SILICON-BASED LIVING BEINGS
The stories of science fiction on which it is suggested the existence of living beings constructed of Silicon instead of Carbon have proliferated in the last decades, for example, on arguments of many movies and TV series.
The idea is not new, therefore it was originated in the year of 1891 (!), when Julius Sheiner wrote about the possibility of extraterrestrial life built with Silicon. Since then, many dreamers have dreamed up around living beings made of strange materials. Even, articles have been published on scientific magazines about the possibilities of Silicon as an alternative to Carbon in building extraterrestrial beings. The question is if it will be possible the existence of Silicon-made living organisms in our Universe.
Truly (and I make an apology for those that have taken it so sincerely), more often than not, I laugh on siliconists’ arguments:
1. In order to be Silicon-made organisms, we would have to eat other organisms made with Silicon. Now, think on how and what we would oust those substances from our body... Unless we were 100%-efficient thermodynamic systems -something impossible in this Universe- it would be extremely hard for us the passage of “those crystals” through “those soft membranes”.
2. If we oxidize a Silicon molecule, the result would be Silicon Dioxide (quartz!). How would we remove the crystals of Silicon Dioxide molecules from our cells? (See good pics of SiO2).
3. Only the molecules constructed with carbon are able to experience the interactions between charged particles through photons to impel the energy from one to other ORGANIC MOLECULES, that is, Carbon-based molecules, to give autonomy to the transference of the cells’ internal energy. Thus, it is that the membranes built with Silicon-based molecules could not, under no circumstances, to experience the Proton Motile Force nor, consequently, life.
4. Now, consider the ineludible problem of the diversity of proteins… We need proteins for each and all processes performed by our body. If there were not proteins, there were not thoughts, there were not reproduction, there were not motility, there were not respiration, there were not photosynthesis, there were not RNA and DNA, there were not DNA replication, there were not… living beings. Do you know a Silicon-based protein? It’s so simple.
5. Have you considered the fact that there is not too much variety of compounds made of Silicon in the observed Universe? In a very conventional model, the evolution would need more than ten trillion spot modifications in DNA molecules to produce the current biodiversity (I think on this calculation remains very short). There is not a single molecule of Silicon that can be compared with DNA or RNA.
6. The first argument of siliconists is that, like Carbon, Silicon has four valence electrons, connoting that Silicon can link to four other atoms. However, Silicon has eight more electrons than Carbon (two in the first level of energy, eight in the second level and four in the third level), which makes Silicon to form very unstable complex compounds. Besides, the silicon-based compounds similar to the Carbon-based compounds always have been synthesized artificially or forced to synthesis and are very unstable compounds. There is not a spontaneous synthesis of those compounds in nature.
7. The main argument of siliconists is that Silicon resides next to Carbon on the periodic table of chemical elements. Boron, Nitrogen, Phosphorus and Aluminum are right next Carbon on the periodic table, and no one has thought on life based on any of those elements. The sticky situation here is that Silicon is a metalloid, while Carbon is a non-metal. There is not a viable comparison between the chemical properties of Carbon and Silicon.
8. Another argument of the siliconists is that the Silicon can form a compound that acts like "a kind of semi-permeable membrane" very similar to the membranes formed by organic compounds because it permits the passage of some substances and prevent the passage of other substances. What the siliconists have forgotten is that there are more than a few types of membranes built with carbonaceos compounds: A bacterial cell membrane is not equal to the cyanobacteria cell membrane, or to a vegetal cell membrane, or to an animal cell membrane. The plasmatic membrane is not equal to the nuclear membrane, to the chloroplasts’ membranes or the mitochondrial membranes. Siliconists also have forgotten that the life is a state of energy that is pronounced on the Proton Motile Force that only can be experienced by membranes made with Carbon. Remember the paraphernalia of substances necessary for the conservation of this state of energy called life. Silicon does not enclose the physicochemical property, or the versatility and flexibility of Carbon to form, spontaneously, this diversity of well-stable products.
Nature tends to trail the most spontaneous way, although it would not be the simplest. If the Silicon-based living beings had been viable to happen in the Universe, the Earth would have them. It’s so straightforward. The proponents of the Silicon-based life must solve numerous puzzles before saying absurdities.
The greatest absurdity of this... hallucination… is that if there were living beings synthesized with Silicon, their processes would be so different from the processes performed by the living beings made with Carbon that there were not a way to know about their existence, nor using the best of our methods.
Do you want to know an animal made of Silicon? Bob Sponge is an animal made of Silicon. No, do not laugh on it. If Bob Sponge copes with an animal group called Phylum Porifera (sponges), and to the order of Demospongia, then Bob’s skeleton would be constructed of many small thorns called spicules. Many sponges have spicules made of Silicon. However, the real-living cells of Bob Sponge are made of Carbon and if Bob belonged to the genus Oscarella, then there were not a single metabolic process where Bob must to use Silicon to be alive; what is more, Bob would not need a skeleton.
This of the siliconists sounds like Vitalism. The vitalists think that life is something that can be transferred or instilled in any class of material. Unlike vitalists, we know that life is only a state of the energy that only can be experienced by a specific molecular array and that life cannot be transferred, instilled or infused. Yes, life can be experienced anywhere in the Universe where the conditions are propitious for it; nevertheless, not any class of molecular array can experience life.
On these facts, things are exceptionally specific. Siliconists have wasted the physicochemical laws! AND DO NOT ARGUE THAT THE GREAT IDEAS ALWAYS HAVE GOT AGAINST THE LAWS! Yes, ideas against the social human laws, but the physicochemical laws of the Universe are unbreakable, ok? YOU ARE ALLOWED TO LAUGH ON ME IF SOME DAY SCIENTISTS FIND SILICON-BASED LIVING FORMS. FOR NOW, I LAUGH ON SILICONISTS...