View Full Version : Likelyhood of Extraterrestrial Intelligence
On first glance, it seems as though the universe is so big there simply must be other life out there. And that may be the case. But is it possible that life is as common as portrayed in the scifis?
Most likely, the answer is no. The truth is, if life were that common, it would be plainly visible. It doesn't take a huge knowledge of statistics to understand.
If an extraterrestrial civilization had existed before us, they should have had something close to half the galaxy's lifetime to collonize it. Collonizing the galaxy seems like a monumental task, especially when you take into account that it is unlikely superluminal velocity is possible. However, in comparison to the age of the galaxy, its size is quite small. It's easy to forget that the galaxy has rotated several times (at much slower than lightspeed) since life got started on EARTH. It's rotated once since the dinosaurs.
So if one extraterrestrial intelligence had existed before us, they had plenty of time to collonize the galaxy. And if they had done so, we would see something. Structure in the galaxy. Mined stars. Artifacts. Radio signals.
Does this mean there is no extraterrestrial intelligence? No. But it does mean it is almost certainly rare. Unless by some freak of coincidence another intellligent race emmerged within a few million years of ours, we are the only intelligent race in our galaxy.
If extraterrestrial intelligence exists, there are two options. They exist in distant galaxies, or they exist in the future.
On a sidenote, it at least seems highly unlikely that only 1 intelligent race would ever form in our galaxy, considering how long it has left to live. A likely time for another one to pop up would be somewhere around twice the age of the present Milky Way's age, assuming intelligent races pop up on a regular basis.
Any thoughts?
jjalexand
Mar18-03, 06:49 AM
Self-organization (complexity theory?) argues for intelligent alien life.
Self-organization derives from positive feedback under constraint.
Gas clouds contract under self gravity (+ve feedback as density increases).
Initial random rotation leads to spin by conservation of momentum.
Spin leads to disks.
Disks lead to rings.
Rings lead to planets.
Thus most stars may have planets.
Co-operative positive feedbacks of self-catalytic loops of co-operating reactions lead to selective reproduction of certain catalytic molecules (+ve fbk).
Reproduction with limited resources leads to competition.
Competition leads to evolution.
Evolution leads to better self-oganization and co-operation.
Thus life will start as soon as there is a viable pathway, and evolve to fill all ecological niches. (As we see in cases of parallel evolution).
Intelligence is a competitive advantage, thus will be adopted by life if there is a viable pathway.
The parallel evolver does not need to know anything about the original or even be on the same planet.
Thus a percentage of planets probably hold life, and some intelligent life.
Why haven't we heard from them?
Perhaps someone somewhere invented computers which led to AI, which out-competed its creators and became inimical to life.
We'll probably know soon enough as the volume of the sphere of our detectable radio emissions (and thus the number of stars able to discover us) is increasing with the cube of time.
Sorry, I've had a few beers, I'm sure there's a better explanation.
:)
Suppose intelligence doesn't necessarily imply science? Maybe they all write poetry and couldn't care less about galactic colonization and radio astronomy.
Somehow that seems worse to me than being alone in the galaxy... [;)]
russ_watters
Mar18-03, 10:38 AM
Most likely, the answer is no. The truth is, if life were that common, it would be plainly visible. It doesn't take a huge knowledge of statistics to understand. If most of what we know about science is even remotely accurate, then this is not correct. With current technology we could not even detect life 100ly away unless they are actively transmitting something we can receive. And through passive detection, we couldn't even find life 10ly away. We don't yet have the ability to even locate earth sized planets anywhere outside the solar system, much less analyze one.
Our galaxy is roughly 150,000 ly in diameter. There could be THOUSANDS of planets with human level life/technology and we won't know it.
If an extraterrestrial civilization had existed before us, they should have had something close to half the galaxy's lifetime to collonize it. Collonizing the galaxy seems like a monumental task, especially when you take into account that it is unlikely superluminal velocity is possible. However, in comparison to the age of the galaxy, its size is quite small. It's easy to forget that the galaxy has rotated several times (at much slower than lightspeed) since life got started on EARTH. It's rotated once since the dinosaurs. So if one extraterrestrial intelligence had existed before us, they had plenty of time to collonize the galaxy. And if they had done so, we would see something. Structure in the galaxy. Mined stars. Artifacts. Radio signals.
There are a couple of problems with this. For starters the technology you describe is not even theoretically possible: Interstellar travel will likely not ever be possible for anyone.
Second, time isn't as wide open as you think: planets with life require second or third generation stars because the ingredients for (solid) planets and life didn't exist in the early universe: they were created in supernovas. So even though the universe is about 15 billion years old, earthlike planets have likely only existed for about the past 5. It also takes a few billion years for the planet to cool enough for life to arise. Then a few billion more for life to evolve. Altogether, intelligent life has probably only been possible in the galaxy for the past billion years.
Also there is the issue of concurrence: It can't be assumed that any life that has ever existed still exists. Hell, many people still think humans will destroy themselves within the next 100 years. Thousands of intelligent species could have lived and died and there is virtually no chance we will ever know about it.
Given all of the statistical analysis I have seen, I think it is possible, even likely that there is other life out there. Intelligent life. But there would need to be THOUSANDS of civilizations existing today for us to even have a chace to find ONE. Despite all of that, I think in the next 20-30 years we WILL find one.
cragwolf
Mar18-03, 10:47 AM
Originally posted by Zefram
Suppose intelligence doesn't necessarily imply science? Maybe they all write poetry and couldn't care less about galactic colonization and radio astronomy.
Somehow that seems worse to me than being alone in the galaxy... [;)]
Yes, I agree with you! Dirac once said the following:
"In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, it's the exact opposite."
Lately I've been thinking that what Dirac said about poetry is true about all art. It seems to me that art is basically just intellectual obfuscation and mental masturbation. Hence the reason it needs to seduce or manipulate our emotions. So for me, an intelligent lifeform that didn't pursue science, but instead pursued some artistic goal, would be a very sad thing. Solipsism of the worst kind.
I think ETs are rare, but the universe is also pretty large. I also think that carbon chemistry need not be the only possibility for self-aware structures. Unfortunately, my imagination is far too limited to dream up alternatives to it.
Couple of things;
I think its already been pointed out that Interstellar travel just might be to difficult or resource consuming for anyone to have achieved.
Another Possibility is the Intelligence turns out to be, in the vast majority of cases, an evolutionary dead-end. That very very few intelligent races survive long enough to develop high-end technology.
Or that upon reaching a certain level, they slip back to a lower level. (A hole that they won't be able to pull themselves out of, because the previous technological society has already used up the easily obtainable resources on their world. )
The universe could be full of low-technology races, and maybe only one or two higher-end technology races per galaxy.
russ_watters
Mar18-03, 11:36 AM
So for me, an intelligent lifeform that didn't pursue science, but instead pursued some artistic goal, would be a very sad thing. Solipsism of the worst kind. I'll go one step further: An intelligent life form that does not pursue science is an oxymoron.
And given the importance of science on this planet, shortly a dead oxymoron.
Also, Michio Kaku once pointed out (in "Journey through the tenth dimension) that the probability of intelligent creatures evolving somewhere else is rather high - but that they would soon discover Uranium, and the probability then becomes extremely high that they would destroy themselves.
Lately I've been thinking that what Dirac said about poetry is true about all art. It seems to me that art is basically just intellectual obfuscation and mental masturbation. Hence the reason it needs to seduce or manipulate our emotions. So for me, an intelligent lifeform that didn't pursue science, but instead pursued some artistic goal, would be a very sad thing. Solipsism of the worst kind.
Agreed. If only more of our own species saw this.
Loren Booda
Mar18-03, 03:57 PM
As I posted elsewhere previously: remember your statistics - just one incidence of life's origin does not carry any significance toward the probability of other, similar occurences.
Originally posted by Loren Booda
As I posted elsewhere previously: remember your statistics - just one incidence of life's origin does not carry any significance toward the probability of other, similar occurences.
I agree with you for the most part, and have made jokes about extrapolating from a single point, but there are some "single instances" with notable impact. The observation of evolution on our one planet is telling. It is not a single point of statistics, it is an observation of the nature of life. I don't think it is unreasonable to assume a high likelyhood that if life exists elsewhere, it will evolve. It is a bit of a jump though to assume that evolution leads to intelligence. It has only been recently that intelligence has proven very useful to life.
I think the biggest flaw in CJames theory is that a civilization would colonize the galaxy just because it could. We are primitive compared to such a civilization, and yet we have begun to develop non-interference philosophies regarding wildlife studies and anthropology. If a civilization learned to satisfy all of its wants before developing interstellar travel, it could plausibly develop the same ideals, applicable on a galactic scale. Assume one civilization is particularly precocious. It then monitors the galaxy with a light touch, preventing latecomers from "despoiling" other planets. I would imagine that would be our own philosophy...after we despoiled a few dozen planets first.
Njorl
Excellent arguments by everybody. Let's see how badly I can defend my "theory." (It's not actually mine. Idea's been around for a while. And it's not a theory.)
