Extraterrestrial life? Alternative biochemistry?

Question

I am interested in the study of extraterrestrial life. I heard that lifeforms can be made of silicon-

http://en.wikipedia.org/wiki/Alternative_biochemistry

This makes me think. This fact is ture-

The Earth, as well as other terrestrial planets, is exceptionally silicon-rich and carbon-poor. However, terrestrial life is carbon-based. The fact that carbon, though rare, has proven to be much more successful as a life base than the much more abundant silicon may be evidence that silicon is poorly suited for biochemistry on Earth-like planets.

That makes sense. Would silicon-based lifeforms be really rare? What would they look like? Or is that impossible to answer?

All of the aliens in the fake movies look way too human. Could intelligent life have some traits that similar to humans like being bepedal or having fingers? Or could they look like anything?

Sorry I know my question is hard to answer, maybe impossible, but I want to know as much as I can. Basically, can you tell me what silicon-based lifeforms would be like, and could extraterrestrial lifeforms evolve similar traits to life on earth? I am not talking extremly similar traits like the same face-structure and noses, but traits like being bipedal and having fingers.

And sorry, I do not know about this subject very much. If I sound like a idiot writing this stuff, sorry. I just want to know.

Answer 1

It could be possible if there are similarities between silicon's structure and carbons properties.

Answer 2

yeah, very, very nice question, but really hard to answer, I've been also wondering what aliens look like I think that they really nothing look liked anything we know too. yeah. they're aliens we don't really know what they look like, maybe they're dumb or highly intellectual, If they are silicon based, hmm... what would they look like?... I think they would look like... err hard to imagine... maybe they are non biological organisms because they are made from silicon?  

Answer 3

>The Earth, as well as other terrestrial planets, is exceptionally silicon-rich and carbon-poor. However, terrestrial life is carbon-based. The fact that carbon, though rare, has proven to be much more successful as a life base than the much more abundant silicon may be evidence that silicon is poorly suited for biochemistry on Earth-like planets.

Makes sense. This reasoning has been known to scientists (and science fiction fans) for almost as long as the idea of silicon-based biochemistry has existed.

>Would silicon-based lifeforms be really rare?

As far as I know, most scientists in the relevant fields agree that silicon is probably too inert to support living chemistries at all, so it is doubtful that any silicon-based life forms exist in our universe. If some do exist, they would probably be extremely simple (more like crystals than like the Earth's carbon-based life forms, and quite possibly simple enough to blur the distinction between life and non-life) and quite possibly be artificial. Another possibility is that silicon and carbon could BOTH be used in an organism's biochemistry, which I suppose would extend the potential for complex molecules but would probably present its own chemistry problems.

>What would they look like?

In science fiction portrayals, silicon-based life forms are usually presented as stony or metallic in texture, looking like rocks, or TV antennas, or silver-colored arthropods, or translucent crystal trees, that kind of stuff. Some artist's impressions can be seen here:

http://upload.wikimedia.org/wikipedia/co...

http://www.moo3.at/strategies/race_picks...

More realistically, actual silicon-based life, if visible at all to the naked eye (it would more likely be microscopic), would more likely resemble a crystal or vein of metal ore. Something along these lines:

http://www.beatrees.com/quartz_crystal_c...

http://webzoom.freewebs.com/mysticallink...

http://www.wonderquest.com/fig2-geode.jp...

>Could intelligent life have some traits that similar to humans like being bepedal or having fingers?

Are you still talking about silicon-based life? Since the idea of silicon-based life forms complex enough to possess consciousness is highly speculative, I'll assume you're talking about life in general. It is likely that intelligent aliens would possess some traits similar to humans, especially traits that tend to go well with intelligence. First off, given how successful bilateral symmetry has been here on Earth, it is reasonable to expect that many aliens would also be bilaterally symmetrical (as opposed to radially symmetrical like a starfish or sea anemone). They would probably have some appendages dedicated to object manipulation, like our fingers, although theirs could be more like elephant trunks or octopus tentacles. Eyes would be very likely as well, as would ears although they may not have external earflaps like we do. Their traits would depend on the environment they evolved in, of course, but intelligence is probably more likely to evolve in environments like our own. Note that this is all assuming that they have not artificially modified their bodies by the time we meet them.

>And sorry, I do not know about this subject very much.

Neither does anyone else! Astrobiology (the scientific field of study devoted to extraterrestrial life) is a highly speculative field, simply because so far we have no example of any native life forms outside the Earth.

Answer 4

It is possible! But, I doubt that other life forms changed and can change to look like us. If it is possible, then that must be very amazing. I doubt it, though. God must be at work...

Answer 5

The Earth is silicon rich, but i would hardly call it carbon poor.

I've heard interesting discussions, back and forth about the possibility of silicon based life over the years.  Sometimes it's said that silicon can form as complex structures as carbon can, and other times they say it can't.  We only have carbon life on Earth, so it's hard to extrapolate.

But we may have silicon life here, and soon.  Once we have computers with bodies that can manufacture themselves, that will fit my definition of life.  And a critical part of that may be silicon based.

Human looking aliens are easier to imagine and put into movies.  I mean, just put a guy in a suit.  The movies are pretty poor at getting science right.

I expect extraterrestrial carbon based life.  The ingredients are common.  There are tons of places it should happen.

Evolved silicon based life, if it exists, would very likely have different needs than we have.  They might be solar powered, and unlike plants, agile.  They may not eat each other.  They may be very stable - immortal.  All this might push them in very different directions than we have been pushed.