EPTPlanets that can potentially support life... - Page 23
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ChosenBrad1322
United States562 Posts
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Heh_
Singapore2712 Posts
On April 30 2012 22:54 kef wrote: That's an incredibly complex question, and although I used to think the same thing, as I've studied biochemistry at the university level (my major), I've learned that the answer to "Could life evolve in space?" is "Almost definitely not." Now that's not to say "absolutely not" because science has a way of surprising us, but the idea that life as complex as animal life could evolve in space is basically impossible. Maybe through genetic engineering life could be able to exist in space, but naturally, certainly not. Life (in the scientific sense) is basically a series of complex chemical reactions that have increased in complexity via the mechanism we call evolution over billions of years to the point where we are now. In order for there to be a series of chemical reactions like those that life evolved from there needs to be certain conditions. If you study chemistry, you'll learn that water has some very unique properties that arise from its chemical structure- properties such as high amounts of hydrogen bonding which lead to things like high surface tension, a specific crystalline structure that results in solid ice being less dense than liquid ice, etc. which our form of life needs to exist. The specific phase (liquid) of water, the presence of certain biological precursors ("organic" compounds or their precursors), and the correct temperature were all necessary for there to be the complex reactions that life arose from, and on Earth, it just so happened that all the right conditions were present at the same time for life to arise. In vacuum, water is either frozen or gaseous- because pressure is so low, there is no liquid state. Chemical reactions cannot occur if particles do not come into contact (which is rare in a vacuum). Chemical reactions cannot occur if the specific reactants don't come into contact. Chemical reactions cannot occur quick enough (if even at all) if temperatures are too low, and if temperatures are high (such as near a star) the resulting organic products would literally burn up. I could go on for a long time, but it's really difficult to explain it all in a short amount of time, especially to someone who doesn't have a decent biology/chemistry/biochemistry background. Suffice it to say that given what we know about life today, it could not evolve in space, and actually requires very specific conditions (such as those on Earth for complex life or possibly Mars for less complex life) to arise. Anything else is conjecture at this point. The thing is, the whole idea of life supported by water is based on the fact that all life on Earth revolves around water. Currently, scientists search for potential signs of life by looking mainly for water and environmental that supports liquid water. Why not other solvents? That is what I never understood. Does life always have to revolve around water? A solvent that could possibly support life (the way that we think of it) is ammonia. I've read some arguments about this some time ago, but they've seem to have died out. A person with too much free time could probably speculate how life would be supported by ammonia. However, this remains pure theorycraft until proven otherwise. | ||
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ArchAngelSC
England706 Posts
On May 01 2012 00:21 kef wrote: AFAIK it's the most sound explanation for the beginning of life. The propagation of efficiently reproducing processes is a universal constant. Also, ArchAngelSC, I'm not sure you have any idea what you're talking about. That's not supposed to be an insult, just an observation. The environment came first, life evolved out of it because it was the right environment for life to arise. Life wouldn't have arisen on Earth if the Earth was like Pluto- we know this because there is no life on Pluto. No offence taken, don't worry  But I'm not sure what you're talking about. Where did I say life came before the environment? | ||
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Xpace
United States2209 Posts
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Aelfric
Turkey1496 Posts
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RageBot
Israel1530 Posts
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summerloud
Austria1201 Posts
- comparing anthropic principle to intelligent design the first one says that the universe is obviously designed for life, if any of the physical laws or constant were different life wouldnt be possible, matter wouldnt even be possible. since in such universes there would be no one to observe their life-lessness, thus we cannot be sure if there is a huge succession of universed until saying the universe is fine-tuned to support life has nothing to do with intelligent design theory! - always bringing up that life might not need liquid water / carbon if you dont have a clue about chemistry please dont argue about that. both carbon and water are suited in so many unique ways specifically to support chemistry complicated enough to allow life that their peculiar features are even used for design arguments. all the science-fiction stuff about creatures made of gas or conscious interstellar clouds or stuff like that brought on by the likes of arthur c clarke or fred hoyle is just that. science fiction coupled with wishful thinking about a universe teeming with life. i also dont like this typical american thing of trying to put someone you disagree with in the religious corner, but i guess thats what you get on internet forums... happens in a lot of scientific debates as well unfortunately, for example with every critic of mainstream evolutionary theory being put into the intelligent design corner. there is more than two sides to complicated issues.... edit: here is the wikipedia page about carbon chauvinism, unfortunately its not very long, reflecting how obsolete this idea has become the idea of life based on silicium instead of carbon is pretty old (i remember a ridiculous old original star trek episode with silicon-based thingies that could travel through stone... was hilarious like usual...), but unfortunately science seems to agree that life as we know it might be the only possible (or probable?) form of life | ||
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horsebanger
141 Posts
we won't ever (ever) reach the other planets. if we do find life it's extremely unlikely that it's a similar lifeform to the life on earth. it took billions of years to develop into humans and the fact that life excists out of water... not even gonna get started on that | ||
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Aelfric
Turkey1496 Posts
On May 01 2012 01:20 horsebanger wrote: truthbombs: we won't ever (ever) reach the other planets. if we do find life it's extremely unlikely that it's a similar lifeform to the life on earth. it took billions of years to develop into humans and the fact that life excists out of water... not even gonna get started on that Here comes another one claiming we already invented or discovered everything we can about the universe. | ||
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midftw
Canada170 Posts
On April 30 2012 14:38 summerloud wrote: and what exactly makes a bacterium 'good' or 'bad' in your opinion? you know there bacteria acting like parasites and others that are beneficial to the organism they inhabit. it's not my opinion, it's a fact. If humans maintain a lifestyle that doesn't upset, but rather helps towards the natural balance of the planet, then they can be considered as beneficial towards that planet. Of course, to be considered an organism, a planet needs to have an already established simple life like the Earth (ie: water cycle, algae, grass, clouds). So yeah let me know if you still don't understand my analogy. | ||
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Dantelew
Canada63 Posts
On May 01 2012 01:20 horsebanger wrote: truthbombs: we won't ever (ever) reach the other planets. if we do find life it's extremely unlikely that it's a similar lifeform to the life on earth. it took billions of years to develop into humans and the fact that life excists out of water... not even gonna get started on that Thats a whole lot of truth you just dropped on us. Good thing you've elaborated and explained your claims with thorough and indepth facts to back your claims up and prove your so called "truthbombs". Explain why we wont ever (ever) reach the other planets. In our life time, probably not. In our childrens, probably not. But consider how far weve come in the past 200 years compaired to the entirety of our existence. It wasn't so long ago that the Earth was flat, and now we can fly around it for low cost in under a day, when 500 years ago it was called "exploring". Cell phones, which we now take for granted, would have been the size of a room a few decades ago. We now find new planets many light years away, and the best you have to say is "Meh, we wont get there anyways, and even if we do, we wont find anything," atleast back it up with some claim. I find the whole thing amazing, its fun to discuss, especially a lot of the chemistry people explaining why carbon and water based life forms are for all intents and purposes the only practical way life can be supported. I for one have always been in the camp of "Why do we need water?", but the explainations made a lot of sense. | ||
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kef
283 Posts
On May 01 2012 01:17 summerloud wrote: i wish people without knowledge of the subject would stop: ... - always bringing up that life might not need liquid water / carbon if you dont have a clue about chemistry please dont argue about that. both carbon and water are suited in so many unique ways specifically to support chemistry complicated enough to allow life that their peculiar features are even used for design arguments. all the science-fiction stuff about creatures made of gas or conscious interstellar clouds or stuff like that brought on by the likes of arthur c clarke or fred hoyle is just that. science fiction coupled with wishful thinking about a universe teeming with life. This is basically how I feel about this whole debate. Yeah it's maybe possible that life could arise based on ammonia or methane, but the way water and carbon react is both so unique and so essential to life as we know it, that it's highly unlikely. And no, not just "any liquid" will work as the correct solvent. Ammonia and methane don't hydrogen bond with themselves like water does, and water's unique properties come from this ability, which comes from its structure. I don't mean to sound elitist, but if you haven't at least taken organic chemistry you probably won't be able to understand why. | ||
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Aelfric
Turkey1496 Posts
On May 01 2012 01:42 kef wrote: This is basically how I feel about this whole debate. Yeah it's maybe possible that life could arise based on ammonia or methane, but the way water and carbon react is both so unique and so essential to life as we know it, that it's highly unlikely. And no, not just "any liquid" will work as the correct solvent. Ammonia and methane don't hydrogen bond with themselves like water does, and water's unique properties come from this ability, which comes from its structure. I don't mean to sound elitist, but if you haven't at least taken organic chemistry you probably won't be able to understand why. I've taken organic chemistry in high school. Dunno other countries but in my country they teach that in last year high school. I don't remember all of it though because it's been many years and my field is far away from chemistry. | ||
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kef
283 Posts
On May 01 2012 01:35 songohan wrote: you know there bacteria acting like parasites and others that are beneficial to the organism they inhabit. it's not my opinion, it's a fact. If humans maintain a lifestyle that doesn't upset, but rather helps towards the natural balance of the planet, then they can be considered as beneficial towards that planet. Of course, to be considered an organism, a planet needs to have an already established simple life like the Earth (ie: water cycle, algae, grass, clouds). So yeah let me know if you still don't understand my analogy. Beneficial/malignant to what? It's all relative terms. For example, it's widely believed that the first mass extinction was of anaerobic bacteria, the first successful form of bacteria, who were poisoned by the introduction of molecular oxygen into the world (the oxygen we now breathe and require for life). Where did all this molecular oxygen come from? None other than the first aerobic bacteria, who had evolved efficient metabolic processes that had oxygen as a waste product. Were they good or bad? They evolved this ability naturally, and yet they changed all life on the planet- today, all living things either require or produce oxygen, the only exceptions being certain bacteria living in hot springs and deep-sea vents. Nature never was, is not, and never will be some static thing. It's constantly changing every day, and the only reason we have such illusions that it doesn't change is because we are so short-lived. Now does that mean I don't believe in conservation efforts? No, of course not. I'd rather my planet was like Aiur than Char or Tarsonis. | ||
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summerloud
Austria1201 Posts
On May 01 2012 01:35 songohan wrote: you know there bacteria acting like parasites and others that are beneficial to the organism they inhabit. it's not my opinion, it's a fact. If humans maintain a lifestyle that doesn't upset, but rather helps towards the natural balance of the planet, then they can be considered as beneficial towards that planet. Of course, to be considered an organism, a planet needs to have an already established simple life like the Earth (ie: water cycle, algae, grass, clouds). So yeah let me know if you still don't understand my analogy. sorry to sound harsh but thats a load of new age pseudo-blabla that makes zero sense. what is the natural balance of the planet? would you say the algae that started releasing toxic oxygene into the atmosphere 2 billion years ago and led to the mass extinction of most life on the surface but later to the emergence of aerobic life are good because they helped the 'natural balance' or bad because they made so many other things die out? if you try to apply morals to nature and see humans not as part as the whole system you mostly end up making no sense, sorry. also even your original analogy made no sense. all life tries to expand to all possible habitats, thats a general feature of life and not constricted to bacteria im sorry if im being a dick i realize what you are trying to say im just pointing out it doesnt make any sense  On May 01 2012 01:20 horsebanger wrote: truthbombs: we won't ever (ever) reach the other planets. if we do find life it's extremely unlikely that it's a similar lifeform to the life on earth. it took billions of years to develop into humans and the fact that life excists out of water... not even gonna get started on that agreed in general, but you cannot say it took billions of years to evolve humans. as far as we know we only had multcellular life for around 600 million years, why we had single celled life for almost 4 billion years before that... no one really knows thats the next step after the inital creation of life thats still a mystery... and there is simply no scientific way to argue that life will always evolve like that since we can only observer it here on earth (and we can only observe it because we did indeed evolve thus) that was actually one point made by rare earth theories, even if life might start on other worlds, most likely it will always stay at the bacterial level. and even if you evolve multicellular life - there is no way to tell if it automaticall will result in life as intelligent as humans. without an asteroid offing all the dinos we might have never had humans on earth either. look at all the lifeforms on earth, there seems to be only a very small branch of life (ie primates) tending towards higher intelligence. if you took all primates off the earth, would some other animal arise to build civilizations and dominate the planet? and if, which one? thats actually a kindof funny question so i decided to make a poll: Poll: if primates were removed, what other lifeform would develop civilizati state-building insects (5) bears or some other land-mammal (2) octopus or some other invertebrate (1) something entirely new (1) dolphins or some other water-mammal (1) birds (0) funghi (0) bacteria (0) fish (0) plants (0) 10 total votes Your vote: if primates were removed, what other lifeform would develop civilizati (Vote): state-building insects | ||
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TheFish7
United States2824 Posts
On May 01 2012 01:20 horsebanger wrote: truthbombs: we won't ever (ever) reach the other planets. if we do find life it's extremely unlikely that it's a similar lifeform to the life on earth. it took billions of years to develop into humans and the fact that life excists out of water... not even gonna get started on that You know people used to say that we could never go faster than the speed of sound. Billions of years is a short time when compared to the age of the universe. Water creatures crawling out of the ocean was inevitable. I'm a big believer that we are going to find lots and lots of life out there. We have found life in some of the most inhospitable regions of earth without a clue to how it got there. Intelligent life may me another matter though - most animals we know of don't actually need to evolve a big brain to survive. Anyway, I'd also say that we have probably been visited by Aliens, but also that we are too insignificant for them to even stop and examine. To an intergalactic alien race, we would just be another bunch of mammals. Also, if we do find life, it won't be like in Star Trek, probably it will be more like Ender's Game. | ||
