# Basis of science's belief that extraterrestrial life is likely? **URL:** \ **Category:** Great Debates\ **Created:** [November 10, 2010, 3:43am UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137 "2010-11-10T03:43:11Z")\ **Posts on this page:** 20\ **Page:** 7
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [November 10, 2010, 3:47pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/121 "2010-11-10T15:47:17Z")
> [@heavyarms553](#): > > Actually you can estimate the probability of any given lotto ticket being a winner if you know the total number of lotto tickets printed, and the total number of lotto winners. Which we do not know because…, we don’t know how many planets have life on them, or even how many planets there are. As for the rest of your post, I have no idea what point you are trying to make. You have admitted that your analogy failed. You have, I think, conceded that my analogy was perfectly apt. I think you should leave it there ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 10, 2010, 3:52pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/122 "2010-11-10T15:52:12Z")
> [@Baboonanza](#): > > Wikipedia describes the antropic principle as “philosophical argument that observations of the physical Universe must be compatible with the conscious life that observes it.” > > Though I would call that a pointless tautology myself. How does that imply that ‘life must arise fast on any planet with intelligent life’? As far as I can tell there is no connection at all, not to mention that you seem to be pushing a philosophical argument as a fact. I agree. And I’ve never seen the point of the Anthropic Principle. As I’ve pointed out earlier, I think the more relevant principle is, [the Mediocrity Principle](http://en.wikipedia.org/wiki/Mediocrity_principle). And note that this principle makes no claim as to whether life is common. It simply _begins_ with the assumption that Earth is not exceptional. > [@Wikipedia](#): > > Ancients of the Middle East and west once thought that the Earth was at the center of the universe, but Copernicus proposed that the Sun was at the center. In the 1930s, RJ Trumpler found that the solar system was not at the center of the Milky Way Galaxy (as Jacobus Kapteyn claimed), but 56% of the way out to the rim from the galaxy’s core. In the mid-twentieth century, George Gamow (et al.) showed that although it appears that our Galaxy is at the center of an expanding universe (in accordance with Hubble’s law), every point in space could be experiencing the same phenomenon. And, at the end of the twentieth century, Geoff Marcy and colleagues discovered that extrasolar planets are quite common, putting to rest the idea that the Sun is unusual in having planets. > In short, Copernican mediocrity is a series of astronomical findings that the Earth is a relatively ordinary planet orbiting a relatively ordinary star in a relatively ordinary galaxy which is one of countless others in a giant universe, possibly within an infinite multiverse. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [November 10, 2010, 3:55pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/123 "2010-11-10T15:55:53Z")
> [@Acid\_Lamp](#): > > **Blake** The point I was driving at is that refusing to play _just isn’t good enough_ when you get to this type of question. Well if that was your point, you failed to make it. > [@](#): > > This is one of those big, brain twisting questions that has so many implications it’s scary. Let’s say this is true, how does it change the fact that there is or is not a scientific basis from which we can produce an answer? Would the answer be more scientific if it was less scary, or more? > [@](#): > > The reason I say hard numbers are irrelevant is because _we currently can’t do any better_; so we’ve got to go with what we have. No, we don’t. Once again, false dichotomy. We can declare that we have insufficient evidence and not “go” with anything until we get more evidence, no? > [@](#): > > Why? Because everyone wants to know what we should do. Most of the 6.5 billion people on this planet could not give a toss whether there is life elsewhere. Even if they did care, there is essentially nothing we can do about it either way. So far from everyone wanting to know what to do, most people don’t care, and those that do can’t do anything anyway. > [@](#): > > Science provides us with real answers about the universe, our place in it, True. > [@](#): > > …and how we should pursue our future as a species. No. Absolutely not. Science can only tell us what is. It can never, ever, ever tell us what should be. > [@](#): > > In this question you can sit out if you like but others WILL step in. Notably the religious. Where science refuses to tread is the stronghold of superstition. Nonsense Firstly, you are contending that “science” should make up facts that don;t exist for fear of religion. That is abhorrent to me. Secondly, science refuses to tread in a great many areas, including issues of what we ought to do. If religion fills the void then that is as it should be, because science can never be applied to such fields And the rest of your post is similarly puzzling and filled with incorrect assertions. I won’t bother to respond to it all, but the provable flaws in every sentence up to here should give you some indication of how bad it is. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [November 10, 2010, 4:00pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/124 "2010-11-10T16:00:36Z")
