellar medium (the “soil”) over time through stellar nucleosynthesis – is this metabolism on a galactic scale?

It may be that these larger-scale metabolic processes occur on such long timescales (millions and billions of years in the case of galactic metabolism) that we simply don’t have enough scientific observations and evidence to answer the question “Is the universe a ‘living system’?” from a scientific standpoint.  I’d love to have biologists weigh in on this issue and see where the cracks are in the argument from their perspective.