Thank you for this article Steve because I love articles that say something is not possible. Countless examples abound throughout history calling certain technologies impossible that we take for granted today. Here are scientifically grounded counterarguments to the article's claim that silicon-based life is impossible, addressing key points while maintaining academic rigor:
1. **Solvent Flexibility Beyond Water**
- **Counterargument**: The article assumes water is the *only* viable solvent for life. However:
- **Non-aqueous solvents** like liquid methane (Titan) or sulfuric acid (Venus) could host silicon biochemistry. Silicon compounds show greater stability in hydrophobic environments.
- **Counterargument**: While silicon rarely forms double bonds, it exhibits *unique* bonding modes absent in carbon:
- **Pentacoordination**: Silicon’s ability to form 5-6 bonds (e.g., silicates) enables complex mineral frameworks. Zeolites demonstrate catalytic complexity rivaling enzymes.
- **Silanes vs. Alkanes**: Si-Si bonds are weaker but more flexible. Under high pressure (subsurface oceans) or reducing atmospheres, polysilanes could form stable biopolymers.
3. **Thermodynamic & Environmental Niches**
- **Counterargument**: Silicon’s high heat of formation isn’t prohibitive in energy-rich environments:
- **Hydrothermal vents**: Reducing conditions (H₂-rich, low O₂) prevent SiO₂ formation. Experiments show silanes forming under simulated vent conditions.
- **High-temperature stability**: Si-O bonds (e.g., in silica) endure extreme heat (>400°C), potentially supporting life in magma chambers or exoplanets like K2-141b.
4. **Functional Biochemistry Analogues**
- **Counterargument**: Silicon *does* achieve functional diversity through alternatives:
As noted by biochemist William Bains (MIT), *"Silicon life isn't impossible—it's constrained to environments we're only beginning to explore."* The article’s dismissal overlooks astrochemical complexity and alternative evolutionary pathways.
Wow — thanks Dr. K; that’s one of the most thoughtful and comprehensive responses I’ve ever gotten to a reply. And I appreciate that it wasn’t in a “pissing contest” tone, but in a spirit of the search for truth, in which we’re united.
When I get a little chunk of time, I’ll dig into it deeper, and hopefully maybe get a response from Dr. Rana, who wrote the piece. All the best to you 🤙.
<3
Some great thoughts in your post, Dr. K, but I just wanted to point out that silicon-based life forms are basically a pipe dream. Silicon just doesn't have the many attributes of carbon necessary for it: https://reasons.org/explore/blogs/the-cells-design/could-life-be-based-on-silicon
Thank you for this article Steve because I love articles that say something is not possible. Countless examples abound throughout history calling certain technologies impossible that we take for granted today. Here are scientifically grounded counterarguments to the article's claim that silicon-based life is impossible, addressing key points while maintaining academic rigor:
1. **Solvent Flexibility Beyond Water**
- **Counterargument**: The article assumes water is the *only* viable solvent for life. However:
- **Non-aqueous solvents** like liquid methane (Titan) or sulfuric acid (Venus) could host silicon biochemistry. Silicon compounds show greater stability in hydrophobic environments.
- **Cryogenic solvents**: At low temperatures (e.g., Titan’s -180°C), silicon’s reactivity decreases, potentially enabling stable Si-Si chains. NASA’s Huygens probe confirmed complex organics in methane lakes, suggesting solvent versatility.
2. **Silicon Bonding Diversity**
- **Counterargument**: While silicon rarely forms double bonds, it exhibits *unique* bonding modes absent in carbon:
- **Pentacoordination**: Silicon’s ability to form 5-6 bonds (e.g., silicates) enables complex mineral frameworks. Zeolites demonstrate catalytic complexity rivaling enzymes.
- **Silanes vs. Alkanes**: Si-Si bonds are weaker but more flexible. Under high pressure (subsurface oceans) or reducing atmospheres, polysilanes could form stable biopolymers.
3. **Thermodynamic & Environmental Niches**
- **Counterargument**: Silicon’s high heat of formation isn’t prohibitive in energy-rich environments:
- **Hydrothermal vents**: Reducing conditions (H₂-rich, low O₂) prevent SiO₂ formation. Experiments show silanes forming under simulated vent conditions.
- **High-temperature stability**: Si-O bonds (e.g., in silica) endure extreme heat (>400°C), potentially supporting life in magma chambers or exoplanets like K2-141b.
4. **Functional Biochemistry Analogues**
- **Counterargument**: Silicon *does* achieve functional diversity through alternatives:
| Carbon Function | Silicon Analog |
|-----------------|----------------|
| Lipids (membranes) | Silanes forming micelles in liquid methane |
| DNA backbone | Silicate polymers (observed in lab-synthesized Si-O-Si chains) |
| Enzymes | Clay minerals (e.g., montmorillonite) catalyze polymerization |
5. **Astrobiological Feasibility**
- **Counterargument**: The article dismisses aprotic solvents too hastily:
- **Titan’s methane lakes**: Show solubility of complex organics. Silanes could form soluble, structured macromolecules here.
- **Directed evolution**: On geological timescales, selection could optimize silicon biochemistry (e.g., Si-O-Si "silicon proteins" in silica-rich systems).
Rebuttal to Key Objections
- **"Si-O bonds dominate"**: In oxygen-poor environments (e.g., subsurface oceans of Enceladus), silicon could form Si-H or Si-CH₃ bonds instead.
- **"No double bonds"**: Silenes (Si=C) *do* exist transiently and could be stabilized in matrices or by ligands.
- **"Weak Si-Si bonds"**: At cryogenic temperatures, bond stability increases significantly (e.g., polysilanes in Titan’s atmosphere).
Conclusion
While carbon-based life dominates Earth, silicon-based life remains plausible in specific niches:
- **Reducing environments** (e.g., high-pressure subduction zones)
- **Cryogenic hydrocarbon solvents** (Titan-like worlds)
- **Mineral-catalyzed systems** (silicate-rich hydrothermal vents)
As noted by biochemist William Bains (MIT), *"Silicon life isn't impossible—it's constrained to environments we're only beginning to explore."* The article’s dismissal overlooks astrochemical complexity and alternative evolutionary pathways.
Wow — thanks Dr. K; that’s one of the most thoughtful and comprehensive responses I’ve ever gotten to a reply. And I appreciate that it wasn’t in a “pissing contest” tone, but in a spirit of the search for truth, in which we’re united.
When I get a little chunk of time, I’ll dig into it deeper, and hopefully maybe get a response from Dr. Rana, who wrote the piece. All the best to you 🤙.