What Silicon-Based Life Might Be Like 92
Nancy_A writes "While the world as we know it runs on carbon, science fiction's long flirtation with silicon-based life has spawned a familiar catchphrase: 'It's life, but not as we know it.' Although non-carbon based life is a very long shot, this Q&A with one of the U.S.'s top astrochemists — Max Bernstein, the Research Lead of the Science Mission Directorate at NASA headquarters in Washington,D.C. — discusses what silicon life might be like."
Easy (Score:5, Funny)
Re:Easy (Score:5, Informative)
For those who don't get the reference: http://en.wikipedia.org/wiki/Horta_(Star_Trek) [wikipedia.org]
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D'oh! I didn't RTEFA or I would have seen that it referenced the Horta (hangs head in shame)
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What, no mention of "Home Soil" [wikipedia.org]", you insensitive ugly bags of mostly water?
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Do they ever mention it being silicon-based?
It was crystalline and of unmentioned metals, but concerning the topic of this thread, and since silicon is a metalloid, the principle is too similar to dismiss.
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And they'll also have a tenuous grasp of English grammar, at best.
Re:Easy (Score:5, Funny)
I'm a doctor, not a bricklayer!
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Yea,straight out of Star Trek TOS(Devil In The Dark) The Horta was such a creature.If you follow the timeline placed by the books,1 served aboard the Enterprise as an assistant science officer.He could munch a rock sample and give you a readout of what it was made of,like a gourmet describing a good meal..
Sci-fi aside,isn't there a deep water crab from the Pacific that is silicon based?(the blue crab).I remember reading about this odd critter quite a few years ago.
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*Theoretical shadow biospheres notwithstanding.
Re:Easy (Score:5, Insightful)
They used to say nothing could survive in the vacuum of space, the bottom of the ocean, in geysers, highly acidic conditions and so many other places. If they knew about the oceanic geothermal vents (like the black smokers) back then, they'd have sworn they would be lifeless.
Now of course, we have the entire category of Extremophiles that live in those very places and conditions.
Additionally, we have lifeforms that have copper based blood instead of iron, ones that respire sulfur instead oxygen, and diatoms build their skeletons/shells/cell walls out of silica. And now they may have found one that exchanges its phospates for deadly arsenic and lives.
All in all, there are significant portions of life on this world that was considered science fiction several decades ago. Does that mean it's possible that life in other parts of the universe can be very different than ours? Sort of. It means that our understanding of what is necessary for life is incomplete due to our exposure to only our own type of biology. There may be very strange biochemistry out there, but most of it that we might recognize as life will probably be similar to ours. (That's the biochemistry, not the form, or if intelligent, culture.)
Re:Easy (Score:5, Interesting)
What's funny about attempts to visualize other types of life forms is, we tend to visualize those life forms in our own environmental terms. That is, we tend to assume some basic atmospheric conditions, pressure ranges, and temperature ranges. We "assume" certain basic conditions that resemble our own conditions.
Silicone? How about we break the cycle by trying to visualize silicone under hundreds of thousands of tons of pressure, and thousands of degrees, with and atmosphere of ammonia? Or, alternatively, in a vacuum at tens of thousands of degrees? Partial pressure atmospheres at near 0 degrees kelvin?
Of course, the question arises then, how and why are mankind interacting with such creatures under such conditions?
Of course, I was enamored with the idea of "living rock" as I child. Some story I read mentioned it, and I had the idea that some rock was really alive. Of course, it isn't - or IS IT?!?!? Nothing says that we are smart enough to recognize alien life when we see it. Geologic time and man's time are so different, that we might not even recognize that a rock actually breathes, or moves, or reproduces. Again, let's step outside our own familiar conditions. Assuming that time might be entirely different for some other life form in conditions that are inimical to us, why would we hang around long enough to collect the data necessary to determine that this or that rock really is alive?
I certainly don't have any answers about the existence of life outside our own experience. But, it amuses me to see the almost idiotic assumptions that people make when considering and debating the possibility. “It’s life, but not as we know it” How about the possibility that a face to face meeting with another life form might be fatal to one or both of the participants in the meeting? His environment is a poisonous atmosphere (to me) and my own body radiating heat might be fatal to him!
Actually... (Score:5, Interesting)
How about we break the cycle by trying to visualize silicone under hundreds of thousands of tons of pressure, and thousands of degrees, with and atmosphere of ammonia? Or, alternatively, in a vacuum at tens of thousands of degrees? Partial pressure atmospheres at near 0 degrees kelvin?
Max Bernstein mentions something very similar to that in TFA.
