Tormod Posted February 15, 2005 Report Share Posted February 15, 2005 Ahem...talk about thread hijacking! :) Link to comment Share on other sites More sharing options...
MortenS Posted February 15, 2005 Report Share Posted February 15, 2005 Back to topic: What about this argument that I just thought out? If life on earth started with the ultimate panspermia, that is the first cells or replicating molecules arrived from space, then the probability for existence of life (previous or current) in other places of the universe is much greater than zero (I would say that the probability is 1) If life started on earth (whether by abiogenesis or the mystical hand of a creator), there is a possibility that we are alone in the universe. I would say the probability ithat we are alone, is somewhere beteen 0 and 1. For the sake of argument, we could say that the probabilty that we are alone is 1. As long as it is not settled which of the abiogenesis theories are correct, and there is a probability greater than zero assigned to each of the theories (you can add other theories of origin as well), the probability of life elsewhere (past or present) in the universe will also be greater than zero. Are there any faults in this argument? Link to comment Share on other sites More sharing options...
C1ay Posted February 15, 2005 Report Share Posted February 15, 2005 Back to topic: If life started on earth (whether by abiogenesis or the mystical hand of a creator), there is a possibility that we are alone in the universe. I would say the probability ithat we are alone, is somewhere beteen 0 and 1. For the sake of argument, we could say that the probabilty that we are alone is 1. I personally don't claim that anything is impossible, however unlikely it may be. I also would not say that creation would necessarily increase our chances of being alone. In just our own galaxy there are billions of stars which could support many planets like our own. Why would a creator start life on just one? I would think that he/she/it would create many world's like ours with the goal of making each one better than the last, much like artists do here on Earth. Heck, maybe there are many creators competing with each other. I also believe there could have been many worlds like ours long before ours so the chance for life to start elsewhere by some abiogenesis before our world even existed is a likely possibility. Link to comment Share on other sites More sharing options...
alxian Posted February 15, 2005 Report Share Posted February 15, 2005 Please, alxian, are you capable of writing slightly more insightful posts? This is a discussion forum, not a hit-and-run fun fair. Please take part in the discussion or stay out of it. There is a fine line between being funny and acting funny. its a genuine question. what is the origin of mitochondria as i keep saying i'm trying to design a planet from the ground up, or in this case the cell up, i'd like my creatures to be more animal than plant, the more information i can gather about energy transport systems the more factual my fiction can be. but if i can't ask a question about a feild i'm researching in my freetime and have only the internet as a source of knowledge beyond television (not being a university student) then i'll stick to long winded pdf documents. and only when appropriate shall i attempt other queries. Link to comment Share on other sites More sharing options...
MortenS Posted February 15, 2005 Report Share Posted February 15, 2005 I don't think Tormod reacted to your question in it self, just the very minimalistic form it had. Anyway, if there is anything you would like to know about the evolution of mitochondria and chloroplasts (according to what science thinks today), I'll be happy to answer whatever I can answer. Link to comment Share on other sites More sharing options...
TeleMad Posted February 17, 2005 Report Share Posted February 17, 2005 Clay, I'm jealous. That's the best quote I've ever seen. ... Did you create it? If you did, I am totally humbled. No, he didn't invent it. It's pretty well known in the computer industry. Link to comment Share on other sites More sharing options...
TeleMad Posted February 17, 2005 Report Share Posted February 17, 2005 IrishEyes: Are WE the only life in the Universe? IMO, NO! I think it is a conceited view for mankind to think that he alone is the only intelligent life in an infinite universe with infinitely many planets like our own. Casting infinity aside though, one must still concede that the finite universe as we know it contains billions of galaxies each with billions of stars. The odds would seem to be greatly in favor of there being many worlds like our own. Another person who considers only half of the equation. Looks like time to bring this up again... Telemad: Okay, let's suppose there are 2 x 10^25 stars and each one has a total of 500 planets and moons. We won't worry about things like the fraction of stars that can produce Earth-like planets: we'll accept all stars and all planets and all moons as being appropriate. That would bring the total number of celestial bodies to 10^28. Huge number, isn't it. Now suppose that each of those celestial bodies gets a trillion trillion trillion trillion – that’s 10^48 - shots are originating life. That would come to a staggering 10^28 * 10^48 = 10^76 shots at generating life in this system of celestial bodies. Wow! But now what if the probability of life arising in a "single shot" is 1 in 10^120? See how much bigger the exponent is on that number than on the number of possible shots? It is so much larger that life's arising independently twice on these celestial bodies should be rejected. And what empirical/scientific evidence do we have that the "single shot" probability of life arising by a prebiotically plausible mechanism can't be as small as 1 in 10^120? None. In fact, some evidence (based on the closest things to an RNA replicase yet produced by directed evolution) supports the notion that it could be that small. Some people get too excited when they think about the number of celestial bodies on which life might arise that they are blinded to the fact that there being other life in the universe depends critically on how probable life's arising under prebiotic conditions is: a number they ignore. Link to comment Share on other sites More sharing options...
C1ay Posted February 17, 2005 Report Share Posted February 17, 2005 Another person who considers only half of the equation. Looks like time to bring this up again... Hardly. You can get an idea of my view of the universe here and here. The limits and odds you discuss of the probablity of life occuring do not hold up in my view of the universe. the fact that there being other life in the universe depends critically on how probable life's arising under prebiotic conditions is Perhaps you can prove this requirement? Are you claiming to understand all possible life forms that could exist and the requirements for their beginning? Link to comment Share on other sites More sharing options...
