Fermi was Jedi. Sagan was Sith.

[N C More]

From the SETI Institute link, part III:

It’s all a bit perplexing, but in fact there’s hope. SETI experiments offer the promise of relegating the Fermi Paradox to the dustbin of historical curiosities by proving that other intelligence is out there. So while it’s interesting and instructive to consider the pros and cons of galactic colonization, we should also make sure that we do some careful observing. In science, speculation is desirable, but experiment is definitive.

I don't think SETI "agrees" with you.

[Van Rijn]

Van Rijn,

Liquid water cannot exist alone in space. Do you really think it is possible that it is in abundance?

We simply do not have the ability to determine, yet, how common worlds with liquid water are in the galaxy.

I will leave your other comments alone because they speak for themself.

One good thing that I draw from my early years as a portrait artist was the habit of studying the subject matter before putting pencil to paper. I have to wonder if others could benefit from such a practice.

I have to agree, to both statements.

Apart from the point about Fermi, the list is intended to answer the "why" we are seemingly alone not "if" we are seemingly alone.

A list of assumptions, not facts.

Fermi's Observation clearly answered the "if".

"Why" it is true is just a matter of being accademic and searching.

Fermi asked a question. Reportedly, he also said we didn't know enough to be able to come to a conclusion.

The only way we can come to any conclusion is to gather evidence.

Like I said, I am suprised you put so much energies into that list. There is no point in trying to disprove something that is simply true.

And that's your problem: This isn't science for you, it is religion. For you, it is "simply true." Evidence, or lack of it, is irrelevent.

And since the SETI Institute agrees with my position, with whom are you arguing against?

I argue against anyone who makes assumptions without the evidence to back it up. I don't care if they assume ET does or doesn't exist.

[Van Rijn]

Also, let me ask you something: How exactly can life not exist in a binary star system? I'm curious.

I suspect he is talking about planet formation models and possible orbital stability issues. However, we don't have enough information to draw conclusions. It is, therefore, an assumption. We are seeing planets in multiple star systems, and planets could have stable orbits as long as the other star(s) aren't too close. You might find this pdf file interesting:

http://planetquest1.jpl.nasa.gov/TPF...sters/p047.pdf

Real answers will have to wait until we have much better planet detection capability.

[SolusLupus]

This episode of Troops clearly shows that there is life in other galaxies. But we are talking about our own right now.

A humorous sidetrack or a sign of impending insanity?

[Wolverine]

That's a large file, and it's polite to inform users of such, as not everyone has broadband at their disposal. I've edited the post to reflect such and issued a similar caveat here. Saw the other thread before seeing the above post.

[William_Thompson]

It is not a matter of what is "good" to believe in vs. what is "bad" to believe in. This is not how we should define "truth".

It is a matter of what is tangable and not tangable. We are alone for all practical purposes simply because noone is around. They mean the same thing.

Using excuses like, "we have not looked long enough" does not work. Fermi knew this.

Asking me to "prove" it is absurd for two reasons. First, because you cannot prove a negative. In fact, many of your comments illustrate this. Secondly, there is no need to prove something that is self evident.

[William_Thompson]

A humorous sidetrack or a sign of impending insanity?

Ad Hominin.

[N C More]

I'm going to try another approach to this, a very simple one.

Since we have yet to do a thorough search of the galaxy, there's no way we can definitively say that there are, or that there are not other advanced life forms in the galaxy. If one hasn't actually looked, one can't come to any conclusion...it doesn't matter one iota what one believes.

[Wolverine]

Ad Hominin.

For the record, it's ad hominem. I don't think Lonewulf's comment was any more serious than yours suggesting that the TROOPS video constitutes evidence of life in other galaxies.

[SolusLupus]

...I mean, you weren't serious about that, were you, Thompson? I'd be worried if you were serious about the video being considered evidence o_O

I meant the argument was growing insane, I wasn't suggesting you yourself were insane.

[Van Rijn]

Using excuses like, "we have not looked long enough" does not work. Fermi knew this.

Reportedly, Fermi didn't know this. That is, he apparently said we didn't have enough information to come to a conclusion.

Asking me to "prove" it is absurd for two reasons. First, because you cannot prove a negative. In fact, many of your comments illustrate this. Secondly, there is no need to prove something that is self evident.

