Paper: On the Potential of Silicon as a Building Block for Life
What would extraterrestrial life be like? Would it be similar to life on earth, or could it be very different? Some have claimed that silicon could be the basis for life on other planets instead of the carbon based life found on Earth. Perhaps there are creatures on other planets that are made of silicon and water or perhaps silicon and sulfuric acid, instead of carbon and water. How would they be similar or different than carbon based life? This has been a common theme in science fiction literature.
A paper was published by the journal Life about a year ago by three researchers at MIT on the possibility of silicon as a basis for life. It is available online in full here:
On the Potential of Silicon as a Building Block for Life
In the Abstract the authors note, “the basis for the plausibility of silicon-based life has never been systematically addressed nor objectively reviewed.” They claim here to provide a “comprehensive assessment of the possibility of silicon-based biochemistry.”
They address the central issue of “whether or not silicon chemistry meets the requirements for chemical diversity and reactivity as compared to carbon” and thus would work as a chemical basis for living organisms. To examine this they “explore silicon’s chemical complexity in diverse solvents found in planetary environments, including water, cryosolvents, and sulfuric acid.” They found that water, the essential solvent for carbon based life does not work well as a solvent for silicon. Cryosolvents also don’t work. “Surprisingly” though, sulfuric acid actually worked better.
However, they conclude that,
In no environment is a life based primarily around silicon chemistry a plausible option.
They conclude that life based “primarily” on silicon is not chemically “plausible.” That’s a downer for those hoping for more possibilities for the origin and evolution of life in the universe besides carbon-based life forms. Life based primarily on silicon doesn’t seem possible based on this study’s analysis. Certainly not complex life. That is the bottom line takeaway from the paper.
I’m no chemist, but I’ve always had a hard time understanding why others have thought silicon based life was possible, so the findings didn’t surprise me. So unless and until further research indicates otherwise, this looks like a dead horse.
Silicon could be used in carbon based life, but that may be it for silicon in living organisms:
Silicon-Based Life May Be More Than Just Science Fiction Scientists are showing that nature can evolve to incorporate silicon into carbon-based molecules — the building blocks of life on Earth.
A popular level article on this paper is:
Silicon-Based Life, That Staple of Science Fiction, May Not Be Likely After All Silicon could still be important for the beginning and end of organic life, however. Air & Space.
What Da Math’s YouTube channel’s comments on this paper is here: