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Fraser
2005-Oct-19, 05:20 PM
SUMMARY: We live in a big galaxy with billions of stars. So, where is everybody? In his classic equation, Frank Drake developed a formula that could calculate the number of intelligent alien species in our galaxy - there should be many civilizations out there. But the Fermi Paradox says, if there are so many alien species, why haven't we met them? Steven Soter has written an article for Astrobiology Magazine that runs tries to get to the bottom of this contradiction.

View full article (http://www.universetoday.com/am/publish/wheres_all_the_life.html)
What do you think about this story? post your comments below.

Aquarius
2005-Oct-19, 07:44 PM
Haven't you ever seen "Men in black"? The aliens are already living amongst us. In disguise, of course. Soon they will be outnumbering us.

TuTone
2005-Oct-19, 08:02 PM
Possibly Aquarius or Earth could be a big Alien Reality TV show where Aliens mixed a whole bunch of different animals (Crabs, Lions, Deer, Ants, Monkeys, etc) with humans (African Americans, Caucasian, Indians, Hispanics, Asians, etc) to watch for their amusement while we humans destroy each other. Africans came from one planet, while deer came from another planet; Asians came from a different planet & so on. The aliens abducted each species from each planet & placed them on Earth to gain ratings & watch us for their amusement.

You're looking at intelligent life when you go to the grocery store. You see all these different species. Aliens are amongst us!

PEACE TO THE WORLD!

foxy
2005-Oct-19, 08:42 PM
I suppose that everyone is familiar with the Khardashev scale for civilisations. When he first proposed this at a scientific seminar in Oslo in 1952 (I think) there was, unusually, not a scientist in the room who disagreed with him.
If he was correct in his assumptions, advanced civilisations would have enclosed their galaxies in shells to gather the energy form their stars, and so would not be visible by telescopes. It might also explain the puzzling patches of 'dark matter'. But it would not mean that they would be unaware of our presence.
As we have not as yet even developed a stage one civilisation there would be no advantage to them in making contact. But I have no doubt that there are entities like Von Neumann probes monitoring our progress, and I have equally no doubt that if we continue to mis-develop our science for the production of ever more deadly weapons they may find it neccessary to apply 'remedial action', if only for their own protection.

howard2
2005-Oct-19, 11:11 PM
The minimum one percent scenario gives a probability of about 1000 space going species in our average sized galaxy.
It goes like this:
Assuming there are 200. 000.000.000 stars in our galaxy. If half of them are multiple stars systems orbiting one -another and probably sweeping up any planetry making material. So that leaves us with 100,000,000,000. Of which only 1% have one planet. (Bare in mind our solar system has 10 Planets and 10% has us. That is why it is called the minimum one % scenario.) That leaves us with, 100,000,000 Planets of which 1% have organic life.
Leavig us with1,000,000. Of which 1% have intellegence, and of which 1% are Say 10,000 of our years ahead of us, and are space travling. (Which is a blink of the eye in cosmological terms.) That leaves us with a 1,000 space traveling biological species out there. Which is only one part in 200,000,000.
We can only look at probabilities, and cosmologists find the building blocks of organic live everywhere they look. So this is a reasonable assumption.
Unless they have developed warp drive the distances from one star to another would be prohibitively expensive. We have only been looking for them for a very brief moment in time, and why would they be interested in us? Way out on a limb of one of the spiral arms of the galaxy. Who are we anyway?

Please comment.

ynot
2005-Oct-20, 04:39 AM
Unless they have developed warp drive the distances from one star to another would be prohibitively expensive. We have only been looking for them for a very brief moment in time, and why would they be interested in us? Way out on a limb of one of the spiral arms of the galaxy. Who are we anyway?

Agreed. Who says planetary development will ever become "easy"? It's hugely prohibitive. And why bother to colonize a system that is light-years away? "Warp-drive" is imaginary, remember, and interstellar travel may remain prohibitive for many more centuries.

The scenarios of "we are agressively territorial" or "our technology is self-destructive" reflects our own politically correct concerns rather than reality. Humans are not any more aggressive than any other species, or self-destructive, we just have to learn to manage ourselves, though perhaps we are getting ready for expansion. But with all the nukes we have, not one has been used in fifty years. Mutual deterrance works very well. We are not so lacking in wisdom, nor will "they" be.

The most likely scenario is that civilisations are as numerous as grains of sand or leaves of grass. We are simply one in a million of like civilisations and hence insignificant and unimportant. And dang far away, and have you seen the price of interstellar gas lately? Seriously, funding and time for interstellar exploration would be just as hard to come by for them as for us.

