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.
I have included a link to their full article here: Davies_etal_Astrobio2009.pdf
Now, while I think that shadow organisms and shadow biospheres are certainly cool enough to blog about, please allow me to take the logical next step by citing yet another intriguing astrobiology paper that came out of the Santa Fe Institute. Published nearly a decade ago 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 (SETI for example) we will likely mistake it for being just a regular old hot rock! So either three things must be true to find life through a telescope: 1. The civilization is at a very precise moment in its development,2. The civilization wants to be found and so sets aside some broadcast space for a message, 3. We know their decompression algorithm and what frequency band to apply it to.
It’s this last possibility that relates to the shadow biosphere in a philosophical sense. Unless we know how to interpret the signs of such life, we may not be able to distinguish it from the natural background.