The Search for Extra-Terrestrial Intelligence (SETI) seeks to answer one of the most basic questions of human identity - whether we are alone in the universe, or merely one civilization among many. It is perhaps the biggest question that any human can ponder.
The Drake Equation, created by astronomer Frank Drake in 1960, calculates the number of advanced extra-terrestrial civilizations in the Milky Way galaxy in existence at this time. Watch this 8-minute clip of Carl Sagan in 1980 walking the audience through the parameters of the Drake Equation. The Drake equation manages to educate people on the deductive steps needed to understand the basic probability of finding another civilization in the galaxy, but as the final result varies so greatly based on even slight adjustments to the parameters, it is hard to make a strong argument for or against the existence of extra-terrestrial intelligence via the Drake equation. The most speculative parameter is the last one, fL, which is an estimation of the total lifespan of an advanced civilization. Again, this video clip is from 1980, and thus only 42 years after the advent of radio astronomy in 1938. Another 29 years, or 70%, have since been added to the age of our radio-astronomy capabilities, and the prospect of nuclear annihilation of our civilization is far lower today than in was in 1980. No matter how ambitious or conservative of a stance you take on the other parameters, the value of fL in terms of our own civilization, continues to rise. This leads us to our first postulate :
The expected lifespan of an intelligent civilization is rising.
Carl Sagan himself believed that in such a vast cosmos, that intelligent life would have to emerge in multiple locations, and the cosmos was thus 'brimming over' with intelligent life. On the other side are various explanations for why intelligent life will be rare. The Rare Earth Hypothesis argues that the combination of conditions that enabled life to emerge on Earth are extremely rare. The Fermi Paradox, originating back in 1950, questions the contradiction between the supposed high incidence of intelligent life, and the continued lack of evidence of it. The Great Filter theory suggests that many intelligent civilizations self-destruct at some point, explaining their apparent scarcity. This leads to the conclusion that the easier it is for civilization to advance to our present stage, the bleaker our prospects for long-term survival, since the 'filter' that other civilizations collide with has yet to face us. A contrarian case can thus be made that the longer we go without detecting another civilization, the better.
But one dimension that is conspicuously absent from all of these theories is an accounting for the accelerating rate of change. I have previously provided evidence that telescopic power is also an accelerating technology. After the invention of the telescope by Galileo in 1609, major discoveries used to be several decades apart, but now are only separated by years. An extrapolation of various discoveries enabled me to crudely estimate that our observational power is currently rising at 26% per year, even though the first 300 years after the invention of the telescope only saw an improvement of 1% a year. At the time of the 1980 Cosmos television series, it was not remotely possible to confirm the existence of any extrasolar planet or to resolve any star aside from the sun into a disk. Yet, both were accomplished by the mid-1990s. As of May 2009, we have now confirmed a total of 347 extrasolar planets, with the rate of discovery rising quickly. While the first confirmation was not until 1995, we now are discovering new planets at a rate of 1 per week. With a number of new telescope programs being launched, this rate will rise further still. Furthermore, most of the planets we have found so far are large. Soon, we will be able to detect planets much smaller in size, including Earth-sized planets. This leads us to our second postulate :
Telescopic power is rising quickly, possibly at 26% a year.
This Jet Propulsion Laboratory chart of exoplanet discoveries through 2004 is very overdue for an update, but is still instructive. The x-axis is the distance of the planet from the star, and the y-axis is the mass of the planet. All blue, red, and yellow dots are exoplanets, while the larger circles with letters in them are our own local planets, with the 'E' being Earth. Most exoplanet discoveries up to that time were of Jupiter-sized planets that were closer to their stars than Jupiter is to the sun. The green zone, or 'life zone' is the area within which a planet is a candidate to support life within our current understanding of what life is. Even then, this chart does not capture the full possibilities for life, as a gas giant like Jupiter or Saturn, at the correct distance from a Sun-type star, might have rocky satellites that would thus also be in the life zone. In other words, if Saturn were as close to the Sun as Earth is, Titan would also be in the life zone, and thus the green area should extend vertically higher to capture the possibility of such large satellites of gas giants. The chart shows that telescopes commissioned in the near future will enable the detection of planets in the life zone. If this chart were updated, a few would already be recorded here. Some of the missions and telescopes that will soon be sending over a torrent of new discoveries are :
Kepler Mission : Launched in March 2009, the Kepler Mission will continuously monitor a field of 100,000 stars for the transit of planets in front of them. This method has a far higher chance of detecting Earth-sized planets than prior methods, and we will see many discovered by 2010-11.
