Having silicon-based life forms look like rocks is, chemically speaking, roughly equivalent to expecting carbon-based life (e.g., us) to look as if it were made out of graphite and/or diamond. The association of silicon with rocks on Earth leads to depictions of aliens that are distinctly rock-like, such as this fellow from the Doctor Who story ' The Hand of Fear.'Įven worse misunderstandings of what silicon-based life would mean occur in another Doctor Who serial, ' The Stones of Blood' (where the supposedly silicon-based organisms are dependent on carbon-based amino acids) or The X-Files episode ' Firewalker,' again with silicon-based life somehow involving carbon-based chemistry or any of numerous other examples. In science fiction, however, silicon-based life is often portrayed quite differently. However, it is by no means inconceivable that silicon-based life could exist in the universe. It is about seven times less abundant than carbon, but more importantly, the silicon atom is larger (2.1 Å, versus 1.7 Å), which makes the bonds it forms longer, and thus weaker, and thus easier to disrupt. However, in practice, silicon has disadvantages. Silicon behaves similarly, since it lies directly below carbon on the periodic table. The feature that makes carbon powerful as a base is that it tends to form four covalent bonds. With the discovery (in the early twentieth century) that molecular biology is based on the interactions of carbon-chain molecules, it was naturally suggested that extraterrestrial life would probably also be carbon based, but it might be based on silicon instead-silicon being the most similar element to carbon, chemically.

Formz sci fi