# Extraterrestrial and Intelligent Life Prediction **URL:** \ **Category:** Great Debates\ **Created:** [December 19, 2012, 5:46pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550 "2012-12-19T17:46:40Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [December 20, 2012, 4:00pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/21 "2012-12-20T16:00:43Z")
Try the [Drake equation:](http://en.wikipedia.org/wiki/Drake_equation) > [@](#): > > The Drake equation states that: > > N = R\* . fp . ne . fℓ . fi . fc . L > > where: > > N = the number of civilizations in our galaxy with which communication might be possible (i.e. which are on our current past light cone); > and > > R\* = the average rate of star formation per year in our galaxy > fp = the fraction of those stars that have planets > ne = the average number of planets that can potentially support life per star that has planets > fℓ = the fraction of the above that actually go on to develop life at some point > fi = the fraction of the above that actually go on to develop intelligent life > fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space > L = the length of time for which such civilizations release detectable signals into space[5] The problem being, of course, that too many of those values are not only unknown to us but, from humanity’s present state of scientific knowledge, imponderable; so the equation is not very useful. Yet. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [December 20, 2012, 7:38pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/22 "2012-12-20T19:38:06Z")
1. I believe the universe is teeming with life; it’s just too vast to be otherwise. And I don’t just mean “life as we know it,” but also life that we may not even recognize as living. 2. If we survive long enough, contact is inevitable. Not using any technology that we can currently imagine though, thus we wrongly tend to think it’s “impossible.” ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [December 20, 2012, 7:53pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/23 "2012-12-20T19:53:50Z")
> [@panache45](#): > > 1. I believe the universe is teeming with life; it’s just too vast to be otherwise. And I don’t just mean “life as we know it,” but also life that we may not even recognize as living. Are rocks living? > [@panache45](#): > > 1. If we survive long enough, contact is inevitable. Not using any technology that we can currently imagine though, thus we wrongly tend to think it’s “impossible.” “Impossible” is a better bet than “inevitable” here, because technological progress is never “inevitable” in its details – we can predict technology will progress so long as economic incentives exist; but, we cannot predict what proposed technologies will prove workable or unworkable, not even the engineers and inventors know that until they build the thing and try it; but, we can predict that, without some major new paradigm-shattering discoveries in physics, neither FTL travel nor FTL communication ever will be invented, simply because they are impossible. ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [December 20, 2012, 7:54pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/24 "2012-12-20T19:54:41Z")
> [@chargerrich](#): > > 1. Yes (and probably hundreds of them) > > 2. Never - Even if humans could achieve interstellar travel before we self destruct and extinguish our civilization, the distance is too great. Yeah, that’s pretty much how I see it. ---
**Author:** ![Bertal](https://avatars.discourse-cdn.com/v4/letter/b/d6d6ee/32.png) [@Bertal](https://boards.straightdope.com/u/Bertal)\ **Post date:** [December 20, 2012, 8:05pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/25 "2012-12-20T20:05:40Z")
1. Science is an isle in the ocean of ignorance. Why bother just one fact that possibly could exist while we don’t know it? Consider it not existing. So the answer to 1 depends on 2. 2. Unlikely. ---
**Author:** ![Blaster\_Master](https://avatars.discourse-cdn.com/v4/letter/b/cab0a1/32.png) [@Blaster\_Master](https://boards.straightdope.com/u/Blaster_Master)\ **Post date:** [December 20, 2012, 8:09pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/26 "2012-12-20T20:09:54Z")
> [@chargerrich](#): > > 1. Yes or No - Do you believe that intelligent civilization(s) exist ANYWHERE else in the Universe? Short answer, yes. For a more complex answer, it depends. Unless our understanding is fundamentally wrong, life must exist in other places. There’s obviously a lot of variables that affect the frequency, not just in terms of what is favorable for life but just the sheer chance of intelligence evolving and not eliminating itself. It could very well be that life is extremely plentiful but the circumstances that favored our evolution are extremely rare. It’s also possible, as someone else mentioned, that we’re actually among the first such intelligent species. There was a long period where, regardless of resources, the universe was inhospitable to life. Further, life as we know it requires heavier elements that requires enough stars to create them, burn out, and for those to recollect in the right proportions with the other important factors. Then you have to consider how long it may take for intelligence to evolve, hell, we had several mass extinctions here before intelligence arose. So, sure, there were billions of years before life arose, and billions more before us, but we could still be early on the curve. I do, however, believe that the universe is sufficiently large that even particularly rare combinations are likely to occur multiple times. So it’s extremely likely that there’s other intelligent life out there. But beyond believe that other intelligent life exists, we don’t really know enough to say whether it’s just a few other civilizations or countless. > [@](#): > > 1. If Yes - When do you believe humans will make contact with such a civilization? I’m going to say unlikely in the next few hundred years, to say the least. It depends on just how common intelligent life is. Even if it is common, it’s quite possible that technology that could help us communicate with them is WAY off, that they’re rare enough that they’ll never be in reach, or that they’re so far ahead or behind us technologically or culturally that we just can’t effectively make contact. Like, for instance, if they were like we are now relative to our technology 500 years ago, even though both civilizations are intelligent, they’d be unable to communicate unless in direct face to face contact. The civilization from 500 years ago wouldn’t be able to receive digital signals, and that’s all the current day technology expects from similar intelligences. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [December 20, 2012, 8:53pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/27 "2012-12-20T20:53:38Z")
> [@Buck\_Godot](#): > > I don’t see how this helps us. If civilization generally lasts 100,000 years before collapsing, at any given spot there is a 100,000 year period over which we have to overlap. Given that life itself is on the scale of millions of years, the probability that a given planet is at the right time in evolution relative to its distance from us is still going to be quite small. Right – I don’t think it affects the results, just the mental image. If the Drake equation is correct, it doesn’t affect the results. But that assumes one-way communication is sufficient for “contact”. If two-way communication is required, then both civilizations need to be in each others’ light cones, which reduces the results dramatically, unless we assume civilizations are extremely long-lived. > [@BrainGlutton](#): > > Try the [Drake equation:](http://en.wikipedia.org/wiki/Drake_equation) Yeah, thanks – that’s the “whatsisname” I so eloquently referred to above. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [December 20, 2012, 9:11pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/28 "2012-12-20T21:11:01Z")
1. Yes - the sample’s large enough so \*some \*other sort of intelligent life would be likely somewhere 2. a) Direct interaction? Probably never. Distance, and its correlated element of non-overlapping time frames before natural or inflicted extinction (genus Homo, never mind H. sapiens, will not exist forever, even if we do NOT self-destruct; being down to only one species does make it a a bit more precarious a position); plus differently-evolved modes of perception. 3. b) Running into evidence of their existence? More plausible but unlikely in the near future, for now we’re limited to listening for signals of such strength and frequency as may be detected by _our_ radio devices, against a universeload of background noise. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [December 20, 2012, 9:13pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/29 "2012-12-20T21:13:25Z")
> [@Learjeff](#): > > . . . If the Drake equation is correct . . . Oh, it’s correct, all right. The problem is, it’s essentially tautologous. It’s a little like saying, “The population of the earth equals the difference between the number of people who ever have been born and the people who ever have died.” It’s true… It just doesn’t actually supply those numbers. That said, it’s still a very nice attempt at reducing the question to more-simply-addressed components (quite unlike my example, which only makes the question _harder_ to answer!) ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [December 20, 2012, 9:19pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/30 "2012-12-20T21:19:00Z")
1. There’s no evidence of ANY intelligent civilization in the universe, including on Earth. But I believe there are some somewhere. 2. Maybe. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [December 20, 2012, 10:05pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/31 "2012-12-20T22:05:25Z")
> [@Trinopus](#): > > Oh, it’s correct, all right. The problem is, it’s essentially tautologous. I suspect you’re right, but there’s always been something nagging at me that the speed of light and distance factor out. I believe that’s true only because of what I said above: one-way contact (detection) versus communication. I haven’t really thought it through. The factors that are listed in the Drake equation are pretty much obvious, just breaking down the “probability of intelligent life anywhere” into a bunch of successive preconditions, none of which we have any idea what the probabilities are. Some of which we might get a clue about, others probably not. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [December 20, 2012, 10:49pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/32 "2012-12-20T22:49:56Z")
As I understand, the universe is infinite. And, with greater than zero probability a star will host inhabited planets, there has to be an infinite number of intelligent civilizations. Drake equation based estimates I have seen, together with predictions of SETA progress, imply that there’s a decent chance we will find good evidence of another civilizations within the next few decades. ---
**Author:** ![marshmallow](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@marshmallow](https://boards.straightdope.com/u/marshmallow)\ **Post date:** [December 20, 2012, 10:56pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/33 "2012-12-20T22:56:40Z")
Good timing, what with the news about Tau Ceti and its Earth-like planet. Twelve light years may as well be forever away with current technology, but it’s theoretically doable to visit eventually. Another potential way to detect ETs besides meeting them or talking to them with radiowaves would be discovering relics, like old probes or megastructure. Pretty unlikely, but you never know. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [December 20, 2012, 11:02pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/34 "2012-12-20T23:02:14Z")
