Is Anyone Out There?

Diamond rings don't reproduce. What if instead of diamond rings, they were viral infections (flu), each one targetted to a host where it could grow. And after a bit of growing, each one would spread again and target new hosts. How great would your chances of running into one be then?

Analogies are fun, but there are already too many variables to keep track of, even with the actual numbers and real cosmology.

Does anyone happen to know the average distance between stars in the Milky Way?

We already know the distance across the spiral (about 100k light years). So we know that traveling at half the speed of light would take an object 200k years to cross the spiral. If multiple objects started near the center, they could each reach the edges in 100k years.

But there's a big difference between crossing the distance, and actually touching all the stars in between. If each object that is colonized, sends out ten more objects every hundred years, I wonder what the dispersal would be. I need to understand that 'percolation' stuff better.

When one looks at the size of human expansion into the universe, a diamond ring on the earth is a very generous comparison (if you want to use a virus, it has only spread within the diamond ring so far). So, if a thousand civilizations the same or "less than" us existed, we would be extremely lucky to know about it.

(Don't hold back Ros, this is how I learn stuff )

Me too

Have you read the links I provided earlier?

Not yet, sorry. I will.

...but I have read a lot of Baxter, Niven, Asimov and Clarke.

Here's a sorta interesting thought game -

A major Interstate Highway runs about 75 miles to my West, another around the same distance to my South. I know that both from maps and personal experience. However, nothing remotely near me references or otherwise indicates either highway, and nothing anywhere on either highway references or otherwise indicates Timberland (yes, there is a Timberland). When "outta towners" ask for directions "back to" either Interstate, blank looks and lotsa detailed directions are typical components of the ensuing conversation, while "Where ya from/where ya headed" conversations even with long-time, well-travelled truckers in the truckstops closest to Timberland on those highways (about 100 miles from Timberland in either case), both of which are major, heavilly-trafficked trans-national thoroughfares, usually involve a phrase something along the lines of "Timberland?!? Where'nhellzat?"

Mostly, the point of this little thought game is that if folks don't have some personal reason to know where Timberland is, its damned unlikely they'll have any idea it exists, let alone any notion of where exactly it might be.


The galaxy might be crisscrossed with the cosmic equivalent of Interstate Highways, and Earth might be of about the same relationship to them as Timberland is to its nearest Interstates.

The original Drake equation (1961) posited ten thousand--i have been generous in assuming tens of thousands. If you read the link i provided, Drake now assumes more planets (in 2004) than he had originally though--but that doesn't change the assumption of a few tens of thousands on my part. I only assume that, however, for sake of discussion. Tediously, i refer again to what you and i have both taken notice of--that there are two many variables to make a reasonable estimate.

For me the principle objection to the Fermi paradox is that it assumes that any technologically sophisticated civilization would engage in colonization (keep in mind that mechanized exploration offers little to no reason for us to assume we'd know if that had been done), and continue to indulge in colonization, endlessly.

Your quoted author says that he prefers the Fermi paradox because he finds the assumptions more reasonable--and objects to the objections because they make assumptions too rigid and universal. But assuming that any civilization which reaches a degree of technological sophistication which allows for space travel will automatically be willing or able to colonize, and will continue to do so endlessly, is just as rigid and universal an assumption as any he objects to among critics.

What you smokin' timber?

This is a point i have been making. I see no reason to assume that any such civilization will send "manned" expeditions, or colonizing expeditions to any great distance, simply because they have reached a high degree of sophistication. Specifically, considering the huge resource expediture to send out colonists, there is no reason to assume that any such civilizations would undertake that lightly or thoughtlessly. To me, continuously colonizing because one can, with out thought to necessity or practicality would be thoughtless. I find the notion of mechanized exploration much more plausible. Then, i would again ask why we should assume that we'd know they'd been here, or why we would assume that they'd know we are here (unless they are within range of our microwave radiation, and current knowledge suggests that there aren't any candidate systems within 70 light years).

