Continuing the theme of ‘How can we find shadow biosphere lifeforms if we don’t know what to look for?’
Everything we think we know about physics is a theory. And theories are replaced with better theories over time. The theory that all life on earth is carbon-based is a reasonable one, given the visible evidence. Just because we don’t know what non-carbon-based life looks like, it doesn’t mean it’s not there. The comparison with Dark Energy and strange behaviour of subatomic matter is apt – theses are theories derived by inference not observation. The shadow biosphere requires quantum thought.
The possibility of strange forms of alien life seems to have just got a whole lot closer to home. Astrobiologists from Arizona State University, Florida, UC Boulder, NASA, Harvard and Australia have recently theorized about a “shadow biosphere” – a biosphere within a biosphere where alternative biochemistry may be thriving in a way that we haven’t yet thought to examine. Such “weird life” may have had, for hundreds of millions of years, their own ecologies right here in our own backyard. Indeed, like Dark Energy and neutrinos, “weird life” may be all around us even now, only in a non-obvious way. Some astrobiologists are now suggesting that “weird life” is just as likely to be found here on Earth as it is in the Martian regolith, the seas of Europa , or certainly the complex bio-hadronistry on the surface of a neutron star.
In an astrobiology related Nature commentary article titled, “Where are the dolphins?” scientists Jack Cohen and Ian Stewart realized (and showed mathematically that it’s already happening here on Earth) that as a civilization advances they begin to use the available electromagnetic spectrum for communication more fully and efficiently until ultimately their radiative emissions are indistinguishable from blackbody radiation. In other words, when we look out into space with telescopes to search for signs of alien life we will likely mistake it for being just a regular old hot rock. Unless we know how to interpret the signs of such life, we may not be able to distinguish it from the natural background.