COROT : This European mission was launched in December 2006, and uses a similar method as the Kepler Mission, but is not as powerful. COROT has discovered a handful of planets thus far.
New Worlds Mission : This 2013 mission will build a large sunflower-shaped occulter in space to block the light of nearby stars to aid the observation of extrasolar planets. A large number of planets close to their stars will become visible through this method.
Allen Telescope Array : Funded by Microsoft co-founder Paul Allen, the ATA will survey 1,000,000 stars for radio astronomy evidence of intelligent life. The ATA is sensitive enough to discover a large radio telescope such as the Arecibo Observatory up to a distance of 1000 light years. Many of the ATA components are electronics that decline in price in accordance with Moore's Law, which will subsequently lead to the development of the.....
Square Kilometer Array : Far larger and more powerful than the Allen Telescope Array, the SKA will be in full operation by 2020, and will be the most sensitive radio telescope ever. The continual decline in the price of processing technology will enable the SKA to scour the sky thousands of times faster than existing radio telescopes.
These are merely the missions that are already under development or even under operation. Several others are in the conceptual phase, and could be launched within the next 15 years. So many methods of observation used at once, combined with the cost improvements of Moore's Law, leads us to our third postulate, which few would have agreed with at the time of 'Cosmos' in 1980 :
Thousands of planets in the 'life zone' will be confirmed by 2025.
Now, we will revisit the under-discussed factor of accelerating change. Out of 4.5 billion years of Earth's existence, it has only hosted a civilization capable of radio astronomy for 71 years. But as our own technology is advancing on a multitude of fronts, through the accelerating rate of change and the Impact of Computing, each year, the power of our telescopes increases and the signals of intelligence (radio and TV) emitted from Earth move out one more light year. Thus, the probability for us to detect someone, and for us to be detected by them, however small, is now rising quickly. Our civilization gained far more in both detectability, and detection-capability, in the 30 years between 1980 and 2010, relative to the 30 years between 1610 and 1640, when Galileo was persecuted for his discoveries and support of heliocentrism, and certainly relative to the 30 years between 70,000,030 and 70,000,000 BC, when no advanced civilization existed on Earth, and the dominant life form was Tyrannosaurus.
Nikolai Kardashev has devised a scale to measure the level of advancement that a technological civilization has achieved, based on their energy technology. This simple scale can be summarized as follows :
Type I : A civilization capable of harnessing all the energy available on their planet.
Type II : A civilization capable of harnessing all the energy available from their star.
Type III : A civilization capable of harnessing all the energy available in their galaxy.
The scale is logarithmic, and our civilization currently would receive a Kardashev score of 0.72. We could potentially achieve full Type I status by the mid-21st century due to a technological singularity. Some have estimated that our exponential growth could elevate us to Type II status by the late 22nd century.
This has given rise to another faction in the speculative debate on extra-terrestrial intelligence, a view held by Ray Kurzweil, among others. The theory is that it takes such a short time (a few hundred years) for a civilization to go from the earliest mechanical technology to reach a technological singularity where artificial intelligence saturates surrounding matter, relative to the lifetime of the home planet (a few billion years), that we are the first civilization to come this far. Given the rate of advancement, a civilization would have to be just 100 years ahead of us to be so advanced that they would be easy to detect within 100 light years, despite 100 years being such a short fraction of a planet's life. In other words, where a 19th century Earth would be undetectable to us today, an Earth of the 22nd century would be extremely conspicuous to us from 100 light years away, emitting countless signals across a variety of mediums.
A Type I civilization within 100 light years would be readily detected by our instruments today. A Type II civilization within 1000 light years will be visible to the Allen or the Square Kilometer Array. A Type III would be the only type of civilization that we probably could not detect, as we might have already been within one all along. We do not have a way of knowing if the current structure of the Milky Way galaxy is artificially designed by a Type III civilization. Thus, the fourth and final postulate becomes :
A civilization slightly more advanced than us will soon be easy for us to detect.
The Carl Sagan view of plentiful advanced civilizations is the generally accepted wisdom, and a view that I held for a long time. On the other hand, the Kurzweil view is understood by very few, for even in the SETI community, not that many participants are truly acceleration aware. The accelerating nature of progress, which existed long before humans even evolved, as shown in Carl Sagan's cosmic calendar concept, also from the 1980 'Cosmos' series, simply has to be considered as one of the most critical forces in any estimation of extra-terrestrial life. I have not yet migrated fully to the Kurzweil view, but let us list our four postulates out all at once :
The expected lifespan of an intelligent civilization is rising.