First, let me reitorate my point. I hadn't said there is no other intelligent species in the universe. I said intelligent life is rare or nonexistant.
Russ_Walters,There are a couple of problems with this. For starters the technology you describe is not even theoretically possible: Interstellar travel will likely not ever be possible for anyone.It is certainly theoretically possible. As you have said, the galaxy is 150,000 lightyears across. That means an absolute bare minimum of 75,000 years allowed to collonize the galaxy. Obviously, that is ridiculous. However, limited to an expansion rate of .01c, for a civilization that first formed on the outer rim of the galaxy, that means 15 million years to collonize the galaxy. So, it is easy to establish that it is at least possible by this time.
It can't be assumed that any life that has ever existed still exists.I agree entirely. As I said, my point was that we are probably the only intelligent species in our galaxy at this time.
Njorl,I think the biggest flaw in CJames theory is that a civilization would colonize the galaxy just because it could.This is a very good point. Considering population growth, however, I would imagine any intelligent species would be scrambling for the nearest planet as fast as possible. If there is another intelligent species in the galaxy, it has either learned to slow it's population growth, or has am extremely slow population growth. (Perhaps living in a different life-expectancey.)
Take care everybody.
cragwolf
Mar18-03, 09:25 PM
Originally posted by russ_watters
I'll go one step further: An intelligent life form that does not pursue science is an oxymoron.
I think you're confusing wisdom with intelligence. Beethoven's Ninth Symphony was clearly created by an intelligent mind. A life form which did nothing of note except create equivalents of Beethoven's Ninth Symphony would be intelligent, but not very wise.
Originally posted by Zefram
Agreed. If only more of our own species saw this.
Don't get me wrong, though. I'm often moved by a great work of art. But to what end? It's mostly my emotions that are affected. As for what intellectual content there is, and there's usually very little of it, I find myself asking, "It took him 500 pages to say that humans are contradictory beings?" [s(]
Yes, I get very frustrated with "intellectuals" who talk a great deal but end up saying practically nothing. I like it clear, concise, and straightforward; to some extent, that's why I enjoy the sciences.
russ_watters
Mar19-03, 01:29 PM
I think you're confusing wisdom with intelligence. Beethoven's Ninth Symphony was clearly created by an intelligent mind. A life form which did nothing of note except create equivalents of Beethoven's Ninth Symphony would be intelligent, but not very wise. Thats fine, but I think the two go together. The brain power associated with the writing of Beethoven's Ninth is similar to the brain power associated with figuring out relativity. Its just brain power applied in a different direction. Intellectual art.
There *IS* a lot of art that is not intellectual though. I tend to think most painging and sculpture it that way. Van Gough for example made some great paintings, but he was certifiably insane. Modern art is even worse. You can sneeze on a piece of paper and sell it.
And since I am of the opinion that "good" art is intellectual, not purely creative, I think an intelligent species will create both intellectual art and science. One that creates purely creative art is not intelligent and it will reflect in the art.
The reason I assume intelligent life would seek to collonize the galaxy is because of the nature of intelligence. Intelligence arises from a curiosity to know things. It is my assumption, and yes it is an assumption, that this curiousity would be a major factor in the desire to collonize the galaxy.
Nicool003
Mar20-03, 07:59 PM
all I can say is hopefully curiosity won't kill the cat if we go explore other galaxies someday. Haha
But on a more serious matter I think that what you said (the part about how curiosity could possibly lead to the colonizaatino of galaxies) is correct, CJames
axeeonn
Mar21-03, 01:10 AM
Don't forget about mass extictions due to asteroids and comets (if not dying stars). They happen roughly every 50-100 million years on Earth, most recent 65 million years ago with the Dinosaurs. Who knows if any other civilization has even gotten the time to develop the technology needed to colonize outside of their home planet.
Greetings !
My very rough SWAG for the MW galaxy :
About 200 * 10^9 stars in the MW.
- double/tripple and so on...
- galaxy core
- probably - stars with low or high metalicity (leaving
mostly the central galactic radius range)
- stars that are too massive and produce
a great deal of UV radiation
- very "light" and cool stars
= let's say 10 - 20 * 10^9 stars.
- stars that are aged over 2-3 billion years
- stars that do not have planets in the
habitable zone around the star (allowing for
liquid water ) or gas giants that allow
water on their moons (example: Europa)
- planets that do not have the appropriate
materials to form a solid core and a stable
surface and materials to result in creation of
large water masses
= let's say 10 - 20 * 10^6 stars and about
a 10% addition for planets
- planets where living cells haven't formed
= let's say (and this is beggining to be very
tricky to estimate) about a half remains
- no complex life forms evolved or they were
destroyed by asteroids/high radiation events/
collisions with other star-systems/system
star's life span ends
= (very very tricky) a complete SWAG - 50,000
- planets where complex life formed but no
"intellegent" life on our level, at least (There is
a great argument about this part, I believe.
Are we a natural stage or a fluke ?)
= unbelievable SWAG : 500
How was I ? [:D]
"Does dice play God ?"
Live long and prosper.
My point is essentially that if there had been even one intelligent species created before us, they would literally be almost everywhere in the galaxy. And the more intelligent species that came before us, and even greater chance that many of them are spread throughout the galaxy. Given five hundred civilizations before us, we would probably see activity as close as the very nearest earthlike planet.
Within our own galaxy, we are most likely the only intelligent species at this time. If that is not the case, I wouldn't expect much more than 3 or so as an absolute maximum, considering the amount of time life has had to spread across the galaxy. Remember, it is life's goal to multiply and recreate itself. Those that recreate less often are killed off evolutionarily. Evolutionary predisposition seems to dictate that any species capable of leaving the planet most likely will.
Given 500 intelligent civilizations that came before us, the galaxy would probably be so populated by now that even Mars would have been collonized. It seems obvious that 500 civilizations is over the top.
Again, this is not proof. But if there are intelligent species out there, they are reclusive. It's hard for me to imagine a world in which it is an evolutionary advantage to multiply slowly, especially if such a world is the type that would harbor intelligent life.
Thank you so much for these debates. Keep it up. --Carter
chosenone
Mar21-03, 01:46 PM
what do you want to know about them,we havbe long talks all the time,they like the name the grays,if you want to know what they like to be called,but anything else you'll have to get pass me being a lunitic,because they still dont give them a reason to lock me up yet,so im doing good!
Greetings !
Hmm... CJames,
What if they don't multiply ?
What if they put their brains in "jars" and living in
great computer simulations where they are
all powerful ?
What if their progress was greately halted by
wars ?
What if they don't want to contact us ?
What if FTL travel is impossible so they saw
life's here and decided not to visit and interfere ?
I can think of a great deal of reasons really.
"Does dice play God ?"
Live long and prosper.
We already have examples on earth of civilisations that don't have technology as the west would recognise it. There could also be religious or cultural ethical consideration that would disallow the applications of technologies even if they knew about them. I once worked on a sci-fi story where all the technology was chemistry based and electricity, as in radio etc., was not a part of it. A race could have developed theory purely mathematically and applied it at a more advanced stage so that transmissions might posess chaotic principles that wouldn't be seen by us to have enough of a pattern to be discerned as created by an intelligence. I have a theory about dolphin communication that they communicate by 'transmitting' abstract images rather than 'words' or patterns which is why we have identified dolphins referring to others by 'name' sounds but uncovered little else.
All that said, if you don't believe in devine intervention, there would seem to be no reason why, chemically speaking, the development of life here could have been pure luck and that the chain of events has never occured anywhere else. Depending on the balance of elements on the planet, they may have achieved a steady state before any 'life-like' properties took over. Perhaps it takes the exact balance of elements that, per chance, happened on earth to achieve life.
Do I believe that there is intelligent life out there??? I'd like to think so, but then again.......
Raavin [?]
ObsessiveMathsFreak
Mar25-03, 06:51 AM
If intelligent life were around they would undoubtedly have either colonised or exploited this solar system by now.
I think the range of conditions on all the planets in the solar system is rather diverse, earth might be toxic to them. And the fact that it has nine planets would make it very important tatically, wouldn't it?
I really, really doubt that they would be benevolent enough to let us stew for a while.
cragwolf
Mar25-03, 04:45 PM
Originally posted by ObsessiveMathsFreak
If intelligent life were around they would undoubtedly have either colonised or exploited this solar system by now.
Why? Why should interstellar travel be inevitable? Why should colonisation be inevitable?
I'm glad somebody here agrees with me lol.
Why is collinization inevitable? It's not entirely inevitable, but it seems the most likely action. Again, life has always tried its hardest to spread. Why do bacteria live in some of the most harsh places on Earth? Because life expands, it breaks into new territories. If the bacterial fossils on Mars were real, we may find that this entire galaxy is inhabited by many forms of life. But it is unlikely any of them are intelligent, because if they had been, they would have left behind remnants, or we would see them nearby. If we don't see evidence of intelligent life within the next few decades, I would put money into the idea that we will never find an intelligent species in this galaxy the same time as us.