I certainly didn't ask you to prove anything. The issue is that you keep bringing forward assertions with a distinct lack of solid evidence, then say these assertions support your position.

[Van Rijn]

Since we have yet to do a thorough search of the galaxy, there's no way we can definitively say that there are, or that there are not other advanced life forms in the galaxy. If one hasn't actually looked, one can't come to any conclusion...it doesn't matter one iota what one believes.

I would agree with this, except that it isn't so much that we haven't made a "thorough search of the galaxy" as "we've barely begun making a search of our galaxy."

We don't know how hard it is for life to start.

We have no idea how common life could be.

We are only familiar with earth life, but chemistry is complex, there very well could be other forms.

We don't know what kind of environments life could inhabit, we can only guess, based on earth life.

We are just beginning to detect planets in other solar systems, and this has already upset speculations of what we thought we might find.

We don't know how many solar systems might have life.

We don't even know if there is other life in our solar system.

We don't know how many solar systems might have technological life.

We don't know what technological life might do, we can only guess based on what we have done so far.

If there are ET civilizations, we don't know how they would develop.

As far as that goes, we don't know how we will develop.

We know almost nothing about the issues involved in interstellar migration. We're like Babbage discussing the fine points of supercomputer design.

We know even less about what is involved in galactic colonization.

We could only detect a hypothetical spacefaring species if:

(a) They came here (to our solar system), are still here, and if they were obvious enough to detect.

(b) They sent detectable signals in our direction at the time we were listening, and we correctly identified the signal.

(c) They build megastructures that are so grand as to be obvious at interstellar distances. (Note that it is thought that we still haven't found half of the nearby stars - it takes a lot to be obvious at these distances.)

I've left a lot of "don't knows" off the list. The long and short of it is we don't know. It is all too easy to assume we have more information that we do.

[Halcyon Dayz]

I like the percolation idea as a solution to the paradox.
Basically it says that cultures mutate, and that an expansionist
civilisation will, over time, inevitably mutate in a non-expansionist one.
Only parts of the galaxy get colonised.

[Wolverine]

Excellent post, Van Rijn.

[SolusLupus]

Excellent post, Van Rijn.

I duly and whole-heartedly agree.

[Chip]

Excellent post, Van Rijn.

I’d like to add that this list of what we don’t know need not be discouraging. In fact, the many questions of what we don’t know in this, (and other topics,) indeed prompts and encourages more observation, experiment, exploration and imagination. If just one unknown is uncovered, it opens new questions and further possibilities. It’s what makes science, (and astronomy,) exciting – and this applies to all the other speculative borders surrounding the seemingly more conventional fields within physics, biology, astronomy and other sciences.

[William_Thompson]

Let me see if I am getting this right.

You are assuming that when I was excited about SETI as well as the SETI @ HOME project, I was correct and intelligent and right thinking and all that stuff.

And when, after a lot of study and thought, I changed my mind about ETI and the likelihood of making contact, I somehow became less informed and incorrect?

Are you also saying that my co-workers in silicon valley whom I also convinced to my way of thinking, I somehow brainwashed into my less correct way of thinking?

[N C More]

Let me see if I am getting this right.

You are assuming that when I was excited about SETI as well as the SETI @ HOME project, I was correct and intelligent and right thinking and all that stuff.

Well, considering all of the "we don't knows" contained in Van Rign's previous post, yeah, I'd say that investigating as best we can (until we can answer some of the "we don't knows") is "right" thinking.

And when, after a lot of study and thought, I changed my mind about ETI and the likelihood of making contact, I somehow became less informed and incorrect?

Study and thought are great, but without the observational data (the ability to explore the galaxy) we still come up with quite a few of those "we don't knows".

Are you also saying that my co-workers in silicon valley whom I also convinced to my way of thinking, I somehow brainwashed into my less correct way of thinking?

Appeal to Popularity. I guess some people just don't care for the "we don't knows" and will choose an answer based on belief, rather than waiting until we can obtain the evidence.

[SolusLupus]

Appeal to Popularity. I guess some people just don't care for the "we don't knows" and will choose an answer based on belief, rather than waiting until we can obtain the evidence.

Right, choosing an answer based on belief -- rather than waiting to obtain evidence -- is something that is, quite frankly, incredibly common (TOO common, if you ask me)

[Van Rijn]

Excellent post, Van Rijn.

Thanks for the feedback! I'm glad folks liked the post.