Telescopic power is rising quickly, possibly at 26% a year.
Thousands of planets in the 'life zone' will be confirmed by 2025.
A civilization slightly more advanced than us will soon be easy for us to detect.
As the Impact of Computing will ensure that computational power rises 16,000X between 2009 and 2030, and that our radio astronomy experience will be 92 years old by 2030, there are just too many forces that are increasing our probabilities of finding a civilization if one does indeed exist nearby. It is one thing to know of no extrasolar planets, or of any civilizations. It is quite another to know about thousands of planets, yet still not detect any civilizations after years of searching. This would greatly strengthen the case against the existence of such civilizations, and the case would grow stronger by year. Thus, these four postulates in combination lead me to conclude that :
Most of the 'realistic' science fiction regarding first contact with another extra-terrestrial civilization portrays that civilization being domiciled relatively nearby. In Carl Sagan's 'Contact', the civilization was from the Vega star system, just 26 light years away. In the film 'Star Trek : First Contact', humans come in contact with Vulcans in 2063, but the Vulcan homeworld is also just 16 light years from Earth. The possibility of any civilization this near to us would be effectively ruled out by 2030 if we do not find any favorable evidence. SETI should still be given the highest priority, of course, as the lack of a discovery is just as important as making a discovery of extra-terrestrial intelligence.
If we do detect evidence of an extra-terrestrial civilization, everything about life on Earth will change. Both 'Contact' and 'Star Trek : First Contact' depicted how an unprecedented wave of human unity swept across the globe upon evidence that humans were, after all, one intelligent species among many. In Star Trek, this led to what essentially became a techno-economic singularity for the human race. As shown in 'Contact', many of the world's religions were turned upside down upon this discovery, and had to revise their doctrines accordingly. Various new cults devoted to the worship of the new civilization formed almost immediately.
If, however, we are alone, then according to many Singularitarians, we will be the ones to determine the destiny of the cosmos. After a technological singularity in the mid-21st century that merges our biology with our technology, we would proceed to convert all matter into artificial intelligence, make use of all the elementary particles in our vicinity, and expand outward at speeds that eventually exceed the speed of light, ultimately saturating the entire universe with out intelligence in just a few centuries. That, however, is a topic for another day.
I've had a little thought about,
http://bryanlprice.com/infinet/SETI.html
That was back in July 1997. (And the email in the feedback is wrong, but I'll correct that later! That's what I get for changing ISPs!)
This gets back to your fourth postulate.
The problem is with encryption and compression. Efficient encryption and/or compression takes a signal that has a pattern to it and makes it a pattern not too discernible from white noise. So, the only thing we're going to have to go on is signal strength. So we may find a noise maker somewhere that's stationary (or not), but if they are just a few more years ahead of us, good luck trying to decode it without any other kind of reference.
There are two other, possibly related, situations that I've thought of, I just haven't thought hard enough to probably write cogently about, but I'll try.
The first is that the technology might exist to push the signal through to where you want it, just. In other words, instead of blasting something out with 1KW transmitter, the transmitter knows it only need to send out a 20W signal to reach the intended receiver. Those numbers are just guess, and place fillers, don't be jumping on me for them! :)
The second is, they've decided that they do not want to be found. I've already heard about the people that have decided that we need to be proactive and pushing out our own signal for us to be discovered by somebody else, than wait for us to discover them, and the backlash against them. (I'm on the side of caution, we don't really need to be spewing out more signals when what we are already putting out should be sufficient. Maybe it's too many Berzerker ™ novels, or too many Space Marine novels from Ian Douglas...)
Posted by: bytehead | May 24, 2009 at 09:03 AM
Bryce,
To account for both situations :
1) There would still be radiation of EM waves in all directions from the era before they had this technology.
2) The second is, they've decided that they do not want to be found.
It is unlikely that all the civilizations (if there are thousands) would make the same decision, and that all would have made it by now. If some do, others would not.
Our observational capabilities by 2030 will be vastly more advanced than they are today, and we will know of thousands of specific planets in the life zone as well.
Posted by: GK | May 24, 2009 at 10:40 AM
You are assuming that advanced civilizations will continue to use some type of EM communication rather than moving on to more advanced, instantaneous methods such as quantum particle pairs. We no longer use smoke signals or the telegraph, and soon enough we will accelerate past EM as well.
Let's say the viewable EM window for an advanced civilization is 100 years before they move on to quantum comm. If there are 10,000 advanced civilizations with such 100 year windows in the Milky Way's history, that means there are only 1 million years out of 15 billion (.00007%) when listening for such a signal would have a result, not even accounting for the fact that many of these signals would be washed out before they reach us.