So why can't we see them? Again, we have only started looking, and our tools are still pathetic. And the smarter, wiser civilisations would know to leave us alone until we were ready. Does this mean there are not rogue, irresponsible peoples out there, like on our own planet? Sure, so let's hope intelligent boors do not visit or colonize us. We should not be too demonstrative of our presence until we know the neighborhood.

Regarding the "systems hidden in shells" theory, I doubt it, but I have noticed that the biggest vulnerability of space is that you can't hide in it. Every planet is exposed for all to see, except for dust clouds...

If they were living "among us", why would they do such a thing except for peaceful science, and if so then why would anyone care? As for colonizing us, if they are so intelligent then why would they be sneaky about it? Rather, they could just say, "Hi, we're colonising you". And why the heck would they "colonize" us anyway? Wouldn't they want a fresh planet not crawling with self-destructive, territorially-agressive competition to plant their own pure species?

Very likely they would want the same things we want - peace, freedom, and resources, a clean, sunny place to raise a family. Otherwise, we're just titillating ourselves with boogeymen theories, which again reflect our own desire to be thrilled by bug-eyed Stephen King monsters more than any rational reason. If you want to know what "they" are like, just look in a mirror, read a book, or watch the news.

We may soon be discovering our own undeveloped civilisations, then we'll be the boogeymen. And how interesting could it be to research a civilisation far less developed than our own? Rather rote and boring I would guess. We would protect them just as we are smart enough to protect our endangered species, or children.

Besides, only geek alien scientists with no lives would be studying us. Wouldn't a more intelligent civilisation have far more interesting things to do? We need to give "them" more a little more credit and a little less hype. And it's probably prudent to keep a little quiet until we know the neighborhood.

rob tillaart
2005-Oct-20, 06:03 AM
Where is everybody?
We want to communicate with aliens while we can't even communicate (well) with dolphins, apes and other intelligent creatures that are abundant on this planet. Lots of work to do before we have that universal translator.

Last holiday I read the sci-fi book 'Revelation Space' of Alastair Reynolds In his book Reynolds has a very intriguing explanation for the fact that we do not see other aliens. The book tells about a planet that belonged to the Amarintin and their civilization dissappeared suddenly while they had reached a similar technological level as the humans (space travel). The book is about the quest why they dissappeared. As I do not want to spoil readers fun I will only tell that I could not lay down the book until it was finished. Very intriguing indeed.

braveheart
2005-Oct-20, 02:03 PM
I agree to some extent with rob tillaart, but want to go even further: We as humans cannot even communicate with each other and are constantly at war with one another. What are we going to do with the aliens!!?

Has anyone perhaps read the book "Why Complex Life is Uncommon in the Universe" by Peter Ward & Don Brownlee? I found it to be a fascinating book which provides a broad synthesis of what is now known about the development of life on Earth and how this sheds light on the possibilities for organic life forms elsewhere in the Universe. From the start however, it is important to distinguish between simple organic life forms, complex animal life forms, and intelligent life forms such as ourselves! I cannot ellaborate on everything here, but at least consider the following:

