[extropy-chat] Scientists Confront 'Weird Life' on Other Worlds

[Robert J. Bradbury]

On Thu, 13 May 2004, Mike Lorrey wrote:

> And carbon can form what? 8 or 12 bonds? That's a good reason right
> there: you get more diversity in possible bonds, thus a more complex
> chemistry capable of interacting in expnentially greater numbers of
> ways.

I don't think so -- carbon forms a maximum of 4 bonds.  In general
atoms in the same column of the periodic table have similar bonding
patterns but with higher molecular weights things become increasingly
complex.

But it gets even more complex depending upon the nature of whether the
atoms involved prefer ionic or covalent bonds.

> Almost ain't quite the same as the same, is it?

True -- but C-C and Si-Si bonds are within 1/10th of 1% of each other
which is significantly closer than many other bond combinations.

> Lets also look at possible catalysts for the two chemistries. Carbons
> greater number of bonds means greater number of possible catalysts.

I think something more complex is going on.  You can get carbon
behaving in an inorganic way in things like calcium carbonate
(limestone, sea shells, etc.) and at the same time get it behaving
in an organic way, e.g. amino acids, fatty acids, etc.  But for
some reason silicon seems to have a much stronger preference for
inorganic bonding modes.  It gets even stranger when you consider
that Germanium, Tin and Lead should have similar bonding properties.

Robert