Originally posted by Devil King
And how should it be differentiated?
while not the case on mars, it's not without the realms of possibility that a planet could be predominantly silicon and not carbon...and thus, because silicon and carbon have extremely similar properties in terms of bonding to other atoms that there could be planets with silicon based life rather than carbon based....the only problem is that silicon has a very high affinity for oxygen and produces a solid on oxidation (whereas carbon produces CO2) and thus would be difficult to dispose of in a respiratory system
Originally posted by jaden101
while not the case on mars, it's not without the realms of possibility that a planet could be predominantly silicon and not carbon...and thus, because silicon and carbon have extremely similar properties in terms of bonding to other atoms that there could be planets with silicon based life rather than carbon based....the only problem is that silicon has a very high affinity for oxygen and produces a solid on oxidation (whereas carbon produces CO2) and thus would be difficult to dispose of in a respiratory system
You're thinking that life has to follow in the footsteps of life as we know it. Aliens lifeforms could breath other gases instead of oxygen, especially ones that are silicon based. Also the possibility of them not breathing at all, though it's hard to imagine life existing without consuming something.
from a biochemical point of view, all life forms have to store energy...carbon based life forms do this as carbohydrates which have to be oxidised in order to be utillised...thus oxygen is pretty essential
the other problem is that most proteins and enzymes are chiral, meaning that they are oriented in a certain way...often reffered to as "handedness" meaning that carbon chiral compounds are opposite but not superimposable...
these chiral compounds are important as it makes enzymes specific to certain biochemical processes...
silicon doesn't form these compounds easily
the problem with life occuring in a wholely different form is that there are only so many elements in the periodic table that are capable of producing the molecules needed for biochemical activity...and these are generally limited to carbon based ones...and in theory, silicon
Originally posted by jaden101
the problem with life occuring in a wholely different form is that there are only so many elements in the periodic table that are capable of producing the molecules needed for biochemical activity...and these are generally limited to carbon based ones...and in theory, silicon
not that I disagree with you or with the probabilities of certain chemicals producing certain necessary reactions, but:
we don't know everything, life could form in ways we do not currently understand as possible, or, something analogous to life could form under completely different circumstances.
Its like Dawkins when he says life on other planets would have to go through some form of evolution. I don't disagree, and believe it to be most likely, I just find it a little, arrogant maybe?, to deem what is absolutely necessary for creatures we can currently only speculate about.
Like, do we know for sure that something that is alive must store energy? Or is it that we don't know of and can't conceive of a way for something to be alive and not consume energy? Can something be behaviourally similar to alive without storing energy (if storing energy is required for something to be life)?
well personally i think if slightly more complext life exists in a different format then it may be something such as non green photosynthesis....which would give some pretty interesting colour schemes to planets...perhaps even photosynthesis outwith the visible spectrum
might also be that other life may employ non water based solvents to conduct chemical reactions such as ammonia
but these would still be limited to carbon based...
Originally posted by jaden101
well personally i think if slightly more complext life exists in a different format then it may be something such as non green photosynthesis....which would give some pretty interesting colour schemes to planets...perhaps even photosynthesis outwith the visible spectrummight also be that other life may employ non water based solvents to conduct chemical reactions such as ammonia
but these would still be limited to carbon based...
I'm not arguing that at all. You clearly know more about this kind of thing than I do. I'm just saying, we don't know everything 🙂
you're right...we dont...but we do know what elements can form what molecules that are neccessary to facilitate systems that life needs in order to exist...and we can eliminate most elements that dont form molecules for these processes
now it's theoretically possible that under different gravitational or radioactive conditions that life might need to utilise different branching elements in order to have properties it needs to survive...even on earth there are examples of some species using arsenic in their biochemistry where in most species it's toxic...
bit like you...i'm just theorising and putting out different ideas
Originally posted by jaden101
....which would give some pretty interesting colour schemes to planets...
Like purple cabbage. There's just something I do not trust about purple cabbage.
I'd defer to your knowledge of the periodic table, but is it possible that there are elements or gases that exist elsewhere that we know nothing about?
Originally posted by Devil King
Like purple cabbage. There's just something I do not trust about purple cabbage.I'd defer to your knowledge of the periodic table, but is it possible that there are elements or gases that exist elsewhere that we know nothing about?
only if there are atoms which are made up of particles other than protons, neutrons and electrons...which is highly unlikely
and if not then it would be heavier elements which would be radioactive and unstable...
although there are still a few gaps on the periodic table
there's no elements 113, 115 and 117...and 110, 111, 112, 114, 116 and 117 are all recently discovered....i think they still have temporary names although this might have changed by now
and i dont trust normal cabbage...never mind purple cabbage... 😄
i fart enough
Does anyone remember the movie Evolution erroneously assigning organisms a nitrogen backbone as a comparison to Earth's carbon? It was presented in the movie as almost apodictic and it was one of those little things that bugged me. They even continued on the same path in the periodic table and ended up with selenium being uberly toxic to the foreign organisms based on fact that arsenic was toxic to carbon based life forms. (They did some sort of translation that got them...its been a few years I don't remember perfectly.)
Yes, all this current banter made me think of this movie. 😐
Originally posted by Robtard
It is more valid (even slightly) on the grounds that we know what life consist off and we can use Earth as model, but still, we obviously don't know everything and there could be life (even non sentient) that is made of something we can't even imagine.
however its illogical to many including myself for a non carbon based lifeform to exist. in fact my belief is that the pattern for evolution is universal. thats not to exclude humanly-evolved reptilians, mollusks, insects, etc (not to sound like deano).
Originally posted by Robtard
http://en.wikipedia.org/wiki/Alternative_biochemistryhttp://www.dailygalaxy.com/my_weblog/2007/06/noncarbon_lifef.html
That's interesting. Maybe my belief that nitrogen isn't as useful as carbon has become antiquated?
However:
"Debate continues, as several aspects of a phosphorus-nitrogen cycle biology would be energy deficient. Also, nitrogen and phosphorus are unlikely to occur in the ratios and quantity required in the real universe. Carbon, being preferentially formed during nuclear fusion, is more abundant and is more likely to end up in a preferred location."
I didn't know that carbon was preferentially produced during fusion (during the last legs of a star's life). I always assumed that it was variant in almost a linear fashion as the atomic weight become larger (up to iron). I guess I could google spectral analysis data from a left over star to see how valid that Wiki claim is...but I don't feel like it.
I didn't know that nitrogen became useful or as useful as carbon when coupled with phosphorus. Conceivably, we could run "evolution" models based on different elements as AI becomes stronger. With enough processing power, trillions of variables can be run in seconds so we could potentially run several models through and come up with some pretty nifty stuff. Computing power and AI is not advanced enough to start playing God "at home"*, though.
I've read that people are already running CG models of evolution in one form or another, so the interest is there. We may answer several questions as it pertains to life and elements.
*The Earth
Future of Mars Exploration: What's Next?