we cannot know all the factors involved in determining the probability of life in the universe, baseed on the fact that there are just too many variables to deal with. If anything, the numbers just get bigger than we can extrapolate from our current body of knowledge. So, as you said Dave w, we can't KNOW the chances of life existing elsewhere in the universe, but we can know that the chances are very minute just based on some simple scientific knowledge about the requirements of life and then a little more knowledge about the conditions of the rest of the universe. Furthermore, the universe is only so bug and so old, and by that fact alone we know that the chances for life to spontaneously generate itself anywhere whithin the universe are severely limited by only these two parameters.
Dave W, why, given the massive body of evidence that we have as to the conditions of the universe in other regions, and given the knoledge we have about the fragile nature of life and the things required to sustain it, can we not know at least in part what the chances of life spontaneously generating itself in this or any other part of the universe is? The universe is not an infinite place, and limitations on how life can be made do exist, as well as knowledge that there are many types of environments that not only preclude the existence of life, but also the formation of planets on which to support the life. Provide some evidence for your statements, because thusfar all I have heard is that I am wrong. That is a terribly easy thing for someone to say, especially for you seeing as how you have definite seniority here and I do not. Try responding with knowledge rather than unsupported assertion. Again I also point out there there is a marked amount of disrespect going on not only towadrs me but towards many people. Just because people dissagree does not give either person liberty to be rude to the other, and even if one person is blatanly wrong, one should respond in such a way that the person takes a new perspective from the debate, not just hurt feelings and shaken confindence. Some of these discussions are downright insulting! What is your purpose here, to help yourself and others to learn or to simply make yourself look good? As this is supposed to be a more philosophical disscussion I would like to request that it foolow the rules of a socratic dialogue, or a discussion in which disagreements are settled (or continue) in a mode of polite debate, not this mindless name-calling that I have witnessed on this and many other exosci message-boards. I think that a general rule should be established, solely for the benefit of the propegation of knowledge, that assertipons be backed by SOME kind of evidence, whether that evidence be in the form of raw data, sources, or some other form of credible corroberation of the claim. Does that not sound like a decent suggestion. That said, you have yet to tell me why we have no basis to say that life has a minute chance of forming on its own in the universe. Please enlighten me, I am waiting.
Dumb, This is a very simple argument, which is why I've avoided spelling it out in it's most simple form. We live on Earth. Our knowledge of how live arises anywhere is very limited (there are many competing theories as to how life actually arose on Earth). So, as a result we can make no definite claims about the mechanism by which life was created. Having no clear mechanism, we can make no claims as to the probability of life formation under Earth-like conditions. Furthermore, we have absolutely NO evidence regarding the probability of planetary formation. Our ability to resolve planetary systems is limited by our technology. Right now we can only resolve systems with planets the size of Jupiter. Untill technology improves such that we can resolve the presence of Earth-sized objects AND a statistically large number of systems are analyzed, we cannot make ANY claims as to the likelihood of planetary formation. So, in other words, your claim that there is a "massive body of evidence" is either a lie or a misinterpretation. And yes, the universe may be finite. Even as such, estimates as to the number of galaxies are in the range of 125 x 10^9 (125 billion). Estimates as to the # of stars in our own galaxy are around 500 x 10^9 (500 billion). Multiply the two, and you find a total number of stars with potential planetary systems to be ~ 6.25 x 10^22. Now, if you're trying to argue creationism on this one, it seems like an awful excess to produce 6.25x10^22 star systems only to have one inhabited with life.
dave w, I do know that there are limitations in our technology that will preclude us ever havnig a full understanding of every detail of the universe. However, there are many common-sense considerations regarding the formation of planets. First of all, the stars which will have planets must be in a galaxy where there are enough 3rd generatin stars to produce heavy elements. Without this, we can have no planets made of anything but hydrogen and helium. Try to form a planet out of this and it will be too light to condense into an even recognizeable shape, much less have the "meat" on it to build the basics of life. By this simple fact of life, I have knocked about 80% of your "possible planetary systems" away. Considerations like this are not blind speculation, they are factual, no matter how bad that may scare you, or not, I dont know. many other proveable considerations exist, whether you want them to or not.