It's not that such advanced civilizations don't want to be found, but that they only want to communicate with other civilizations that have achieved realtime communication. What's the point of talking to primitive people that it takes lightyears to hear back from? And what's the point of continuing to project an EM beacon so emerging civilizations can learn that there are other civilizations out there when in 50-100 years they will also have instantaneous quantum comm?
Posted by: Peter Y | May 24, 2009 at 12:59 PM
Peter Y,
1) It is unlikely that there will be no role for any type of EM communication, even if other technologies are also used.
2) The EM signals they emitted during earlier phases will still be pushing outward from their planet.
3) Even if what you suggest is true of Type III civilizations, it would not be true of Type I and many Type II civilizations.
4) Even if some choose not to be detected, it is unlikely that thousands or millions of civilizations would make the same decision, and all would be in compliance at this time.
5) We are not talking about 2-way dialog. We are simply talking about detection.
Posted by: GK | May 24, 2009 at 02:27 PM
1) It is unlikely that there will be no role for any type of EM communication, even if other technologies are also used.
It is HIGHLY likely that once a better communication mechanism is discovered with a cost that rapidly approaches zero, that it will replace all previous forms of communication. EM is no different than the telegraph. Already the vast majority of Internet communication is in fiber and short wavelength wireless.
2) The EM signals they emitted during earlier phases will still be pushing outward from their planet.
No, the EM signals will push out during the 30-100 year window from their source and then will cease to be pushed out. They can be detected years later lightyears away, but at the destination they are still in a 30-100 year window.
3) Even if what you suggest is true of Type III civilizations, it would not be true of Type I and many Type II civilizations.
As you point out in your post, the window for a Type I and Type II civilization is remarkably short. No one is going to get stuck for tens of thousands of years using EM comm. It is going to be <100 years.
4) Even if some choose not to be detected, it is unlikely that thousands or millions of civilizations would make the same decision, and all would be in compliance at this time.
It is not that they don't choose to be detected. All these civilizations use EM for <100 years. Then a new comm technology comes out that is faster and cheaper. They switch to it, and use that new technology for thousands if not tens of thousands of years. They listen for and reach out to other civilizations using this new technology. And yes, none of them care so much to listen for or broadcast the EM they used for 100 years.
5) We are not talking about 2-way dialog. We are simply talking about detection.
We are talking about detection of communications technology, and why we don't hear from distant civilizations. That is because it is likely they have moved on to instantaneous communication technologies. And we are wondering why none of these civilizations are trying to discover each other with EM. That is because they are all likely discovering each with instantaneous communication technologies.
You seem very logical in your own thought process, can you try mapping that ability to a distinct logical thought process?
1) We are already using quantum encryption and have already discovered that changing the spin of a particle in one place immediately changes the spin of a paired particle. Do you not think that it is possible that within a 25 year window we switch to realtime quantum communication methods? How else will the law of acceleration be maintained for communication speed?
2) After such quantum communication becomes possible and approaches the cost of zero, how long do you think before it replaces EM communication, in particular high wattage EM communication such as that from radio towers and satellites?
3) If and when we start using quantum communication for thousands of years after a short 100 year EM window, which technology do you think we would use to try to discover other civilizations?
:)
Peter
Posted by: Peter Y | May 24, 2009 at 04:29 PM
Peter,
You are essentially saying that as soon as we invent the capability to use quantum communications some decades from now, that we will immediately go from knowing about no other civilizations to knowing about a vast number of them.
That is not too different from the events of Star Trek : First Contact, except that they used transportation technology (warp drive) rather than communication technology as the trigger.
You should read Ray Kurzweil's 'The Singularity is Near', if you have not already. The specific chapter on SETI accounts for your idea of communications advances beyond EM, but says that there would still be a role for EM waves, even if only as byproducts of other processes.
Nonetheless, going back to point 4) the 100-light-year-thick EM shell would still be moving outwards, and would still be detectable to us for 100 years, while Earth is within the 100 ly thickness of that shell. If the number of civilizations is large, and each has a 100 ly thick EM shell drifting ever outwards, surely many would still be detectable to us, even if they have since moved beyond EM.
Lastly, remember that Type II civilizations will have created planet-sized or larger megascale engineering projects that would be easy for us to detect. It is not only communication, but actual objects that could be found.
We'll see. I still say that the accelerating rate at which we can discover planets (especially life-zone planets) has to have some close corelation to our ability to detect a civilization.
