# Alien civilisations - less likely?



## Anthony G Williams

A couple of years ago I posted a review of a non-fiction book by Stephen Webb: *Where is Everybody? Fifty Solutions to the Fermi Paradox*  (http://sciencefictionfantasy.blogspot.com/2009/05/where-is-everybody-fifty-solutions-to.html). In this book, the author considers the Fermi Paradox; that given the number of stars in this galaxy alone and the length of time it has existed, there should be swarms of high-technology Extra-Terrestrial Civilisations (ETCs) around, so why haven't we detected any? He examines a wide range of possible explanations before concluding that our planet is uniquely fortunate and may host the only technological civilisation in the galaxy.

My own conclusion was slightly different from the author's, in that I speculated that given the age of this galaxy, with the average age of its stars being some two billion years older than our sun, there have probably been plenty of ETCs around but that it could be rare for more than one to be in existence at any one time, since they may not last all that long.

One of the unknowns, until very recently, was how many stars have planets - particularly planets like ours, rocky and in the CHZ (continuously habitable zone): which is to say, at the right distance from its sun for the billions of years needed for not just life (or our understanding of it) but advanced intelligence to evolve. The habitable zone is popularly known as the "Goldilocks" zone: not too hot and not too cold for liquid water to exist on its surface (i.e. average surface temperatures within the 0-100 degrees centigrade range). However, this gap in our knowledge is rapidly being filled by astronomers who, by using highly sensitive instruments and sophisticated data processing techniques, have discovered over 1,200 exoplanets orbiting nearly 1,000 stars, with the numbers steadily growing. What they have discovered so far has been summarised in a couple of recent issues of the *New Scientist* magazine (_Astrobiology_ supplement by Caleb Scharf, 7th May; and _No Place Like Home_ by Lee Billings, 14th May) and is discouraging to those keen to find ETCs.

First, I had better summarise the three different indirect methods by which exoplanets are detected (even the biggest of them around the closest stars are far too small to observe directly). 

The first method used is the *Doppler or radial velocity* technique. This relies on the fact that planets do not, strictly speaking, orbit their stars. The planets and their stars orbit a common axis whose position is determined by their relative masses; if a star and planet were both of the same mass, the axis would be half-way between them. Generally, stars are vastly more massive than any of their planets so the common axis is within the star, but not in its centre. The star therefore wobbles slightly as the planet moves around it, and this can be detected. The speed of the wobble indicates the period of the planet's orbit and therefore its distance from the star; the size of the wobble indicates the relative mass of the planet. Obviously, if a star has several planets, each exercising its influence on it, then its pattern of wobbles can be very complex and require lots of number-crunching to resolve. This method favours the discovery of large planets orbiting very closely around their stars, as these create the biggest wobbles. This may mask the existence of smaller planets further out.

The second method is known as *transit photometry*, which is based on measuring the slight dip in a star's brightness as a planet passes in front of it. The degree of the dip indicates the planet's size, the time period involved indicates its speed and therefore distance from the star. This method also has its disadvantages. An obvious one is that the planet's plane of orbit has to be side-on to us, otherwise it wouldn't pass between its star and our planet, so any planets with different orbital planes will fail to be detected. It is also necessary for three transits to be observed to be certain that this is a genuine effect, which in the case of a planet the same distance from its star as ours means that it will take two to three years to confirm. Jupiter's orbit takes twelve years, so confirming the observation of a similar planet would take 24 to 36 years. So once again, bigger planets close to their stars are the easiest to detect.

The third method is called *gravitational microlensing*, which relies on the fact that massive objects bend the fabric of space. In practical terms, it means that a star exactly in between us and a far more distant star will act as a lens, focusing the light of the distant star.  If the nearer star has planets, these can produce a subsidiary focusing effect which can be analysed to determine the planets' masses and orbital distances. However, the opportunities for such observations occur very rarely.

I find it amazing that no only can such miniscule observations result in confident estimates of the size and mass of planets orbiting distant stars but that the nature of the planets can also be deduced: whether they are rocky worlds or gas giants. Data from their stars also allows astronomers to deduce whether or not a particular planet is within the habitable zone.

At first only the largest planets were observed, but more recently (and especially with the use of the Kepler telescope launched into orbit in 2009) it has become possible in some cases to start building up a picture of entire solar systems, identifying the number, size and orbits of several planets orbiting the same star. The results are demolishing some long-held beliefs.

The theories of solar system formation which have developed over the centuries have of course all been based on a sample of one: ours. They tended to conclude that all of the planets will be more or less in the same orbital plane with close-to-spherical orbits, and that planets in close orbits will be small and rocky, with gas giants further out. All of these conclusions have turned out to be flawed.

What astronomers have observed so far might be summarised as follows: planets and panetary systems are the norm, but while some systems have an even more regular structure than ours, others can best be described as chaotic. Gas giants are found in close orbits, the most spectacular example being Upsilon Andromedae which has a planet 1.4 times the mass of Jupiter so close to the star that its orbital period is just 4.5_ days!_ Furthermore, that same star has a super-massive gas giant, 14 times the mass of Jupiter, with its orbital plane at a 30 degree angle to the first one. And there is a third giant in that system, 10 times the mass of Jupiter, in an extremely elliptical orbit with a different orbital plane again.  This kind of chaotic structure would have a huge effect on any smaller planets in the system, wildly disturbing their orbits and making it impossible for them to remain in the habitable zone for any length of time.

One possible consequence of such gravitational instability is that planets can end up being flung out of their solar systems altogether, presumably accounting for the recent discovery of many such homeless planets floating around our galaxy, only detectable via their gravitational lensing effect. In fact, a later *New Scientist* news item suggests that so many of these loose planets have now been discovered that they must be considerably more common than planets which are still orbiting stars.

This is really significant since in order for life to evolve to a human level of intelligence on any particular planet, that planet has to remain within the Goldilocks zone for billions of years. And that means above all that stability is required. Not only does the orbit of the planet have to be fairly circular and the star itself be stable, but other planets in that system have to be in stable, near-circular orbits in more or less the same orbital plane. 

Of the 1,200 planets detected so far, only 366 are rocky and of Earth or super-Earth size (the initial requirement for supporting Life As We Know It). Of these, just *six* are in the habitable zone. While most seem to be in reasonably stable orbits at present, that does not mean that they have been, or will remain, in that zone for the length of time required to develop intelligent life.

Exploration continues and conclusions are sure to change as more data comes in, but initial indications are that our Earth's characteristics and history have been unusually favourable to the development of intelligent life. Which suggests that it is unlikely that other civilisations exist anywhere near us.

