Si-Based Life

[Acreator]

< I will be posting this Topic in the Organic Chemistry section as well, it is up to moderators or anyone else to get rid of it in any section. >

 

Alright, I know there are a lot people that believe that Silicon-based life is not possible, and there is science to prove a lot of it. 

However, it is an interesting field and I think we shouldn't discredit it.

While it might be improbable for an organism to evolve to be entirely silicon-based (the planet might have to be 1000 C just to start trying) we have the advantage of computers and molecule visualization programs to let us think them up.

 

Now, my proposition is this, if there is anyone who believes that we could try and design Si-life, I invite you to join my thought process and start thinking of how it could happen.

Anyone who does not believe in it, please don't slam my idea, just give me constructive criticism or slam in such a way that I don't understand (not hard btw!  ).

 

I think we should start with either an autotroph or really basic cell level, in which case, a deep investigation into Archaea and Prokaryotes may be in order.

 

I hope some of you are interested!

[beecee]

"It's Life Jim, but not as you know it".

Spock: Star Trek: 

[Acreator]

"Live long and prosper!" 

[Moontanman]

Silicon or silicone? Silicone based life would have to be hot but silicon life would have to be cold... very cold... Titan has been suggested as a place suitable for silicon life but Venus is closer to what silicone life would require... 

[Acreator]

Silicon based life, but if you be so kind as to explain why silicone life would need extreme heat compared to silicon needing cold.

Sorry if I seem ignorant, I mainly want to learn as much about this as I can, and I want the data on this thread.

 

[Moontanman]

6 minutes ago, Acreator said:

Silicon based life, but if you be so kind as to explain why silicone life would need extreme heat compared to silicon needing cold.

Sorry if I seem ignorant, I mainly want to learn as much about this as I can, and I want the data on this thread.

 

Silicone refers to chains of silicon and oxygen atoms joined in a chain

https://en.wikipedia.org/wiki/Silicone

Silicon in this context refers to chains of silicon atoms arranged like carbon chains. 

https://en.wikipedia.org/wiki/Silanes

[studiot]

Excellent answer, Moontanman, +1

You have been doing your homework.

[Moontanman]

3 hours ago, studiot said:

Excellent answer, Moontanman, +1

You have been doing your homework.

I do try! 

[Sensei]

Plant to grow needs CO₂ and H₂O, which are gases and liquid on the Earth, at current temperatures and pressures.

On the other hand SiO₂ is solid and has extremely high boiling point 2950 C.

 

In your hypothesis about silicon-based life, you should start from searching for silicon compounds. Make a list of them with their properties. Which silicon compound will be food for building silicon-cells by silicon-lifeforms. Which solvent can be used instead of water to dissolve silicon compounds. Which silicon compounds will be playing RNA/DNA role, for storing genetic information.. etc. etc.

 

Edited May 12, 2018 by Sensei

[Acreator]

2 hours ago, Sensei said:

Plant to grow needs CO₂ and H₂O, which are gases and liquid on the Earth, at current temperatures and pressures.

On the other hand SiO₂ is solid and has extremely high boiling point 2950 C.

 

In your hypothesis about silicon-based life, you should start from searching for silicon compounds. Make a list of them with their properties. Which silicon compound will be food for building silicon-cells by silicon-lifeforms. Which solvent can be used instead of water to dissolve silicon compounds. Which silicon compounds will be playing RNA/DNA role, for storing genetic information.. etc. etc.

 

Thanks Sensei, 

I was hoping we could all contribute, but as you say, there are some basics that need to be addressed. 

While a silicon-based life-

form might not have similar functions to us, if we want them to be land-based, gas-breathing, gas-exhaling, liquid-ingesting beings, there has to be some similarities in function.

I was thinking about Silicon Tetrafluoride as an exhalation, as it seems to be the only Si-gas at our temperature, and might still be a gas at the low temperatures needed for the organisms.

With a melting point of -90^oC and a boiling point of -81^oC SiF₄ seems like a decent bet, if we are saying they live in a super cold environment.

However they don't have to exhale silicon. Our process of exhaling carbon seems a large waste of usable materials. They could keep all the silicon they ingest and just get bigger as they age because every molecule would be used to build more, however there might be some waste in any excrement or possibly for other reasons. Who knows!

[Moontanman]

On 5/12/2018 at 9:02 AM, Acreator said:

Thanks Sensei, 

I was hoping we could all contribute, but as you say, there are some basics that need to be addressed. 

