6 ms·

"non-carbon based life" I guess isn't silicon the only other that bonds four ways? Not a chemist but I feel that 4 bonds are a big thing.

teucris 7y ago
I had a debate about this with a friend - is there a chemical cycle using silicon that could work like respiration does for organic life? Silicon dioxide is, well, glass...
- p1necone 7y ago
  Are you referring to it being a solid? Silicon dioxide would be a gas at some temperature - likewise CO2 is solid below -78.5c. Extraterrestrial life doesn't have to be anywhere near the same temperatures as us. Also I don't see why you couldn't have an organism that "breathes" solid material.
  - m1el 7y ago
    I researched this topic for a while, and I came to conclusion that Si-based life is nearly impossible for several reasons. > Silicon dioxide melting point: 1710 °C No complex chemistry can survive these temperatures. SiO2 is only soluble in HCl and HF, which are very reactive, so no solubility either. > Also I don't see why you couldn't have an organism that "breathes" solid material. All of known biological chemistry relies on some sort of solubility for reagents. I don't think there's any known organism that can get rid of solid waste from the entire volume of the organism.
    - ars 7y ago
      You could react silicon with fluoride instead of oxygen. Silicon tetrafluoride melts at −90 °C (and boils at -86). You can also have chlorine as your oxidizer and make Silicon tetrachloride which melts at −68.74 °C and boils at 57.65 °C, that temperature range is perfect. What else will change by having a chlorine instead of oxygen atmosphere?
- otikik 7y ago
  Is breathing a requirement for "life"?
_Microft 7y ago
This might be interesting: https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Non-carbon-based_biochemistries https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemi...
mannykannot 7y ago
I don't think it is just the valency but also that the strength of the bonds it forms with many other elements fall into a 'goldilocks' range. Between them, carbon and water have a bunch of unique properties. AFAIK, its hard to come up with any other suite of materials offering the same prospects for complexity, at any temperature.

teucris 7y ago

I had a debate about this with a friend - is there a chemical cycle using silicon that could work like respiration does for organic life? Silicon dioxide is, well, glass...

p1necone 7y ago
Are you referring to it being a solid? Silicon dioxide would be a gas at some temperature - likewise CO2 is solid below -78.5c. Extraterrestrial life doesn't have to be anywhere near the same temperatures as us. Also I don't see why you couldn't have an organism that "breathes" solid material.
- m1el 7y ago
  I researched this topic for a while, and I came to conclusion that Si-based life is nearly impossible for several reasons. > Silicon dioxide melting point: 1710 °C No complex chemistry can survive these temperatures. SiO2 is only soluble in HCl and HF, which are very reactive, so no solubility either. > Also I don't see why you couldn't have an organism that "breathes" solid material. All of known biological chemistry relies on some sort of solubility for reagents. I don't think there's any known organism that can get rid of solid waste from the entire volume of the organism.
  - ars 7y ago
    You could react silicon with fluoride instead of oxygen. Silicon tetrafluoride melts at −90 °C (and boils at -86). You can also have chlorine as your oxidizer and make Silicon tetrachloride which melts at −68.74 °C and boils at 57.65 °C, that temperature range is perfect. What else will change by having a chlorine instead of oxygen atmosphere?
otikik 7y ago
Is breathing a requirement for "life"?

_Microft 7y ago

This might be interesting: https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Non-carbon-based_biochemistries https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemi...

mannykannot 7y ago

I don't think it is just the valency but also that the strength of the bonds it forms with many other elements fall into a 'goldilocks' range. Between them, carbon and water have a bunch of unique properties. AFAIK, its hard to come up with any other suite of materials offering the same prospects for complexity, at any temperature.