(An extract from my SFF blog)


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## Vertigo

That's very interesting Anthony, I might have to get a copy of that book for a read. It seems to be pretty much in line with my own thoughts, though I hadn't realised that we seem to be finding chaotic systems to be the norm. When combined with the problems of the galactic centre and the galactic fringes it really does seem to me that our system is proving to be the exception rather than the norm. Not a bright prospect for the discovery of alien civilisations.


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## J Riff

Fabulous. We live right next to a major tourist attraction and aren't even allowed to talk about it, let alone go there.
 Theoretically - there should be an equasion for the possibility of Aliens _not _finding our system. I'd place the odds somewhere near zero.
 I guess, the Earth kids still aren't ready for Mars, too depressing yknow..... that was the reason_ bion,_ but... things change.


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## J-Sun

Very nice write-up. Related article on cancelled missions.


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## william b

Very interesting.  Maybe we are getting a better idea of what the chances are, but there are always those times of discovery when the universe turns out to be different than we think, we discover some interesting fact that opens up new doors.  
All it takes is one discovery.  
And actually, I'm of a mind that a truly advanced civilization might not want to meet us.  We act like we're the cheerleader everyone wants to date, but isn't that a little arrogant?  Maybe we are one of the unpopular kids in the universe.   Or at least too immature to hang out with the cool kids.   I'm willing to bet that there are still many secrets in our universe.


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## Anthony G Williams

william b said:


> Very interesting. Maybe we are getting a better idea of what the chances are, but there are always those times of discovery when the universe turns out to be different than we think, we discover some interesting fact that opens up new doors.
> All it takes is one discovery..... I'm willing to bet that there are still many secrets in our universe.


 
Unquestionably - if you intend "secrets" to mean "things we don't know". It is important to keep an open mind and to be receptive to new evidence. 

However, it's also important to stress the need for objective, validated evidence in forming our theories and understanding. There is no evidence which suggests the existence of other technological civilisations anywhere at all - not a shred of it. So while it's interesting to speculate about why this is so, it is important to bear in mind that it is only speculation.


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## Stephen Palmer

Very interesting... we know so little.


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## Vertigo

Anthony G Williams said:


> Unquestionably - if you intend "secrets" to mean "things we don't know". It is important to keep an open mind and to be receptive to new evidence.
> 
> However, it's also important to stress the need for objective, validated evidence in forming our theories and understanding. There is no evidence which suggests the existence of other technological civilisations anywhere at all - not a shred of it. So while it's interesting to speculate about why this is so, it is important to bear in mind that it is only speculation.


 
Very well put Anthony, a nice summary of where we are on this today! As you say there is no evidence to suggest the existence of other technological civilisations and of course there is also no hard evidence to suggest their non-existence either. However a lack of evidence does suggest a lack of existence more strongly than the reverse.


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## J Riff

As always, human beans will put profit ahead of truth, a virtual Law, if you will, of nature.


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## RJM Corbet

J Riff said:


> Fabulous. We live right next to a major tourist attraction and aren't even allowed to talk about it, let alone go there.
> Theoretically - there should be an equasion for the possibility of Aliens _not _finding our system. I'd place the odds somewhere near zero.
> I guess, the Earth kids still aren't ready for Mars, too depressing yknow..... that was the reason_ bion,_ but... things change.


 
What' all this about Mars, Riff? C'mon. I won't tell anyone, I promise ...


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## Null_Zone

I can't help feeling the answer to the Fermi Paradox is:-

Just like humanity is out there exploring the stars.


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## Vertigo

My pessimistic side tends to agree with you there Null Zone. Maybe there is no convenient get around of our known laws of physics, and without FTL (or maybe even with it) the economics of star travel make it prohibitive for any technological race. It's hard to imagine there are any significantly different resources out there than we don't already have here in our solar system (us being already unusually high in heavier metals). So what would you trade to make it worthwhile? Think of the cost in resources and time for transport and the risk of going out there and never finding anyone to trade with.


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## J Riff

Trade? 
Conquer! Enslave. That's what humans'll do, innit?


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## Stephen Palmer

We do love, as well.


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## J Riff

Half do, the other half overrun and dominate, and they don't go away cos you are a love-god! And I oughter know.


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## Anthony G Williams

J Riff said:


> Half do, the other half overrun and dominate, and they don't go away cos you are a love-god! And I oughter know.


Is that because you're an unappreciated love-god?


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## J Riff

No, it's because I live in Canada.
I'm reading _Uninvited Visitors -a biologist looks at UFOs, _
and it talks about OOPOs- out-of-place objects - 
stuff that fell on Earth, in the times before the Media was completely leashed, and the list is awesome.
 Blood, metal cannisters, animals, weird things that took weeks to die, all kinds of junk. Barns carried away, Angel-hair, all sorts fun stuff floating down.
The best ones, which we heard about when it happened, were the chunks of living....stuff, that took weeks, or in one case, two years to die.
 It gets crazy. Chickens disappear, then fish rain down. Were 'they' trying to be nice and pay back for stealing the chicken coop? 
 Also, the Philadelphia Experiment letters are looked at. What the h*ll happened there?


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## Metryq

With all those chaotic planets out there, the mission of the _Dark Star_ is sounding more plausible. Just be wary of bomb number 20.



> *Vertigo wrote:* It's hard to imagine there are any significantly different resources out there than we don't already have here in our solar system



Ha! What a thought. The Orion slave girls are always greener on the other side of the fence? After incredible breakthroughs in physics and a massive economic and engineering effort, the first starships from Earth find a plentitude of intelligent life subsisting at pre-industrial levels. Given the opportunity, they'd all come to _our_ Solar system as the prime real estate anywhere.


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## Vertigo

Ah well I wasn't considering Orion slave girls when I made the post...

But seriously we have a solar system unusually high in all the elements including the heavier ones. It is just hard to think of anything that would be worth transporting at such high cost. Seeds of useful alien plants perhaps, though that probably wouldn't be allowed. The only other thing I can think of that might be worth trading would be technology - knowledge rather than artifacts.

Compare with good old Earth; even here as transport cost continue to steadily rise, more and more effort is made to use local produce rather than incur those high costs and their carbon footprint. And that's just transporting a few thousand km rather than light years. Maybe that will change if we can ever develop some kind of *cheap* FTL drive but frankly I doubt it.


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## clovis-man

I'm sticking with the current mantra: If there were anyone else out there, they would have dropped in by now. So, by definition, they cannot exist.


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## Stephen Palmer

?

that's hardly a definition...


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## Vertigo

clovis-man said:


> I'm sticking with the current mantra: If there were anyone else out there, they would have dropped in by now. So, by definition, they cannot exist.