Dorminey â" DO YOU THINK THAT SILICON-BASED LIFE MIGHT EXIST SOMEWHERE OUT THERE?
Bernstein â" Maybe deep below the surface of a planet in some very hot hydrogen-rich, Oxygen-poor environment, you would have this complex silane chemistry. There, maybe silanes would form reversible silicon bonds with selenium or tellurium.
How about the possibility that a face to face meeting with another life form might be fatal to one or both of the participants in the meeting? His environment is a poisonous atmosphere (to me) and my own body radiating heat might be fatal to him!
A biochemist's vision of such an encounter, for your listening pleasure. [youtube.com]
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Isaac - one of my heros. The man was one of mankind's greatest geniuses, IMHO.
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The two assumptions that I see most often are these: that other life will function on similar time scales to us (which you mention), and that it will exist on similar spatial scales to us (i.e., big enough for us to see, small enough to notice us). What if life existed as, say, self-replicating patterns of magnetic turbulence in the lobes of radio galaxies, with each organism being thousands of light-years across? Or as microscopic agglomerations of nuclei in the condensed matter on the surface of a neutr
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"Silicone"? Sorry, can't take your post seriously, or be bothered to read it, if you cannot distinguish between a compound and an element.
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We "assume" certain basic conditions that resemble our own conditions. Silicone?
Like Pamela Anderson, you mean?
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What's funny about attempts to visualize other types of life forms is, we tend to visualize those life forms in our own environmental terms. That is, we tend to assume some basic atmospheric conditions, pressure ranges, and temperature ranges. We "assume" certain basic conditions that resemble our own conditions.
There's little to no point in imagining alien life if you can't get with it, Captain Kirk-style, and everyone knows that.
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There was a pretty insightful comment (Score:1)
.. on there talking about pre-conditions.
As RNA may have been a pre-condition to DNA, carbon-based life could very well be the pre-condition for silicon-based life.
Life doesn't need to come about naturally, there is no universal definition, if it happens it happens.
Silicon life forms may actually need to be designed by intelligence because of how hard it is to get a stable start up in environments. It could be some sort of really rare form of life due to the energies required.
Likewise that case of arsenic
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Re:There was a pretty insightful comment (Score:5, Informative)
The problem is of people envisioning silicon-based life in a manner that's too similar to carbon-based life. Silicon life, if ever found, is essentially guaranteed to not have any long Si-Si-Si-.... chains; they're not stable. The silicon equivalent in terms of stability is Si-O-Si-O-Si-O... etc (silicone). Silicon also has some fascinating complex chemistry in the form of silanols, which can form membranes, catalysts, and all sorts of other fascinating stuff [ic.ac.uk]... so long as they don't get too hot or in too acidic or basic of a chemical environment.
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so long as they don't get too hot or in too acidic or basic of a chemical environment.
Isn't this also true of carbon-based proteins (usually what membranes and catalysts are made of)?
Caps Lock Elevates Accessibility (Score:5, Funny)
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Bernstein is not deaf, just a little hard of hearing.
If they survive to meet us (Score:1)
Why not here? (Score:5, Informative)
Why not evolve Si life here?
Dorminey — WHERE ARE THE LARGEST CONCENTRATIONS OF SILICON HERE?
IN SAND?
Bernstein — In sand or rock. There are literally megatons of silicate minerals on Earth.
Talk to a geologist like my ex roommate. I knew there was something fishy about that so I checked the actual numbers:
http://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth's_crust [wikipedia.org]
Silicon 277200 ppm second only to oxygen
Carbon 300 ppm second to pretty much everything but vanadium and stuff like that. By weight the earth has about as much Rb as C.
For all intents and purposes the earth is not the idea place for a carbon based life form. Its the equivalent of a unit train full of high fructose corn syrup tank cars for a silicon lifeform. If they can't form here and absolutely gorge themselves on what to them would be the equivalent of a giant pizza, there is not a more ideal place out there to form...
The reason why we're made out of relatively rare C instead of tremendously available Si is C chemistry is incredibly better than Si chemistry for bio, or heck, chemistry in general. The fine article didn't give it enough justice or maybe the editors edited out the chemistry rants. Lets just say that Xe biochem is not all that more unlikely or difficult than Si biochem would be (in other words, nearly totally freaking almost incomprehendibly impossible vs just merely incredibly extremely impossibly unlikely)
It all has an air of speculative fantasy fiction, like trying to intellectually debate if its easier to make vampires, werewolves, or zombies...