DCK-- Somewhere around here, Boris and I traded ideas on differentiation of matter and energy, variance in density, and methods of accretion. Now ... that's somewhere in these 180+ posts; I yield to Boris' constructions regarding these ideas. However, recent findings suggest an open, infinite, continuously expanding Universe, as opposed to a closed, eventually-retracting Universe, or the fixed-volume Primum mobile of medieval thought, which contained the Universe, which reached just beyond the planets we could see with the naked eye. Overall, academia's call for an infinite, expanding Universe is compelling, and Dave has stated a fine case in the event of a finite universe. Now, check those numbers (Dave's) as a starting-point to infinity. Consider Einstein and General Relativity. Differentiation of density, and 'twixt matter and energy, happened early after the Big Bang. If the Universe has an infinite opportunity to combine and balance matter and energy, it must necessarily get around to the combination that equals organic life. You can throw as astronomically huge numbers into the mix as you want, or as quantum-tiny as you like. But what do any of those numbers mean as a fraction of infinity? It might be one in a billion odds that something happens, but what about the probability that it will happen, having infinite opportunity to try? When you talk about odds, you're looking for a single event. It's like rolling, say, a billion-sided die. Every specific roll means that there is a 1/1,000,000,000 chance that you will hit the number 6. But what about the idea of hitting the number 6 once within the set of ten-billion rolls of the die? Okay--you are the Universe, on vacation in Monte Carlo. You roll the Big Die; only one result will win. But you're the Universe, and have no bankroll to account for, so you can throw as many times as you like. (Daddy needs a new pair of shoes!) thanx, Tiassa Please Register or Log in to view the hidden image! ------------------ The whole business with the fossilized dinosaur eggs was a joke the paleontologists haven't seen yet. (Good Omens, Gaiman & Pratchett)
Dumb, You are entirely correct that there are stringent conditions needed for the formation of life, as we know it. However, to prove your point that the spontaneous creation of life is impossible, you must go beyond simply showing it to be improbable. Your argument is: - there is an infinitely small probability of life being created spontaneously, yet the universe is finite. Thus the existence of life must mean it was created non-spontaneously by some divine creature. As stated, this argument itself isn't perfect. More seriously, you are failing to realize that your probability is not infinitely small. Your probability is infact finite. So, you are now have a finite possibility over a finite set. The ultimate result is still a finite possibility. You cannot claim that for all stars life will not exist if there exists a finite possibility that life could exist.
dave w, you are right when you say that all the parameters I have set forth are finite. Sorry if I said otherwise. The universe is finite, the chances of life propegating in the universe are fintity small, but the point is that the chances are still astronomically tiny. Ask any statician and they will tell you that chances that low equate to something being not realistically possible.
1) The actual magnitude of the probability doesn't matter. It doesn't change the argument. 2) You don't know the actual magnitude, because: a) you don't know the number of relevant parameters and b) you don't know the probability of most of the parameters. Unless you can prove that the theoretical probability of any of the parameters is exactly zero, your argument will fail.
dave w, my argument will not fail depending on uncertainty, it will simply just be incomplete, more or less. Probability is still valuable in deciding whether or not it is realistic to believe that life can propegate itself independantly of any intervention, anywhere in the universe. just because the whole of a thing cannot be seen does not mean that it does not pose valid concerns. [This message has been edited by dumb college kid (edited April 07, 2000).]
So your argument is entirely independant of any evidence! How does it differ from the ramblings of a madman?
DaveW, I think what DCK (Dumb is so obvious and you should be above name calling) is trying to say is that like, he's seen a headlight peeping out from behind the curtain and he assumes the rest of it is a car. I think it's a reasonable assumption to make even if there are chances that he's wrong. I wouldn't call it the ravings of a madman, that's reserved for me! ------------------ Oh my God it's the funky shit!!!
Tab, The name looks like, first, middle, last. Selecting the first name should be acceptable, even though it might have apparent unfortunate implications, but that was his free choice. Our approach isn’t necessarily derogatory but more on the lines of good humor, I’m sure he selected the name with that in mind. However, DCK sounds like dick, did you mean to imply that? I think you are also incorrect in the evaluation of his approach. He is a Christian attempting to prove the existence of a god by implying a supernatural force created the universe. Such a claim must be supported by clear, precise, unambiguous, and proven facts, beyond any reasonable doubt. Dave has shown that he has failed in this attempt. Whether Dave believes in a god or not is irrelevant, but he has shown an error in the logic and it only takes a single error, no matter how minor, to invalidate the entire claim. The reference to a madman is also valid. This was not an accusation of the person but a comparison with the invalid logic of the argument. However, if someone were to persist with continuous irrational arguments then perhaps the subtle distinction might become eroded.
