- difference in bond angles, where silicon prefers to bond with oxygen than itself, so you don't get long complex chains like with hydrocarbons
- difference in energy to bond, which carbon does with less energy
- difference in solubility, where carbon doesn't dissolve immediately in water (the universal solvent) but silica (sand, 1 silicon and 2 oxygen) does instantly, requiring a different solvent for silicon based life
P.s. cool that our names are so close.
Well, I guess theoretically, you could have chemical pools on an exoplanet shocked by lightning which luckily grow processor boards or simple robots, which collect the borders like a hermit crab shells, until they reach sentience and start building better versions of themselves.
But generally, it seems like most exolife would really be robotic or technological ruins, different types of probes etc. The economics of a generation ship vs. a probe or even a ship which would then clone Earth based life on another planet implies a lot of probes and very few humans around, or humans with limited connection to Earth (unless we develop FTL travel.) But even with FTL drives, AI models are already more capable than humans at many tasks and far quicker to "raise".
Perhaps it works out differently for hiveminds, but I believe most species will die out (or evolve!) before their robots die out. And you may very well never interact with the living specimens, with AI long since surpassing them, or acting as a defense layer for them.