 
The problem with that "definition" is that *we* are here and unless we can find some physics that lets us get around the speed of light (unlikely in my opinion) we are unlikely to be going out there and dropping in on anybody else out there, which doesn't mean we don't exist. 

So maybe there's lots of alien civilisations out there (personally I doubt it, but maybe) and they are faced with the same physics as us so have never been realistically able to go out visiting other civilisations. 

As to why we haven't "heard" them, the timescales are very long and we, for example, are gradually getting much more efficient at how we transmit and receive radio. Within a decade or so I suspect we won't be blasting out very much in the way of undirected radio signals of a power strong enough to be picked up light years away. So maybe there's only a very small easily missed window of opportunity for detecting another civilisation by their radio emissions. They may be out there but we might never detect them. Personally I doubt there is much other intelligent life out there but for other reasons that I have expressed elsewhere, such as those that are the topic of this thread.


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## clovis-man

Stephen Palmer said:


> ?
> 
> that's hardly a definition...


 
Nah. Just Fermi's conundrum. I would only say that mathematical models cannot be considered realistic when used to project the "odds". The word "likelihood" in and of itself begs the question.


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## Anthony G Williams

J Riff said:


> No, it's because I live in Canada.
> I'm reading _Uninvited Visitors -a biologist looks at UFOs, _
> and it talks about OOPOs- out-of-place objects -
> stuff that fell on Earth, in the times before the Media was completely leashed, and the list is awesome.
> Blood, metal cannisters, animals, weird things that took weeks to die, all kinds of junk. Barns carried away, Angel-hair, all sorts fun stuff floating down.
> The best ones, which we heard about when it happened, were the chunks of living....stuff, that took weeks, or in one case, two years to die.
> It gets crazy. Chickens disappear, then fish rain down. Were 'they' trying to be nice and pay back for stealing the chicken coop?
> Also, the Philadelphia Experiment letters are looked at. What the h*ll happened there?


 
In years gone by, I read lots of books by people claiming the most amazing things and stating lots of evidence in support.

The problem was that none of the evidence was independently verified by anyone. It was basically hot air - and it doesn't sound as if anything has changed...


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## Starbeast

Anthony G Williams said:


> The problem was that none of the evidence was independently verified by anyone.


 
True, only the fortunate lucky few like astronauts get to see...........







 







 ​The way these guy talk is no wonder why the NASA channel doen't show much of real time space with a clear picture, we always get mostly fuzzy black and white footage and long boring shots of mission control with personel standing around. Don't get me started about the so-called Earth Channel, no real time cameras with clear views of Earth there either. I clicked on that channel many times and I can't even make out the Earth, even though at the bottom of the screen it says "Earth View".

But of course, none of this proves the existence of alien space craft flying around constantly.​


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## J Riff

Why worry about saucers, when the alines would be down here, impersonating human beings and doing horrific things, because they were raised in an insect culture. 
 Once they get onto welfare, there's no stopping them.


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## Starbeast

J Riff said:


> Why worry about saucers, when the alines would be down here, impersonating human beings and doing horrific things, because they were raised in an insect culture.
> Once they get onto welfare, there's no stopping them.


 
A few people have written books about aliens from elsewhere among us humans, some had worked in the government and said:

"What worries the governments is the fact that some alien races either look human or can appear to look human."

If this is true, how would the average person know who is human and who isn't? Are they here to observe people close up or are they up to no good? Sometimes I think about how cruel humans can be to one another, maybe the outworlders want to analyze us because we do such unspeakable things to each other without care.


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## Anthony G Williams

Starbeast said:


> True, only the fortunate lucky few like astronauts get to see...........
> 
> 
> But of course, none of this proves the existence of alien space craft flying around constantly.​


 
You are right, it doesn't. Eyewitness evidence is notoriously unreliable and certainly never counts as "verified" by itself.


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## Starbeast




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## J Riff

Some things are too weird. People won't believe them, no matter what.
I think that every SF movie has an element of the truth, added together it's a real mess. Space-rats. Energy Vampires, protoplasmic leeches... all the things that might hang around a nice place like Earth. )


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## Anthony G Williams

You can't even rely on video evidence. Apart from the fact that most of it has been faked, even that which hasn't can be seriously misleading. I've posted this before but it bears repeating:



> Many years ago there was a programme on UK TV concerning a UFO sighting. A passenger on an internal flight had a cine camera and had been filming out of the window. When the film was developed, he had a shock: a small dot in the distance rapidly enlarged to a lens-shaped object which briefly hovered alongside the plane before rushing away again at incredible speed. The film was shown on TV and it was extremely convincing; the image was sharp and clear, and there were irregular white markings which could not be identified along the rim of the object. The cameraman was entirely credible and was shaken by it himself. I was also rather shaken, because I've never seen such convincing evidence for what looked like an alien craft.
> 
> Fortunately the programme producer had an enquiring mind and was not disposed to jump to conclusions. He borrowed the man's camera, loaded it with the same type of film, and gave it to a professional cameraman who sat in the same seat of the same aeroplane following the same route, and started playing about with the camera. It wasn't long before he saw the same thing, and he discovered that he could make it come and go just by shifting position slightly.
> 
> A close inspection of the window revealed what was happening: the window glass had a bevelled edge, and this was refracting a distorted image of the tailplane, making a section of it appear to be detached and floating in mid-air. The white markings around the rim were just where the paint had worn off on the leading edge of the tailplane. So as the camera lens was moved slightly to one side of the bevelled area, the "UFO" could be made to appear and disappear.
> 
> That was a real object lesson, both in not believing what your eyes appear to be showing you, and in how to investigate such reports.


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## Starbeast

*Unbelievable and no evidence......*



J Riff said:


> Some things are too weird. People won't believe them, no matter what.


 


Anthony G Williams said:


> You can't even rely on video evidence.


 
You both are right. (excluding liars and hoaxers) How can a person speak of bizarre events and unearthly things that he or she has witnessed without being subjected to skepticism? Who would listen to someone ranting about uncanny circumstances that were experianced? It is near impossible.

To those out there who've seen or been a part of incredble things, they are the ones who have the memories that can never be forgotten. Some were inspired, while others were traumatized, both had their lives changed forever..........I salute them.


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## Anthony G Williams

*Re: Unbelievable and no evidence......*



Starbeast said:


> To those out there who've seen or been a part of incredble things, they are the ones who have the memories that can never be forgotten.


 
Unfortunately both human perceptions and memory are frighteningly unreliable (memory in particular is extremely plastic, and people can be entirely wrong about what they firmly believe they remember).