Why would one assume that each colony would send out ten more "objects" each hundred years? If by objects you mean mechanized exploration, that's not unreasonable--but still does not suggest that we'd know such a mechanized mission had passed our way, nor that such an expedition would have detected us. This is why Mr. Landis' pet assumptions are no more reasonable to me than are the objections to the thesis. It entails core assumptions about how civilizations act which are just as rigid and universal as those to which Mr. Landis objects in the critics. Particularly, it ignores what we do know from the one technological civilization with which we are familiar, which suggests mounting a single colonization effort would be difficult, never mind continuously mounting such expeditions. Finally, it ignores the meaning of alien--we may not be in the midst of a great silence--we may just be "deaf."

set Do you realize how bound in the impressed thinking that our knowledge of physics dictates, that is implicit in your response. Take A caveman sitting in his cave, watching the glaciers melt says, "Ya know Murray, we aint ever gonna have television"

The malleability of the laws of physics require time for us to discover the "loopholes" that allow us to discover how to further bend the rules. I believe (sincerely) that , exploration by thecitizens will be the ultimate goal of any civilization. Otherwise, whats the point? If they are sentient, they are curious. I think all beings with self awareness will evolve to that point if thyere not assaulted by bad luck and a planet shaterring meteorite or asteroid. Weve already found about 20 (in the Milky way) solar systems already exist with a distribution of smaller inner planets and outer , large "vacuum cleaner" sized planets.

Our first tool that makes us part of a deep space "culture" is the ability to "sense optically or electromagnetically" whats going on in the neighborhood. Our fields of inquiry are limited to a few thousandths of a degree in arc at a time. As our sensors get better and better, I think we will be surprised one day and get a "Hey, hows yourself?" and then, just like a bunch of PBB habitues, Well start planning our first get-together.

The didactic of "This is the common sensical" way of exploring is all well and good. However, just as weve decided to go back to the moon, we still dont have (IMHO) a good enough answer to the question "Why are we going back to the moon?" So far , the only answer Ive heard that even sounds half intelligent is, "Well, weve got better stuff now and we wanna show it off" . I guess its a reason , but I dont get a woody from it. I believe a really compelling reason to begin going further away from home, will arrive and one of theleast supreficial reasons is "were answering a call "
I think its a damn interesting subject and one that we can take up sides and talk sense and nonsense. However, the time will come in the futur. We will hear from ET and that alone will cause us to shift into a higher gear for space journeys and colonization.
Until we break the present limiting theories of physics, we are a bunch of Richard Owens who stated that "everything has been invented that could be invented", and we all know that was bullshit.

If I had the resources, and the technology, I would send unmanned probes year after year to as many points as possible, and I would not use the probability of life as a sole criterion. After all, we are not looking for intelligent life when we send probes to comets and Venus. Eventually, something might turn up; meanwhile, look at all the new information you would have. I say all this as a non scientist, of course.

I just picked some numbers which seemed doable with an advanced technology. I wanted to explore the math of expansion first without worrying about motives for the moment.

Self replicating machines might be programmed simply to move to the nearest new solar system and start consuming raw materials and churning out new copies. They could be rogue machines with no other function. Or they might have a motivation we can't anticipate.

FM, i am about to address the subject of what the point of a civilization might be, from the point of view of those who control it. One basic flaw i see in the thesis is that it assumes what you have articulated--but how do we know that will be true. If there 100,000 planets with sentient species capable of manipulating their respective environments, the crucial question is how many will develop unitary cultures which will achieve space travel, and want to expand and explore. It is on that basis that i become skeptical of the thesis--it universal and rigidly assumes what you have articulated.

EB--i have already pointed out that if the exploration is conducted by mechanized means, they could have been here, and we wouldn't know it, and they might not have been here recently enough to know that we are here. Furthermore, i don't think we can ignore Terry's point that they may not want to contact us because of mistrust. Once again, there are so many variables that i question the core assumptions of the thesis.

Ros, look out. To me, the lack of consideration of the motive is one of the basic flaws in the thesis. Motive would be especially important to justify the creation of self-replicating systems which simply move from one system to the next, chewing up the resources and spitting out copies of themselves. If the object were not to provide resources for the inventors of the self-replicating systems (which would entail a return to the point of origin), what would be the motive for creating them.

All of you need to look out, i'm about to spam the thread with some observations on culture and civilizations.