1994 : Zero planets confirmed (although a couple candidates discovered before then were retro-confirmed
much later).
2009 : 300-400 confirmed.
2030 : Tens of thousands confirmed.
Posted by: GK | May 24, 2009 at 04:39 PM
Let's go point by point here:
>You are essentially saying that as soon as we invent the
>capability to use quantum communications some decades from
>now, that we will immediately go from knowing about no other
>civilizations to knowing about a vast number of them.
>That is not too different from the events of Star Trek :
>First Contact, except that they used transportation
>technology (warp drive) rather than communication technology
>as the trigger."
i am not saying that we will invent a new comm technology and everything will be like star trek. you are saying that there probably isn't any intelligent life out there because we can't detect anyone else using primitive EM waves. i am saying once we get to a more advanced comm technology, particularly a real time one, we will be much more likely to find other civilizations. You seem to agree that there are more advanced comm technologies than EM. So do you think the likelihood of finding other civilizations will increase or decrease once we figure out quantum comm? Do you think once we have quantum comm we will still be trying to find EM waves out there? Can you try to actually answer these questions rather than ignoring them so we can have a discussion?
>You should read Ray Kurzweil's 'The Singularity is Near', if
>you have not already. The specific chapter on SETI accounts
>for your idea of communications advances beyond EM, but says
>that there would still be a role for EM waves, even if only
>as byproducts of other processes.
i have read kurzweil extensively. the byproduct EM is much harder to detect than satellites and radio towers.
>Nonetheless, going back to point 4) the 100-light-year-thick
>EM shell would still be moving outwards, and would still be
>detectable to us for 100 years, while Earth is within the 100
>ly thickness of that shell. If the number of civilizations is
>large, and each has a 100 ly thick EM shell drifting ever
>outwards, surely many would still be detectable to us, even
>if they have since moved beyond EM.
Well you are repeating what you are saying, but not backing it up with probability numbers. Let me repost my math, which does not even address that SETI does not have a wide coverage area, perhaps you could put up some math if I am getting this wrong:
"Let's say the viewable EM window for an advanced civilization is 100 years before they move on to quantum comm. If there are 10,000 advanced civilizations with such 100 year windows in the Milky Way's history, that means there are only 1 million years out of 15 billion (.00007%) when listening for such a signal would have a result, not even accounting for the fact that many of these signals would be washed out before they reach us."
>Lastly, remember that Type II civilizations will have created
>planet-sized or larger megascale engineering projects that
>would be easy for us to detect. It is not only communication,
>but actual objects that could be found.
Planet-sized is a stretch, moon-sized is more realistic. We are nowhere close to seeing structures that small.
>We'll see. I still say that the accelerating rate at which we
>can discover planets (especially life-zone planets) has to
>have some close corelation to our ability to detect a
>civilization.
I agree that now we know where to look. But what should we be looking for:
By-product EM - If it even exists, we don't have anything that can detect this.
Artificial moon-sized structures - We can barely detect planets twice the size of Earth and are guessing at their composition.
Advanced Comm - We don't know know how this works yet.
So give it some time. This is all hypothetical and guesswork, the alternative view is just as logical and valid!
Posted by: Peter Y | May 25, 2009 at 12:49 AM
Peter Y,
To keep it short, let me summarize :
1) Even when we move to a new type of communication process that does not use EM waves, they would still exist as a byproduct of other processes. Even if only for a portion of the thousands or millions of possible civilizations. In the fictitious Star Trek science, EM waves still exist. Just like paper letters still exist for many purposes in an age of email.
the byproduct EM is much harder to detect than satellites and radio towers.
Except that it is not one civilization emitting it, but rather thousands or even millions.
2) A Type II can easily produce planet-sized, or much larger, megascale projects. A Dyson sphere (whether practical or not) would be something a Type II could potentially build, which is not just planet sized, but 2 AU in diameter for a G-type Sun-like star. A Dyson sphere (or even a Dyson Ring) is 200X the diameter of the Sun, let alone the Earth, and we would easily be able to see it by 2030 even at a distance of 20,000 ly, a radius covering most of our half of the galaxy. Your moon-sized limitation would apply to a high Type I, not a Type II.
By the way, the Milky Way was formed in May of the Cosmic Calendar, so is 10 billion years old, not 15 billion. It did not exist for the first 5 billion years after the Big Bang.
You have also made a two-decimal point error in converting the fraction to a percentage. It is 0.007%.(one out of 15,000). You have 2 zeroes too many.
So your theory is really 0.01%, given the age of the MW and your decimal error.