ok, first off, either way you look at it, God existing vs God not existing, must take a bit of faith regardless of what side you are on. No 100% proof exists anywhere, ever. If anyone says that they have proved something 100% they are approximating or lying. Even special relativity, one of the most thoroughly tested fundamentals of physics, is only proven to about 99.8%, does that make it invalid? As far as clear, precise, unambiguous, and proven facts, beyond any reasonable doubt I gave you a list about 3 feet long on page 7! Precisely because we cannot know all the factors does not make something like probability invalid! Whether the proximities of life, and the conditions of the universe, are the way we understand them today or not, the parameters I have set forth on page 7 do not change that much. Realistically, statistical probability still works against the random formation of life in the universe, bottom line. You want evidence, look on page 7, or if you are too lazy, I will just repost it, we'll see. Depends on how long we wish to argue this out. An analogy to the body of evidence we have restricting the random formation of life is this: the infrmation we have is correct, but by no means complete, much like a collection of coins. We have coins from years past, but not all years past. Does this invalidate our collection? No, we simply add to it, and it gets bigger, more complicated. The evidence we have putting restrictions on life based on the requirements of life and the conditions of the universe are correct and testable. There are too many variables to collect ALL the evidence out there, but that does not work against my argument, but rather for it. Every day we are discovering how much more complicated life is, and how much stricter its requirements are. This makes the chances get smaller and the whole process more complicated, not more lucid. As for the madman bit, we both have taken opposing positions. I think I am right based on what I perceive to be good evidence, and you think you are right based on what you perceive to be good evidence. Therefore, if I am a madman, so are you based on the fact that our arguments are just opposite images of each other. But hey, a little madness makes life fun! Good wishes, micah [This message has been edited by dumb college kid (edited April 07, 2000).]
well, a level of good humor should be held throughout most disscussion, or else what fun is it? However, I have seen alot of very malicious statements about people, particularly directed at myself. I have called no one any bad names. With that in mind, I would appreciate it is we were all a bit more consciencious of the name-calling. It is very unprofessional, and even in good humor can be hurtful. I am not whining or saying I have been hurt, but I am just saying that the name-calling demonstrates a lack of maturity and does no one any good. I have seen posts where someone sets forth a portion of knowledge (incorrect or otherwise!) and people have ersponded by saying "my you're ignorant" and giving no reason as to why. What good does that really do? Notta, nothing. I hope we can all grow up a bit, myself included. I chose the name "dumb college kid" out of good humor and also to remind myself that I have got a lot to learn about everything under the sun. I have seen enough message boards at other sites just crawling with people who call themselves "mr. all-knowing" and "omniscient one" and whatnot, you just can't take those people seriously!! In debating with them, it is hard to keep a straight face. Humility is a first step toward wisdom. Good wishes micah [This message has been edited by dumb college kid (edited April 07, 2000).]
dck, welcome. You're making progress. If your arguments are worthwhile then they must be able to withstand tough scrutiny. I think you are actually having an easy time so far. I admire your courage. You are making the claims so you must do the work to produce the proof to the satisfaction of your audience. To say we are lazy and that the answer is in the library somewhere just won't wash. The onus must be on you to pick and choose the precise evidence needed to prove your point of view. There are some bright people here and they will support you if you make a good case. I’m not going to respond to your arguments until I see you make a valid case. Have fun and enjoy it. You can learn a lot here, especially about yourself. Cris (alias Wizard)
No we're not. In fact, we're discovering the exact opposite. As a microbiologist, I can tell you that the last 50 years have provided huge amounts of insight into exactly how flexible life actually is. The conditions that microbial life can exist under are truly astonishing. These forms of extreme life can exist under the harshest conditions, from deep sea hydrothermal vents to extremes of temperature, pH, salinity etc. No they're not. Any valid logical proof is universally valid. I never said anything about God. In the absence of conclusive proof, one must take a neutral position. Since you're obviously not understanding my argument, I will repeat it. You must show that the value of at least one parameter is exactly zero. If you do not, you must conclude that the probability is greater than or equal to zero. To use your coin example, what the hell is an invalid collection of coins?? You're throwing around terminology out of context. Anyways, you claim to have an incomplete set of coins. Now, a coin collector asks you to prove that a certain coin was produced in a given year. Alas, your coin is not in your collection. Since you have no coin, you cannot conclusively say that such a coin exists. You tell the collector that your collection is ever-expanding, and that one day you might find the required coin, at which point you'll have a conclusive answer. However, to prove the coin doesn't exist (ie. probability of zero), you must either show there to be a logical contradiction (or physical impossibility) required for the coins existence (perhaps the mint was shut down that particular year), or you must survey the entire set of all coins to show that the coin isn't in the set. Unfortunately, you must inspect 6.25x10^22 coins. So, you probably give up. You must accept the fact that you'll never know the answer, so when the coin collector comes by again, you'll just have to shrug your shoulders. Absolutely not. My belief is entirely open. I claim that the probability is greater than or equal to zero. You claim the probability to be zero. If our beliefs were exact opposites, I would claim the probability to be only greater than zero (ie. that zero was impossible). And yes, in that case I'd be a lunatic, because I'd be producing a conclusion without any justification. Please Register or Log in to view the hidden image! [This message has been edited by DaveW (edited April 07, 2000).]