> [@Cheesesteak](#): > > Ok, I’ll answer your questions You didn’t. If you didn’t understand it then tell me so and I will cheerfully post the relevant quote, so that everybody can see that you are unable to follow the argument. If you did understand it then this is a deliberate strawman and everyone can see that you are not posting in good faith. Asking me to clarify doesn’t in any way tell me which of these options you are invoking. Did you not understand what was posted, and need me to re-post it? OR did you understand and construct a deliberate strawman. ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [November 10, 2010, 4:13pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/125 "2010-11-10T16:13:34Z")
> [@Blake](#): > > If you didn’t understand it then tell me so and I will cheerfully post the relevant quote, so that everybody can see that you are unable to follow the argument. I don’t understand your argument. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [November 10, 2010, 4:14pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/126 "2010-11-10T16:14:08Z")
> [@Acid\_Lamp](#): > > **Blake** The point I was driving at is that refusing to play _just isn’t good enough_ when you get to this type of question. This is one of those big, brain twisting questions that has so many implications it’s scary. The reason I say hard numbers are irrelevant is because _we currently can’t do any better_; so we’ve got to go with what we have. Why? Because everyone wants to know what we should do. Science provides us with real answers about the universe, our place in it, and how we should pursue our future as a species. In this question you can sit out if you like but others WILL step in. Notably the religious. Where science refuses to tread is the stronghold of superstition. Finding life elsewhere won’t invalidate god, of course. Nothing can, but it would invalidate any number of special creation hypothesis and relegate a great deal of literalism to antiquity. It has huge implications on how we might expand our species to other planets, and even if we SHOULD be thinking about doing that. It has bearing on our understanding of the definition of life itself. THAT is why you can’t just sit out. It’s fine to say “we can’t really be certain until we find it.”, but the world doesn’t work that way. Funding for research is doled out on the basis of bets and odds, as is public support, and interest in developing further technologies that are relevant. > > Science can’t just sit out, because the public doesn’t hear: “We can’t be certain because of a complex logic loop that may invalidate our findings”. They hear: " We are incompetent in our ability to even make a guess." When that happens, science loses support of all types, and we go backwards. What you’ve said implies that the scientific community should conspire to lie to the public about its state of knowledge concerning extraterrestrial life? Is that really what you want to imply? ---
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [November 10, 2010, 4:17pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/127 "2010-11-10T16:17:05Z")
> [@Xema](#): > > This is skating on very thin ice. It seems to be saying that scientists should not be honest about what conclusions can properly be drawn from available evidence because the political consequences of that honesty might be troublesome. No, I’m saying that when asked for answer that cannot be conclusively given, we should say so, but not be afraid to speculate either when pressed to guess. The speculation, the hypothesizing is what drives the whole process. If you refuse to even hazard a guess, why should anyone place confidence, trust or money in your research? The worst thing you could be was incorrect, but in finding yourself so you obviously discovered new information. That is a step forward. You can state: “Our previous speculation turned out to be incorrect. It turns out upon new discoveries that the blah blah blah… We NOW believe that x, y, z…” ---
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [November 10, 2010, 4:19pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/128 "2010-11-10T16:19:54Z")
> [@Frylock](#): > > What you’ve said implies that the scientific community should conspire to lie to the public about its state of knowledge concerning extraterrestrial life? > > Is that really what you want to imply? Answered above. Don’t be ridiculous. Not everything is a binary statement. There is nothing wrong with stating: “We can’t be certain because of a number of factors, but I believe the available evidence supports or refutes the existence of extraterrestrial life”. ---