While a silicon-based life-

form might not have similar functions to us, if we want them to be land-based, gas-breathing, gas-exhaling, liquid-ingesting beings, there has to be some similarities in function.

I was thinking about Silicon Tetrafluoride as an exhalation, as it seems to be the only Si-gas at our temperature, and might still be a gas at the low temperatures needed for the organisms.

With a melting point of -90^oC and a boiling point of -81^oC SiF₄ seems like a decent bet, if we are saying they live in a super cold environment.

However they don't have to exhale silicon. Our process of exhaling carbon seems a large waste of usable materials. They could keep all the silicon they ingest and just get bigger as they age because every molecule would be used to build more, however there might be some waste in any excrement or possibly for other reasons. Who knows!

Fluorine is so rare the possibility of it being used by biology would severely limit the size of any ecosystem and virtually all the fluorine would end up locked in rocks..  

[StringJunky]

20 minutes ago, Moontanman said:

Fluorine is so rare the possibility of it being used by biology would severely limit the size of any ecosystem and virtually all the fluorine would end up locked in rocks..  

Fluorine has a terrestrial abundance of a third that of carbon. It is the 13th most abundant element on Earth.

http://periodictable.com/Properties/A/CrustAbundance.an.html

[Moontanman]

Just now, StringJunky said:

Fluorine has a terrestrial abundance of a third that of carbon. It is the 13th most abundant element on Earth.

http://periodictable.com/Properties/A/CrustAbundance.an.html

That is interesting, thank you, I was quoting what is said when considering fluorine as a breathing gas, oxygen the gas we breathe, the element used in water as well is number one. For fluorine to work as a replacement for oxygen, which is what is basically being proposed here, the abundance of fluorine would have to be orders of magnitude more common than it is. Fluorine is so reactive that all of it is locked up in minerals which of course would soak up even more enormous quantities of fluorine if it was available.  

[StringJunky]

7 minutes ago, Moontanman said:

That is interesting, thank you, I was quoting what is said when considering fluorine as a breathing gas, oxygen the gas we breathe, the element used in water as well is number one. For fluorine to work as a replacement for oxygen, which is what is basically being proposed here, the abundance of fluorine would have to be orders of magnitude more common than it is. Fluorine is so reactive that all of it is locked up in minerals which of course would soak up even more enormous quantities of fluorine if it was available.  

Yes, it's the most reactive naturally occurring element and likely does not exist in the free form in useful quantities.

[Janus]

On 5/12/2018 at 6:02 AM, Acreator said:

However they don't have to exhale silicon. Our process of exhaling carbon seems a large waste of usable materials. They could keep all the silicon they ingest and just get bigger as they age because every molecule would be used to build more, however there might be some waste in any excrement or possibly for other reasons. Who knows!

The carbon we exhale as CO2 is a waste product of our converting the food we ingest into energy the body uses to run its metabolism.  It is, in effect, the "ashes" from the "fire" that runs our body.   To use this to build tissue would require energy.   In order for the organism to use all the food it ingests for tissue building, it would have to have some other source of energy for running its metabolism ( plants do this by using the energy in sunlight) .

For an organism to exhale Silicon Tetra-fluoride would require a metabolism in which this is the low-energy waste product, and this metabolism would need to be able to operate in the temperature range in which it is a gas. 

The challenges of Silicon life is that you need to be able to build complex molecules that are both flexible and reactive enough to run a metabolism yet robust enough to hold together at the energy levels needed to run that metabolism.  Carbon seems to be particularly suited to this. Silicon is not quite as suited. 

[studiot]

Until 2000 it was 'believed' that lifer could not exist and develop at the bottom of the deep oceans.

https://science.nasa.gov/science-news/science-at-nasa/2001/ast13apr_1

http://www.ucl.ac.uk/mathematical-physical-sciences/maps-news-publication/maps1526

https://www.chemistryworld.com/feature/hydrothermal-vents-and-the-origins-of-life/3007088.article

 

The hydrothermal vents and associated lifeforms were discovered.

Although not silicon based they have quite a different biochemistry form the rest of life on Earth.

For instance Hydrogen Sulphide plays an important part.

 

You might like to look at these articles for some inspiration and cast your net a bit wider.

 

Edited May 14, 2018 by studiot

[YaDinghus]

On 5/11/2018 at 10:21 PM, Acreator said:

< I will be posting this Topic in the Organic Chemistry section as well, it is up to moderators or anyone else to get rid of it in any section. >

 

Alright, I know there are a lot people that believe that Silicon-based life is not possible, and there is science to prove a lot of it. 

