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Related: Editorials & Other Articles, Issue Forums, Alliance Forums, Region ForumsIt's very, very unlikely humanity is unique across the sweep of cosmic space and time...
http://www.cbsnews.com/news/across-cosmic-history-intelligent-life-common/What are the odds that intelligent life evolved on Earth and nowhere else among the 20 billion trillion stars in the observable universe across 13.8 billion years of cosmic history?
About one in 10 billion trillion, according to researchers writing in the journal Astrobiology -- meaning it's very, very unlikely humanity is unique across the sweep of cosmic space and time.
Put another way, even if life evolves on only one planet in a billion orbiting in the habitable zone of its star -- the region where water can exist as a liquid and life as it's known on Earth could, in theory, evolve -- "that still means it's happened on the order of 10 trillion times," said Adam Frank, an astronomer at the University of Rochester.
Armed with data from NASA's Kepler space telescope showing planets are commonplace, Frank and Woodruff Sullivan, an astronomer at the University of Washington, decided to take a fresh look at the Drake equation, developed in 1961 by astrophysicist Frank Drake as a way of making a rough estimate of how common technological civilizations might be across the Milky Way galaxy.
The Drake equation combines three terms from astronomy -- the frequency of star formation, the fraction of those stars that host planets, and the number of planets with environments suitable for life -- with three "biological" terms -- the fraction of such planets with life of any sort, the fraction that might have developed intelligent life, and the number of civilizations capable of making their presence known across interstellar distances.
A seventh term indicates how long civilizations might maintain the technology needed to make their presence known.
/snip
This could cause a kerfuffle or two with some fundies I know.
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Kalidurga
(14,177 posts)I can't get my head around how young our universe is.
TreasonousBastard
(43,049 posts)Lots of easy answers to that one, but our brains are simply too feeble to understand what really happened.
Another one is wondering just how far out there infinity is.
Kalidurga
(14,177 posts)
Warren DeMontague
(80,708 posts)
Corporate666
(587 posts)It's difficult for people to comprehend that time started when the universe started.
Think of it like holding a laser pointer in your hand and pointing it up into the sky and turning it on.... creating a line that extends infinitely in one direction.
The line, like the universe, has no end. It continues for infinity and it is infinitely long. But if you travel from any point along the line to the origin, you find a beginning. And if you said "but what was before the origin". There was no before... the line didn't exist until the origin. So although it's infinitely long, it came into existence at a specific point and prior to that point there is nothing.
Warren DeMontague
(80,708 posts)We don't know, is the honest answer.
It's also not just "difficult for people to understand", its difficult to explain outside of the context of time. To wit, go back through your post and look at the places where you used words like "started" and "until" and remember that outside of the context of time, those words have no meaning.
It is possible that our universe is everything and everything including time "started" at the singularity we call the big bang, but that is by no means the only explanation out there, or even the preferred one among all cosmologists.
https://en.m.wikipedia.org/wiki/Eternal_inflation
Corporate666
(587 posts)My use of "until" was in reference to the line analogy. Before the origin of the line, there is no 'before'... and it's correct to say time started at the big bang. At least, time as we know it. There may have been a previous universe, or our universe may have sprung into existence due to some sort of event (random or otherwise) in another universe... but it's difficult for humans, as beings that exist only within time, to conceive of the absence of time or something outside of time.
So I agree with you that we don't really know in terms of the nature of the universe and how it began (or, perhaps more accurately.. or less accurately) why it began, but we do know that the time we know only started when the universe started.
Warren DeMontague
(80,708 posts)The higher you get up the physics food chain, the more physicists will tell you that time is something we don't yet understand.
SheilaT
(23,156 posts)other intelligent life.
There are lots and lots of possible answers. One is that any species will only last so long, maybe a million years at best, and so the possibility of one intelligent species overlapping another is somewhat small. And then there's the vastness of interstellar distances. Not to mention the even greater vastness of intergalactic distances.
Here's another thought: we tend to assume that intelligent species will evolve on planets somewhat like ours, where all they have to do is look up, see the stars, and start asking questions. What, if instead, intelligent species evolve on a planet like Europa, where an ocean is covered by an ice crust. Maybe they would never break through that crust, never have any clue that the universe is anything other than their one planet. Or what if some sort of gaseous intelligence evolves inside of stars? How would they perceive the Universe? Would they even venture to the edge of their star to see what else is out there?
Personally, I can think of many answers to the Why haven't we been contacted? question.
Photographer
(1,142 posts)my more logical answer would be vast differences in technologies in that radio waves may not be their choice of communication.
You do ask some great questions though. What if they are spacial, existing of only energy with no need to communicate outside of their own hive/existence? 
