[extropy-chat] Most star systems are single

[Amara Graps]

>Amara, as I'm sure you are aware (as should be Spike), the "habitable zone"
>is only a relevant concept for "primitive" life that requires a solvent (e.g.
>water) to allow significantly increased probabilities that simple molecules
>will run into each other and form more complex molecules.

Robert,

I do know that the 'habitable zone' is that based on life as we know it
on earth with water as the basis/solvent. I will be more careful in
using that expression in the future on transhuman/extropy-chat lists,
since the assumptions are usually different than the astrobiology texts!

However, the other issues about M-class stars' variability and
synchronous rotation _could_ be an issue though for the emergence of life,
at least for chemical life (not based on water as a solvent).

btw, Robert and I wrote on the cosmicvariance thread about searching for
life last week, see:

http://cosmicvariance.com/2006/05/24/further-away-from-the-lamp-post/

Amara

-- 

Amara Graps, PhD      www.amara.com
Istituto di Fisica dello Spazio Interplanetario (IFSI), Roma, ITALIA
Associate Research Scientist, Planetary Science Institute, Tucson