But I think your theory is wrong, since :
a) The MW is 100,000 ly in diameter
b) Each civilization has a 100 ly-thick EM shell pushing ever outward, even if assuming that EM totally stops after 100 years, and there is no residual EM use (both of which I disagree with, but I'll let that slide for now).
c) Thus, if there are 1000 civilizations, we should be in the EM shell of at least one (100/100K) at any given time. If there are 10,000 civilizations, we should be in the shells of 10.
d) If the EM shell is 200 ly thick, then each value doubles.
3) We are nowhere close to seeing structures that small.
If it even exists, we don't have anything that can detect this.
We are talking of our detection capabilities through 2030, not today, as I have written in large font. Our detection capabilities will be several thousand times more powerful by then, which is why I have clearly stated that I am reserving judgement until then.
4) If you have read Kurzweil extensively, then I can specifically refer you to pages 348-349 of 'The Singularity is Near'. I agree with that assessment of detection/EM waves.
I have not said 'No' today. But I will say 'No' by 2030 if we find nothing by then. You must recognize that what we find in the 21 years from 2009-2030 will be thousands of times more than what was found in all of time up till 2009.
So your points are flawed on precisely three fronts :
a) You need to reflect a 2030 level of findings, not a 2009 level, in order to disagree with what I have actually written in big letters.
b) You are assuming that all EM fully stops after a new technology starts being used. Paper hasn't stopped entirely in an age of email.
c) You have to recognize that a Type II can create structures much larger than the Sun, let alone the Moon. I said a Type II would be easy for us to detect by 2030. Revisit the difference between a Type I and Type II.
That is what our disagreement comes down to.
Posted by: GK | May 25, 2009 at 02:30 PM
I agree with most of your hypothesis.
But the Drake equation is missing one important factor in computing the odds of other civilizations. The possibility of some star like Betelgeuse going supernova and destroying all life in a sphere of several hundred or several thousand light years.
David
Posted by: David | May 26, 2009 at 02:09 AM
David,
That would be accounted for in the final parameter, fL, as that estimates the end of life of any civilization, whether through self-inflicted or natural causes.
Posted by: GK | May 26, 2009 at 09:10 AM
I wonder at one aspect of the Drake equation. Given that the Earth is 4.5 billion years old, and that life took hold within the first 100 million years, the vast, vast majority of the Earth's existence it did not harbor any intelligent life.
Therefore, even if advanced cilvilizations last 10,000 years, the percentage of a planet's existence they are around is very small (0.0025%). So, it would seem that the chnaces of their being two advanced civilizations in the galaxy at the same time would be quite small.
Also - there is an assumption here that quantumm communications are undeetctable. We think they are, today. But in 30 years, when they become widespread...?
Personally I think there is a very strong chance we are alone in this galaxy.
Posted by: Geoman | May 26, 2009 at 11:42 AM
Geoman,
You too have made a decimal error. 10,000/4 billion : check again. Although you missed only 1 zero, not 2 like Peter.
However, if you look at the Carl Sagan clip about the Drake equation, his assumptions lead to 1 billion civilizations ever. If a civilization lasted 10,000 years out of 10 billion of total star/planet life, or 1/1 millionth, that would still be 1 billion/1 million = 1000 civilizations right now, meaning that each one would be about 3000 light years apart on average.
But I, too, think that if we don't find anything by 2030, then the odds are against there being a civilization within several thousand light years.
Posted by: GK | May 26, 2009 at 01:00 PM
ooops.
Not disagreeing with you The Futurist - the questions that sagen posed will be solved by 2030. I just think we can guess the answer now.
Just like a habitability zone around stars, there is likely a habitability zone in the galaxy. Too close in and the radiation and gravitational perturbances will sterilize all planets. To far out and the metallicity is so low planets are unlikely to form, or if they form they would not have the necessary elements for life to arise. The spiral arms are dangerous - too much star formation going on. Our Sun is unusually metal-rich for a star of its age, type, and galactic location. It has an unusually circular orbit around the galactic center, reducing crossings of the galactic arms to a minimum (unlike 95% of the other stars in the galaxy).
So, I believe we are starting with a very low number of possible earth like planets at any one time. Maybe a few dozen ever. Factor in the short span of time that technological cultures exist, and we are very likely alone in the galaxy.
I'd also add - maybe a third of the galaxy is not really observable (and never will be) since we are trying to see what is on the other side of the core. If technological civilizations exist on the other side of the galaxy, we will never detect them.
One other factor I'm always amazed at is how few people factor in the likelihood that intelligent life would become ...technological life. As if the evolution of our own technology was an inevitable outcome.