SheilaT
(23,156 posts)listening to the frequencies we broadcast on, but on some other range that I don't quite understand. Of course, it's important to understand that our own radio and TV signals cannot really be picked up, even by the right receivers, much past the Moon. So the charming s-f meme of aliens receiving our signals, correctly interpreting them, and then translating the language and understanding our culture, is nothing but fantasy.
But your suggestion "What if they are spacial, existing of only energy with no need to communicate outside of their own hive/existence?" is another good one.
Have you read the Terry Bisson story "They're Made Out of Meat"? Just in case you've missed it, here's a link: http://www.terrybisson.com/page6/page6.html
A truly stupid video was made and is available of youtube, but it's beyond dumb, so don't bother. Anyway, the Bisson story exemplifies what we've been discussing.
Corporate666
(587 posts)It could be that the interstellar distance problem is simply insurmountable based on the physical laws of our universe. That would really be a bummer because it means we will never be able to realistically visit other worlds except those in our solar system. I like to believe this one isn't the case, but so far the laws of relativity and quantum mechanics seem to suggest that the energy required to overcome these problems would essentially be infinite.
Another thing to keep in mind is that it's likely that any life will necessarily have to have evolved to propagate and to survive. Propagation requires consumption of resources and survival requires eliminating threats to one's survival. We have no idea what else is out there right now, and if we ever were contacted by an alien race, we would necessarily develop the technology and weaponry to defeat them if there ever was a conflict. And they would do the same. And given that resources are not infinite, it would necessarily mean conflict would happen at some point. And knowing this, and the alien race knowing this, would lead to one side initiating conflict as soon as they believed they were in the superior position. Knowing this, we would redouble our efforts not to let that happen. And so on and so on. And knowing all of this, most civilizations would probably rather remain anonymous and undetected rather than precipitate inevitable conflict.
SheilaT
(23,156 posts)of whether or not a truly alien species would recognize us as sentient. Or vice versa.
There is an understandable inclination to expect alien species to be rather similar to us. You see that clearly in Star Trek. But in reality, a genuine alien species may not strike us as sentient. Again, I present "They're Made Out of Meat".
On our own planet, spend some time thinking about other species we hang out with. Dogs. Cats. Horses. Guinea pigs. Most of you reading this will have had some sort of mammal pet. Dogs are wonderful, and it is obvious to the most casual observer that they've been evolving alongside humans for a very long time. Cats and Horses haven't been with us quite so long, and they each have their own unique attributes which are partly a result of their time with us, and more a result of their own history.
Now think about octopi. There's that recent story of the one who escaped from captivity in New Zealand. And then there's the story I heard not that long ago on NPR. A researcher who worked with octopi, who had one who always squirted her. She was then away from that lab for several years, and the very first time she walked back in the creature squirted her. Deliberately. Octopi are very intelligent, and of a totally different kind of intelligence and experience with the world than we have. If you spend some time thinking about octopi with genuinely advanced intelligence, you'll start to understand that even an earth-bound alien intelligence won't be any where as different as might really exist out there.
I will question your assumption that "most civilizations would probably rather remain anonymous and undetected rather than precipitate inevitable conflict." You need to recognize that the "inevitable conflict" notion is firmly rooted in your experience as a human on this planet. Other intelligences out there might not have the same conflict bias.
KatyMan
(4,190 posts)Are beautiful, thank you.
I especially like your last paragraph, SheilaT; who was it that said even if a lion could speak English, we still wouldn't be able to communicate (or something similar)?
Corporate666
(587 posts)in a friendly way. I would love to hear more about your perspective on this.
My perspective isn't based on my experience as a human on this planet, but rather my objective (as best as I can) thinking about life.
I think we would agree that evolution isn't something limited to the earth, and species that exist on other worlds would also evolve.
And given that, evolution would preferentially select those with the best instincts and processes for survival. I don't necessarily mean selfishness or war, but rather I am saying things like the desire to procreate would have to be instilled within the very fiber of any life form as an inherent need.
And given that an alien life form must be driven to procreate and that conservation of energy would tell us that any living thing must consume resources to survive... that would mean that an alien race would have to be expansionist and consume resources. Since resources are finite on given planets, then on a very macro scale (millions of years), competition for resources would necessarily be a thing. It wouldn't be limited to the earth, it would be a common characteristic of life itself.
And given that, we could presume that any two alien races who come into contact with each other could coexist peacefully only to the extent that there are plenty of available resources. But since resources are finite, that situation cannot last forever, which means that conflict would ultimately be inevitable.
And on the heels of the above, since all races would have experience with conflict, then all races would have some sort of military capability. If two races meet and (as would be the case) they have unbalanced capability, the lesser of the two would work hard to increase their capability, which would spur the greater of the two to maintain the lead.
It doesn't mean that they would necessarily engage in war right when they meet, but it would be an inevitable final outcome that must happen at some point. Peace could last for millennia, but never forever - not unless the two races integrated and became one.