Mr. Landis objects that critics of the Fermi paradox have less reasonable positions, because he alleges those positions are rigid and universal. I have pointed out that it is not to be wondered at that Mr. Landis prefers his own point of view. That is not churlishness on my part, but rather, and objection to his objections on exactly the same basis--that the Fermi paradox assumes conditions in technologically sophisticated civilizations which are rigid and universal. I will address the first, major objection which i have to a universal and rigid assumption implicit in the thesis, even though not stated.

The thesis assumes that civilizations which reach a level of technological sophistication which is sufficiently high to allow for interstellar travel will unquestionably begin a process of colonization, which process will be endlessly continuous. Implicit in that assumption is that such a civilization will be unitary across the entire cradle planet. I consider that assumption implicit because we know from physics that there is an enormous cost in resources and energy to escape the gravity well of the home planet with large amounts of equipment and resource--and large amounts of equipment and resources will be necessary to send out colonists. There would need to be a sufficient number of colonists to assure that there will be sufficient genetic variety among the colonizing population, and a sufficient number of colonists to survive initially hostile conditions or initial resource deprivation, until such time as the colony can become self-sustaining. When the Virginia Company established a colony at Jamestown early in the 17th century, 90% of the original colonists, and about 90% of all newcomers in each new arrival, died within a year. One might object that the Jamestown colonizers were relatively technologically unsophisticated, but that would ignore that they had sufficient technological resource to establish in Virginia a style of life equivalent to the agrarian standards of their home civilization in England. One might object that many succumbed to the hostile attacks of Indians in Virginia--but that objection would entail an assumption that interstellar colonizers would meet no hostile environmental conditions, and no hostile species. That is one more assumptive nail in the coffin of the thesis. An intelligent species would want to assume that conditions may well be initially difficult, and probably even lethal to a proportion of the colonists, and very likely a high proportion of the colonists. Coming to a new planet from either suspended animation, or worse, from generational reproduction on board the colonizing vessel or vessels, the colonists will be ill-prepared to deal with the new gravitaional conditions on the new planet, and are likely to not yet have sufficient knowledge of their new environment to immediately establish a self-sustaining colony.

So, such a colonizing civilization would need to send out a very large single vessel, or many more moderate groups of colonizers--and to obviate the problems of establishing resource production on the new colony, would need to send a good deal of resources with the colonists, or vessels on which food, at least, can be produced. This means a very large investment of resources and of energy. This is why i say that the thesis assumes a culturally unitary civilization. The United States has the largest, most effective military on this planet, and the largest ecnomony--yet we haven't the resources to meet the needs and wants of our population, and invest huge amounts of resources in a venture such as would be entailed in sending out a very large, or several small, colonizing expeditions. It is unlikely, although certainly not impossible, that any one dominant culture on a planet could accumulate the necessary resources, while living among other cultures which were unwilling to contribute, and any number of which might be hostile to the dominant culture. This suggests to me that the thesis assumes (even if the promulgators of the thesis don't realize it) a unitary, planet-wide culture.

I have also objected on the basis that in any such technologically advanced civilization, the needs, wants and demands of individuals are likely to divert a significant amount of resources to individual or small group pursuits. While acknowledging that we probably don't have any good reason to assume that alien civilizations will mirror our own, i consider this objection crucial because of the nature of civilization as we do know it.

I will start another post to describe from human experience the complex probabilities for a civilization which is technologically sophisticated, but not necessarily unitary.

The first "imperial dynasty" of China, the Shang, was not in fact an example of a dominant, unitary civilization. The Shang arose and flourished and then fell in a period from roughly 3800 years ago to 3000 years ago. Although culturally largely dominant, the Shang (or Yin) dynasty actually represented the culturally dominant organization of ancient china, but a culture which was neither militarily nor administratively dominant. It relied for control upon the cooperation and/or the dominance of petty aristocratic districts within what was only notionally an empire. The Shang was preceded by the Xia, the records for which are legendary (and to which i do not therefore refer), and it was succeeded by the Zhou, which was no more successful at creating a unitary and dominant culture, but which was sufficiently literate to have left us a record of the Shang--the Shang itself does not leave historical records, although there are inscriptions on bronze artifacts and turtle shells and bones--all historical records of the Shang come from the records of the Zhou.