Hi drag, love your debates always
Hmm... CJames,
What if they don't multiply ?
What if they put their brains in "jars" and living in
great computer simulations where they are
all powerful ?
What if their progress was greately halted by
wars ?
What if they don't want to contact us ?
What if FTL travel is impossible so they saw
life's here and decided not to visit and interfere ?
I can think of a great deal of reasons really.All these "what if"s would solve the problem. That's not the point. How likely is it that any of these are the case? Evolution dictates that life multiply. Why would they put their brains in computer simulations when doing so would jepardize their safety from the death of their star? Wars wouldn't halt expansion, it would encourage it. They don't have to want to contact us. If they are close enough, we would see plenty of signs of their existence. And considering how long they've had to get close, they would be close. It doesn't matter if FTL travel is impossible, I demonstrated how that doesn't matter when you are collonizing the galaxy.
So of course it's possible there is other intelligent life in our galaxy. But it appears to be an unlikely scenario.
Take care. --Carter
DrChinese
Mar25-03, 11:03 PM
Originally posted by drag
Greetings !
My very rough SWAG for the MW galaxy :
About 200 * 10^9 stars in the MW.
- double/tripple and so on...
- galaxy core
- probably - stars with low or high metalicity (leaving
mostly the central galactic radius range)
- stars that are too massive and produce
a great deal of UV radiation
- very "light" and cool stars
= let's say 10 - 20 * 10^9 stars.
- stars that are aged over 2-3 billion years
- stars that do not have planets in the
habitable zone around the star (allowing for
liquid water ) or gas giants that allow
water on their moons (example: Europa)
- planets that do not have the appropriate
materials to form a solid core and a stable
surface and materials to result in creation of
large water masses
= let's say 10 - 20 * 10^6 stars and about
a 10% addition for planets
- planets where living cells haven't formed
= let's say (and this is beggining to be very
tricky to estimate) about a half remains
- no complex life forms evolved or they were
destroyed by asteroids/high radiation events/
collisions with other star-systems/system
star's life span ends
= (very very tricky) a complete SWAG - 50,000
- planets where complex life formed but no
"intellegent" life on our level, at least (There is
a great argument about this part, I believe.
Are we a natural stage or a fluke ?)
= unbelievable SWAG : 500
How was I ? [:D]
"Does dice play God ?"
Live long and prosper.
Not bad - actually very good - but I think you are off on the high side.
Realistically, you have to allow 4.5 billion years for life to evolve on the planet. That being what it took here, and certainly you would have say the laws of chance were with us. So planets less than 4.5 billion years old... well, that means their sun is also a yellow star like ours, which is rare. Most burn out much quicker, 10-100 million years. And would have to have formed about the same time as our sun, universe about 9 billion years old. Could not have formed too much earlier, because there weren't enough heavy elements around. So perhaps high by a factor of 100, since you did mention some of these factors.
As to planets, the planet would have to be very close to the exact orbit we are in. You mentioned this. Also, can't have an elliptical orbit either. High by another factor of 100.
Probably need a moon as well. And the ocean. And an atmosphere. High by a factor of 1000.
As to the formation of life, this is far and away the biggest issue we have. Because of the complexity of our genetic structure, it must have taken a lot of random mutations to get where we are today. I can easily imagine thousands of other planets in the universe filled with plants and fish.
And then there is human life. Humans having several rather unique attributes when you think about it: a voice box capable of speech; unusally large brain (compared to other mammals even); fingers; walk on 2 legs; extremely long development period after birth before can even walk. I'd say one in a million on this one.
Net, I would say odds are more like one in 200 million galaxies. I think we live in a very lonely universe.
Greetings !
Originally posted by DrChinese
Not bad - actually very good - but I think you are off on the high side.
Thanks !
I think... [:D]
It was an amateur attempt (I actually done this
some time ago in a more consistent manner, but
the result was about the same - a few hundred.)
Originally posted by DrChinese
Realistically, you have to allow 4.5 billion years for life to evolve on the planet. That being what it took here, and certainly you would have say the laws of chance were with us. So planets less than 4.5 billion years old...
First of all, the Earth exists less than 4.5
billion years which is the time the Sun formed.
Second, life formed about 3.5-3.9 billion years
ago.
Third, "complex" life formed almost half a billion
years ago.
Fourth, there's no apparent reason why this
couldn't've happened earlier and I disagree
with the chance part - "If the conditions
are right...".
Originally posted by DrChinese
well, that means their sun is also a yellow star like ours, which is rare. Most burn out much quicker, 10-100 million years. And would have to have formed about the same time as our sun, universe about 9 billion years old. Could not have formed too much earlier, because there weren't enough heavy elements around. So perhaps high by a factor of 100, since you did mention some of these factors.
I DID say - "stars that are too massive and produce
a great deal of UV radiation".
Stars that peak at visible wavelenght and lower
do exist for billions of years. Even if you have
a smaller star with peaks at infrared - I can
see no reason why a close enough planet couldn't
have water and evolve life. The larger stars are
not a majority.
Also, the Universe is about 13.7 billion years old...[;)]
And, I did talk about the mettalicity factor.
Originally posted by DrChinese
As to planets, the planet would have to be very close to the exact orbit we are in. You mentioned this. Also, can't have an elliptical orbit either. High by another factor of 100.
Well we are probably in an almost ideal location,
but I think that this could easily be a 100 million
kms or wider distance range (depending on the
planet too - its own rotation cycle, material
and so on). I do not think that an elliptical
orbit is a great hazard.
(I once read "The Fire Cycle" by Hall Clement -
it's a sci-fi book but he talks of a planet
that has an elliptical orbit and is populated
by two civilizations. One "wakes up" during the
"summer" and the other during the "winter".
Of course, it's a sci-fi book... [;)] [:D]
However, on Earth, life is found EVERYWHERE !
So, after it forms, the rest is not that
difficult - adaptation.)
Originally posted by DrChinese
Probably need a moon as well. And the ocean. And an atmosphere. High by a factor of 1000.
Moon/s - why ?
Ocean - I included water - not necessarily in
the form of surface oceans like ours (look at Europa).
Atmosphere forms with time and effected by life,
the "start" conditions are local.
Originally posted by DrChinese
As to the formation of life, this is far and away the biggest issue we have. Because of the complexity of our genetic structure, it must have taken a lot of random mutations to get where we are today. I can easily imagine thousands of other planets in the universe filled with plants and fish.
So, it won't be "us"... So what ?
It is an intellegent civilazation of
non-humans, not possible in your opinion ? [:)]
Do you know that we only have about 50%
more genes than the most primitive organisms ?
If you are in general familiar with Chaos
theory and your PC then you know that the simplest
patterns and the simplest differences in them
can produce great complexity and differences in it.
Originally posted by DrChinese
And then there is human life. Humans having several rather unique attributes when you think about it: a voice box capable of speech; unusally large brain (compared to other mammals even); fingers; walk on 2 legs; extremely long development period after birth before can even walk. I'd say one in a million on this one.
Like I said, the question is - Are we a natural
stage or a fluke ?
My personal opinion is that we are a "fluky"
natural stage... [:D]
Originally posted by DrChinese
Net, I would say odds are more like one in 200 million galaxies. I think we live in a very lonely universe.
"Net" = are you Russian ? [:D]
Anyway, I hope you're wrong !
Even if the opposite is not good for humanity,
it would be sad if the Universe as a whole
was such an "empty" place, in my opinion.
Be optimistic ! And ready your X-ray gun ! [:D]
Live long and prosper.
Greetings !
Originally posted by CJames
Hi drag, love your debates always
Thanks ! [a)]
Originally posted by CJames
All these "what if"s would solve the problem. That's not the point. How likely is it that any of these are the case? Evolution dictates that life multiply. Why would they put their brains in computer simulations when doing so would jepardize their safety from the death of their star?
Who cares ?
In a perfect simulation you can have infinite
fun ! Many sufficiently advanced civilizations,
in my opinion, will realize that that's the most
important thing... [;)] [:D]
Originally posted by CJames
Wars wouldn't halt expansion, it would encourage it.
That was a "shallow" argument, wan't it... [g)]
You're right, of course.
(Unless they almost totally destroy themselves.)
Originally posted by CJames
They don't have to want to contact us. If they are close enough, we would see plenty of signs of their existence. And considering how long they've had to get close, they would be close. It doesn't matter if FTL travel is impossible, I demonstrated how that doesn't matter when you are collonizing the galaxy.
I'm not certain about that. What if we're
not evolved enough to detect those signs ?
Or, they take measures for us not to be able
to detect them ?
Originally posted by CJames
So of course it's possible there is other intelligent life in our galaxy. But it appears to be an unlikely scenario.
Aah... pessimists... [:(]
"When I examine myself and my methods of thought,
I come to the conclusion that the gift of fantasy
has meant more to me than my talent for absorbing
positive knowledge."
Albert Einstein
Live long and prosper.
DrChinese
Mar27-03, 11:47 PM
Originally posted by drag
Greetings !
Thanks !