This has been starkly demonstrated in various experiments (some shown on UK TV not long ago) involving incidents being "staged" in front of witnesses who were then interviewed about what they saw. Despite the incidents being staged right in front of them, in broad daylight, their recollections varied from being slightly to completely faulty.

This is why no one person's memories can be regarded as serious evidence unless they are corroborated by other sources of evidence - much more solid ones than memories.


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## Starbeast

*The mind and beyond......*



Anthony G Williams said:


> Unfortunately both human perceptions and memory are frighteningly unreliable (memory in particular is extremely plastic, and people can be entirely wrong about what they firmly believe they remember).


 
The mind is an amazing organ, using one's mental strength a person can break stone with their hands like martial artists, change the speed of their heartbeat like yoga masters, or even become intuned with nature like some native american indians. Yet, there are those who are born with mental deficiencies, some suffer from brain degeneration, while others abuse thier mind with drugs. And there are still some people who've gone through mental breakdowns do to trauma they've experianced, even others who are weak minded that have poor memories.

I agree that perception is also a factor, one person can see a plane in the sky while another swears it's an alien space ship. Strange atmospheric phenomenon, light reflections or even those who know nothing of astronomy can imagine all sorts of things.

I know you are a great skeptic Mr Williams, I think it's good that you question everything, I'm skeptical too, since I was a child. However I am aware there are things that are supernatural and beyond us, like God, I never try to convince anyone he exists. A person can read all of the holy books on Earth, and say those are just random thoughts of humans, therefore those books are worthless and God does not exist.

I've known something for a long time which I find very true in all things, if you're really trying to find what you are looking for, no matter how long it takes, you will eventually find an answer, if not the solution.


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## paranoid marvin

Even if it's a triliion-to-one chance that another planet evolved in a similar way to the Earth and developed life , there would still be lots of inhabited planets out there.


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## clovis-man

Starbeast said:


>


 
Somehow, just wiping his nose repeatedly and saying "Wow" and "Incredible" several times does not convince me of the veracity of the person supplying the assertions.


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## Starbeast

clovis-man said:


> Somehow, just wiping his nose repeatedly and saying "Wow" and "Incredible" several times does not convince me of the veracity of the person supplying the assertions.


 
I live near Chicago, and this only one of the authentic UFO stories that made the news, and I found it interesting because the clip showed the news anchorman chatting about it before he went on the air. The employees who worked at Ohare airport were told not to talk about, yet civilians who witnessed this incident still talk about. A few employees from Ohare airport have come forward and were interviewed, but their identities were withheld. I saw it on local news and read about it in my local newspaper, according to all witnesses, a metallic looking saucer was seen hovering.


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## J Riff

Well, I've seen the stuff, so I'm out of the argument.
I'll bet 'they' are watching this city, right now, as there are huge swarms of people filling the streets for the hockey game. 
Swarm, swarm..... ants like swarming. * )


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## Starbeast

J Riff said:


> Well, I've seen the stuff, so I'm out of the argument.
> I'll bet 'they' are watching this city, right now, as there are huge swarms of people filling the streets for the hockey game.
> Swarm, swarm..... ants like swarming. * )


 
Yeah, it's probably just the government messing with our heads again.

I'm not a hockey fan J Riff. Are you up for some 3 Stooges?


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## clovis-man

Starbeast said:


> I live near Chicago, and this only one of the authentic UFO stories that made the news...


 
I think this all depends on what you would call authentic. I don't want to pull the thread way of track here, but just a group of people saying they saw something doesn't convince me. If authentic means "Yup! I seen 'em!", then sure. But if it means verifiable via independent data that is more than just a verbal account of a visual experience, this one doesn't qualify.

When I was in U.S. Army basic training at Fort Ord in the 1960s, I and my entire training platoon observed a UFO. It was at night and we were going through what was called an "infiltration course". We had to maintain absolute silence. So when the glowing object that traversed the entire horizon from west to east was sighted by us, it was difficult to maintain discipline. But we all saw it. The next day we snuck down to nab a newspaper and saw that it had been chalked up to a "missile from Vandenburg". Last time I checked, missiles didn't hug the horizon for three or four minutes from one side to the other like this one did. But you see my point: all the discussion and a couple of dollars may get you a cup of coffee, but that's all.


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## Starbeast

*Secret Aircraft?*



clovis-man said:


> I think this all depends on what you would call authentic.
> 
> When I was in U.S. Army basic training at Fort Ord in the 1960s, I and my entire training platoon observed a UFO. It was at night and we were going through what was called an "infiltration course". We had to maintain absolute silence. So when the glowing object that traversed the entire horizon from west to east was sighted by us, it was difficult to maintain discipline. But we all saw it. The next day we snuck down to nab a newspaper and saw that it had been chalked up to a "missile from Vandenburg". Last time I checked, missiles didn't hug the horizon for three or four minutes from one side to the other like this one did. But you see my point: all the discussion and a couple of dollars may get you a cup of coffee, but that's all.


 
I only use the word authentic when an object is described by hundreds of witnesses seeing the same thing, this one happened in the early part of the afternoon. But, like you said, they could have been mistaken.

However, one of the best incidents I remember was back in the 1980's, I was at work when I suddenly heard the DJ pop on the radio saying he was getting all these weird phone calls about something going on at Lake Michigan. He said the phone callers were talking about giant cylinders hovering above the water, flying saucers of different colors zipping through the sky and many millitary helicopters at the scene.

My jaw dropped and I almost left work to check it out since I was only 15 minutes away from Lake Michigan and it was roughly about two in the afternoon. I stopped and thought: "Bah! That's just crazy talk. I'm not falling for some prank people are playing on the DJ." So I changed the radio staion and went back to work. The next day I checked the newspaper and it only mentioned a huge millitary exercise happening by Lake Michigan that scared a bunch of people, so I didn't think anything more about it.

A few years later I met a friend of a friend, we chatted about our interests, then we began talking about UFOs, I mentioned the radio DJ who got a lot of weird calls about UFOs at Lake Michigan and said I almost left my job to check it out.

He said to me: "I heard talk about that on the radio too. I had the day off and I went to see for myself....and I saw helicopters flying over the lake, there were these big long metallic looking things hovering above the water. But what scared my friends and me was this big bright green lighted disk that flew over my convertible (his car). It came from behind us and it was so low that we all ducked as it passed over us. My mind went into overdrive and I hit the gas pedal and raced to lake's shore, but when we got there all these army guys told us to get the hell out of here."