I am sorry I have been misleading somehow thusfar. I did in no way mean to say that the probability of the random formation of life is zero, I just meant that it is astronomically small. The chances of it happening, as you have probably heard before, are smaller than the chances of a tornadoe passing through a junkyard and randomly assembling a 747. Not absolutely impossible, but so improbable that people would laugh at you if you suggested that to be the origin of all 747's. Again, I am truly sorry if I led you to believe I meant that the chances were exactly zero. I dont think that you are hearing me about the number of stars capable of establishing planets. According to everything that we have thusfar seen, only 20 percent of the stars in our galaxy are capable of producing the heavy elements required to form these planets. Also, in order to have life, you must have a reasonably low level of radiation. I as a first year college student know this, you as a microbiologist must. Radiation kills life. Again, according to what we have observed of the universe, only 5% of the galaxies are of the proper shape (spiral) to fall into this catagory, as the other 95% are too elliptical or too irregular. This mere pair of parameters takes your number down to 1% of its original size. Of the stars that remain possible candidates for planets, only 0.1% of those are class G stars like the sun. Any bigger or smaller and life would be exterminated because of excess heat and radiation, or would require that the planet be so close to the star that tidal interactions that the star exerts on the planet would slow its rotation to a crawl, destroying life by intense heat during the day and intese cold at night. Given the right star and the right kind of galaxy, one must have the proper position within the galaxy in order to make life possible. Too close to the galactic center and life is prevented as gravity from other stars makes the orbits of planets erratic, too far and there is not enough raw material left over from supernovaew to make the planets at all. The amount (from what we have been able to see and to deduce) of stars in THIS galaxy, which behaves very similarly to other spiral galaxies of its magnitude, only 20% of stars fall into this region. The percentage of the original number is now at 0.00005% I am detecting a pattern here, the numbers just keep getting smaller. I think perhaps that we are at an impass. I will therefore do some more resaerch and get back to you with further information. Good wishes Dave W micah
Since you're ignoring my logical arguments, I will directly contest your numbers. You claim: a habitable star system must involve a G-class star, and only 0.1% of all stars are G-class. Reality: 1) the habitability of a star system is more involved than simply the star class: a) It is generally agreed that a multiple-star system would not work, since planetary systems would be unstable. ~50% of systems have a singular star. b) "Main sequence" stars (ie. the set of stars excluding brown dwarfs, red giants etc. where luminosity correlates well with temperature) are generally thought to be necessary. ~90% of stars are main sequence. c) G-class. Your estimate is wrong. 5% of stars are G-class. d) F and K class stars are very similar to G-class stars. The temperature range is not extreme, and can be adjusted simply by moving the habitable zone inwards or outwards to compensate for differential in temperature. ~ 10% of stars are F or K class. So, the actual percentage of viable stars is ~ 0.5 x 0.9 x (0.05 + 0.10) = 6.75% 2) # of stars with planetary systems: current estimates range from ~5% - 50% 3) # of habitable planets within a planetary system. Well, there's at least one (perhaps two) in our solar system, so let us be conservative and say there will be 0.5 habitable planets within an appropriate planetary system. 4) All that remains, now that we have a viable star with a planetary system which includes a planet within the zone of habitability, is to determine how often life arises. Now considering how effectively life has flourished on Earth, I might say that life will arise 50% of the time when given the appropriate conditions. However, I'll humour you and be ultraconservative and say that for every 10,000 viable planets, only one will produce life. So, using the most conservative values for the parameters (this is only within our galaxy of 100-500 billion stars), we can conclude that: 6.75% x 5% x 50% x 0.01% x 100 billion = 16875 life-bearing planets Let us use the more liberal values: 6.75% x 50% x 50% x 0.01% x 500 billion (note I'm still using the ultra-conservative # for the formation of life) = 843750 life-bearing planets Now, I will admit that some of the values are hardly certain. But the values are widely accepted as being roughly appopriate. If you'd like to argue over the values or parameters, I'd be interested IF you can provide data from a credible source. I expect you will complain that many of your parameters have not been addressed. If you wish to complain regarding any specific parameters that are essential, please do. I'd rather not address all 62 (though I might have to, the way things are going), since most of them deal with either universal constants (which are irrelevant) or quality-of-life issues that don't really affect the actual creation of life. [This message has been edited by DaveW (edited April 08, 2000).]
dave, your argument does sound pretty good I must say except that I have no idea how, given that the only known exaple of life in the universe is earth, you can say that, given the right conditions life will self-generate 50% of the time. This is quite an assertion! Do you have some evidence to back that up? All the same, I think that this argument has gone way too long, and I am at a disadvantage right now, as I am but an ignorant little student and you are a microbiologist. I am not admitting defeat, but I am going to concede to the fact that arguing with you is getting neither of us anywhere. That said, good luck in life, I honestly hope you have a wonderful springtime (thank God for the warmth, a luxury which is rare in Alaska where I live). I am taking college finals in about two weeks, so I am going to have little time to debate, rest assured I will come back when I have the time. You seem like a very intelligent man, God bless you. micah