I think... [:D]
First of all, the Earth exists less than 4.5
billion years which is the time the Sun formed.
Second, life formed about 3.5-3.9 billion years
ago.
Third, "complex" life formed almost half a billion
years ago.
Fourth, there's no apparent reason why this
couldn't've happened earlier and I disagree
with the chance part - "If the conditions
are right...".
I DID say - "stars that are too massive and produce
a great deal of UV radiation".
Stars that peak at visible wavelenght and lower
do exist for billions of years. Even if you have
a smaller star with peaks at infrared - I can
see no reason why a close enough planet couldn't
have water and evolve life. The larger stars are
not a majority.
Also, the Universe is about 13.7 billion years old...[;)]
And, I did talk about the mettalicity factor.
Well we are probably in an almost ideal location,
but I think that this could easily be a 100 million
kms or wider distance range (depending on the
planet too - its own rotation cycle, material
and so on). I do not think that an elliptical
orbit is a great hazard.
Moon/s - why ?
Ocean - I included water - not necessarily in
the form of surface oceans like ours (look at Europa).
Atmosphere forms with time and effected by life,
the "start" conditions are local.
I was trying to pay a compliment. Naturally, one of the problems of this kind of analysis is that different people will come up with different estimates. I acknowledge that mine is no more "correct" that yours or anyone elses'. If there are a statistically large number of civilizations predicted to exist in the universe, then the analysis becomes more meaningful. I am biased towards the lower end of predictions: so few that we can't expect to make contact during the next million years.
The requirement that the sun be of the right type is pretty restrictive. Ok, there is a range of possible start times for the creation of the star. Sure seems that the earth was created fairly late in the game given the amount of iron on the planet. Yet, we have needed 99.9999+% of the lifetime of the planet to get to this point. It is certainly possible a candidate planet could have formed a bit earlier, and it is certainly possible that intelligent life could have formed in less time. But there is still a narrow time window and a narrow solar type range.
I believe you already excluded binary star systems, correct?
But, we have an ocean and an atmosphere. And a moon that creates tides, which is what I was referring to. I am guessing that the sloshing of the ocean was needed to create and distribute early simple life. Assuming (and it is an assumption) that these are necessary for the ultimate formation of intelligent life, you have some additional restrictions. Mars has no atmosphere (ok, a little) and no ocean (ok perhaps some buried ice). So how did earth end up with all the water, and Mars has no intelligent life? Or is that a coincidence?
It is generally (?) believed that the earth's atmosphere was at one time primarily CO2. It was later "cooked" by cyanobacteria into O2. This may have taken 500 million years.
Another - as you mentioned - restrictive requirement is the orbit shape and distance from the star. A planet like earth could orbit at any distance from the sun, even as far out as Pluto. Yet only a small range - perhaps 80-100 million miles from the sun (depending on mass of the star) would provide a temperature for water which would allow life to exist. If an elliptical orbit brought the planet too close to the sun, life would boil off. So the eccentricity could not be much.
So personally, I can't imagine more than a few hundred earthlike planets orbiting suns of the correct mass/age and in the proper orbit per galaxy. And that is before we start talking about the evolution of intelligent life on such a planet.
Just my thoughts :)
Greetings DrChinese !
Originally posted by DrChinese
I was trying to pay a compliment.
Like I said - thanks ! [:)]
Originally posted by DrChinese
Naturally, one of the problems of this kind of analysis is that different people will come up with different estimates.
Indeed. I simply prefer optimism, and you with
CJames apparently side with the pessimists. [:D]
Originally posted by DrChinese
The requirement that the sun be of the right type is pretty restrictive.
Why ?
Is there a problem with a smaller star with
radiation mainly around the infrared ?
Originally posted by DrChinese
Yet, we have needed 99.9999+% of the lifetime of the planet to get to this point. It is certainly possible a candidate planet could have formed a bit earlier, and it is certainly possible that intelligent life could have formed in less time. But there is still a narrow time window and a narrow solar type range.
I don't know. How narrow and why ?
After all, the "surge" of complex life forms
on the planet began just a few million years
ago. I don't know what triggered it (there was
a lot of orgamisms for billions of years before
that). Also, if it weren't for that Yukatan
astroid, you'd probably have huge dino-cities
covering the planet by now and dinos expanding
in the galaxy. I recently saw a program where
they were talking about a dinosour just a bit
larger than us that had a brain as complex as
that of our pets. It evolved "just" before the
above "accident".
If someone does know what triggerd "complex"
life - please tell us !
Originally posted by DrChinese
I believe you already excluded binary star systems, correct?
Yes, I excluded all multiple star-systems.
Originally posted by DrChinese
I am guessing that the sloshing of the ocean was needed
to create and distribute early simple life.
Hmm... I suppose that the Moon did help a bit,
but I think that surface instabilities and
planetery rotation have considrable roles too.
Originally posted by DrChinese
Mars has no atmosphere (ok, a little) and no ocean
(ok perhaps some buried ice).
According to the latest estimates that "some"
buried ice could've covered the entire planet's
surface (if it were flat) and be 100 meters deep.
There's also the part about oxygen on Earth
being freed by microbes or something over the years.
Mars is too far-away from the Sun and hence
too cold, and it has a lower mass which also
makes the atmosphere part problematic.
BTW, if all the CO2 that is estimated to be in
the "dirty" ice covering its poles is relased
into the atmosphere the planet can "heat up"
considrably, I think.
Originally posted by DrChinese
Another - as you mentioned - restrictive requirement is the orbit shape and distance from the star. A planet like earth could orbit at any distance from the sun, even as far out as Pluto. Yet only a small range - perhaps 80-100 million miles from the sun (depending on mass of the star) would provide a temperature for water which would allow life to exist. If an elliptical orbit brought the planet too close to the sun, life would boil off. So the eccentricity could not be much.
I'm not certain about the range being so limmited.
If Earth was as far as Mars it is possible that
life could form and exist there. (Denser CO2
atmosphere - higher tempratures.) And, like I
mentioned before, there are other options
(like the case of Europa).
As for eccentricity, I don't have the scientific
data and calcs to support this, but I think that
planets at relativly close proximity to the star
(below say half a billion miles for Sun-like and
smaller stars) would not ussualy have very eccentric
orbits becuase of the way they are formed.
Originally posted by DrChinese
So personally, I can't imagine more than a few hundred earthlike planets orbiting suns of the correct mass/age and in the proper orbit per galaxy. And that is before we start talking about the evolution of intelligent life on such a planet.
My estimate was about 50,000 for planets
that at least evolved the most basic life forms
(bacteria) including those that evolved more
complex life but not intellegent yet or where
intellegent life was already destroyed.
NOT necessarily earthlike planets.
I'm optimistic, I know... [;)]
Live long and prosper.
I don't think it is pessimistic to look at the data and come to conclusions about the odds. Then again, maybe I'm pessimistically construing the data. ;)
Who cares ?
In a perfect simulation you can have infinite
fun ! Many sufficiently advanced civilizations,
in my opinion, will realize that that's the most
important thing...I hate to say it drag but that...that sounds pessimistic! To think that every intelligent species out there surrenders reality and decides to live connected to meaningless existences in simulated realities is about as depressing an idea to me as I can think of...sorry.
I probably won't be able to respond for a while my iternet is down and this is somebody elses. :(
DrChinese
Mar29-03, 12:14 PM
Originally posted by drag
Greetings DrChinese !
I don't know. How narrow and why ?
After all, the "surge" of complex life forms
on the planet began just a few million years
ago. I don't know what triggered it (there was
a lot of orgamisms for billions of years before
that). Also, if it weren't for that Yukatan
astroid, you'd probably have huge dino-cities
covering the planet by now and dinos expanding
in the galaxy. I recently saw a program where
they were talking about a dinosour just a bit
larger than us that had a brain as complex as
that of our pets. It evolved "just" before the
above "accident".
Mammals started about 120+ million years ago. I don't see anything that requires that an intelligent species would come to dominate a planet as we do (I guess "dominate" may be subjective). Anyway, what I am saying is that there could be 1000 planets with tigers and monkeys as the highest intelligent lifeforms for every one that ends up with intelligent civilizations.
Hmm... I suppose that the Moon did help a bit,
but I think that surface instabilities and
planetery rotation have considrable roles too.
According to the latest estimates that "some"
buried ice could've covered the entire planet's
surface (if it were flat) and be 100 meters deep.
There's also the part about oxygen on Earth
being freed by microbes or something over the years.
Logically, buried ice itself means very little. Look at Antarctica - not exactly a hotbed. And the oxygen on Earth came from our CO2 atmosphere. So there is clearly a minimum size of planet - so as to provide an atmosphere.
As for the tides, I admit that rotation of the planet makes a difference. The planet would then need to rotate, which it probably does anyway to insure that the temperatures don't get too extreme. So I am not certain I am right about the moon being necessary.
But I think the ocean is a requirement so as distribute early life forms over the planet to give them new areas to evolve. Patches of water would essentially require all of the early evolution - before the advent of legs - to occur in a tiny area.