SheilaT
(23,156 posts)You are assuming that an alien species would be competing directly with us for resources, should we ever meet. Maybe the alien species would be so incredibly different from us that we won't be competing for resources. Of course, if we are so different it increases the possibility that we won't recognize each other as actual intelligent species. Again, imagine intelligent life on Jupiter, inside a star, on the surface of Pluto, in the ocean of Europa.
Here's another thought: Humans are almost universally war-like. We happily murder each other both one at a time, and in vast numbers when we have the chance. That inclination to war and violence is probably routed in competition for resources, as you've noted. I'm willing to hypothesize alien intelligence that somehow never developed this sort of competition. However, the argument could certainly be made that it is precisely this sort of competition that ultimately led to our modern technology. A truly pacific species might never develop much technology of any kind.
Clearly, until such time as we actually have that First Contact, all any of us can do is speculate.
I suspect that you read science fiction. I do, and I enjoy First Contact stories. And I'm sure you're more than familiar with the Roswell incident, whatever it may have been. There are many who believe that was a FC, and lots of interesting s-f has been written about Roswell. I tend to enjoy reading them myself.
Anyway, thanks again for your insight.
NickB79
(19,233 posts)And that's AFTER almost initiating a global nuclear war in the 1960's-1980's.
My guess? Most intelligent species wipe themselves out, or knock themselves back to the Stone Age, long before they master interstellar flight.
And that's AFTER almost initiating a global nuclear war in the 1960's-1980's.
My guess? Most intelligent species wipe themselves out, or knock themselves back to the Stone Age, long before they master interstellar flight.
This is my assumption as well. We can look at our own history and see that there's been a concerted effort on our part to destroy everything we touch. Well, those who follow the mandate that God put the Earth under our control, and it doesn't matter what happens, because Resurrection, at least.
Other intelligent species are either staying away on purpose, or haven't the capabilities to reach out any more than we do, and likely even less so.
killbotfactory
(13,566 posts)We are close to reaching that point, and we've only been transmitting radio waves into space for about a century, which on cosmic timescales is no time at all.
Once that point is reached we have no idea what's going to happen.
Maybe it will figure out a way to contact and interact with alien species, but in a way that takes a lot longer than a single human lifetime.
Rex
(65,616 posts)You have to find them at the right place and in the right time period.
Even if we don't destroy our planet ourselves through human-induced climate change, no species stops evolving. At some point homo sapiens will be no more. Maybe our distant descendants won't be interested in contacting other intelligent life. And no matter how you run the numbers, the chance of two interstellar traveling intelligent species overlapping and coming across each other is pretty small, even within one galaxy. And travel between galaxies is pretty much never going to happen.
The universe is already almost 14 billion years old, and even though it's possible microbial life evolved very early on, as in only fifteen or so million years after the Big Bang, it probably would have taken a lot longer for intelligent life to evolve. We know our own planet has only been around some 5 billion years, relatively late in the current age of the Universe.
I don't think AI is the answer, either. It has been postulated that a sufficiently advanced species (and supposedly we are pretty close to being able to do this) could build a self-replicating explorer that goes out into the galaxy, reproducing itself wherever it finds the right sort of raw materials, launches its "children", and the process repeats. I've seen it said that it would take surprisingly little time, only a few million years, for our entire galaxy to be colonized by such machines, and the entire Universe in only a few billion. And this of course assumes traveling well under the speed of light. So why haven't we seen such machines?
Because either no other species even thought of it, or it's not that easy to do. In the long run, the reproduction comes to a halt, the machines themselves can only last so long.
I also think that while intelligent species may well be out there, the inclination to look up and decide we want to go out there might be rare. If there were intelligent life on Venus, or within the gas atmosphere of Jupiter, they might not have any clue there's anything else out there.
We tend to assume that alien intelligence will be a lot like us in many, and are typically depicted as quite benevolent and want to help us, or vicious destroyers as we are all too often. I do think they might be so alien, so very different from us that we'd never recognize each other as intelligent.
Rex
(65,616 posts)We tend to assume it will be Little Green Men...when it could be some kind of rock or treelike structure, something we would not identify at first as intelligent life.
Sen. Walter Sobchak
(8,692 posts)the potentially space-faring intelligent life since the technology for space flight and the ability to render your own planet uninhabitable sort of go together.
stopbush
(24,396 posts)oldandhappy
(6,719 posts)1) I want aliens to be real and I want to know this in my lifetime.
2) I want my spirit to be able to soar thru the galaxy when I am no longer earth bound.
Pleeeeeeze!!
MFM008
(19,804 posts)
LiberalArkie
(15,709 posts)Corporate666
(587 posts)is that the scale and quantity of the unknowns are so large that the end results can be off by many many orders of magnitude. It's such a huge margin for error as to make the results completely irrelevant.