In the case of the Shang and the Zhou (the Zhou begins before the collapse of the Shang, at about 3200 years ago, and lasts until about 2500 years ago, but was actually dissolving in the "warring states" period before it disappeared altogether) neither dynasty was able to assure its military, administrative and social dominance within China. This does not occur until the Qin dynasty, so called for the first true Emperor in China, Qin Shi Huang, also known as Huang Ti--called traditionally the Yellow Emperor, and acknowledged in Chinese history and culture as the first successful unifier and undisputed ruler of China. Huang Ti established his dynasty in 221 BCE. In the Shang, Chinese bronze production began, and it was technologically (and most reliable art critics allege that was artistically) superior to any bronze production anywhere on the planet at that time. In the Zhou dynasty, the earlier forms of writing rationalized into the idiographic Chinese writing which has been used up to modern times. Also in the Zhou dynasty, iron was first used, and it was technologically equivalent to or superior to iron technology anywhere on the planet. Late in the Zhou, in the period known as the warring states, the crossbow was invented and proliferated. This was well before the classical Greek civilization, and represented the highest development of military technology of its time--and was sufficiently effective to have been used for thousands of years.

From the time of the Qin dynasty, Chinese dynasties have succeeded one another (the Qin lasted for only three generations) with an almost unvarying pattern (the Later Han dynasty's collapse lead to the fragmentation of China for several generations before another unitary dynasty was established, and the Yuan dynasty was actually foreign--it was the dynasty of the Mongol conquerors). Each new dynasty, beginning with the Han, was established because a semi-barbaric (by Imperial Chinese standards) but militarily competent clan would succeed in conquering the empire. Initially vigorous and effective, each such new dynasty would use the old bureaucratic methods of the Mandarins, leaving the Mandarins in place, but would be independent in policy, and would promote trade with neighboring people--barbarians in the eyes of the Mandarins. As each dynasty aged, the Mandarins would gradually assert their primacy in administration, which would entail the gradual taking of control of policy. The Chinese called themselves the "Middle Kingdom," which was not a geographical description, but a "metaphysical" description--they lay between heaven and earth, and earth was the home of a howling wilderness of barbarian tribes. As the dynasties matured, the Imperial clan would become more and more sinicized, which meant that the Imperial clan was further and further removed from direct governance and policy control, and became more and more embroiled in palace intrigues, which, if more important to them, and always eventually fatal to the dynasty, had little effect outside the palace precincts until the final collapse.

As the Mandarins re-asserted their control of policy, they had reference to their historical records, and the precedents for policy decisions; this was very much like the legal procedure in the West of referring to precedents of judicial rulings. The ethic of the Mandarins which held that all people outside the empire were barbarians in a howling wilderness lead them to prohibit trade and contact with said barbarians. The eventual result in all cases was military pressure from outside China, and very often rebellion within. When the Mandarins were fully in charge of policy, not only would no trade be allowed, but the Chinese themselves were prohibited from leaving the country, and were under a sentence of death if they did leave and attempted to return. Although China produced the earliest sophisticated pottery and bronzes, the highest quality iron weapons and tools, the first clock, the first paper currency, the first moveable type--a host of technological advances, the Mandarins decreed that these developments would not be traded outside China, and would remain the sole province of the Mandarins, the Imperial clan, and the great aristocratic clans from whom administrators and military leaders were chosen. New Chinese inventions became curiosities in the Forbidden City, and gathered dust over the ages, so that many were invented over and over again (clocks and printing presses are good examples), only to be forbidden the people, and forbidden for trade. Gunpowder was only ever used for entertainment fireworks, or rockets to frighten the horses of attacking barbarians.

China was then, cyclically, an introverted civilization, whose high degree of technological development did not serve to expand the empire or for trade with China's neighbors. When, early in any dynasty, the Chinese did trade, just about the only valuable commodities which were allowed for trade were pottery, bronze and silk. Because of the introverted, the insular policies of the Mandarins, which inevitably asserted themselves in every dynasty, the great potential of the Chinese people over thousands of years was squandered.