Mars is too far-away from the Sun and hence
too cold, and it has a lower mass which also
makes the atmosphere part problematic.
BTW, if all the CO2 that is estimated to be in
the "dirty" ice covering its poles is relased
into the atmosphere the planet can "heat up"
considrably, I think.
An atmosphere from buried ice? I think you watched "Total Recall" too many times. (Just a little joke.) That's definitely a stretch, because it would have to melt, release an entire planet's worth of gas, and then not blow out into space. Considering we are trying to talk about the probabilities, not the possibilities, I say that doesn't fly.
I would be the last person to deny the possibility of another intelligent species in the universe. Obviously, what was possible on Earth is possible elsewhere.
I'm not certain about the range being so limmited.
If Earth was as far as Mars it is possible that
life could form and exist there. (Denser CO2
atmosphere - higher tempratures.) And, like I
mentioned before, there are other options
(like the case of Europa).
As for eccentricity, I don't have the scientific
data and calcs to support this, but I think that
planets at relativly close proximity to the star
(below say half a billion miles for Sun-like and
smaller stars) would not ussualy have very eccentric
orbits becuase of the way they are formed.
Live long and prosper.
I would grant that life could possibly exist on a planet whose orbit went out farther than Earth's, not sure about all the way to Mars. But it couldn't go much farther in, either. Maybe the range is 80-110 millions miles from the Sun. That would need to be the limits for the eccentric orbit as well.
Greetings !
Originally posted by DrChinese
[B]Mammals started about 120+ million years ago. I don't see anything that requires that an intelligent species would come to dominate a planet as we do (I guess "dominate" may be subjective). Anyway, what I am saying is that there could be 1000 planets with tigers and monkeys as the highest intelligent lifeforms for every one that ends up with intelligent civilizations.
Ooops... Did I say "a few million years" ?!
I meant "a few hundred million years"(400-500).
But, after that I made a point about the
dinasours heading in the big brain direction too.
So, this may not be a must, but I think that
given sufficient time (say up to a billion years),
complex life is likely to evolve "intellegent"
(at similar to our level) beings. It took a lot
less on Earth, after all.
Then again, dolphins have brains that are larger
than ours and yet you don't see them building
civilizations. I guess this is an open question
until we get some alien "examples".
Originally posted by DrChinese
An atmosphere from buried ice? I think you watched "Total Recall" too many times.
Arnold Shwartzneger rocks !!! [:D]
Originally posted by DrChinese
That's definitely a stretch, because it would have to melt, release an entire planet's worth of gas, and then not blow out into space. Considering we are trying to talk about the probabilities, not the possibilities, I say that doesn't fly.
Yeah, it's a VERY long shot, but I once considered
what would happen if we nuked the poles
"big time". All that CO2 got'ta add a degree
or two...
Live long and prosper.
Pauly Man
Apr5-03, 06:25 AM
I remember having a huge debate with one of the Physicists at uni about this. He had just written an article on the probability of intelligent life forming in the universe, and came to the conclusion that it wasn't too unlikely. Can't remember the exact figures.
In it he used statistical analysis to arrive at his answer. He used the evolution of life here on Earth as his statistical sample. A smaple size of 1!!!
I argued with him for an entire leture about that. I tried to tell him that the sample size was 1, and he tried to use the fact that life on the seperate continents had been evolving seperately for millions of years, and that on each continent there had evolved a relatively intelligent life form had evolved. And therefore it was a sample size of greater than 1. Further more that each continent had experienced differences and therefore the samples were independant.
To me that was a load of crap. The sample all came from the same blue green planet. That is a sample size of 1, with a few independant replicates. If he had provided evidence of evolution on Mars, perhaps I would have backed down.
I think it was Loren Booda who said earlier that a sample size of one tells you very little, and that I agree with.
Anyway. Basically all I'm saying is that life on Earth probably tells us very little aboutlife elsewhere. That being said I agree with CJames, in that if intelligent life exists in our galaxy and it is at all common, we would probably have seen it evidence of it by now.
O Great One
Apr5-03, 06:08 PM
Did the Intelligent Designer(s?) create life elsewhere?
Interesting thought....
DrChinese
Apr5-03, 09:33 PM
Originally posted by Pauly Man
I remember having a huge debate with one of the Physicists at uni about this. He had just written an article on the probability of intelligent life forming in the universe, and came to the conclusion that it wasn't too unlikely. Can't remember the exact figures.
In it he used statistical analysis to arrive at his answer. He used the evolution of life here on Earth as his statistical sample. A smaple size of 1!!!
Where to start? Single positive indication of life in the universe, our own? So of course you are right to criticize that the sample size is way too small.
But I think it is even worse than that. It needs to be a random sample. Starting out with a positive that supports your position? I think that borders on scientific fraud. If, of course, it was about something other than intelligent life in the universe, for which this problem has long been recognized.
So I agree with you 200%.
In 1962 (forgot the exact date) an object was spotted over the Atlantic Ocean and travelled to Arizona in 16 minutes. This object was detected on 2 different types of RADAR systems and fighters scrambled after it. This is all documented and fact.
At first the Military claimed it was an asteroid. This would make sense since according to witnesses it was very bright. But 1,000s of other people in different cities saw it maneuver, stop occasionally, and travel back on its' path. This is why the Military scrambled fighters. Do you think they would be able to catch a meteorite that can travel from the Atlantic Ocean to Arizona in 16 minutes?
Apparently the object exploded over the Arizona desert for unknown reasons.
This object was no atmospheric phenomena since it was tracked on 2 Different RADAR systems. Not to mention if it was an atmospheric phenomena then why would the military scramble fighters over it?
The Military then said it was a jet exercise since those were highly popular in that era. They made a clever mistake when they said it happened over a period of hours. The Military used Zulu time and Pacific time in their report. When you calculate it out by witnesses and by their mistake it turns into 16 minutes. Not hours.
What man made object can travel from the Middle of the Atlantic Ocean to Arizona in 16 minutes making incredible maneuvers and hovering over cities? I just call it a UFO. Doesnt mean it's extraterrestrial though. But it sure makes you think about it.
Rashid, can you please provide a link to an article about that as I would really like to question its validity.
Actually without hype it was on I believe the Discovery Science 2 nights ago here in Seattle WA I believe. If it wasnt on Discovery Science it was on Sci-Fi or the History Channel. I always seem to catch those episodes. I usually don't listen to them since they are full of Hollywood hype and exageration but this show presented it's information without overexagerated voices or people. It simply stated the facts as if it was doing a presentation. I think I caught it on the TV at about 1-2:00am Pacific time.
Most of those TV shows that show UFO evidence don't hold much ground or seem overdramatic for me to watch. But this was a show that covered various topics so they couldnt stay on the UFO topic too long.
I did a quick Google search and here's what it yeilded. http://www.nicap.dabsol.co.uk/1962.htm This site just lists various UFO sightings on different dates.
http://www.ufo-ufo-ufo.com/53.htm This is a site I just found doing the same search. Seems kinda thrown together and thus might loose credibility. I know that what I see on the Television might be wrong information but the program I watched took the time to interview people who witnessed the sighting (could be actors) and provided Official government documents from the Freedom of Information Act about the problem. They even shown the news paper articles of the first and second Military explanations of the incident.
Sorry to not have the exact information the show presented available at this moment but this is what I watched and remembered about the show. I rarely forget such things. The only thing I seem to forget are womens names.
Sincerely,
Rashid
http://www.nicap.dabsol.co.uk/bigsur1.htm
It seems that this site is all about UFO's and doesn't really touch on Extraterrestrial activity. It talks about theories about UFO and the connection to "aliens" but really focus's on actual proof of UFO's.
I highly reccommend checking it out.
http://www.nicap.dabsol.co.uk is the main page for the site. The other link above is an interesting event I never really knew about.
Sincerely,
Rashid
maybe if one day we can create life in a laboratory (come on now, it shouldn't be THAT difficult) i will consider the posibility of life being abundant in our universe, but until that day i'll consider it a very very rare gift.
Greetings !
Welcome to PF HazZy !
Originally posted by HazZy
maybe if one day we can create life
in a laboratory
What do you mean ?
In many ways we have, already.
Do you mean watch it form from chemicals
into organic molecules and single-cells ?
Live long and prosper.
thanks!
life from non-life hasn't been accomplished yet to my knowledge. in fact i believe the law of biogenesis is still alive and kicking. i may be wrong, but i'm pretty sure about this one, if you know otherwise please inform [;)].
How do we know that they didn't? It's possible that we ourselves are a result of their seeding our planet with DNA. That would certainly be more plausable than making the trip with thousands of settlers over vast distances for long periods of time.
Another thought, maybe they did, toward the center of our galaxy where the stars are not so far apart and ingored the outskirts where the pickin's are so slim. It will be generation before we could ever know.
Greetings !
I'd like to point out that we are living in
the most likely strip (about 10-15 phousand
light years across) of the galaxy in terms
of potential formation of life. The center of
the galaxy is too violent and the stars have
too much metalicity. The outskirts have stars
with low metalicity. The centers of the galactic
"arms" aren't very hospitable either. We're on
"prime" galactic realestate, you might say.