I froze in astonishment staring him, then I asked him about more details, he told me everything exactly as it happened. He told me it inspired him to make a t-shirt design, and the very next day he showed me the t-shirt he airbrushed, it had helicopters, the cylinders over the water and the green disk that buzzed him and his friends in the car.

I wish I had seen what he saw, I'm still amazed by the fact that that incident was kept quiet. I began to wonder about other incredible incidents that are hushed up around the world.

Is it all secret aircraft?


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## RJM Corbet

So many observations, thousands and thousands and thousands -- and even if 99.99% are wrong, just ONE has to be true, yet mention the subject gives everyone the right to treat you like what Riff calls a _nutbar_, even if you're a highly trained pilot, or even an astronaut -- or even if your name's Buzz Aldrin ...


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## J Riff

Then there's Phoenix, was it 2007? A ship far too big to believe coasted over the city, escorted by five spheres.
 What's wrong with the sighting is the lack of photos. There is footage of the 5 balls, but none of the giant craft. Therefore... somebody is holding on to this evidence until the proper moment, which may be nearing. Wahoo.
 A tourist ship, the first of many to come? Will they they have shiny beads and magic beans? Do we really have to wait until 2012? What's wrong with, say, next Thursday?


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## Anthony G Williams

While the vast majority of "UFO reports" have been found, on examination, to have simple and mundane explanations, a very small number have not (so far) been so explained.

So there are some genuine UFOs - but note that UFO simply means "Unidentified Flying Object". It does *not* mean alien spacecraft! It means "we don't know what the hell that was so we'll park it as 'unknown' until an explanation comes along."

The automatic association of UFOs with aliens which some people make is pure fantasy, with no credible evidence to support it.


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## RJM Corbet

Anthony G Williams said:


> While the vast majority of "UFO reports" have been found, on examination, to have simple and mundane explanations, a very small number have not (so far) been so explained.
> 
> So there are some genuine UFOs - but note that UFO simply means "Unidentified Flying Object". It does *not* mean alien spacecraft! It means "we don't know what the hell that was so we'll park it as 'unknown' until an explanation comes along."
> 
> The automatic association of UFOs with aliens which some people make is pure fantasy, with no credible evidence to support it.



Yes, and anyone deciding to have a serious look at UFO 'sightings' is bound to become acutely aware of all that at an early stage -- especially the simple point that 'unidentified' doesn't mean 'extra-terrestrial'. 

Credible and serious people have devoted serious time and research to the subject, and there are MANY extremely credible reports by extremely credible observers mixed in with the vast majority of hoaxes and nutbar stuff ...


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## J Riff

Authentic. All the authentic people have stepped up already. What does this tell you?
The people with the real story are not regular Govt. people at all.
I can sit here and tell you I've been up, seen them, talked to them, and I can tell you that for ten years straight, and would have been, except there's no point without Govt. backup.
 However, if the true story is put up here, and the military types back it up... what then? Because that's where it sits at this moment.
 People DO know. Convincing anyone is not even part of it, it's been holding it back so the shock isn't so great.
 And, no normally-trained Govt/Military type could deal with such a mission anyway - one-on-one dealings with aliens, it's far too weird, and you need an artistic, highly-imaginative, compartmentalized person who can forget the whole thing for about thirty years, because that's about how long it will take to condition people to it.
 All the disclosure people are strictly observational and above board, the hands-on, invisible people are all that's left, and as I said, everyone is now supposedly 'off the hook' and allowed to talk... which seems to indicate that they expect the whole issue to be redundant soon, due to an unmistakable appearance by Aliens.
 What will the aliens do? Maybe they track this board, of course they do.... hey guys! How about a ring around the moon? 
 What would you like to see the aliens do when they show up, to prove they exist oncet and for all? 
According to rumors, the next big tourist ship won't be here until February, and I'm getting impatient.


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## RJM Corbet

President Carter was (allegedly) refused access to documents by George Bush senior, then director of the CIA -- and so was President Clinton (allegedly) denied access to documents by the CIA. US nuclear warheads were (allegedly) based on British soil without the knowledge of the British people.

So who really runs the show?

That's the question, isn't it?

Big oil? Those nice guys?

*UFO witnesses:*

http://www.youtube.com/watch?v=7vyVe-6YdUk&feature=player_detailpage
(Two hours -- poor sound quality)


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## Anthony G Williams

RJM Corbet said:


> President Carter was (allegedly) refused access to documents by George Bush senior, then director of the CIA -- and so was President Clinton (allegedly) denied access to documents by the CIA. US nuclear warheads were (allegedly) based on British soil without the knowledge of the British people.


 
Credit is due for putting in the "allegedly" qualifier - but almost anything can be and has been alleged by someone at some time, so why bother mentioning them? Wait until there is evidence...


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## RJM Corbet

Anthony G Williams said:


> Credit is due for putting in the "allegedly" qualifier - but almost anything can be and has been alleged by someone at some time, so why bother mentioning them? Wait until there is evidence...



It's in that video link in my previous post ...


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## J Riff

Rather than wait for further 50-year old evidence, I tossed off an eMail to the Barackster himself, and he responded politely with some doubletalk about waste spending or some such, avoiding the issue smoothly. I wonder if he's even able to so much as twitch when it comes to UFOs or Mars, or any of it. No idea.


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## Anthony G Williams

RJM Corbet said:


> It's in that video link in my previous post ...


Wait until there is _solid, independently verified,_ evidence...


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## J Riff

Hee hee. As if evidence or proof to civilians means anything at all.
Reverse field a moment, and concede that it's not real, any of it. It's faked. Thousands in on it. Pilots, crypto-clearance people, everyone back to biblical times. A real nifty scam.
All faked or hallucinated or nutbar. If you consider that a while, you'll see it's a worse problem than the real thing. It would qualify, in fact, as a full-blown racial mental illness.
It's one or the other. I choose to believe in the giant spider, rather than a planet of nutbars.


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## Varangian

Pre-existing alien life has already been found on Mars...just not intelligent life (fossilised bacteria for instance). 

Something that is quite interesting is that one of Mars' moons (Phobos from memory) has given serious grief to NASA. Each time a satellite comes within close proximity of the moon, the satellite malfunctions and NASA loses comms with it. *Que X-files music*. 

As far as intelligent non-earth entities are concerned, if they are very advanced, would they want to come and watch a bunch of monkeys bash each other over the head? And what's more, would they really want to be discovered by said monkeys?