However, it is an interesting field and I think we shouldn't discredit it.

While it might be improbable for an organism to evolve to be entirely silicon-based (the planet might have to be 1000 C just to start trying) we have the advantage of computers and molecule visualization programs to let us think them up.

 

Now, my proposition is this, if there is anyone who believes that we could try and design Si-life, I invite you to join my thought process and start thinking of how it could happen.

Anyone who does not believe in it, please don't slam my idea, just give me constructive criticism or slam in such a way that I don't understand (not hard btw!  ).

 

I think we should start with either an autotroph or really basic cell level, in which case, a deep investigation into Archaea and Prokaryotes may be in order.

 

I hope some of you are interested!

Something similar to water can still work as a solvent. Bear in mind that it doesn't have to contain Si to be a solvent, after all, H2O has no C either. 

Similar to water in this context would mean that it is amphoteric and spontaneously bounces around charged particles in its liquid state. Now I'm being deliberately unspecific regarding the structure of the charged particles. Electrons and protons are what we're looking at in water-solvent redox and acid/base reactions, which are literally vital to life on earth. I would imagine that if Si-based life is possible this should be the case as well. It might however also be small molecule ions transporting the charges in the solvent. However I don't know quite enough about chemistry to truly fathom such a solvent and the small molecule ions involved.

[Moontanman]

50 minutes ago, YaDinghus said:

Something similar to water can still work as a solvent. Bear in mind that it doesn't have to contain Si to be a solvent, after all, H2O has no C either. 

Similar to water in this context would mean that it is amphoteric and spontaneously bounces around charged particles in its liquid state. Now I'm being deliberately unspecific regarding the structure of the charged particles. Electrons and protons are what we're looking at in water-solvent redox and acid/base reactions, which are literally vital to life on earth. I would imagine that if Si-based life is possible this should be the case as well. It might however also be small molecule ions transporting the charges in the solvent. However I don't know quite enough about chemistry to truly fathom such a solvent and the small molecule ions involved.

How about sulfuric acid as a solvent? 

[CharonY]

On 5/14/2018 at 3:44 AM, studiot said:

Until 2000 it was 'believed' that lifer could not exist and develop at the bottom of the deep oceans.

https://science.nasa.gov/science-news/science-at-nasa/2001/ast13apr_1

http://www.ucl.ac.uk/mathematical-physical-sciences/maps-news-publication/maps1526

https://www.chemistryworld.com/feature/hydrothermal-vents-and-the-origins-of-life/3007088.article

 

The hydrothermal vents and associated lifeforms were discovered.

Although not silicon based they have quite a different biochemistry form the rest of life on Earth.

For instance Hydrogen Sulphide plays an important part.

 

You might like to look at these articles for some inspiration and cast your net a bit wider.

 

That does not sound right. I am pretty sure that as undergrads we had discussed chemolithotrophic organisms quite extensively (and that was quite before 2000, to my dismay). In fact, I am pretty sure that some extensive studies on microbial mats near deep-sea vents were published sometime in the 80s and we reviewed them as part of a seminar, I believe. There may be details that have emerged from recent studies, but they certainly were not discovered only around 2000.

[YaDinghus]

7 hours ago, Moontanman said:

How about sulfuric acid as a solvent? 

How exactly would that work? To my knowledge, H2SO4 is a very strong acid; would it accept a proton to form H3SO4+? I find that unlikely. Or do you mean H2SO3? It's still pretty strong, also it's not as eager to oxidize everything around it. Still having a hard time imaginibg H3SO3+

[Moontanman]

12 hours ago, YaDinghus said:

How exactly would that work? To my knowledge, H2SO4 is a very strong acid; would it accept a proton to form H3SO4+? I find that unlikely. Or do you mean H2SO3? It's still pretty strong, also it's not as eager to oxidize everything around it. Still having a hard time imaginibg H3SO3+

H2SO4 at high temps.

https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry

Quote

Sulfuric acid in liquid form is strongly polar. It remains liquid at higher temperatures than water, its liquid range being 10 °C to 337 °C at a pressure of 1 atm, although above 300 °C it will slowly decompose. Sulfuric acid is known to be abundant in the clouds of Venus, in the form of aerosol droplets. In a biochemistry that used sulfuric acid as a solvent, the alkene group (C=C), with two carbon atoms joined by a double bond, could function analogously to the carbonyl group (C=O) in water-based biochemistry.[35]

Lot of possibilities but I take them all with a grain of salt. Water is superior in nearly every way at temps we are familiar but chemistry would seem to allow other possibilities at other temps but the question is do these other temps have chemistry to support them... The best replacement for carbon might be boron or boron nitrogen pairs but boron suffers from a lack of abundance in the universe...  