It's a mathematical certainty that we are not the only life in the universe, and the more we learn, the more it appears that there is more potential for life than we imagined (i.e. the abundance of planets, the abundance of water, the abundance of stars, the abundance of carbon and other elements needed for life as we know it). But there are still too many unquantifiable variables in the equation to produce any real answer.
stone space
(6,498 posts)Just sayin'...
The article doesn't say that it is unlikely.
rock
(13,218 posts)Somewhere that isn't insane. That's good.
Spider Jerusalem
(21,786 posts)life may be quite common, intelligent life, possibly not (not if we're using humans as our basis for "intelligent", anyway). Humans are unique among the millions of species that have ever existed on earth in their capacity for language and complex tool use. There may not be other technologically-advanced life forms anywhere in the universe...or there may be, given the odds, but either way it's not likely that we'll ever know (given the vast distances of space).
For a contrary view:
Perhaps the most influential of the life-is-out-there advocates, astronomer and SETI Institute founder Frank Drake, made his bones in the extraterrestrial game with his eponymous equation, a satisfying—if coldly arithmetical—case for the likelihood not only of life in space but of intelligent life. According to Drake, the n in his equation—the number of civilizations in the Milky Way alone capable of producing detectable radio signals—equals the rate of the formation of sunlike stars in our galaxy, times the proportion of stars that are orbited by planets, times the proportion of those planets that would offer life-supporting conditions, times the fraction of those on which life does exist, times the fraction of life-forms that are intelligent, times the fraction of intelligent life-forms capable of transmitting signals, times the length of time such a civilization actually sends those signals before either perishing or going silent for any other reason.
Simple, right? Honestly, it kind of is. Filling in all of the x’s in the Drake equation—which, admittedly, is itself an act of conjecture, albeit highly informed conjecture—typically yields an estimate of thousands of civilizations. Drake himself put it at 10,000. The late cosmological popularizer Carl Sagan estimated the figure at an astounding 1 million. Even if they were off by a factor of 10 or 100 or 1,000, it is clear we are not remotely alone.
Unless we are.
Paul Davies, a cosmologist at Arizona State University and the author of the book Eerie Silence—which takes exactly the dim view of our ever encountering an alien intelligence that its title suggests—finds almost no part of the intelligent-life argument persuasive. The biggest hole he finds in the Drake equation is the one involving the subset of planets that could support life that actually do. The fact is, we have absolutely no empirical data that allows us to put a value on that variable in a responsible way. We know of precisely one world on which life has existed, and the rest is largely guesswork. Fill in that one Drake blank with a zero, and the entire equation collapses to zero too.
Davies, though, goes well beyond the flaws of the equation, arguing that there is a perfectly credible case to be made for the presence of life on Earth as a result of a succession of flukes, each more improbable than the one before it, which, together, could occur only a single time in a trillion trillion tries. A chimp randomly pounding a typewriter might indeed come up with Hamlet. Once. It wouldn’t matter if there were 40 billion other chimps hammering away, just as, as Davies has written, it doesn’t matter if there are 40 billion planets in the Milky Way capable of sustaining life. Only a single one will.
http://time.com/3747812/life-in-space-alone/
KatyMan
(4,190 posts)Of saying humanity is unique, an earth-centric point of view not unlike the old fashioned religious point of view? Sort of an egotistical earth idea. But life is so abundant and malleable and capable of incredible diversity on just this planet, why wouldn't we give every planet in the Goldilocks Zone in the galaxy the same chance at intelligent life ours has?
Spider Jerusalem
(21,786 posts)and a few improbable events conspired to make it happen: first the early impact that created the moon also caused a significant portion of the earth's early atmosphere to be lost (and also gave the planet its axial tilt and rotation speed, and oceanic tides)...had that not happened Earth would've been a Venusian hothouse; second, the Chicxulub impact led to the extinction of all non-avian dinosaurs (the formerly dominant terrestrial species) and paved the way for the mammalian evolution that eventually led to humans. The fact that intelligent life evolved on THIS planet is pretty much an unlikely fluke. Merely existing in the habitable zone of a star isn't sufficient, other conditions need to be present. Could the chance of that be one in a trillion? Possibly.
hunter
(38,310 posts)I suspect it goes two ways: A species gets clever enough to destroy itself, or it quickly retreats into a universe of its own making, invisible and inaccessible to this universe.
Maybe this universe is just an incubator.
L. Coyote
(51,129 posts)Most animals run when they see a human, and for good reason.
karadax
(284 posts)Cosmologically there isn't much around us. Once we start travelling around into the more crowded areas of the Galaxy I am certain we will find someone or something.
L. Coyote
(51,129 posts)It is that simple.
Major Nikon
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