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## Vertigo

Varangian said:


> Pre-existing alien life has already been found on Mars...just not intelligent life (fossilised bacteria for instance).
> 
> Something that is quite interesting is that one of Mars' moons (Phobos from memory) has given serious grief to NASA. Each time a satellite comes within close proximity of the moon, the satellite malfunctions and NASA loses comms with it. *Que X-files music*.
> 
> As far as intelligent non-earth entities are concerned, if they are very advanced, would they want to come and watch a bunch of monkeys bash each other over the head? And what's more, would they really want to be discovered by said monkeys?


 
The idea that fossilised bacteria have been found on Mars is as yet inconclusive. A couple of scientist revisited some old data and claimed they had found something. But I believe it is generally held that the evidence was way too thin to make any conclusions.

As far as I'm aware there has only been one incident associated with Phobos which was the Russian Phobos 2 probe. Communication was lost with this probe close to Phobos and it was determined to be an on board computer failure. There was some speculation about a couple of the last images sent but these oddities have been put down to a being the shadow of Phobos on the surface of Mars.

On your last point I agree absolutely


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## TheTomG

I've always been intrigued by a civilisation so advanced they can travel vast distances between stars at speed that must allow that in a reasonable timeframe, sustaining life all the while, only to have the brakes fail when they get here and crash.

Unlucky!


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## Vertigo

You should read Poul Anderson's Tau Zero TTG, that's essentially what happens to them except instead of crashing they keep on accelerating... for ever!


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## bobbo19

to tell people the honest truth, We still just know absolutely **** all about the Universe. Wait for the civilisation to mature a few thousand years then we will have a better idea.


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## psychotick

Hi,

Its always occurred to me, as was mentioned at the start, that there may be only a very limited timeperiod in which alien civilizations would be observable to us. The Earth after all is something over four billion years old, mankind's had radio etc for a bit over a century - a relative split second. Now I'm not saying that we're finished and that all civilizations follow the same route to self destruction. But surely at some stage even if we don't wipe ourselves out, our technology will advance to a point where it won't be recognisable by our current technology. So maybe they are out there and we simply can't recognise them.

As for them coming here - why? What have we got that would rate more then maybe a scientific curiosity mission? And if they did come here, that speaks volumes about their tech. It'd be so far advanced over ours that we'd surely barely even recognise it. And in any case surely they could crack invisibility if they can transverse interstellar distances - we'd never know they were here.

Cheers.


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## Anthony G Williams

psychotick said:


> Hi,
> 
> Its always occurred to me, as was mentioned at the start, that there may be only a very limited timeperiod in which alien civilizations would be observable to us. The Earth after all is something over four billion years old, mankind's had radio etc for a bit over a century - a relative split second. Now I'm not saying that we're finished and that all civilizations follow the same route to self destruction. But surely at some stage even if we don't wipe ourselves out, our technology will advance to a point where it won't be recognisable by our current technology. So maybe they are out there and we simply can't recognise them.
> 
> As for them coming here - why? What have we got that would rate more then maybe a scientific curiosity mission? And if they did come here, that speaks volumes about their tech. It'd be so far advanced over ours that we'd surely barely even recognise it. And in any case surely they could crack invisibility if they can transverse interstellar distances - we'd never know they were here.


 
Can't argue with any of that. 

Researchers are already working towards invisibility (although currently on a very small scale and at limited frequencies) so we'll certainly get a "cloaking shield" impervious to visible or invisible radiation long before we have any practical means for manned interstellar travel (if indeed we ever do).


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## TL Rese

i think the likelihood of a technological species evolving is very small.  so many elements have to be present.  just look at our own planet - home to countless species over the years, yet we're the only ones who have gone into space.

however, leading astronomers aren't spending millions to find extraterrestrials because they think there's no hope.  the universe is a Huge place, and we've only just started exploring it.  who knows what we'll find in the next couple of centuries?

btw, there Is profit to be had in outer space.  we're fast using up our own earth's resources - we could always use more minerals, water, etc.  not to mention that our ever-expanding population needs more places to live.  land is something that our species has always needed and been hungry for, so it's only a matter of time before we acquire land on other planets.  and w/ our expansion into outer space, there will likely come an increased knowledge of space travel, the universe in general, and of life on other planets.


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## Anthony G Williams

rese3282 said:


> we're fast using up our own earth's resources - we could always use more minerals, water, etc. not to mention that our ever-expanding population needs more places to live. land is something that our species has always needed and been hungry for, so it's only a matter of time before we acquire land on other planets. and w/ our expansion into outer space, there will likely come an increased knowledge of space travel, the universe in general, and of life on other planets.


 
That's a tad optimistic. I find it impossible to conceive of any such emigration making any noticeable difference to the Earth's population. At the moment the population is increasing by over 200,000 *every day*. Just think about that - to keep the population constant we would not only have to find a way to transport 200,000+ people per day, every day of the year, we would have to find somewhere to put them all - fancy trying to build accommodation for 200,000 on a new planet, every day? Plus the extra farmland needed to feed them? It's just inconceivable. 

We're going to have to solve the Earth's problems on Earth.


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## TL Rese

Anthony G Williams said:


> That's a tad optimistic. I find it impossible to conceive of any such emigration making any noticeable difference to the Earth's population. At the moment the population is increasing by over 200,000 *every day*. Just think about that - to keep the population constant we would not only have to find a way to transport 200,000+ people per day, every day of the year, we would have to find somewhere to put them all - fancy trying to build accommodation for 200,000 on a new planet, every day? Plus the extra farmland needed to feed them? It's just inconceivable.
> 
> We're going to have to solve the Earth's problems on Earth.


 
of course we have to take care of mother earth, and i'm not saying we're going to start colonizing other planets tomorrow, but like you said, "population is increasing by over 200,000 *every day" - *where is everyone going to go if not to outer space?  unless you suggest murdering off some people or telling people not to have children.  we can't stay on earth forever.  what if something catastrophic happens to earth, like a comet?  we'll face the very real possibility of extinction.  stephen hawkings himself said that expanding to other planets is key to our species's survival.

those numbers mite seem big to us now, but not long ago, cities consisted of only a few thousand people - now they're home to millions.  in a few centuries, what seems impossible to us now may very well be possible.


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## J-Sun

Exactly - I'm all for solving Earth's problems but, if we fail, I'd like to have some clumps of 200,000 humans somewhere else rather than just piling up here.


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## Quokka

I don't think space colonisation can ever be significant in affecting total population on Earth, the numbers are too large and we'd fill any void too quickly. If England had moved a larger percentage of it's population to America initially, even say 10% (and today that would be ~700 million in global population), I wouldn't think that their current population today would be significantly lower?