Therefore, why would it be reasonable to assume that highly sophisticated technological societies would automatically look outward, and want to expand outward, unless the motive were dire necessity? It is equally plausible that a highly sophisticated civilization, even if representing a unitary culture, might well be insular such as were the ancient Chinese dynasties, and would not necessarily have an impulse to expand. The Fermi paradox entails a rigid and universal assumption that all technologically sophisticated civilizations will want to expand--and i consider that a naive and simplistic point of view.

I will examine in yet another post the "hive mentality."

A little over eight hundred years ago, from the wreck of earlier civilizations in the highlands of what is now Peru, and building on the culture of the failed societies of the coastal deserts, an empire arose which we commonly call the Inca civilization. In fact, they called their empire the Tawantin Suyu, or the "four united regions," which suggests that either four aristocratic societies which were culturally identical or similar merged, or that one of them united all four by conquest. Inca actually refers to the title of the supreme ruler, who was basically a combination of high priest and supreme military commander.

This society was socially very sophisticated, and made provisions for all of the population, and for all members of aristocratic clans. The latter provision was intended to prevent rebellion and so that upon the death of the Inca, there would be no motive for disputing the succession. It was remarkably effective at obviating palace revolts and disputed successions--all Incas were descended from the original Inca, and the aristocratic clans were given the hereditary rule of the four provinces and their subdivisions. There were more than 500 local languages and dialects, but there was only one "official" language, and one lingua franca used in trade with the mountain peoples who were conquered and put under Inca hegemony. Within the society, all men were entitled to a measure of land sufficient for him to raise food for himself, a wife and up to six children (if they produced more than six children, they were on their own to feed them) and a specified surplus which fed the royal family, the aristocracy (which provided administrators, priests and military officers) and the army. A certain proportion of men were given a living for themselves and a spouse and children if they were assigned to other tasks, such as handicrafts or mining. If a man died, the village would be required to provide labor to work the land which had been assigned to him to provide the support for his widow and his orphaned children. If a woman died, the village would be required to provide child care while the man worked. This was regularized as the mita, the public service requirement of every adult. All functions other than food and craft production--mining, the army, engineering work forces, etc., were produced under the mita regime, which was regulated by the priesthood (recruited from aristocratic clans) and which was alleged to be ordained by God, who was incarnate on earth in the person of the Inca.

The civilization reached a high degree of sophistication--fresh fish were brought to Cuzco from the coast by relays of runners, snow and ice would be brought to cities and towns for the use of the royal family and aristocrats by the same method, and relays of runners carried communications throughout the empire at a pace as good as or better than what was then common in Europe (using the quipu, knotted cords which formed messages based on the size and placement of the knots, and the color of the fabrics used--the culture was otherwise illiterate). As engineers, these people rivalled the Greeks and Romans, creating monumental architecture and roads of a quality which Europeans had not produced since Roman times and would not produce again until modern times. Cisterns or wells were located at regular distances along the roads to serve the runners and those who transported goods, as well as the army.

The Inca culture conquered most of its neighbors, although it failed to penetrate very far into the forests of the upper Amazon basin, largely because of logistical problems. They pushed north and south, conquering the kingdom of Quito (roughly, modern Ecuador), and accomplishing the heroic feat of crossing the punishing deserts to the south to enter what is now Chile, where they were stopped by the Mapuche tribe, an Araucanian tribe (ethnically, all of the tribes of lower South America, north of the primitive people of Tierra del Fuego were Araucanians--they were the most populous in what is now Argentina).

