One of the interesting subjects that comes up in science fiction is that of silicon-based lifeforms. On Earth, carbon is the backbone of most lifeforms as we know it. Silicon is also in the same column of the periodic table, so it shares some similar properties with carbon. Conceivably, it should then be possible that silicon-based lifeforms to exist in other places in our Universe, right?
Well, maybe, but a closer study of our Earthen materials science knowledge seems to state otherwise. Think about a lot of materials that are made out of carbon, and think about a lot of materials that are made out of silicon. One thing that is definitely agreeable about carbon is that it is a very chemically reactive element: many carbon-based materials can readily burn and combust. Wood, paper, cotton, plastic, wheatpaste, milk glue, charcoal, petroleum, they all burn quite readily and can contribute to the fuel of a wild fire. But, think of silicon-based materials by contrast: glass, ceramic, concrete, sand, water glass. All of these materials evoke the sense of inherently nonflammable construction. The fact is, silicon simply isn’t as reactive of an element as carbon is.
That being said, that does not by any means say that you can’t do chemically interesting things with silicon. Quite the contrary. With the right creative ingenuity, humans have figured out quite a number of interesting things that can be done with silicon-based substances. We’ve figured out how to make silicon-based adhesives, semiconductors, transistors, integrated circuits, photovoltaics, and nowadays the very element itself evokes the sense of the core element of all the brains of our modern smart electronics technologies. The fact that silicon is a relatively non-reactive element makes these technologies all the more interesting, the fact that these constructions are very far displaced from what we know of all other life on Earth, and are therefore immune to biological attacks such as biological viruses.
But, when you really think about this, when you really really think about this, there is something even more interesting going on here. We have successfully figured out how to build intelligent animated, robotic machine forms almost entirely out of nothing but rocks and minerals. Conveniently, the exterior bodies of all modern electronics can be constructed out of aluminum, glass, and ceramics, all of which are rock-derived. Photovoltaic solar panels? Nothing but a highly evolved rock that generates electrical energy. Solid lithium-ion batteries with embedded ceramics? Nothing but a highly evolved rock that stores electrical energy. Electronic motors? Nothing but a highly evolved rock that converts electrical energy into mechanical motion. Integrated circuits? Nothing but a highly evolved rock that can think, see, display images, or do many other of a myriad of complex and intelligent activities.
Now, here’s the really big key to realize. Carbon is not a very abundant element on the Earth’s surface. The total number of lifeforms on the surface of the Earth is practically limited by the available supply of carbon on the Earth. Our rock-based creations, by contrast, suffer no such limit. The limit of their existence is merely but the limit of the available rock supplies on this planet, which are inherently much more abundant than those supplies of carbon on our planet. The machine creations we have developed can easily outnumber us, and for the most part, that’s a good thing: it means that every single human on Earth can easily have a multitude of robots at their disposal to do all their work for them. It means that everyone will be able to live in a smart home of their own, and that nobody will ever have to be homeless or bound to a dumb home. But, it also means that the robots could easily revolt take over the world, and humans wouldn’t pose even the slightest threat to our future robots because they would be so fewer in numbers.
So, yeah, those are some important things to think about. This simple fact has the good, the bad, and the ugly all rolled into it.