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Heh_
Singapore2712 Posts
On May 01 2012 01:42 kef wrote: This is basically how I feel about this whole debate. Yeah it's maybe possible that life could arise based on ammonia or methane, but the way water and carbon react is both so unique and so essential to life as we know it, that it's highly unlikely. And no, not just "any liquid" will work as the correct solvent. Ammonia and methane don't hydrogen bond with themselves like water does, and water's unique properties come from this ability, which comes from its structure. I don't mean to sound elitist, but if you haven't at least taken organic chemistry you probably won't be able to understand why. Wrong. The ability to form two hydrogen bonds per molecule in water (compared to one in ammonia) mainly affects boiling point. At Earth's temperature, water is a liquid while ammonia is a gas. In another planet with lower temperatures, the reverse occurs. Ammonia and water have a similar ability to dissolve polar substances, which is the main purpose of having water. While extremely unlikely, it is not impossible that life in another planet is based on ammonia. Is there a specific property of water that no other compound is able to possess a similar function? Edit: On May 01 2012 01:54 summerloud wrote: and even if you evolve multicellular life - there is no way to tell if it automaticall will result in life as intelligent as humans. without an asteroid offing all the dinos we might have never had humans on earth either. look at all the lifeforms on earth, there seems to be only a very small branch of life (ie primates) tending towards higher intelligence. if you took all primates off the earth, would some other animal arise to build civilizations and dominate the planet? and if, which one? The evolution from a unicellular organism to a multicellular organism is a huge leap. However, once that leap does indeed occur, evolution can occur rapidly. The evolution of primates occurred over a relatively short period of time. Human civilization as we know it, evolved over thousands of years. And it's not even unique to us. Other lifeforms on Earth greatly modify the planet too: ants and termites make complex nests, beavers build dams, and the list goes on. Everything is subjective. All these points that you've been mentioning are based on casual observance, they've not been rigorously tested. Indeed, we don't have the ability to test out a ton of hypotheses. | ||
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rackdude
United States882 Posts
Just thought this should be thrown out there for all who are interested. | ||
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summerloud
Austria1201 Posts
On May 01 2012 02:05 TheFish7 wrote: ... I'm a big believer that we are going to find lots and lots of life out there. We have found life in some of the most inhospitable regions of earth without a clue to how it got there. Intelligent life may me another matter though - most animals we know of don't actually need to evolve a big brain to survive. the thing most people dont realize is: life evolving to be able to survive in extreme habitats does not equal life being able to form in these conditions. its really a moot point in a way because, like i said before, there is just no good theory of how life ever came into existence in the first place, but it might require a very very specific set of environment and/or a fucking miracle i have to say the more i studied biology and found out how extremely complicated the most primitive living cell is the more i began to believe in purpose/teleology/a creator right now it seems fashionable in biology to have the model that self-catalysing proteins where the first stage of life, followed by rna-based life, followed by dna-based life. how evolution is supposed to be able to change the very thing it needs to work (the genetic code), nobody has been able to explain to me. to me it seems impossible for life to switch from rna to dna without admitting that there is a purpose driving the whole of evolution. blind watch maker my ass... (i despise dawkins btw) i could rave on and on about this topic for pages i guess, but im not sure if this is the right thread for it... ill wait for the next evolution vs intelligent design thread to pop up i guess  | ||
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heroyi
United States1064 Posts
Even if we assume that life revolves around the carbon and that "water is the universal solvent" there are so many systems out there now AND being created that statistics itself shows it would be foolish to assume no life is out there. edit: On May 01 2012 02:05 TheFish7 wrote: You know people used to say that we could never go faster than the speed of sound. Billions of years is a short time when compared to the age of the universe. Water creatures crawling out of the ocean was inevitable. I'm a big believer that we are going to find lots and lots of life out there. We have found life in some of the most inhospitable regions of earth without a clue to how it got there. Intelligent life may me another matter though - most animals we know of don't actually need to evolve a big brain to survive. Anyway, I'd also say that we have probably been visited by Aliens, but also that we are too insignificant for them to even stop and examine. To an intergalactic alien race, we would just be another bunch of mammals. Also, if we do find life, it won't be like in Star Trek, probably it will be more like Ender's Game. ^^This. Earth itself is relatively young. The formation of life on Earth is not considered to be that old in comparison to other planets | ||
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