**Author:** ![heavyarms553](https://avatars.discourse-cdn.com/v4/letter/h/779978/32.png) [@heavyarms553](https://boards.straightdope.com/u/heavyarms553)\ **Post date:** [November 10, 2010, 4:31pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/129 "2010-11-10T16:31:23Z")
But you see… I… Ugh… This is pointless. OP is trolling the board so hard. His post rate, preponderance for large text and argument evasion makes it clear that he is currently manic and not open to rational debate. I bet you 10 bucks he responds asking me where he evaded. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [November 10, 2010, 4:41pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/130 "2010-11-10T16:41:34Z")
> [@Acid\_Lamp](#): > > No, I’m saying that when asked for answer that cannot be conclusively given, we should say so, but not be afraid to speculate either when pressed to guess. The speculation, the hypothesizing is what drives the whole process. It can drive things in a useful direction if it’s a testable hypothesis based on verifiable evidence. Without evidence, it has no value at all, and is thus something any scientist worthy of the name should refuse to indulge in. Someone who uses his stature as a scientist to pass off ignorant speculation as science is undermining the position of honest scientists. > [@](#): > > There is nothing wrong with stating: “We can’t be certain because of a number of factors, but I believe the available evidence supports or refutes the existence of extraterrestrial life”. Provided there’s some evidence available. ---
**Author:** ![Gustav](https://avatars.discourse-cdn.com/v4/letter/g/919ad9/32.png) [@Gustav](https://boards.straightdope.com/u/Gustav)\ **Post date:** [November 10, 2010, 4:41pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/131 "2010-11-10T16:41:43Z")
Bit disappointing really. All this back and forth about aliens, principles, lottery tickets and god knows what, and it turns out to be just another “science should never make any claims because they can’t be 100% sure” sequel. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [November 10, 2010, 4:55pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/132 "2010-11-10T16:55:41Z")
> [@Gustav](#): > > … it turns out to be just another “science should never make any claims because they can’t be 100% sure” sequel. Funny - I took it as “science should never make claims not based on evidence.” Any details of which we’re even 10% sure would be useful here. ---
**Author:** ![Diogenes\_the\_Cynic](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@Diogenes\_the\_Cynic](https://boards.straightdope.com/u/Diogenes_the_Cynic)\ **Post date:** [November 10, 2010, 5:08pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/133 "2010-11-10T17:08:20Z")
Science does not make a claim that life definitely exists elsewhere, only that it’s unlikely - given the size of the universe and the ubiquity of the conditions and bulding blocks that led to abiogenesis on earth - that earth has somehow been uniquely special and magic in its ability to produce replicating molecules. ---
**Author:** ![Acid\_Lamp](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@Acid\_Lamp](https://boards.straightdope.com/u/Acid_Lamp)\ **Post date:** [November 10, 2010, 5:14pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/134 "2010-11-10T17:14:29Z")
> [@Xema](#): > > Funny - I took it as “science should never make claims not based on evidence.” Any details of which we’re even 10% sure would be useful here. We are sure of lots of things about the nature of life; The problem as posed by the OP is that we are inherently biased because it is our own planet we are using for an example. I’m not certain that argument holds water when talking about something on the scale of planetary biology though. As I noted to Blake, until we either develop the tech to get out there and look, or it comes to us, we won’t be able to categorically prove or disprove it. All we can do is look at the life we have here and make inferences about the odds for or against. You want a simple calculation? In our known sample size, we have one planet in our solar system that has definite life. So that gives us 1 in 9. To make things simpler let’s stack the deck against and say 1 in ten. We KNOW that to be factual. Now if we look at other stars we see that lots of them have earrth like planets or moons in the goldilocks zone as well. Many of them have more than ten bodies, some less. Even if we assume that only 1 in ten is suitable, and then assume that only one in hundred of those has actual earth like conditions, and then assume 1/100 of THOSE has condition after condition, When you place that against the staggering amounts of stars in our own galaxy, let alone the universe, you can only come to the conclusion that it is more likely that there is life of some type, than not. You simply roll the dice way too many times for it not to come up in the right combination occasionally. it isn’t really a wild assed guess, if the lottery is like one in 26 million, and I’ve got thousands of trillions of rolls, I’m going to win, over and over. True, we don’t know the entirety of the spread, but the more we learn, the more it looks like the odds are not so great. The resiliency of life, and commonness of many of the precursors to it seem to indicate that it would occur on earth over and again until the conditions became prohibitive to the chemical reactions. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [November 10, 2010, 5:23pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/135 "2010-11-10T17:23:57Z")
> [@Blake](#): > > The passage through oceanic vents that Miller (of Urey-Miller fame) posited as the reason why life need to arise fast, are still sterilising the entire ocean every few million years. What? The _entire ocean_ does not get sterilized “every few million years”. (which I’m reading as more than 3, less than 20) If this were the case, mass extinctions would be much more common. Cite! Really, Blake, I’m in general agreement with your basic point on this issue (that we really can’t say what the chances are, and it’s unscientific to extrapolate from a sample of one, is how I’m reading it), but I think you’re getting a little careless in your zeal. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [November 10, 2010, 5:31pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/136 "2010-11-10T17:31:23Z")
> [@Blake](#): > > I can’t remember the figure that Miller uses, IIRC it was something like 10 million years for all seawater to pass through hydrothermal vents and be sterilised. …and immediately get contaminated again. This tells you nothing about boundary periods for life formation, it’s a total\* non sequitur\*. It also contains the assumption abiogenesis happened in the oceans, which is not necessarily so. ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [November 10, 2010, 5:46pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/137 "2010-11-10T17:46:39Z")
> [@Blake](#): > > Ahh, no. > > If you follow the discussion Saganist and I are having, you will see that the presence of intelligent life is in fact a core issue. > . Ah, no. MY question started the other thread. I was referring to scientists belief that “life” - rather than NOT-life, is likely to exist elsewhere. Any kind of life. Including not-so-bright bacteria, insects, etc. If you and Saganist are off on a tangent, enjoy yourselves. ---
**Author:** ![Stoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stoid/32/272_2.png) [@Stoid](https://boards.straightdope.com/u/Stoid)\ **Post date:** [November 10, 2010, 5:54pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/138 "2010-11-10T17:54:52Z")
> [@Superfluous\_Parentheses](#): > > In my experience, the people who assert such a position generally do so out of an inflated sense of the importance of earth-bound, if not human, life. That doesn’t mean everybody who does so is that arrogant, but humans have an amazing capacity to think of themselves are precious special creatures. I don’t think of humans as precious and special so much - but I certainly think of the whole of life on this planet absolutely is, and we take it far too much for granted. I think it’s arrogant to assume that because a planet like this exists that there must be loads of them. Earth is pretty spectacular both in its life and in its landscapes and I think that as a species we DO think of every single human life as special to the detriment of everything else. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [November 10, 2010, 5:59pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/139 "2010-11-10T17:59:55Z")
> [@Acid\_Lamp](#): > > The resiliency of life, and commonness of many of the precursors to it seem to indicate that it would occur on earth over and again until the conditions became prohibitive to the chemical reactions. Yet it seems to be widely accepted that it happened just once on Earth, which can be taken as evidence that it’s highly unlikely even here. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [November 10, 2010, 6:03pm UTC](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137/140 "2010-11-10T18:03:14Z")
> [@Stoid](#): > > Ah, no. > MY question started the other thread. I was referring to scientists belief that “life” - rather than NOT-life, is likely to exist elsewhere. Any kind of life. Including not-so-bright bacteria, insects, etc. Blake’s point about intelligent life relates to the anthropic principle. [Previous page](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137.md?page=6) [Next page](https://boards.straightdope.com/t/basis-of-sciences-belief-that-extraterrestrial-life-is-likely/560137.md?page=8)