Live long and prosper.
Originally posted by Royce
How do we know that they didn't? It's possible that we ourselves are a result of their seeding our planet with DNA.That is indeed a possibility. However as I said we would expect to see more evidence.
That would certainly be more plausable than making the trip with thousands of settlers over vast distances for long periods of time.[??] What do you mean? In order to seed a planet you have to have been there...
Another thought, maybe they did, toward the center of our galaxy where the stars are not so far apart and ingored the outskirts where the pickin's are so slim. It will be generation before we could ever know.The way life has spread so far on Earth has demonstrated that species don't move together in large groups. Instead, they simply expand outward, evolving along the edges of migration as conditions change. Even on the short time scale, a collony of bacteria doesn't move from area to area, it spreads.
It will be a very long time before we can know for sure that this galaxy is empty, and as a (future) scientist I don't wish to make assumptions. I'm simply stating that the most likely possibility seems to be that this galay is entirely or nearly devoid of intelligent life anywhere but on Earth.
We're on
"prime" galactic realestate, you might say.Which is why we should expect to find extraterrestrial life right here if it is very common.
pete1141
Dec20-03, 08:07 PM
I think the notion of E.T life falls into the same category as believing in life after death. It's just wish fulfilment. There seem to be an almost infinite degree of variation in forms of cosmic bodies both inside and outside our own galaxy. So why would it be unthinkable that we were unique ? I am not a mathematician /statistician, but would love to know what the odds are or even if it is possible to work out the odds mathematically. My intuitive guess is that the odds for and against ,given present knowledge, are even. I personally think we are unique and all the UFO watchers and yearners for ET life are kidding themselves. I will donate a large summ of money to charity if you can prove me wrong.
Stellar Tourist
Mar5-04, 02:10 AM
If life is found, one thing is certain they will be no where near our level of technology or civilisation. They will be either so far behind or way ahead of us.
"human beings do not carry civilisation in their genes"
M Mead NY
Chronos
Jul14-04, 12:26 AM
Statistical treatments are interesting, though controversial. Even though this planet is a sample size of one, the fact that 'intelligent' life exists here does have certain implications. Given the sun is a very average main sequence star, it is reasonable to assume a probability that:
a] stars similar to our sun have companion planets
b] some such planets have chemical compositions similar to Earth.
c] some of these planets have orbits amenable to life.
d] life is likely to arise on such planets.
e] intelligent life will likely to evolve on such planets, given enough time.
Given the large number of stars similar to our sun, even assigning modest probabilities to each of these assumptions results in many planets inhabited by intelligent life forms within this galaxy.
It is, however, very improbable that any two planets, are sufficiently near in space, time and technological capability, to detect each other. We are not detectable by any other civilization, with technology similar to ours, at a distance of more than about 50 light years. Since we have not discovered super-luminal means to send messages, we are not detectable by any other civilization in the universe beyond this distance, unless they have super-luminal means of travel or detection.
The question then becomes why would such an advanced civilization need or wish to disturb one as primitive as ours [assuming they even considered us 'intelligent']? My guess is they would have laws forbidding tampering with us, or our habitat [prime directive thing]. We already know what happens on this planet when advanced societies collide with primitive societies. If technologically far advanced societies exist, and are aware of us, I suspect they would be very careful how they interact with us. Their scientists, most likely, would insist on it.
pete1141
Jul14-04, 07:08 AM
Chronos . I think your argument is very well put together . However because of the extreme distances involved we ,in al likelyhood will never know the truth. I am a sceptic and am not convinced . I still say there is just as much possibility of there being no life elswhere as there is life. I think we are driven in these arguments as much by our human driven desires and emotions, as by cold logic. The universe contains vast areas about which we know nothing . Objects which defy physical description ,at least by our puny human brains , abound. Yet we are still convinced that there is a 99.99999% possibility that life exists elswhere. I say there is a counter argument that there is a 99.99999% possibility that life does not exist elswhere which people do not like to contemplate ,because of the dread of the possibility of our utter isolation in the universe.
Statistical treatments are interesting, though controversial. Even though this planet is a sample size of one, the fact that 'intelligent' life exists here does have certain implications. Given the sun is a very average main sequence star, it is reasonable to assume a probability that:
a] stars similar to our sun have companion planets
b] some such planets have chemical compositions similar to Earth.
c] some of these planets have orbits amenable to life.
d] life is likely to arise on such planets.
e] intelligent life will likely to evolve on such planets, given enough time.
Given the large number of stars similar to our sun, even assigning modest probabilities to each of these assumptions results in many planets inhabited by intelligent life forms within this galaxy.Some time ago I amused myself by making some estimates of probabilities like these. With a twist; instead of a single number, I made two guesses for each - 'seems very unlikely to be higher than this', and '(ditto) lower'.
First though, what is the current state of observational data, relevant to this question? Sun-type stars are reasonably easy to see, at least out to several thousand parsecs. While I doubt anyone is actually counting them, from sample, we could estimate there are ~100 million in the Milky Way (+/- 1 OOM).
Of the ~100 exoplanets detected so far around main sequence stars, none are of ~Earth mass. While most of the parent stars of these planets are ~Sun mass, IMHO, there's simply too little data to draw well-constrained conclusions about how common 'our' solar system is.
- - - - end of data, start of speculation (Milky Way) - - -
'Sun'-like stars: 1 billion (Hi); 10 million (Lo)
... with companion planets: 800 million; 100,000
... and chemical compositions similar to Earth: 300 million; 1,000
... with orbits amenable to life: 100 million; 10
... with life: 80 million; 1
... with intelligent life: 1,000; 1
In the next two decades I expect that the probability ranges for each of Chronos' steps will be better constrained, except for the last step. This improvement will come from programs to detect exo-planetary systems, and the finding of (extinct?) life on Mars and/or Europa (or not).
It's the last of Chronos' steps that I think is the most problematic. Making a probably unjustified generalisation, it seems that physics/astronomy folk believe intelligent life is pretty much inevitable, once life starts on a planet - as Chronos says, it's just a matter of time. OTOH, biology folk tend to believe intelligent life is pretty much a fluke; there's nothing in evolution or the geological history of the Earth that favours intelligence. Although it's somewhat dated now, the Carl Sagan/Ernst Mayr SETI debate (http://www.planetary.org/html/UPDATES/seti/Contact/debate/default.html) gives a flavour of this difference.
Of course, the Milky Way is but one (spiral) galaxy among billions ....
Chronos
Jul23-04, 02:16 AM
I try not to get philosophical about matters of science, but, I think it is just as arrogant for us to assume we are the center of the universe as it is to assume we are its most unique product... after thought. assuming life arises on any planet, evolution will compel it to become increasingly intelligent to compete. We have numerous intelligent species on this planet. Unfortunately, we fail to acknowledge the nature and level of that intelligence. One night I drank too much and slapped my dog upside the head for absolutely no reason. The next morning I woke up and the old pooch was laying there right beside me licking my hand. Who was more intelligent?
Chronos
Jul23-04, 02:41 AM
Footnote: I am subscribing to the principle of mediocrity. There is a reasonable probability we are pretty average when it comes to sentient life forms that have ever evolved over the history of the universe. The premises I used [at least 1 thru 4] look fairly solid. The timeline [how many are within communication distance at any given time?] appears to be the main issue. That possibility appears to be the most remote. Perhaps the silence of the cosmos is testimony of how rare civilizations arise within communication distance of like civilizations at the same time. That premise is difficult to disprove given our current state of scientific knowledge.
After-after thought. So, write to your political representative [senator, or whatever you call them] and strike up this conversation:
Citizen: Hey Senator [minister or whatever], I just had a great idea, let's spend billions to build a beacon that will last for a billion years and advertise the fact we were once here.
Senator [minister or whatever]: I like your idea, but, since we will all be dead in a billion years and nobody will give a comets tail, I am going to raise your taxes to defray the cost of answering silly questions like yours.
I try not to get philosophical about matters of science, but, I think it is just as arrogant for us to assume we are the center of the universe as it is to assume we are its most unique product... after thought.For all we know, the most 'advanced' form of life in the universe is dark matter creatures who inhabit the halos of dwarf galaxies!
Surely it's more important to build from existing knowledge than to make assumptions of any kind?assuming life arises on any planet, evolution will compel it to become increasingly intelligent to compete.Yes, that's a common view of many physics and astronomy types, including Sagan. As I said earlier, biologists generally have a hard time with this line; there's precious little to show evolution produces direction of the kind you assert. Further, complex life is pretty recent - why did it take so long after life got going for it to show its face? And, talking of complex life, why not plants? After all, as complex life, plants were there way before animals!
Footnote: I am subscribing to the principle of mediocrity. There is a reasonable probability we are pretty average when it comes to sentient life forms that have ever evolved over the history of the universe.That's fine, except it doesn't address Fermi's question (Where are they?)