I agree that it will increase humanity's chance of survival and I think the first step is relatively simple. If there was a need great enough to make failed attempts and loss of life politically/socially acceptable I think we'd have a fair chance of setting up a (initially very small) self sustaining population on mars even today. Colonising our solar system (planets, moons and artificial satelites) has to be achiveable, not 2012 but within 1000 years?, if our science and knowledge continues on as you'd expect it to... and history would suggest it may well jump ahead and into places we'd consider impossible now. 

It's that next step, to other stars that is just so immense from our current point of view. The distances are so great that traversing it by a stargate/wormhole type invention doesn't seem any sillier than flying there in a space ship but maybe by that point we'll have created a big enough beacon fire to get some help .




All just imo of course...


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## Anthony G Williams

I agree about the desirability of establishing self-sustaining colonies elsewhere in case some disaster (natural or man-made) strikes the Earth, but that's an entirely different issue from solving our population problems by shipping people to another planet. As Quokka says, the numbers are too large (not just of people, but in terms of distances to be travelled). 

The Earth's population is currently 7 billion. It will almost certainly rise to 9-10 billion by the middle of this century (simply because there are so many children who will inevitably have children of their own) but after that, no-one knows. The UN's current "low" estimate by 2100 is 6 billion, their "high" estimate is 15 billion. We can control our population by the decisions we make, and that is what we need to do. The best approach is to provide education, contraception and economic opportunities for women in the developed world, where the numbers are rising fast. Experience shows that when women have these, they resist having large numbers of children.

Apart from anything else, the technical and human problems of sending people even to the nearest stars are so immense that they are not likely to be solved this century - let alone the vastly greater problems involved in mass emigration. So as I said, we have to solve our problems on our planet - there's no other option available to us.


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## Rob Sanders

Perhaps unrestrained breeding / overpopulation is a natural phenomenon in human beings and part of the biological forces that push our race to successfully (if sometimes immorally) expand and occupy new territories.


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## Anthony G Williams

Well, breeding's certainly natural  and any species expands as far as it can until limited by predation (no longer a worry for humans - except by other humans, of course) or disease, or lack of natural resources.

However, in many countries in the developed world, the birthrate has dropped well below the replacement level of an average of 2.1 children per woman. It's the developing world which still has rapid growth. So as the developing world becomes more developed, their birthrates ought to drop.


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## Rob Sanders

Anthony, do you think it a sign of a 'developed' culture that it controls its birth rate? : )


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## TL Rese

i'm not talking about short-term solutions to population problems - but if we are expanding in numbers, then it seems in our favor to colonize other planets in the coming centuries (plural), rather than having all that population concentrated in one area (ie. earth).  but population may not keep increasing at the same rate - people are having smaller families now than back in the day, and many choosing not to have kids at all.  "education, contraception and economic opportunities for women in the developed world" are definitely good short-term solutions, but we should definitely also be looking long-term into space colonization for a variety of reasons - even something small, like the recent manned mars simulation, could prove to be v. useful in the long run.

"the numbers are too large (not just of people, but in terms of distances to be travelled)." - shipping people vast distances in giant numbers is not beyond the realm of possibility. - of course, not tomorrow, but in the next few centuries (again, plural).  today, the airline industry transports Millions of people every day around the world in a matter of hours.  this would have been completely inconceivable to people living 500yrs ago, back in christopher columbus' time, when it took months just to putter across the atlantic - when they didn't even kno the americas existed and when the size of the earth was even in question.  if you had suggested airplanes or walking on the moon to these people, they would have laughed in your face.  in the same way, the coming centuries can bring similar inconceivable leaps in knowledge and technology.

anyways, i feel like i've started a tangent that's diverted the topic away from alien civilizations, so i'll stop. =P


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## Boneman

No, don't stop! This is incredibly helpful for a Utopia essay I've got to do!! And although 200,000 arrive every day, how many depart? 

If you leave it, 'Nature' will take care of it - any over-population of a species eventually runs out of enough food to supply them all, and the weakest and the least able die, and the fittest/strongest continue. The problem is, man's superior ( I use that term advisedly) intelligence now means those 'most able' to survive, doesn't mean the 'best'. 

We know there's a problem with population, but we do nothing about it. Somewhere down the line famine will reduce the population for us, it's inevitable. Food wars and disease will have a hand in it, of course. Trying to leave the planet in sufficient numbers won't happen before that occurs. It's whether they learn anything from it... or repeat it in another few centuries. 

Can you imagine the scenario when mankind arrives on an Alien planet and tells the indiginous population why we've come? Causae belli at its simplest. The collective responsibility for humanity rests with humanity alone.


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## Anthony G Williams

Rob Sanders said:


> Anthony, do you think it a sign of a 'developed' culture that it controls its birth rate? : )


 
Only the Chinese do that (with their "one-child" policy). Everywhere else, women make their own decisions about the number of children they're going to have, based on their circumstances and opportunities. Overwhelmingly, they choose to have few (or no) children when they can.

This is a long-term trend, not a short-term fix - provided of course that some huge spanner isn't thrown in the human works by some major disaster (in which case the population will drop anyway). The problem is that we have a huge population bulge to absorb during this century.


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## Anthony G Williams

Boneman said:


> And although 200,000 arrive every day, how many depart?


200,000 is the *net* increase - what's left after you've subtracted the deaths from the births.

Google for the Wiki article on population growth.


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## J-Sun

Anthony G Williams said:


> I agree about the desirability of establishing self-sustaining colonies elsewhere in case some disaster (natural or man-made) strikes the Earth, but that's an entirely different issue from solving our population problems by shipping people to another planet.



Okay, I got ya. We're in complete accord then. Some people who say "[w]e're going to have to solve the Earth's problems on Earth" mean "cut all space research funding because it's useless" which I don't agree with. And I do think advances in scientific knowledge of whatever kind may be helpful even if the immediate applicability isn't apparent. But I also agree that actual space emigration is not an overpopulation solution, so far as we can project it now.

I will say that if you could imagine some anti-grav space-drive forcefield magic being invented and placed in every car, plane, train, and ship and all of them whizzing off to other stars instantly, it would work wonders for the population.  But constructing a Mars survey ship at the cost of billions of dollars that carries a crew of a dozen or so - or even any reasonable extrapolation, such as a fleet of a dozen which carry a couple hundred people - is obviously useless in terms of reducing Earth's population.

-- In fact, while some of the discussion hits on it, one of the problems with population reduction measures is that, insofar as they work, they fail. If you reduce population pressures by some measure people will tend to breed more and cancel it out - any reduction in pressure means a comparative vacuum to fill. Like was basically said - population tends to increase until war, plague and famine say otherwise.