Re:Why not here? (Score:5, Informative)
Re:Why not here? (Score:5, Interesting)
There's more ways to form a complex compound than just Si-Si-Si-Si... chains (which, as you note, tend to oxidize into crystaline silicon dioxide). As a random example as proof, look at silica gel. Si-O-Si-O-Si-O... etc. Chain it pretty much as long as you want, functionalize the side chains, etc.
When it comes to LNAWKI (Life Not As We Know It), I think a lot of people lack creativity to a tremendous degree -- envisioning the situation as altering only one parameter (say, substituting silicon for carbon but otherwise keeping the chemical structures roughly the same).
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OK, I would concede the general point that it somewhat depends on how one defines "life", but I would still argue that the grandparent posts are largely correct:
As noted above, the fact remains that Si - Si bonding is much weaker than C - C bonding due to the relative positions of these elements in the periodic table, which means that any kinds of polymerized molecular species that you might want to try to kick off life with still probably wouldn't last as long in a primordial environment as their carbon-ba
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Long Si-O-Si-O chains are all through the mineral kingdom, forming chains, linked chains, sheets, 3-D cages, and I don't know what else.
Worried that the bonds are too stable? Evolve it in a hotter environment.
Re:Why not here? (Score:4, Informative)
where you get silicon & oxygen in sufficient quantities
Everywhere on the earth's crust? [wikipedia.org]
I don't actually understand enough about the chemistry of Si & C to make a direct comparison, but regarding the issue of bonding strength you mention, wouldn't other factors, like temperature and pressure affect this? Possibly even making Si-based life fitter for some environments?
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Which is why silicon-based life would primarily use Si-O chains instead of C-C chains, as previously mentioned. Once again, you reinforce my main point: most people are way too uncreative, only looking at a direct C/Si substitution, which isn't at all realistic. You want to talk stability? Bake cookies on a plastic sheet sheet, then bake them on a silicone baking sheet, and tell me which survives the ordeal better.
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Which is the whole point: we're not talking about a direct substitution. Your argument is like saying "Java programs can't exist, because if you substitute a line of C code in a C program with a line of Java code, the program breaks."
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My argument is a lot less like substituting a line of code into
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In *ours* and every living thing that evolved from primitive carbon-based organism on *Earth*'s bodies. We're not talking about life on Earth. We're talking about xenobiology. You're arguing from a dataset of precisely one element. The question is not what is life on Earth like, but whether all life must be like it is on Earth.
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Re:Why not here? (Score:5, Informative)
The reason 90 % of the known compounds are organic is because a) there is amble supply different carbon-based compounds to manipulate, as life has made sure, and b) they are more interesting as pharmaceuticals then inorganics. Based on pure chemistry, boron is nearly as versatile as carbon, but starting blocks for boron chemistry is harder to come by, as is funding.
Boron and Sulfur (Score:1)
Sulfur is another candidate often cited for its bonding capabilities.
Re:Why not here? (Score:5, Insightful)
vlm answered the musical question:
Why not evolve Si life here?
Thusly:>/p>
Carbon 300 ppm second to pretty much everything but vanadium and stuff like that. For all intents and purposes the earth is not the idea place for a carbon based life form.
Incorrect, I'm afraid.
If you exclusively look at the abundance of carbon in the Earth's makeup, you miss the most crucial aspect of hydrocarbon-based biochemistry: the abundance of water as a solvent for hydrocarbons, particularly here on the surface of the planet, where the incredible profusion of possible compound-producing reactions benefits tremendously from sunlight as a source of energy input to trigger the making and breaking of hydrocarbon bonds.
A world where carbon is greatly more abundant - but water is largely absent - wouldn't necessarily be more conducive to the evolution of life.
The reason why we're made out of relatively rare C instead of tremendously available Si is C chemistry is incredibly better than Si chemistry for bio, or heck, chemistry in general. The fine article didn't give it enough justice or maybe the editors edited out the chemistry rants. Lets just say that Xe biochem is not all that more unlikely or difficult than Si biochem would be (in other words, nearly totally freaking almost incomprehendibly impossible vs just merely incredibly extremely impossibly unlikely)
This, on the other hand, is a much better point ... and, IMnsHO, one deserving of an "Insightful" upmod.
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The reason why we're made out of relatively rare C instead of tremendously available Si is C chemistry is incredibly better than Si chemistry for bio, or heck, chemistry in general. The fine article didn't give it enough justice or maybe the editors edited out the chemistry rants. Lets just say that Xe biochem is not all that more unlikely or difficult than Si biochem would be (in other words, nearly totally freaking almost incomprehendibly impossible vs just merely incredibly extremely impossibly unlikely)
One explanation I've heard is simply that silicon atoms are larger than carbon. Thus there is more space to attack the bonds. For example, in SiH_4 the hydrogen atoms are further apart, compared to CH_4. The technical explanation probably involves the variety of orbitals as well, since carbon only has s and p, but silicon also has d orbitals, again making the attack space bigger.