Surveying human cultures, of the thousands of cultures that came and went throughout our history, some of which were far advanced, all failed to become technological until western Europe circa 1700. Why the heck did the Europeans colonize the rest of the world, when arguably, the rest of the world had more ancient and advanced cultures for much of our history? The rest of the world had thousands of tries, and thousands of years to evolve to a technological level, and they failed. Not their fault - becoming a technological society seems to be really, really hard.
Imagine, the continents are a bit smaller and more compact, and Mandarin China gets the upper hand. We could have had a static pre-technological society that lasted thousands and thousands of years...until snuffed out by some sort of cosmological calamity.
So, I'd put money on no detection of technological life in this galaxy...ever.
I agree - we will probably know within a few percentage points what the odds are by 2030. What an amazing thing to contemplate....solving the Drake equation with some degree of reliability.
Posted by: Geoman | May 26, 2009 at 06:06 PM
If we really can't detect 19th century or less civilizations right now, won't your "by 2030" premise only prove that we we haven't found cultures more advanced than us while the jury will still be out concerning less advanced than us?
But even by 2030, I believe we'll be able to detect the spectra bounced off of the atmospheres of individual extra-solar worlds. We should be able to detect pollution (coal) of late agricultural/early industrial activities on some of the 19th century worlds, should they exist and should we directly target our search for such signs.
Posted by: Zyndryl | May 26, 2009 at 06:32 PM
Geoman,
All true. The Rare Earth hypothesis (which is what you are describing) is hard to disprove without any countering data. I'm holding out until 2030 before I say that the odds are slim (but still not zero). The assimilation of telescope power into a Moore's Law-type trajectory will give us some answers.
Before, we knew about no civilizations, but also no planets. By 2030, we will certainly know about thousands of life-zone planets, so if there still is no evidence of a civilization by then, that goes a long way towards answering the question.
Zyndryl,
More advanced than us (Type I and Type II) = probably easy to detect.
Vastly more advanced (Type III) = hard to detect.
Less advanced than us : Remember, it is hard to be precisely 200 years behind us (out of 4.5 billion). It might as well be 20 million years behind us. That is the point. 200 years behind vs. 20 million years behind is no difference, but 200 years ahead would make it a Type II, so substantually more advanced than us.
A world populated by large, unintelligent creatures would provide spectroscopic evidence of life through the composition of its atmosphere. But an advanced civilization is still easier to detect due to outward-emanating EM waves. This is balanced by the fact that Earth had large vertibrates for 400,000,000 years, but radio-astronomy for just 71 years, making the former 5 million times more common under current parameters.
Posted by: GK | May 26, 2009 at 08:01 PM
ET stills probably uses smoke signals for long distance communications- an extrasolar version of "Germs,Guns and Steel" book theme. Life not rare,its technological civilization that's rare,because it takes so long to develop.
Check our own history,the ancient Greeks developed mechanical calculators,toy steam engines,etc,and CENTURIES had to pass before we re-discovered those ideas.The Chinese and Arabs all failed to achieve a true scientific/industrial revolution.
Maybe Earth is unique,but not for the reasons one might believe.
Posted by: curious_undergrad | May 31, 2009 at 10:57 PM
GK,
Don't you think it's too early to call on all this? With things like Gliese 581 d being thrown up, who knows what's around the corner? My thoughts tend to not be so certain that technology, no matter how marvelous and paradigm-shifting, will ever satiate the curiosity for what's out there while ET remains elusive. just my gut, I am quite the jack-ass when it comes to these matters.
Kyle
Posted by: KYLE | June 07, 2009 at 07:12 AM
Kyle,
Exactly what is being 'called' before 2030?
Posted by: GK | June 07, 2009 at 05:31 PM
It's a fascinating discussion. My feeling is that a natural stepping stone for a starfaring species would be to colonize the solar system with space habitats, i.e. orbitals. This way you could manage gravity requirements (via spin) and eliminate natural disasters and basic climate inconveniences. Of course I wouldn't imagine cramped little boxes but massive "Culture Orbital" structures mined from moons and asteroids and filled with lush plant and animal life and habitats and filled with 100m "people". The habitats are then placed at strategic points in the interplanetary highway, both to facilitate transportation and to assert some control. Now the question is, would we be able to detect this kind of civilization with current or near current-technology. I think not - and maybe that's perhaps an advantage in building such a set of structures. If we were all floating around in 60-80 orbitals around Mars, Jupiter, etc, communicating by point to point microwave traffic, and mining the moons and asteroids and shipping goods back and forth in small freighters, that would be an incredibly advanced civilization capable of hitting type I or type II status, especially if it spread to a few local stars. Yet, would you be able to detect it through observation? I think not.
