# Intelligent life in the galaxy **URL:** \ **Category:** Great Debates\ **Created:** [February 17, 2000, 5:00pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502 "2000-02-17T17:00:00Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Rabbi\_Sam](https://avatars.discourse-cdn.com/v4/letter/r/ecc23a/32.png) [@Rabbi\_Sam](https://boards.straightdope.com/u/Rabbi_Sam)\ **Post date:** [February 17, 2000, 9:58pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/21 "2000-02-17T21:58:00Z")
## All your comments are very interesting, but I am still trying to find **“intelligent life”** on planet earth, much less the galaxy or rest of the universe. 🙂 shema yisrael adonai eloheynu adonai echad ---
**Author:** ![Sake\_Samurai](https://avatars.discourse-cdn.com/v4/letter/s/bc79bd/32.png) [@Sake\_Samurai](https://boards.straightdope.com/u/Sake_Samurai)\ **Post date:** [February 17, 2000, 10:25pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/22 "2000-02-17T22:25:00Z")
First a couple of factual errors I noticed. Galen, you say: > [@](#): > > Even if we were never able to travel faster than 10% of the speed of light, we could explore the galaxy in much less than a million years However, it would take exactly 1 million years at 10% LS just to travel from one end of the galaxy to the other in a straight line. The galaxy is not linear, however, nor can one (most likely) travel through the center. So we are talking well over 80 billion years to navigate every system in the Milky Way. Wally, you stated that: > [@](#): > > And then there is the size ratio of the Moon and Earth, which is the largest in the solar system. In fact, it can be thought of as a double planet system. This may be a very rare circumstance. Now, Charon is a whopping 50.5% the size of Pluto while the Moon is only 27.2% the size of the Earth. Then again, I am of the Pluto-is-not-a-planet crowd so never mind. galen, there’s much wrong with your conclusion. You seem to be basing your hypothesis on the fact that sentient life must be identical to homo sapiens. I will agree with you that it is becomming increasingly unlikely that there are other human-like species anywhere near us. However, I think the variety of life out there is mindbendingly uncomprehensible. From vast nebulaic energy gods the size of galaxies to teeming microscopic infestations - hell the viruses on this planet may well have come from some ancient system on the other side of the galaxy. Maybe they are in the process of colonizing this planet for the imminent arrival of the bulk of their species. I don’t much think this is a viable debate. We are **far** too ignorant to even speculate. * * * Yet to be reconciled with the reality of the dark for a moment, I go on wandering from dream to dream. ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [February 17, 2000, 10:23pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/23 "2000-02-17T22:23:00Z")
Polycarp wrote: > [@](#): > > Sobering thought: _We_ may be the Elder Race of the galaxy. I refuse to believe that the species that gave us Marcel Marceau is the most sophisticated in the universe. * * * The truth, as always, is more complicated than that. ---
**Author:** ![WillGolfForFood](https://avatars.discourse-cdn.com/v4/letter/w/82dd89/32.png) [@WillGolfForFood](https://boards.straightdope.com/u/WillGolfForFood)\ **Post date:** [February 18, 2000, 12:52am UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/24 "2000-02-18T00:52:00Z")
BTW, I just perused the SETI FAQ - [http://www.seti-inst.edu/faq.html](http://www.seti-inst.edu/faq.html) - lots of interesting stuff there, and after describing their and other efforts in this area they make the following point: “while there are hundreds of billions of stars in our galaxy, less than a thousand have been scrutinized with high sensitivity” …so there’s quite aways to go before we get to decide that we’ve looked everywhere. ---
**Author:** ![galen](https://avatars.discourse-cdn.com/v4/letter/g/ecc23a/32.png) [@galen](https://boards.straightdope.com/u/galen)\ **Post date:** [February 18, 2000, 2:09pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/25 "2000-02-18T14:09:00Z")
> [@](#): > > Originally posted by TomH: > I think this is the weak link in the argument. Such beings would still be bound by the laws of physics, so no faster-than-light travel. There is no particular reason to suppose that they would be blessed with spectacular longevity (not to mention high boredom thresholds). > > That means that, basically, colonising the galaxy would involve building spacecraft capable of supporting life in deep space for more than one generation, and packing off a group of astronauts to breed in space, never to be seen again. Why would they bother? Good points. Of course there is no faster than light travel, but the figure I used was 10% of the SOL. This will very probably be doable for an advanced civilization. Why would they? Because they are intellegent; they are curious and even if not every extraterrestrial civilization takes to the stars, over the eons, given innumerable such civilizations, some would. * * * The philosophers have only interpreted the world in various ways; the point, however, is to change it. (Karl Marx, 1845) ---