[YaDinghus]

15 hours ago, Moontanman said:

H2SO4 at high temps.

https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry

Lot of possibilities but I take them all with a grain of salt. Water is superior in nearly every way at temps we are familiar but chemistry would seem to allow other possibilities at other temps but the question is do these other temps have chemistry to support them... The best replacement for carbon might be boron or boron nitrogen pairs but boron suffers from a lack of abundance in the universe...  

I'd take a boulder of salt... I guess H2SO4 would dissolve enough other materials to form a stabile solvent with a HSO4- - H2SO4 balance or even an SO4(2-) - HSO4- balance. Then it's still a very powerful oxidizer, but that's what extremophiles at hydrothermal vents like about it, so I guess it could serve the same purpouse for life on other planets. So conceivably there could be an extraterrestrial ocean wjth a balance of HSO4-, SO4(2-), HSO3- and SO3(2-) facilitated by a plethora of dissolved Kations, which alien, perhaps even Si-based life, could thrive in.

Another question could be: could life be Si-C hybrid based? Why would Si-bases life not use Carbon, which is more abundant and chemically useful...

[Moontanman]

9 hours ago, YaDinghus said:

I'd take a boulder of salt... I guess H2SO4 would dissolve enough other materials to form a stabile solvent with a HSO4- - H2SO4 balance or even an SO4(2-) - HSO4- balance. Then it's still a very powerful oxidizer, but that's what extremophiles at hydrothermal vents like about it, so I guess it could serve the same purpouse for life on other planets. So conceivably there could be an extraterrestrial ocean wjth a balance of HSO4-, SO4(2-), HSO3- and SO3(2-) facilitated by a plethora of dissolved Kations, which alien, perhaps even Si-based life, could thrive in.

Another question could be: could life be Si-C hybrid based? Why would Si-bases life not use Carbon, which is more abundant and chemically useful...

 

Isaac Asimov wrote about the possibility of Silicone chains with Carbon linked to the Silicon and the Silicon attached to each other via Oxygen atoms. The chains would be very stable at our temps, too stable, but at high temps they might just be the ticket. Sulfuric acid would be stable at some of those temps and pressures but Azimov seemed to think that liquid silicones might be a better solvent for silicone life... 

Thomas Gold proposed silicon life on earth deep underground at the very high temps and pressures that exist there. In fact he proposed that Gold deposits connected to carbon deposits (called carbon leaders by prospectors) might be left by life that uses gold as chemical energy source. Deposits of  Quartz and Gold, according to Gold, could be the result of silicone life that used gold as a source of energy as well... 

Edited June 12, 2018 by Moontanman

[YaDinghus]

5 minutes ago, Moontanman said:

 

Isaac Asimov wrote about the possibility of Silicone chains with Carbon linked to the Silicon and the Silicon attached to each other via Oxygen atoms. The chains would be very stable at our temps, too stable, but at high temps they might just be the ticket. Sulfuric acid would be stable at some of those temps and pressures but Azimov seemed to think that liquid silicones might be a better solvent for silicone life... 

Thomas Gold proposed silicon life on earth deep underground at the very high temps and pressures that exist there. In fact he proposed that Gold deposits connected to carbon deposits (called carbon leaders by prospectors) might be left by life that uses gold as chemical energy source. Deposits of  Quartz and Gold, according to Gold, could be the result of silicone life that used gold as a source of energy as well... 

Why look for alien life on exoplanets if it may be at our doorstep...

[Moontanman]

1 minute ago, YaDinghus said:

Why look for alien life on exoplanets if it may be at our doorstep...

Well if it was native to the Earth it wouldn't be alien... but still an exciting discovery. Very little effort has been put into checking for a deep super hot biosphere of silicon or carbon. Closer to the surface the idea of checking the Earth for shadow biospheres is a possibility that should be addressed as well.... 

https://en.wikipedia.org/wiki/Shadow_biosphere

Quote

A shadow biosphere is a hypothetical microbial biosphere of Earth that uses radically different biochemical and molecular processes than currently known life. Although life on Earth is relatively well-studied, the shadow biosphere may still remain unnoticed because the exploration of the microbial world targets primarily the biochemistry of the macro-organisms. The term was coined by Carol Cleland and Shelley Copley in 2005.[1]