Contact? Not if you mean 2-way. _Detection_ of intelligent life is much more likely. ---
**Author:** ![Max\_the\_Immortal](https://avatars.discourse-cdn.com/v4/letter/m/6de8d8/32.png) [@Max\_the\_Immortal](https://boards.straightdope.com/u/Max_the_Immortal)\ **Post date:** [December 20, 2012, 11:50pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/35 "2012-12-20T23:50:32Z")
> [@marshmallow](#): > > Good timing, what with the news about Tau Ceti and its Earth-like planet. Last I heard, it was simply in the star’s habitable zone. I haven’t read any indication that the planet would be Earth-like rather than Mars-like or Venus-like or any of a wide number of ways to be totally unlike Earth. ---
**Author:** ![stui\_magpie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stui_magpie/32/11010_2.png) [@stui\_magpie](https://boards.straightdope.com/u/stui_magpie)\ **Post date:** [December 21, 2012, 2:28am UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/36 "2012-12-21T02:28:36Z")
Pray that there’s intelligent life somewhere up in space, 'Cause there’s bugger all down here on Earth. — Mr. Pink, Monty Python’s The Meaning of Life In response to the question: 1 yes 2 yes, inevitably, but not for a loooong time yet. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [December 21, 2012, 2:51am UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/37 "2012-12-21T02:51:16Z")
1. I don’t know. If there are other forms of life you’d assume their advancement would be all over the board. I don’t know if they would be limited by the speed of light in travel or communication, I’m assuming a species millions of years more advanced would find ways around that. If they were real they’d have communicated. UFOs have been seen, but nothing truly concrete has happened as far as I know. No aliens have landed at the UN to communicate with us or anything. 2. Don’t know. Even with an extra 200 years of technology, the human race will be unrecognizable by 2212 I’m assuming. So it is highly unlikely we are the most advanced intelligent civilization in the universe. So even a species 500 years more advanced than us would probably know how to travel and communicate faster than light. If they haven’t contacted us I don’t see why we wouldn’t contact them. Also some people would say ‘the aliens have a prime directive or something similar’. But it is unlikely that ‘all’ of them would share the same directive. On earth explorers would travel all over the planet to meet new people. I see no reason ‘all’ the aliens would want to hide their presence by just engaging in subtle interactions like people seeing UFOs. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [December 21, 2012, 3:00am UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/38 "2012-12-21T03:00:44Z")
> [@Wesley\_Clark](#): > > So even a species 500 years more advanced than us would probably know how to travel and communicate faster than light. It’s quite likely genuinely impossible to travel faster than light; therefore, it doesn’t matter how advanced they are, they can’t go FTL. > [@Wesley\_Clark](#): > > Also some people would say ‘the aliens have a prime directive or something similar’. But it is unlikely that ‘all’ of them would share the same directive. On the other hand if we are inside the territory of a species that has such a principle, then the policies of other species may not matter. ---
**Author:** ![akennett](https://avatars.discourse-cdn.com/v4/letter/a/ee59a6/32.png) [@akennett](https://boards.straightdope.com/u/akennett)\ **Post date:** [December 21, 2012, 11:44am UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/39 "2012-12-21T11:44:52Z")
1. Yes or No - Do you believe that intelligent civilization(s) exist ANYWHERE else in the Universe? No. There is simply no evidence to suggest such civilizations exist, hence there is no reason to believe that they do. I would not, however, be surprised that such civilizations do exist if, by some mysterious means, we ever did get such evidence. Until then, though, such a belief (that they do exist, not that they may) is no more reasonable than belief in the existence of gods. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [December 21, 2012, 12:23pm UTC](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550/40 "2012-12-21T12:23:28Z")
> [@Napier](#): > > As I understand, the universe is infinite. There hasn’t been a concensus on this since Hubble’s time. I don’t know if there’s even been a majority, but the general feeling has shifted between infinite and finite several times since. I’m not sure what the current feeling is, but arguments for and against are deeply conjectural, as I understand it. > [@](#): > > Drake equation based estimates I have seen, together with predictions of SETA progress, imply that there’s a decent chance we will find good evidence of another civilizations within the next few decades. I don’t think any Drake estimates are good enough to pin much hope on. Note that Drake is limited to the galaxy. Note that even if SETA improves dramatically, there’s no guarantee that intelligent life elsewhere wants to advertise itself. In fact, if there is IL and it’s fairly common in denser areas of the galaxy (common enough for them to discover each other) they may have learned that it’s unwise to advertise! If there’s any evidence that SETA would be good enough to detect “unintended advertising”, I’d be very interested. But I believe that so far it depends on very high energy signals radiated in all directions, which would need to be intentional. If SETA were good enough to detect incidental radiation (like our TV signals), then I’d be wrong. But I doubt that. [Previous page](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550.md?page=1) [Next page](https://boards.straightdope.com/t/extraterrestrial-and-intelligent-life-prediction/644550.md?page=3)