1. If our Universe is 12-13 billion years old and our solar system about 4.3 billion years, then the whole evolutionary life cycle of solar systems like ours "from "supernova to supernova" could have happened 3 times since the "Big Bang"!
2. When we consider "habitable" planets, one should bear in mind that earth was not created as cosy and hospitable as it is today! It took countless (probably many of them quite rare) planetary and cosmic events to create earth's "habitable" conditions (it's position and size relative to other planets in the solar system, size of our moon, asteroid/comet bombardments, several extinction events directing further evolution, the timing of these events, there specific impacts on existing life forms at the time, etc.).
3. Add to this that perhaps our location "out on a limb" in our galaxy is our saving grace, since we may have evaded supernovas and gamma ray bursts which could have annihilated all life forms had we been closer to the galactic centre! So a long enough period of relative "safety" from cataclysmic events is required for complex life forms to evolve.
4. Consider the myriad events which shaped the evolution of life on earth: Primitive forms may have been present for billions of years, but complex animal life only for hundreds of millions. Yet, despite millions of years of dinosaur evolution, no "intelligent" ones evolved. Some (perhaps unique) events ultimately resulted in intelligent life evolving very rapidly during our most recent past.
5. Even on the time scale of only OUR solar system, the time period during which "technologically advanced intelligent life" has existed on earth is infinitesimally small. On the time scale of the universe, what are the odds that TWO intelligent civilisations (given the multitude of events which had to occur in such precise order/progression) exist at the SAME TIME (even if we allow for the fact that one civilisation may be several thousand years more advanced than the other). This is confounded by the vast distances which might (probably) separate us (even at the speed of light it could take thousands, millions or even billions of years for even communication signals to reach either). So, unless technologies are developed in which space/time can be manipulated to make reciprocal communication possible, you still need such technologies to exist in the same time frame (or by the time any signals reach us or them they/or us would have evolved immeasurably, or do not exist at all anynmore!)
6. To conclude: Recent scientific findings that life (at least simple microbial life) is extremely enduring and may exist in previously unimaginable extremes, seems to indicate that such life may be quite common in the universe, our galaxy and perhaps even our own solar system. However, the vast number of seemingly unrelated (yet intimately tied and perfectly timed) factors required to play in perfect harmony for complex animal (and more so "intelligent") life to evolve might prove that the vastness of our universe (or multiverse?) and billions of years of cosmic/galctic evolution have all been essential requirements for the cosmologically unique event we call the evolution of intelligent life! At this stage we do not know whether or not any one event in cosmic/earth evolution may have been critical to evolution of intelligent life. Since we also cannot determine absolute values for any part of the Drake equation, if ANY one factor should turn out to have been essential/critical and unique in Earth's history (something that was not duplicated exactly or in precisely the same order anywhere else in the Universe), that would mean that for OTHER similar civilisations a value of zero would have to be substituted in a part of the equation, which yields a result of ZERO!

gymcoach99
2005-Oct-20, 02:18 PM
Query? There has been little discussion on the biological implications of alien species living together. Perhaps in the scheme of things it is not possible and therefore colonisation of space can only take place on barren planets - very hostile to life any way. The colonisable barren would, I suspect be rare given the view that water based planets would already be colonised by 'life' and therefore by implication uncolonisable.

moonbiter
2005-Oct-20, 04:56 PM
One huge assumption that is not mentioned in this article is the availability of an energy resource that would allow a civilization to bootstrap itself to a tech level sufficient for interstellar communication.

Consider: much of, if not most of the modern technology that we take for granted has only been possible because we have available to us large amounts of fossil fuels which we are able to exploit. Without the help of oil, natural gas, and coal, a civilization just isn't going to get a chance to develop to a level that will have radio technology -- and at the end of the day, that's what's important for those who are listening to the skies in hopes of getting a phone call.

Now, we have no idea how common fossil fuel formation is on other worlds -- it could be something that is very common on worlds with a long history of life, or it could be the very rare result of some specific circumstances. But whatever the case, it is a unknown variable that needs to be thought of when considering such an equation.

Personally, I don't see why the question is such a big deal to folks. Whether or not other intelligent life and civilizations exist in the universe is not something that affects humanity in any real way in the present, unless we are hoping for gifts from the gods (i.e., technology from benevolent advanced aliens who want to give it to us because their business plan is 1) give inferior civilization advance tech, 2) ???, 3) profit!!!). I'm more of the mind to get our own affairs in order before checking out the neighbors.

Still, I guess as a general search for knowledge thing it's a valid subject.

ynot
2005-Oct-21, 12:50 AM
I think finding other civ's out there is the most exciting thing imaginable. The thing is, they must be out there, so it's just a matter of time to find them, or them to find us. It's exciting, like finding long lost relatives. There has got to be at least 100's or 1000's in our own galaxy.

As for intelligent life, I think most life forms are "intelligent" in the sense of deserving of respect as a living, potentially conscious being. I think most animals in particular are just as emotionally intelligent as humans, even more so, they just can't develop their awareness, communicate it or form concepts to share it.

As for the "chance events" that allowed life on earth to develop, I think we have to consider that these events were far too convenient to be merely "chance", which opens a big ball of wax (which I don't want to get into). But I believe it.

The correct-sized asteroids hitting us at PRECISELY the correct geological times necessary, repetitively, to further our evolution is not chance. The only conclusion can be that the product of the universe is not biology, but reflexive consciousness and the non-physical, ethical spirit of beings. All of nature cooperates to produce these beings and this spirit, and to see that they are not destroyed. All we have to do is cooperate with nature and the ethical demands of natures spirit.

ToSeek
2005-Oct-21, 05:08 PM
Discussion ongoing here (http://www.bautforum.com/showthread.php?t=33783) as well regarding the same article.