Basically, the Inca civilization was a "hive" civilization. All of the people were organized to feed and supply themselves, and to produce a surplus to support the royal family and the aristocratic clans. The records we have of their culture are scant, and are based upon the oral traditions which the Spanish clargy recorded after the conquest, and archaeology. The evidence of that oral tradition, and of archaeology, however, is strong on one point. The Inca were not inventive. Having translated existing social structures to a larger scale with the unification of the four regions, they imposed them on all territories conquered. The mita appears to be based upon methods already employed for centuries before the empire arose. Although ornamentation developed, the forms of pottery and fabric were unchanged from their predecessors. Their engineering was an extension into road building of the architectural methods which are apparent in the civilizations which preceded them by thousands of years. The innovation of the quipu was significant and crucial to communication--but it did not lead to a written langauge, and "literacy" in terms of understanding the meaning of the quipu was confined to the priestly class (which included by implication the royal family). The royal family and the aristocratic clans were educated in schools, but were taught the same things over centuries--there is no evidence that any form of scholasticism was ever practiced. Animals were domesticated, but never used as beasts of burden, and the wheel was never invented--all goods were transported on the backs of men. Only the most primitive metal smelting was practiced--in gold, silver and copper--and was a survival of earlier periods, used only for ornamentation. All of the sophisticated stone and flint tools were survivals of earlier periods. All the needs of the people, the royal family and the aristocratic clans were met for centuries, and the evidence is that having met their needs, the culture looked no further. If there were invention or innovation, it was either suppressed or ignored. Beyond the quipu, there is no evidence of any material innovation, except perhaps to note the excellent roads which they built, which were based on the monumental architecture which they had inherited. The Incan culture was as close to a "hive mentality" of which i know in human history.

Certainly one can allege that had there been no Spanish conquest, the culture may eventually have become innovative--but the record of almost four centuries is that the culture produced no innovations beyond what has been noted. However, the knowledge of just how effective the Inca empire was at achieving its goals, without recourse to invention or the further development of existing technologies, strongly suggests that a sentient species could evolve on a planet, and attain great heights of social and administrative organization, without every proceeding to the stage of scientific inquiry and conscientious invention. For that reason, i object to the Fermi paradox thesis because it assumes, universally and rigidly, that all planets on which sentient species arise will lead inevitably to civilizations which attain to scientific sophistication.

More than that, the experience of a "hive mentality" in a human culture suggests to me that continual innovation and invention can only arise in a culture which tolerates individuality to a high degree. It that is so, then it provides yet another reason to reject the implicit assumption in the thesis that technologically sophisticated cultures will be unitary on a planet-wide basis. To revert to the example of the United States on our planet, simply being the dominant culture is no guarantee of commanding sufficient resources for large scale interstellar travel. If the tolerance of individuality is the currency paid to achieve innovation and invention, then is even more reason to object to an implicit assumption of unitary culture, and to point out that the demands of individuals are likely to be a drain on resources--a drain which would mean that concerted, large-scale colonization projects are only likely to occur from obvious and dire necessity, and are likely to cease as soon as needs are met. I think that would be the crucial determinant of what "interstellar percolation" would entail.

Lets inquire into the very nature of humanity to explore. Youve given 3 examples that fit one side of the discussion. (eg my wife was very adept at the quipus, she wrote a paper for an aty history course that showed how messengers were able to sort out calculations of important resource amounts by providing successive messengers with the results of their "calculators"-There are a number of resource materials on how quipus provided a menas of "tax calculation etc, and werent such an obscure knowledge as you seem to state).

Anyway. Lets go back a few millenia to a time that before the Inca, involved a spirit of travel into an unknown land or lands seem to trump your concepts.

Homo ergaster and Homo heidelbergensis both began intercontinental wanderings that took them beyond their comfort zone to open up an entire planet. I dont think they had a plan to govern their global wanderings

The Paleo H sapiens wandered to discover and populate an unknown Series of Continents(thus predating the Inca by about 13000 years at least).

Norsemen left their own comfort zones and made the journey all the way to Newfoundland and some say mid Maine.

Resources, lebensraum, whatever, when we get the phone call from ET, we will begin a cross Galactic plan for deep space exploration. Why? well firstly, we as a species dont trust anything to unknowns. We will quickly begin to look at fusion reaction (which we have scheduled to develop by no later than 2050) to keep our comfort zone comfortable and then begin to seek our real destinies.

I say that humanity is more like the Norse and the Polynesian rather than the Maya or most Eastern Cultures. There is a reason for the "beehive cluster"type of civilization , just as there is for the"wandering man". I think the wandering man will win out and we will plan our destiny around sexcursions beyond this solar system. Course, we can bet all we want, well never know .

slow catching on here. Profound thought CT, though somewhat armadilloist.

Strange we seem to find comfort in the idea that we are not alone. But what if WE ARE? Chilling eh?

And that sucks.

But the 'sexcursions' thing sounds interesting. Sounds like Flesh Gordon all over again