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## TL Rese

J-Sun said:


> Some people who say "[w]e're going to have to solve the Earth's problems on Earth" mean "cut all space research funding because it's useless" which I don't agree with. And I do think advances in scientific knowledge of whatever kind may be helpful even if the immediate applicability isn't apparent.


 
yup, i definitely agree with this - we cannot just focus on earth.  

as for population, as has been said, it'll likely only expand as far as natural resources, etc. allows - but i think it's difficult for us to project what life would be like centuries from now.  if population growth slows (which i think is likely, given the current trend of smaller families and the popularity of contraception) AND there is immigration en masse to other planets, then conceivably space colonization will help earth's population.  it's definitely better than just staying on earth and encouraging people not to breed.  

think about it - if our ancient ancestors had never left africa, then it would be a very crowded continent w/ all 7 billion of us on there.  of course, that likely wouldn't happen, due to famine, disease, war - but that's far from a favorable scenario.  throughout history, the human species have grown in numbers and spread out - we're the only species to have colonized every corner of the globe.  space is the only logical next frontier.  

as for natural selection, if you are here, then nature has selected you.  humans are just another part of nature, even tho we tend to think of ourselves as somehow magically apart from nature.  anthropologists even think that one of the keys to our species' success is our expanding population - you kno what they say, "two heads are better than one", or in our case, "billions of heads".

- sorry for the slow reply, btw - usual excuse, life, bills, work, and all.


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## Anthony G Williams

TL Rese said:


> think about it - if our ancient ancestors had never left africa, then it would be a very crowded continent w/ all 7 billion of us on there. of course, that likely wouldn't happen, due to famine, disease, war - but that's far from a favorable scenario. throughout history, the human species have grown in numbers and spread out - we're the only species to have colonized every corner of the globe. space is the only logical next frontier.


 
But the rest of the world was not colonised by large numbers of people leaving Africa - small numbers left and spread out over the globe, then bred in their new locations. 

If Africa had been the only land mass on Earth, then its population would probably be more or less what it is now - limited by resources. 

So if we do end up in a few millennia with billions of humans living on other planets, you can be pretty certain that it won't be because billions travelled from Earth - it will be because small numbers travelled and then bred on the new planets.


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## TL Rese

well, obviously, back then they were travelling on foot out of africa.  w/ space colonization, it'll most likely be a "few" numbers at first, but at the pace things move nowadays, it'll quickly catch on.  if we already have the ability to move millions of people around the world daily pretty much effortlessly today, then in 500yrs or so, who knows?


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## Anthony G Williams

Travelling on foot out of Africa is an absolute doddle compared with travelling between the stars in any foreseeable future.

Mass migration would only become feasible if something like "stargates" could be established to allow people to step from one planet to another. But that is fantasy rather than science fiction since there is no way that even the most way-out physicists can conceive that it might be even theoretically possible. But still, I notice that you're a fantasy writer so there's no reason why you shouldn't use the idea!


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## TL Rese

i think the first satellite to be colonized would be the moon, which obviously does not need a stargate teleportation device to reach.


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## Anthony G Williams

It would be immensely difficult (as well as incredibly expensive) to establish a self-sustaining colony on the Moon. Note the "self-sustaining" bit - they would have to generate all of their own air, water and food, plus have all of the facilities needed to equip, maintain and extend their sealed habitat. It would always be vulnerable to disasters like a minor asteroid strike, against which it has no atmosphere to provide protection. The same applies to any other colonies which are not sited on a human-friendly planet.

It we just need more living space it would be vastly easier to colonise the Antarctic, where the air and water come for free, temperatures are much warmer and transport is a miniscule fraction of the cost.


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## TL Rese

like i said:


TL Rese said:


> today, the airline industry transports Millions of people every day around the world in a matter of hours. this would have been completely inconceivable to people living 500yrs ago, back in christopher columbus' time, when it took months just to putter across the atlantic - when they didn't even kno the americas existed and when the size of the earth was even in question. if you had suggested airplanes or walking on the moon to these people, they would have laughed in your face. in the same way, the coming centuries can bring similar inconceivable leaps in knowledge and technology.


 
maybe the antarctic will be colonized at some point - i'm not saying it won't be - but if our species is still around in a few centuries, we will most likely have the means to colonize space.  just because it seems impossible/difficult now doesn't mean it will be in the far future.  and i think it'll be unlikely that a colony will be "self-sustaining", given the interconnectedness of everything nowadays.  even back in american colonial times, we still had trade w/ britain.


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## Anthony G Williams

If the principal reason for establishing a colony off Earth is to provide a back-up in case a giant asteroid strike or something wipes us out, then by definition the colony *has* to be self-sustaining.

It is by no means a given that human science and technology will continue to develop. Our society is very interconnected, as you note, but that brings its own vulnerabilities. A lethal and highly contagious disease could spread around the world extremely quickly (especially if it has a long incubation time). If people stopped turning up to work for fear of catching the disease this could rapidly cause the progressive collapse of our society. Other possible causes of disaster might be a serious (but not extinction-level) asteroid strike, or simply huge shifts in the global climate caused by a runaway greenhouse effect. Any of these could shatter our fragile interdependence and lead to a death toll in the billions.

If anything like this happened, while humanity might survive it, the technology level would probably be much lower. Just think about what it takes to make the PC on your desk - the rare minerals mined from all over the world, the sophisticated chip production techniques concentrated in very few factories in other countries, and so on. Making that computer involves a high technology functioning via a complex international web. Break that web and how do we make computers? 

Furthermore, once we lose our advanced technology we can probably never regain it (at least not in its present form). All of the easily obtainable minerals and fuels have already been mined out. To get at the rest we need very high-tech methods (e.g. deep ocean drilling for oil). So without that technology we couldn't get at them...a post-catastrophe human civilisation would probably have to be based on wood, not metal!


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## TL Rese

well, it depends on what you mean by "self-sustaining".  our world is currently very interconnected, but if, let's say... china disappeared tomorrow, then yea, we'll go thru a difficult period re-adjusting our business structures, etc. but we'll eventually recover.  we most likely won't go extinct.  it'll be the same principle w/ space colonization.

anyways, i think space colonization is an interesting topic, so i'm gonna open this up on an exclusive thread.  as soon as i figure out how to link to this thread...


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## Vertigo

Did anyone see the program on BBC 4 tonight: The Search for Life: The Drake equation. I'm pretty sure it was a repeat (first shown in 2010) but this was the first time I've seen it and I was pretty impressed by the relatively balanced view; largely echoing many of our comments here. If you've not seen it then I'm sure it will be avilable on iPlayer or for those outside the UK it is probably available on the web somewhere.


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