Also, another factor that perhaps hasn't been considered by the engineering grads is our unique organizational ability. Humans can combine tens of thousands of specialists under good management and build space shuttles, aircraft carriers, computer systems, etc. However, they've only been able to do it in certain free societies that share knowledge, have a common work culture, share values, etc - i.e. it is an evolutionary adaption that has not even become universal *here* on this planet, where we see its success every day. (You know the nationalistic phrase I'm trying hard not to use!) There's no guarantee that the Bugs or Skinnies ever got past Command & Control, and if that's the case it may take them 10,0000 years to do what we do in 100. Just a thought.
- Author Enhanced Indexing Strategies, Writer Pajamas, Futures & Options, Investopedia
Posted by: [email protected] | June 16, 2009 at 11:57 PM
Fergit a big-blast newkyalur war. As soon as a cheap, easily mass produced good-enough VR comes along then civilization begins to falter. Progress slows. In cosmological time, the collapse will be almost instantaneous.
C'mon, you don't think it's the wimmin who built all the comforts of civilization do you? Take men, especially young men, outta the game and it's game over for civilization.
I figure you already sense this, GK, 'cuz of yer remarks about divorce an' all.
Posted by: Micha Elyi | June 24, 2009 at 12:09 PM
this ia quite an interesting discussion. you may be interested to learn that there is a minority of scientists and intersted parties who believe that pulsars are these ETI beacons. its funny who scientists are willing to consider the existence of ETI in the abstract, but when you show them a collection of radio beacons whose transmissions have mathematical fundamentals such as the golden ration encoded in them, in numbers large enough to answer any fermi paradox, they wont even acknowledge the possibility.
http://www.etheric.com/LaVioletteBooks/Book-Pulsars.html
http://www.etheric.com/LaViolette/abstract.html
http://www.etheric.com/LaVioletteBooks/Zeitlin-2001.pdf
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Posted by: Alpha male | September 13, 2010 at 10:22 PM
I do believe extra-terrestrials are alive and well in the universe...Heck! even our own milky way. I believe it's not a matter of if but a matter of when they will land their ships here on our planet.
Posted by: Blake | November 06, 2010 at 11:57 PM
Write a book already! A book of such like essays.
Posted by: DoesNotMatter | October 24, 2011 at 11:55 PM
When we get to a certain threshold, someone will be there to meet us. It won't do us much good to try to picture that--not right now. In our current form, our thoughts are too guided by extant paradigms and metaphors to work around fundamental, pre-comprehended assumptions about our own subjectivity, the structure of our thought, our relationship with space and time, and things of that nature. Our best bet is to work hard, stay healthy and make the world as compassionate, equitable and civil a place as possible. I must believe that humanity--i.e. that which is humane--fits into the equation somewhere. After all, we're one of the galaxy's civilizations that has managed NOT to nuke itself into oblivion a mere 200 or so years into its industrial/technological coming of age. Now maybe we could do a little better to share that Class I technology, and health care, and housing, and food, and education, and chance to contribute--the singularity will amplify our better angels, rather than our dystopian ones. (PS--I'm not a liberal, just a conscientious singulatarian).
Posted by: Will Sucari | May 31, 2013 at 10:20 AM
There is another sub-scenario not discussed much, and that is intelligent civilization which have radiocapability usually annihilate themselves at about the same time. It is not unreasonable, considering intelligence and violence are correlated in evolution. This would have the paradoxical effect that even if intelligence arose commonly, we would never likely be able to detect them, since we cannot even detect an "I love Lucy" broadcast from our nearest star. The only hope for our civilization would then be to create a large scale eavesdropping SETI, which would be capable of detecting such weak signals, perhaps by arrays on the far side of the moon, provided we don't follow then the way of the others beforehand. Such an effort is technologically feasible if we put all our effort into it, would answer the question with a high degree of certainty, give us statistics on the frequency and stability of intelligent civilization(s), provide information on parallel technologies close to our own stage of technological development, and might save our own civilization by knowing how to prevent our own demise. It might be worth it, if we are worth it.
Posted by: Selcuk | July 25, 2014 at 11:49 PM
Hi Kartik
Your prediction might be coming true here.
Apparently NASA just released today the discovery of , 7 exo planets and of which 3 are potentially habitable and in the same solar system.
Posted by: Sunny | February 22, 2017 at 08:00 PM