Assume it takes 5,000 years for a sentient life form to travel from one stellar system to another, once it reaches homo sap's current level of understanding of physics and astronomy. In much less than one galactic year (~200 million years) the whole Milky Way would be thoroughly colonised. If sentient life were reasonably probable, the Milky Way would've been colonised well before the Sun was formed.The premises I used [at least 1 thru 4] look fairly solid.Agreed, and once we've done some more digging on Mars, as well as Europa (and Ganymede and Callisto), we'll have much more to go on re these.
... including factors often missed in these kinds of discussions; e.g. probability of life on the moons of gas giants (most discussions quickly dive into estimates of 'Earth-like planets').
But how will we ever address the question of whether 'life not like us' exists?
Chronos
Jul26-04, 05:05 AM
The issue, I think, is how probable that a civilization, such as ours, can find another civilization near enough, intelligent enough, and technologically able to communicate with us at any given time?
How would you go about making an estimate of that probability?
Chronos
Jul30-04, 04:48 AM
A rough, though reasonable [imo] way to estimate that probability is
http://www.pbs.org/lifebeyondearth/listening/drake.html
I do agree, however, that approach only considers the probability of how many other civilizations exist in the galaxy. It does not consider the likelihood that any other is sufficiently near and technologically compatible for us to communicate with. That probability, I think, is the one that best explains the Fermi objection.
Pythagorean
Aug11-04, 09:05 AM
maybe we'll design a ship that hitches rides on planets and asteroids to conserve fuel. :tongue2:
furreal though:
in short:
we could establish stations on nearby planets and begin mining their resources.
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in breaths:
If we started colonizing planets and establishing stations and finding ways to mine resources, we could eventually come to a situation where we're using say, Mars to produce and manufacture interstellar ships; and have drop ships from various planetary stations dropping the needed supplies on Mars that have been gathered from various planets where we've established resource-gathering stations.
It probably couldn't be established in our lifetime, but it seems like the only way to go about it if you want to be able to produce the resources required for something like planetary colonization.
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Also, whose to say we won't find an efficient way to manipulate atoms in such a way that we can turn any element into any element?
Basically, I refuse to be amung those whose ancestors didn't believe a TV or a satelite were ever possible.
The biggest problem would be waiting for the discovery that sparks the interest of an investor by implying that such technologies are actually persuable AND profitable.
edit: pursuable?
the life thats out there might be what you all have least expected and all keep that one to myself
Perhaps the people who enjoy posting in a forum such as this are also a "sample of one." As I was reading I noticed how thought patterns seemed constrained around certain viewpoints of science, and of "scientific" observation of the universe.
As much pride in intellect as I see in these forums (or in my own mind), it is a fact that our species is more moved by emotion than thought: on a ratio of about 99.99 to .01, I would estimate. Hence, art in some form or other (especially "other") is far more important to our species than Science, regardless of how much the "sample of one" in this forum may have opposite views. Almost everything we as a species or as individuals do is emotion-motivated. Most of our rational thought is devoted to rationalizing our emotion-driven actions. If you are a scientist, you can no doubt recognize this fact, however you may wish to value that fact. Nor is it sensible not to accept who we are. Scientists accept reality.
Intuition has to do with how we feel about actions and values, as opposed to how we think about them. I lived in Trinidad and Tobago. Honestly, it seemed near-devoid of overt thinking and planning. As an outsider, I constantly asked people why they did the things they did. Usually, the simple answer was, "My heart told me to." I concluded these people had little-to-no communication with their minds. But the funny thing is, the intuitive process of Trinidadians often resulted in success. Probably no more, but certainly no less, than the number of successful results rational thought would have achieved. The clincher for me was that Trinidadians, person per person, were a far happier people than people of my native USA. Happiness, not riches, was the goal of Trinidadian life. Technologically backward they may have been, but their low crime rate, overall joy in life, acceptance of peoples of all faiths and races, and freedoms of expression, were a more-than-profitable offset from mere material wealth.
I concluded that we, who are so much emotion, must use both rational and heart-based thinking, if we wish a society that progresses both materially and spiritually. In the end, he who dies with the most happiness wins. Since material progress and intelletual attainment also brings happiness, a balanced society would think with both its heart and its head. In cases of a tie, go with the heart.
It is true that thoughts of the heart often cannot be proven via science. On the other hand, thoughts of science often cannot proven via the heart. Science without spirit devolves into crass materialism, while spirit without science degenerates into superstition.
A scientist is supposed to learn from experience. In our history, we have seen how the predominance of superstition in the form of powerful churches sacrificed science on its alter. All those years of potential progress and thought gone. The flip side of the coin is now turned up. Science has weeded the spirit from its garden of knowledge. Yet without both heart and mind, how may we truly be human?
I am not advocating dismissing the dispassionate in proving scientific modelling or observation. However, if we listened to our heart, may we not have been observing or modelling different ideas altogether? Perhaps our models would have developed differently.
It is only lately that any society has had the affluence to develop real science. We are babies in getting the most benefit from it. To think that we may now make grand conclusions about a galaxy we just discovered is to put ourselves in the position of the first European settlers of America, who thought it was all theirs, and it was all the same as the tiny strip of land they first stood upon. In all the glory that now unfolds before us, brought by our fledging and exciting science, we are yet babies, whose eyes are just starting to focus. We think our mother is the world and our egocentric selves own her.
It is with the extraordinary impetus of science starting in the 1800s that we first started breaking our chains of superstition that allowed the churches for so long to proclaim themselves the sole harbingers of Truth. A prophecy of both Christianity and Islam is that in the Last Days the stars will fall from the heavens. Scientific enlightment was partly responsible for the Luminaries of Religion, turned superstition, to be cast from the heaven of understanding. But as scientists filled the vacuum as the exponents of Truth, mankind had already the learning curve.
There is a now a backlash against science. It started with the use and deployment of nuclear weapons. It gathered momentum with the discovery of how “progress” resulted in ecological destruction. It snowballed with the stalling of the U.S. and Soviet space programs, which achieved but one giant step, instead of a series of steps. The science of medicine, which contained such thrilling hope, is now a political football for arguing about costs. Examples go on. It did not take long for the Luminaries of science also to be cast from the heavens.
We are going to see, eventually, that there is only one Truth. We will need every road that leads to It. We will see that all truth is interconnected through Truth. This includes the truths of the poet and philospher, the primitve and sophisticate, Religion and Science, mathematics and playthings, the venerated and the childlike. The famous Traveling Salesman problem of Networking, which no computer could solve because the sheer number of permutations grew too great, was first solved to optimality with soap bubbles.
I suspect Truth is infinite in scope. If there are other intelligences, I bet we will need their divergent ways of relating to their cosmos to grow in understanding.
Consequently, the speculation about the intelligences of other species and what they must do and what they must value and what they must feel, is nothing more than an echo of Manifest Destiny all over again. As scientists we must purge ourselves of such specie-ist thinking. "If they are not like us, they are bad!"
As for the speculations about under what conditions life may develop, I suggest this, too, is nothing more than specie-ism. Chlorine is as corrosive as oxygen. Silicon, like carbon, has eight electron rings. I do not say life will be based upon other chemical bonds and reactions. I say I am a baby to the study of the galaxy, and I need make no conclusions as yet. Most especially, I do not have to conclude that the galaxy revolves around me.
The one fact of life on our planet that may be generalizable is that if there is a way for life to occupy an ecological niche, life will so occupy it. We have life in the snow valleys of the Himalayas, under the Antarctic icecap, in tiny pockets of warmth around magma vents at the bottom of the ocean, in the solid stonework of the lava tubes of the Pacific isles. We have life everywhere you could not expect it.
The most important lesson that science is now teaching us is that we need to develop a Science of Truth. We must become, through our minds, more than we are now to grow in understanding and wisdom.
Some of you may find the next few paragraphs a re-statement of much of René Descartes’ “Meditation 1: OF THE THINGS OF WHICH WE MAY DOUBT.” Also, the slug’s world described below may remind some readers of Edward Abbott’s "Flatland: A romance of many dimensions."
Consider a simple slug crawling upon a sheet of glass. This creature’s world contains but 2 dimensions. Since it is simple, it has no understanding of the time dimension. The slug may move left or right. The slug may move back or forth. That is all it “knows.”
Now assume you have a ray gun that shrinks, without otherwise affecting, whatever you irradiate. You shrink the slug until it becomes so tiny that the otherwise-unperceivable flaws in the glass become small humps over which it must crawl. By changing only the creature’s size, you have caused it to behold a new dimension: up and down. Note that the glass (the creature’s cosmos) did not change. Because the slug’s physical size changed, its perceptions of reality changed.
So it is with humans. We are tiny, in 4 dimensions, in relation to our Cosmos. If we were tinier still, would we directly perceive the 9 dimensions postulated by string theory? Would our understanding change merely because we underwent a change in size? Without doubt, some of our understandings of the nature of the Cosmos would be different. An irrevocable conclusion, then, is that our size distorts our understanding of Reality. Although we understand our finite minds are unable to perceive reality in toto, we dismiss the idea that we, in fact, may know NOTHING of True Reality. After all, we have our physical senses, and our ability to measure observable phenomenon.