[Hugh Jass]

Let me see if I am getting this right.

You are assuming that when I was excited about SETI as well as the SETI @ HOME project, I was correct and intelligent and right thinking and all that stuff.

And when, after a lot of study and thought, I changed my mind about ETI and the likelihood of making contact, I somehow became less informed and incorrect?

Are you also saying that my co-workers in silicon valley whom I also convinced to my way of thinking, I somehow brainwashed into my less correct way of thinking?

Not at all what everyone is saying is calling Sagan evil and everyone who doesn't agree with your stand point wrong, is wrong.
Personally I think you are interpreting Fermi incorrectly and contradicting your own statement. We are apparently alone. Well yes, as was some random tribe of natives in the Amazon. We don't see anyone else in the galaxy so for all intents and purposes we are alone. They didn't see anyone other than their small tribe so they were for all intents and purposes alone.

Jumping one step further and saying there is absolutely no possible way any other intelligent life exists in the galaxy, and no possibility of ever finding evidence of any, is an illogical conclusion.

Its an opinion, you are fee to have an opinion but why force it on others when the question is so obviously still up in the air?

[UBorba]

If there is a purpose to the Universe it is NOT to produce and support Life.
It is very much in the nature of Nature to leave us out here alone without a neighbor within sight or knowing.

Who knows? We're just begining to search.

[Gullible Jones]

Ye gods, how much longer will this stupid, pointless thread go on? It was ripe for locking days ago.

Look, William_Thompson, why can't you take we don't know for an answer? It's the only answer we've got... So I don't see the problem with trying to find out a little more, rather than making blind assumptions!

[agingjb]

I'd have to say that I find it hard to follow the reasoning behind the suggestion that the SETI program is so certain not to produce results that it should therefore be abandoned. In any case, whether or not SETI discovers cultures analogous to modern humanity, it is, as with any sustained program of observation, likely to turn up something unexpected.

[Wolverine]

Personally I think you are interpreting Fermi incorrectly and contradicting your own statement. We are apparently alone. Well yes, as was some random tribe of natives in the Amazon. We don't see anyone else in the galaxy so for all intents and purposes we are alone. They didn't see anyone other than their small tribe so they were for all intents and purposes alone.

Jumping one step further and saying there is absolutely no possible way any other intelligent life exists in the galaxy, and no possibility of ever finding evidence of any, is an illogical conclusion.

Its an opinion, you are fee to have an opinion but why force it on others when the question is so obviously still up in the air?

(Emphasis mine.)

An excellent summation.

[Wolverine]

Ye gods, how much longer will this stupid, pointless thread go on? It was ripe for locking days ago.

Easy now. It would be appreciated if you'd contact one of the forum staff should you have concerns about a given topic, discussion, or post instead of venting your frustration in such a manner. Such comments can unduly exacerbate the situation.

[HenrikOlsen]

Right, choosing an answer based on belief -- rather than waiting to obtain evidence -- is something that is, quite frankly, incredibly common (TOO common, if you ask me)

Partially hardwired survival strategy.
Hear a noise, guess it's a lion and run => you survive. Even if it was a hyena, or a mouse.
Hear a noise, wait to obtain enough evidence to know what it is => you're dinner, unless it's a mouse.
Guess which type of mind is selected for.

[Lance]

Partially hardwired survival strategy.
Hear a noise, guess it's a lion and run => you survive. Even if it was a hyena, or a mouse.
Hear a noise, wait to obtain enough evidence to know what it is => you're dinner, unless it's a mouse.
Guess which type of mind is selected for.

Brilliant! Absolutely brilliant!

[SolusLupus]

Partially hardwired survival strategy.
Hear a noise, guess it's a lion and run => you survive. Even if it was a hyena, or a mouse.
Hear a noise, wait to obtain enough evidence to know what it is => you're dinner, unless it's a mouse.
Guess which type of mind is selected for.

That's strange. When I watch the nature channel, when prey species hear a noise, they look up and make sure they know what it is before they do anything. And predator species are a bit different. They can fight back.

But eh, maybe you're right. Would explain why people assume that alien civilizations are either nonexistant or totally, completely, irrevocably evil and will kill us all.

[Gullible Jones]

Prey can fight back too. Ever seen lions vs. water buffalo? Them's some sharp, nasty horns. Being a predator is very dangerous business.