Star Trek: The Original Series

I had forgotten The Devil in the Dark.  The worst episodes were badly thought out commentsries on social problems of tge 1960s such as This Side of Paradise.  Some of the best science fiction such as The Devil in thr Dark did not survive advancing science.  The Horta was a silicon-based life form living deep with a planet with human miners.  While it easy to sympathize with the Horta's cries for its unborn children, the notion of life where silicon took the place of carbon did not long survive Linus Pauling's work on chemical bonding.  

Carbon's unique bonding capabilities are dependent on the availability of both p and s electron shells in a way that silicon cannot.  This is why there are very long alkane chain molecules (methane, methane, propane, butane) but not much past silane (SiH4).