But we know what happens at temperatures and pressures -> things break down and become less interesting.
SiO2 is quartz. At a T high enough to melt it (never mind a vaporize it to have a cycle analogous to the C-CO2 cycle), Si chemistry breaks down.
Carbon chemistry is unique because it occupies a unique chemical niche. It makes interesting and stable compounds at T high enough to have appreciable rates, but low enough that things don't just rip themselves apart.
Not to mention at T high enough to vaporize SiO2 you won't have water, which is a pretty nifty solvent for life to have.
Think of it this way. We know the bond strength of the various chemical bondings. We cant get around that and each type of bonding is responsible for several unique and fundamental moiety in biological replication.
SiO2 is quartz. At a T high enough to melt it (never mind a vaporize it to have a cycle analogous to the C-CO2 cycle), Si chemistry breaks down.
Carbon chemistry is unique because it occupies a unique chemical niche. It makes interesting and stable compounds at T high enough to have appreciable rates, but low enough that things don't just rip themselves apart.
Not to mention at T high enough to vaporize SiO2 you won't have water, which is a pretty nifty solvent for life to have.
Think of it this way. We know the bond strength of the various chemical bondings. We cant get around that and each type of bonding is responsible for several unique and fundamental moiety in biological replication.