We have 5 physical senses. In some ways, they are weak and “tiny” in relation to the cosmos. In other ways, they are powerful and large. Since scientists dismiss PSI powers, ESP, astral travel, and the like, scientific investigation relies upon the combination of the input from the senses and the deductions our rational faculty makes from that input. We know our senses may be fallible (e.g., seeing a mirage). We also know our ignorance causes us at times to to perceive inaccurately. Consequently, we sometimes conclude erroneously because of what we fail to perceive. Our ignorance also causes us to conclude wrongly based upon what we do perceive with more accuracy.
For the most part, the technology we use is only an extension of the senses we have. For examples, sonar is increased hearing. Analysis of microwaves and radar are vision widened across the electromagnetic spectrum. Our physical characteristics, then, place us in the same position vis-à-vis perception as the slug’s size places the slug in its perception of its cosmos. Yet, we see that the slug cannot perceive 2 of its dimensions. We believe, on the basis of not much at all, that we are different from the slug, because our cosmos has an up and down, and because we have a rational mind. This is ego. It is the same pride that once believed in the geocentric universe. Because we have the limitations we have, we, even with science fiction and other imaginative delights, do not currently know that which we do not know.
Which brings us to the flaw in scientific investigation. Science investigates observable phenomena. We pretend we can validate scientific deductions because they explain the universe as we see, hear, smell, taste and touch it. This is circular reasoning, and hence fails to prove anything. Because we can only see, hear, smell, taste and touch, we only prove those things that those limited senses tell us make sense to investigate and prove. This investigation of Truth is close-minded. We slugs have proven, via simple movement along all possible paths, that the world has but 2 dimensions.
Who knows what phenomena are not observable to the 5 senses? Who knows what phenomena are observed incorrectly or incompletely?
Imagine that the slug lives inside an enormous baking dish. A slug travels straight towards the side of the dish. Because it is a slug, and because objects in motion tend to stay in motion, when it reaches the side, it unwittingly travels up. When the slug initially starts to travel up, part of its body is still on the bottom of the dish and part is on the vertical side. Suddenly it has 3 dimensions, however briefly. Being a slug, it may not notice. Nor will gravity affect its slimy crawl in any noticeable way.
Once the slug is moving up the side, its world reverts to 2 dimensions. The slug does not realize that the up-and-down dimension has replaced the back-and-forth dimension. The slug is secure in its knowledge that its world is 2-dimensional: left and right, back and forth. Since the brief period of time in which the slug’s world had 3 dimensions is not a repeatable (and hence, verifiable) phenomenon, that observation of 3 dimensions is dismissed as a mistake in measurement or deduction.
Now imagine you are in a spaceship traveling towards a distant star. As you approach the star, at some point you enter the star’s gravity well. When you do, the dimension of back and forth in which you WERE traveling has now become your up-and-down dimension. Although to you it seems as if your journey is still along the same forward-and-back spatial dimension, you are now traveling up and down relative to your prior dimension of travel. You never noticed. Your senses are too flawed to distinguish the dimensional shift.
The point of these speculations is that we do not know what dimensions we do not perceive, nor is there any “real” spatial dimension to our senses. However, our senses tell us that there is.
This is the first Age in which we may find ways to overcome the "size" of our senses. One way (and it is important to stress that we must find infinite ways) of "re-sizing" our minds (since we cannot re-size our physical bodies nor our 5 senses) is to use linear (sometimes called matrix) algebra as an analogous framework for perception of Truth. Even, for example, Scriptures and Science can be "matricised", to reveal their relation, the vector of enlightenment you get by grouping one subset of the Scripture and Science of the matrix, the determinant permitting the inversion of the entire set of Scriptural and Scientific understandings to get a new matrix of understandings, the "eigenforce" of the truth lying along the multidimensional vector of the matrix, and the ways of combining other sets of vector matrices of Scripture and Science to achieve new perceptions of reality. I am using one such matrix herein to show how the stars fell from the heavens, both materially and spiritually.
This is a powerful analogy and tool. Matrices are what mathematicians and scientists have to use because the Cosmos is too vast and too inter-related to use simple one-line or one-curve mathematics.
Understanding Heisenberg's Principle on the quantum level led to the realization that observers on the macro level also unavoidably alter what they observe. Hence, we are limited in what we can know about anything, because learning one fact about that anything alters what used to be the reality of that anything into a new reality.
It also ALTERS THE OBSERVER.
Statistics has this thing called "losing a degree of freedom." Every constraint you place upon the object observed (e.g., It is going THIS fast) steals a freedom from you to make another statement about the object (e.g., It is located HERE). In statistics, the reason for the loss of the degree of freedom is analogous to Heisenberg's Principle, but has a different cause. Whatever you measure is known in statistics to be a sample of the entire reality. Because you cannot know whether a sample is reflective of the true Reality (e.g., SOMETIMES it goes THIS fast, instead), when you make an observation, you limit with what certainty you can generalize ALL of your conclusions about the sample to the whole Reality. That is, you increase the likelihood that all of your conclusions together are wrong.
Contained within statistics, is everything I am saying about our perception of the Cosmos. Everything we can see, every use of our senses, steals multiple degrees of freedom from us to be able to generalize what we "know" as being the True Nature of the Cosmos. We increase the probability that altogether our conclusions are wrong. The 4 dimensions we perceive may exist because we are tiny or large in relation to the Universe. Hence, physical size is one of the famous "rose-tinted spectacles." Who knows what non-electromagentic forces regularly exceed c?
Consequently, scientists believe gravity to be one of the 4 forces of the universe. In fact, it may not be a force under any understanding. It may merely be the "grid" that allows the plot of the 4 dimensions that we do perceive to exist and to relate to one another.
Everytime I turn around, I find 1 more indication that gravity is the original "ether" that both underpins and causes physical reality. By defining the relationship of the 4 dimensions, gravity makes the speed of light "c".
Perhaps, the first Unified Field Theory will treat gravity, not as a force in relation to the 3 forces, but as a forceless, active but non-reactive pre-existence that molds (curves) the dimensions; that, in fact, causes those dimensions to exist by creating matter and energy. It is ok by me to call that force other than gravity (Higgs field, perhaps). Even with the Big Bang theory, we come back to gravity, and maybe matter, pre-existing the cosmos. It pre-existed the laws of our cosmos.
We have thought we had invented the Science of Truth many times already. Every time, we found that how we looked at Truth was limited.
For the first time, the understandings of the rational faculty can blend and harmonize with the understandings of the heart (the spiritual or intuitive faculty). Heretofore, the spiritual faculty has proclaimed itself the sole bringing of Truth. However, as prophesied, in the Last Days, when the Order of Things passed away, the stars of religion fell from the heaven of understanding. New Luminaries, the scientists, soon sat upon the throne of Truth.
Man in all actions follows a pendulous motion. For too long he moves in one direction. Suddenly he reverses his movement, and then he goes too far in the other direction.
Consequently, the new Luminaries of science also quickly fell from the heavens of understanding. The Special Theory of Relativity was the greatest leap of Science since Newton. In but a few short years the heavy elements, existing on this planet solely because of supernova (literally, stars falling from the sky), were made to bring thermonuclear reactions (the power of the stars) to earth (the stars fell to earth in yet one more literal way). The first use of this power of heaven was to destroy great numbers of humans. The scientific path to Truth had gone too far on its pendulum swing away from the heart, and created weapons of unthinkable destruction.
Science was going to save us all. Science caused way more problems than it solved. The pendulum must swing back and stabilize. We must not lose Science the way we lost Religion.
We begin with the understanding that everything the 5 senses perceive is not just limited, which everyone grants, but maybe, an out-and-out lie. The scientific method, at this time, will recognize ONLY the reality that the 5 senses perceive. As much as I love the scientific method, I believe the future will demonstrate it to be a superstition as limited, and as damaging to progress, as the beliefs of our ancient ancestors, at which we now poke fun.
Due to a deliberate misconstruing of the story of Adam and Eve, women have been subjected for thousands of years. Religion, channeled down the wrong paths in its conceptual stages, has cost us much progress, welfare, peace and understanding. Science is now in its conceptual stages. One of the first major acts of Science was to use the stars that fell from the sky to annihilate masses of people. In part, this is a price we paid by subverting Religion at its conception. It is inconceivable to me that a society that had had women as full partners for these thousands of years could ever have degenerated to the point where use of nuclear weapons upon its own species was a sustainable concept.
What seeds is Science, in it infancy, now planting?
I believe it is the kind of thinking seen here about "other intelligences" that could be weed seeds, instead of fruitful seeds. We must "re-size" our minds.
jon_pan
Mar26-06, 02:26 AM
wow.......GREAT post owl3951. I agree 100% on everything you said.
but did you read the original question? jk, a little off topic thought, into philosphy science arts. but your main scientific points are:
-that life doesn't have to exist the way it exist on our planet,
-we're ignorant to our senses, and there's alot more beyond them
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