The science behind the probability of extraterrestrials

[MrFun]

[MrFun]

hmmm . . . . . .


my equipment is not picking up any wave signals from UR's location

[Urban Ranger]

Originally posted by MrFun
Well if you don't like that link UR, then check out any of the others provided in this thread.


Or google to your heart's content.

Thanks for the link. My question is, have you read the fine article? Here is a quote from page 3:

The weak anthropic principle is interesting and unobjectionable.

So I guess you need to try again.

Furthermore, the article talks about the application of the (W)AP in Cosmology, but I am not. I am talking more along the lines of language positivism, or about the meaningfulness of statements.

[MrFun]

funny how you "forgot" to quote the important sentences after what you quoted




It qualified the one sentence that you quoted with several "buts."

[MrFun]

here is a link to a multitude of sources on extraterrestrial life

sources

[DaShi]

Originally posted by Urban Ranger


Really? Do explain why the Weak Anthropic Principle is bunk.

How rude! Mr. Fun, I don't see why you even bother explaining it to him. He won't give you the same courtesy. Just tell him he's wrong and watch him flounder.

[Urban Ranger]

Originally posted by MrFun
funny how you "forgot" to quote the important sentences after what you quoted

So? The WAP is not a scientific principle.

[Ramo]

It's all bull****. I don't think anyone has a half-way decent estimate for the probability of life arising.

[Flandrien]

For billions of years, the only life on earth was strictly bacterial, so when we find life on other planets, chance is high that it will be bacterial only as well.

Originally posted by Boris Godunov
Or the nearest inhabited world is 10,000 light years away?

My guess would be something like that as well.

On a side note, what would a civilisation that is a few million years more advanced than us look like ?

[Boris Godunov]

Originally posted by Drake Tungsten

I think the problem is your failing to comprehend basic words...

Yes, because we all know that context is not important to interpretation at all. I'm sure he really meant that human life isn't possible...

Did you see his follow-up?

You seem to be the one putting words in his mouth, not I. Sorry if I took what he said to be what he meant. I think the "context" of someone saying something is "impossible" is pretty damned clear...

The anthropic principal is a load of ****. Bringing it up carries about as much weight as claiming god created everything.

Funny how what you linked to on wikipedia actually refutes Dissident. At any rate, the anthropic principle is used by IDists exactly the way Diss was, which was why I mentioned it. From Wikipedia:

"Proponents of the intelligent design conjecture assert support from the anthropic principle."

My point was that Diss was engaging in extreme Anthropic bias.

There are varying applications of the AP, some valid, some clearly not. And the Cosmological AP is hotly debated, but has by no means been shown to be "bunk."

[reds4ever]

Originally posted by Ramo
It's all bull****. I don't think anyone has a half-way decent estimate for the probability of life arising.

Could n't have put it better myself!

[lord of the mark]

the book "The Rare Earth Hypothesis" had an interesting discussion of the Drake equation and its implicit simplifications. Forex, the Drake eq assumes that a planet is either in an inhabitible zone or its not. It says nothing about how long the zone stays habitable. The authors discuss why evolution to intelligence is likely (though this cant be proven, and of course we have only one data point) to a long time, and how many things can CHANGE in a star system and its neighborhood during that period that could lead to mass extinction events, which could either kill off all life, or kill off everything thats evolving in the direction of intelligence, and thus reset the clock to zero. Their conclusion is that intelligent life is extremely rare - probably arising no more than a few times in a galaxy the size of the Milky Way.

OTOH they suggest that one celled life is probably quite common, based on recent discoveries of extremophile bacteria.

[Boris Godunov]

Yeah, I read that we happen to be in a relatively stable, safe portion of the galaxy that is not subject to the turmoil that most parts are. For one thing, most areas are subject to a lot more asteroid/comet activity, which makes the presence of a life-bearing planet a more hazardous proposition.

[Dauphin]

Originally posted by Ramo
It's all bull****. I don't think anyone has a half-way decent estimate for the probability of life arising.

I disagree, I estimate it to be somewhere between 0 and 1 inclusive.

Oh right, you meant meaningful estimate....

[Dauphin]

Originally posted by Boris Godunov
Yeah, I read that we happen to be in a relatively stable, safe portion of the galaxy that is not subject to the turmoil that most parts are. For one thing, most areas are subject to a lot more asteroid/comet activity, which makes the presence of a life-bearing planet a more hazardous proposition.

Comet activity has been suggested as a seeding for life though (extreme case being panspermia, not so extreme being just the provision of raw materials for life), so increased activity could lead to a peak of life bearing planets before it becomes overly destructive.

I make no comment on the accuracy of the said theory of panspermia though.