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For all intents and purposes the earth is not the idea place for a carbon based life form. Its the equivalent of a unit train full of high fructose corn syrup tank cars for a silicon lifeform. If they can't form here and absolutely gorge themselves on what to them would be the equivalent of a giant pizza, there is not a more ideal place out there to form...
Assuming, incorrectly, that complex, silicon-based chemistry works well within...
a) in the presence of later amounts of water
b) in the presence of free atmospheric oxygen at Earth temperatures
c) at a wide variety of pH ranges, including the common neutral pH of water.
It turns out that none of these are true. Earth is an absolutely horrible place for silicon-based life, if it's even possible. If silicon-based life uses oxygen-based respiration, its by-product is a solid at Earth temperatures. Water reacts
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Though not proof, I think your reasoning is sound. I've begun to wonder whether or not DNA isn't a fluke any more than say, carbon monoxide, or water, or methane. Molecules have specific ways...finite ways...in which they can form...one cannot just make up new bonds and create crazy random molecules. DNA follows the rules. Why wouldn't it exist elsewhere?
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I do think that carbon-based life that dwells in ammonia and carbon dioxide is more likely than silicon-based life, but I don't think t
Mammals? (Score:5, Funny)
Ob (Score:2)
Sort of like a white spiky coral that kills everyone unless they hide in a cave with an android.
It can be killed with music.
Where will the anus be? (Score:2, Funny)
Just wondering.
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Just wondering.
Why? You mean to tell me that they're speculating on the mere possibility of silicon-based life......and already you want to fuck it?
Jesus...
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silicon based religions (Score:5, Funny)
will believe the universe only exists since 1.1.1970.
Re:silicon based religions (Score:4, Funny)
If there is no Silicon Heaven, then where do all the calculators go?
Stupid rocks (Score:5, Insightful)
There should have been a question like "is there an environment that might make it more plausible for Silicon life"? What about planets that are molten or have oceans, lakes, and rivers of acid. Why would an intelligent rock walk around in place where they will become immobile? Sounds like something only dumb rocks would do.
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Why would an intelligent rock walk around in place where they will become immobile? Sounds like something only dumb rocks would do.
Most plants are relatively immobile but you wouldn't call a tree dumb would you? I mean I probably have called one dumb but it's usually me being dumb and walking into one of them.
The real evolution of intelligent silicon (Score:1)
"Honey? When did your boobs start talking?"
Hmm (Score:2, Insightful)
Interesting. Though I am curious why Silicon life hasn't already evolved on the Earth.
Think about it. There isn't necessarily a reason why Silicon / Carbon / other-based lifeforms can't all evolve in the same environment. There's no law, save those of Physics / Chemistry / etc., that says that if you have one, you cannot have the other.
So, why is earth filled with only Carbon-based lifeforms (to our knowledge)? Perhaps there is something poisonous about our planet, with regards to Silicon lifeforms, such th
Poor guy must be deaf by now. (Score:2)
I would imagine it was hard to respond to questions calmly and intelligently when THEY WERE ALL SHOUTED AT HIM by Dorminey.
No, no, no, wrong! (Score:2)
Real life is NOT based on your computer and its silicon chips. Real life is in the outside world, away from your computer!
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Real life is NOT based on your computer and its silicon chips. Real life is in the outside world, away from your computer!
How would we know?
Silicon dioxide respiration considered difficult (Score:1)
I've Seen 'Em (Score:2)
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What I said there (Score:3)
If you think about it, the people claiming that advanced civilizations would create self-replicating Von Neumann machines that would spread throughout the galaxy, are really claiming that carbon-based life would create (and maybe be supplanted by) silicon-based life. In the same way that RNA-life may have been necessary to get to DNA-based life, carbon-based life may be a necessary pre-condition for silicon based life. (We might think of those Von Neumann machines as robotic spacecraft, but those that can evolve would likely supplant those that cannot, and in a few billion years take on forms that we cannot predict.)
They would have (Score:1)
We don't know (Score:3)
Although non-carbon based life is a very long shot...
Isn't this a really big assumption? Sure, we haven't seen any non carbon-based life, but we also haven't found carbon-based life on more than one little planet.
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maybe (Score:1)