**Author:** ![Jai\_Pey](https://avatars.discourse-cdn.com/v4/letter/j/a4c791/32.png) [@Jai\_Pey](https://boards.straightdope.com/u/Jai_Pey)\ **Post date:** [February 18, 2000, 2:51pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/26 "2000-02-18T14:51:00Z")
Hey all, in response to Wally’s post of several above here: > [@](#): > > The Universe may well be teeming with life, but there’s no reason to think that intelligence is common. Our own history proves it. > Intelligence arose here only once, and that was yesterday, geologically speaking. And it may have never happened if a huge comet hadn’t struck earth 65 million years ago. See, I’m not the best evolutionist you ever saw, but if some planet’s ecology is teeming with life, wouldn’t Mr Gould agree that intelligence would be, in the long run, beneficial to a species? I find it hard to believe that if evolution is in play (macro, micro, or otherwise) intelligence would be difficult to find if LIFE were already in a place. If intelligence is as vaulted as we say it is, for survival, any modicum, however minute, would count to the good for whatever species had it. It’d \*\*\*only \*\*\* be a matter of time before intelligence came about. Intelligent life arose only once? Says who? > [@](#): > > Steven Jay Gould says that even with the impact, if the whole thing was replayed, we wouldn’t be here. And it doesn’t follow that some other species would win the lottery and develop intelligence. The lottery then, for intelligent life, if two-fold? ONE: Life must develop (billion to one, liberal guess) and TWO: Intelligence don’t come cheap either (another billion to one?) I think this is cart before the horse number crunching, to be honest. Life’s the determining factor… if it doesn’t emerge, then its useless to talk about intelligence, isn’t it. Whether or not we’d recognize other intelligence is questionable (I don’t think we can do it on Earth let alone elsewhere) and whether or not we’d recognize other LIFE is debatable. Kudo’s to the marine biologists who discovered life in the dark of the oceans trenches. > [@](#): > > There are millions of species here, and they get along just fine without technology. Darn straight they do, does that mean they’re not intelligent? How about a myriad of aquatic mammals, we can’t tell if whales, dolphins, and kin are INTELLIGENT, per se… at least, (a) we don’t think they’re intelligent to our standard (humanistic self-centredness, nothing new there) (b) we don’t bother to measure or recognize “other” intelligence… :rolleyes: Obviously, they can’t be intelligent, they haven’t developed a computer, let alone one that’s immersable in water and STILL works. Never mind they have a language. Regards, but I think this is full of holes too. If this is what SJ Gould’s sayin nowadays, he’s lost me again. ---
**Author:** ![Occam](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@Occam](https://boards.straightdope.com/u/Occam)\ **Post date:** [February 18, 2000, 4:10pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/27 "2000-02-18T16:10:00Z")
The OP assumes intelligent creatures would act like us. Like he said before, we evolved yesterday, maybe when our race matures we wont really care if there are others out there. Of course, if there are intelligent creatures out there and they do think like us, I can imagine them never trying to find others because they couldn’t find any artificial radiation. ---
**Author:** ![G.B.H.Hornswoggler](https://avatars.discourse-cdn.com/v4/letter/g/c67d28/32.png) [@G.B.H.Hornswoggler](https://boards.straightdope.com/u/G.B.H.Hornswoggler)\ **Post date:** [February 19, 2000, 6:01am UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/28 "2000-02-19T06:01:00Z")
> [@](#): > > Originally posted by Sam Stone: > \*\*Da Ace - What are you talking about? Our deep-space tracking system could pick out a 3-watt signal from Pluto. When I was in engineering I designed a communications system for a Saturn probe as my final project, and the amount of power you need to be detected is pretty small. The bitrate of the signal is proportional to the power, so you couldn’t send information very quickly on a low-power carrier, but we could detect it. > \*\* Well, I’d gotten that factoid from Achenbach’s **Captured by Aliens** , which unfortunately doesn’t have equations or really specific numbers. But the context was that Achenbach was talking about SETI (interviewing Jill Tarter, IIRC), and was told by the SETI scientists that they could only detect a major broadcast – i.e., that only a civilization that was going out of its way to say “Yo! I’m over HERE!” would be found. Achebach specifically noted that a civilization like our own (with substantial radio/etc. leakage) would _not_\* be detectable by the SETI equipment. And they’re looking at fairly close-in stars (not quite Alpha C – I think that one’s been checked out quite thoroughly – but in our region). I think the difference between that and the probes you designed is that it’s much harder to detect a leaked signal than a directed one. (My reference to Pluto was a bit of an overstatement, but I still believe that an alien civilization would need to be in our solar system or specifically broadcasting to other races to be heard.) The part of your message that I snipped said many of the things I was trying to get at – that civilizations (if ours is a good guide, which is a big if) will go through a relatively short “broadcasting” phase before settling into more efficient point-to-point or cabled transmissions. And, again, my main point is that there’s a lot of room for debate here – no one knows, and no one can tell. Even the best scientists who’ve been working on the problem for decades violently disagree about the biggest questions. (What’s the percentage of planets that have life? Of stars that have planets? Of biospheres that generate intelligence? and so on) * * * …but when you get blue, and you’ve lost all your dreams, there’s nothing like a campfire and a can of beans! ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [February 18, 2000, 7:38pm UTC](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502/29 "2000-02-18T19:38:00Z")
The ‘backup’ signal from the Mars Polar Lander is a ‘leaked’ signal (i.e. an omnidirectional broadcast instead of a focused dish). It has the power of roughly a cell phone. And if it had worked we could have picked it up just fine. Amateur radio operators can use as little as a few hundred milliwatts of power when sending low-density information (Morse Code) around the world, and this is through a hostile environment with lots of stuff in the way and lots of radio interference. [Previous page](https://boards.straightdope.com/t/intelligent-life-in-the-galaxy/17502.md?page=1)