Fishteacher73 Posted February 17, 2005 Report Share Posted February 17, 2005 TeleMad and I have gone round and round about this very issue...look back in this thread. I will admit (although my opinion is the other side of the coin of Tele's) that his argument does have some validity. Many of the estimates that are used to computate the probabilities are just that estimates and guesses without any real backbone other than intuition to be their guide. One aspect that I read yesterday that I think supports the idea of life forming under "Earth-like" conditions is the reasonably high is the speed at which life showed up on Earth. The planet solidified between 4 and 3.9 billion years ago. Life showed up at about 3.85 billion years ago. Unless one supports a creationist ideal or panspermia(which just delays the quest to find the origins of life and definatly supports ET life), it seems that life popped up pretty quickly. The speed at which this occured seems to imply the ease at which it will happen under pre-biotic conditions. Link to comment Share on other sites More sharing options...
TeleMad Posted February 19, 2005 Report Share Posted February 19, 2005 One aspect that I read yesterday that I think supports the idea of life forming under "Earth-like" conditions is the reasonably high is the speed at which life showed up on Earth. The planet solidified between 4 and 3.9 billion years ago. Life showed up at about 3.85 billion years ago. Unless one supports a creationist ideal or panspermia(which just delays the quest to find the origins of life and definatly supports ET life), it seems that life popped up pretty quickly. The speed at which this occured seems to imply the ease at which it will happen under pre-biotic conditions. Well, directed panspermia was proposed by one of the greatest biologists who ever lived: Francis Crick. There is some circumstantial support for this position. And if life did arrive here, instead of arise here, then the amount of time needed for life to have arisen could potentially be a billion years or more. Link to comment Share on other sites More sharing options...
TeleMad Posted February 19, 2005 Report Share Posted February 19, 2005 Telemad: ... the fact that there being other life in the universe depends critically on how probable life's arising under prebiotic conditions is ... C1ay: Perhaps you can prove this requirement? Yeah, it's called math. Here's the main logic. Knowing how many shots you have to suceed doesn't tell you how many times you will probably succeed: you also have to know how probable/improbable the event is. Tell you what. I'll give you 100 tries, dealing yourself 10 cards each time after thoroughly shuffling the deck between deals, to get sneargoflaps. Now, how many times do you think you'll succeed? C1ay: Are you claiming to understand all possible life forms that could exist and the requirements for their beginning? No. Are you claiming that life unlike that we know of exists? Link to comment Share on other sites More sharing options...
frostbitte Posted February 20, 2005 Report Share Posted February 20, 2005 Statistically, I can't see us as being the only life in the universe. Even though it's not yet proven so, I think we will eventually find out otherwise. Heck, we're still finding new types of life forms here on Earth where we never expected to. I think once we do find out a lot of us will start to realize how big things really are we'll get a good kick in our complacency. Link to comment Share on other sites More sharing options...
C1ay Posted February 20, 2005 Report Share Posted February 20, 2005 Are you claiming that life unlike that we know of exists? No! I am claiming that it's possible. Would you say it's impossible? Link to comment Share on other sites More sharing options...
TeleMad Posted February 20, 2005 Report Share Posted February 20, 2005 Statistically, I can't see us as being the only life in the universe. How can you do any "it must be"-type statistics when one of the key probabilities is unknown? frostbite: Heck, we're still finding new types of life forms here on Earth where we never expected to That confuses where life can survive after adapating to those conditions, with where life can arise: two very different things. Link to comment Share on other sites More sharing options...
TeleMad Posted February 20, 2005 Report Share Posted February 20, 2005 TeleMad: Are you claiming that life unlike that we know of exists? C1ay: No! I am claiming that it's possible. Would you say it's impossible? Impossible? No. But anyone who uses life-not-as-we-know-it in their scenarios is relying upon pure speculation, and therefore, the burden of proof falls upon their shoulders, not their opponent's. Link to comment Share on other sites More sharing options...
C1ay Posted February 20, 2005 Report Share Posted February 20, 2005 Impossible? No. But anyone who uses life-not-as-we-know-it in their scenarios is relying upon pure speculation, and therefore, the burden of proof falls upon their shoulders, not their opponent's. I disagree. IMO, there are likely life forms the human race will not have the technology to detect or understand until some point in the future. Link to comment Share on other sites More sharing options...
TeleMad Posted February 20, 2005 Report Share Posted February 20, 2005 I disagree. IMO, there are likely life forms the human race will not have the technology to detect or understand until some point in the future. Right, IN YOUR OPINION that is likely. That's not fact. You have not one ounce of empirical evidence that such life exists ... none. It's pure speculation. All life we know of is related and based on the same general biochemistry: that is the position with all the empirical evidence. Those whose position relies upon pure speculation, when the other side has all of the empirical evidence, has the burden of proof. C1ay: To think we are all knowing is ludicrous. To think I claimed we are all knowing is retarded. C1ay: You claim the burden is mine when you yourself use a bunch of numbers you can't even substantiate as factual for your own analysis. And note how I qualify all of my statements such as that with "if" and other such phrases. I don't claim there is not other life out there, but rather that neither side can legitimately assert that they are right and the other side is wrong. You, on the other hand, are arguing that the position that there might not be other life out there is wrong. C1ay: How do you know there aren't a googolplex of planets out there just like our very own? In our "universe"? Because there aren't even that many elementary particles. C1ay: He which claims it is so, simply because he thinks it is so, has nothing left to learn. Why are you talking about yourself like that? Link to comment Share on other sites More sharing options...
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