Expectation of extraterrestrial life

[Von Bismarck]

Recent discoveries of planets similar to Earth in size and proximity to the planets' respective suns have sparked scientific and public excitement about the possibility of also finding Earth-like life on those worlds.

But Princeton University researchers have found that the expectation that life — from bacteria to sentient beings — has or will develop on other planets as on Earth might be based more on optimism than scientific evidence.

Princeton astrophysical sciences professor Edwin Turner and David Spiegel, a former Princeton postdoctoral researcher, analyzed what is known about the likelihood of life on other planets in an effort to separate the facts from the mere expectation that life exists outside of Earth. The researchers used a Bayesian analysis — which weighs how much of a scientific conclusion stems from actual data and how much comes from the prior assumptions of the scientist — to determine the probability of extraterrestrial life once the influence of these presumptions is minimized.

Expectation of extraterrestrial life built more on optimism than evidence, study finds

[bison]

I read the linked article through. The argument of the scientists strikes me as weak. To get to a position that advanced life in space is rare, one must assume that Earth is not typical; that we occupy a 'special' place in cosmos. Such thinking was common in the past, at various times, and in different forms. The Earth was once held to be at the center of the universe, and the only world to exist. Later we placed ourselves at the hub of the solar system, with even the Sun revolving around us. Still later , it was assumed that our solar system stood at the center of the galaxy. Not that long ago, it was seriously suggested that planet formation was a fluke, and would very seldom occur at other stars. In each instance, improvements in knowledge destroyed the former conviction of uniqueness, Today, the contrary position, that we are, on this planet, quite a typical example of what the universe holds in abundance, is close to being a scientific working principle. It's called ' Non-uniqueness of viewpoint'.

[Space Commander Travis]

How can these people possibly draw any conclusions that satisfy their rigorous scientific criteria if they only have a sample of one to go on? That surely is unscientific in itself?

"In fact, the researchers conclude, the current knowledge about life on other planets suggests that it's very possible that Earth is a cosmic aberration where life took shape unusually fast. If so, then the chances of the average terrestrial planet hosting life would be low."

What? We have no current knowledge about life on other planets, so surely it's arrant nonsense to draw that conclusion from it. It may be possible, but it's no more possible than any other conclusion.

"Fossil evidence suggests that life began very early in Earth's history and that has led people to determine that life might be quite common in the universe because it happened so quickly here, but the knowledge about life on Earth simply doesn't reveal much about the actual probability of life on other planets," Turner said.

Well, exactly, until we have a decent sized sample to compare it with, i don't see how they can possibly draw any conclusions. It all seems decidedly unscientific to me.

[spud the mackem]

If the rock had not hit us wiping out the nasty dinosaurs we would not be here anyway as we would have made nice snacks for them..

[DONTEATUS]

How can these people possibly draw any conclusions that satisfy their rigorous scientific criteria if they only have a sample of one to go on? That surely is unscientific in itself?

"In fact, the researchers conclude, the current knowledge about life on other planets suggests that it's very possible that Earth is a cosmic aberration where life took shape unusually fast. If so, then the chances of the average terrestrial planet hosting life would be low."

What? We have no current knowledge about life on other planets, so surely it's arrant nonsense to draw that conclusion from it. It may be possible, but it's no more possible than any other conclusion.

"Fossil evidence suggests that life began very early in Earth's history and that has led people to determine that life might be quite common in the universe because it happened so quickly here, but the knowledge about life on Earth simply doesn't reveal much about the actual probability of life on other planets," Turner said.

Well, exactly, until we have a decent sized sample to compare it with, i don't see how they can possibly draw any conclusions. It all seems decidedly unscientific to me.

Agreed 747400 ! THe big thing with me and my way of tinking,Is We dont even know just how many planets like earth are out there. going on the assumptions of thisscientific criteria,and the so called rigorous studys made by our leading Wiz-bangs brain-iac`s. This would put the possibility ofTrillions upon Trillions of Earth Like Planets ! remember We dont know the size. and from where I stand, I will bet we may never know the size !

Its like we expand until we keep expanding. Until we never quit expanding. As the planets and stars keep making more and more of this so called star stuff.

Now If we take only ooooo.ooooooo1eth of a % and place all our hopes on a intelligent being to evolved upon it ! THen were still talking Millions of Life bearing Planets !

So ! What`s ya gonna do when they come for you ? THe way I see it We need not worry ! BEcause space is so Big,and Expanding we are it ! But it makes for great talk,movies, stories, Dream time !

See yaz !

[keninsc]

Well, let's assume that we do make contact with a highly technologically advanced civilization......just for giggles.

It's reasonable to assume they aren't going to just start handing over technology without some sort of equivalent exchange........what would we have that we can trade for it? No one gets something for nothing and no one gives something for nothing, there's always a catch. If they have a technology that can traverse the stars then what could we possibly have that they could want?

[Ashotep]

I find it hard to believe we are the only ones in this vast universe. There's probably life forms out there far more advanced than we are. I think they have been here. If there are no other intelligent life forms out there then does that mean God created man.

[Englishgent]

Well, let's assume that we do make contact with a highly technologically advanced civilization......just for giggles.

It's reasonable to assume they aren't going to just start handing over technology without some sort of equivalent exchange........what would we have that we can trade for it? No one gets something for nothing and no one gives something for nothing, there's always a catch. If they have a technology that can traverse the stars then what could we possibly have that they could want?

Maybe we could give them the scientists who composed the above report. Who knows, they may have comedy shows on their planet too

[keninsc]

Maybe we could give them the scientists who composed the above report. Who knows, they may have comedy shows on their planet too

Oh Great! We'd become the Monty Pythons of the galaxy.

[S2F]

The article has a point. Life in the universe, based on observable evidence and not wishful thinking coupled with maybes, seems to be a rare occurrence. Even finding planets of similar composition and water (liquid) content to Earth are no guarantee that they have life on them. Admittedly we are only just beginning our search and the possibilities are wide of range however I think we may just be getting ahead of ourselves with regards to the probability of alien life. We need more information and more research to find the data that will point us in the right direction.

[DONTEATUS]

Well, let's assume that we do make contact with a highly technologically advanced civilization......just for giggles.

It's reasonable to assume they aren't going to just start handing over technology without some sort of equivalent exchange........what would we have that we can trade for it? No one gets something for nothing and no one gives something for nothing, there's always a catch. If they have a technology that can traverse the stars then what could we possibly have that they could want?

ITs the only thing in question? What would they want from us ? They maybe Us ! from the future,or the way-back past ! They would want to say Hello ! How Can we be best served ! WHats there fav`s Drink and music ?

THen the party will begin !

[keninsc]

ITs the only thing in question? What would they want from us ? They maybe Us ! from the future,or the way-back past ! They would want to say Hello ! How Can we be best served ! WHats there fav`s Drink and music ?

THen the party will begin !

Naaaaw, if they wanted us in that way they'd just come and take anything and anyone they wanted and there wouldn't be a damn thing we could do about it. Personally, I'm hoping for a nice, cold, long anal probing.

[Space Commander Travis]

The article has a point. Life in the universe, based on observable evidence and not wishful thinking coupled with maybes, seems to be a rare occurrence. Even finding planets of similar composition and water (liquid) content to Earth are no guarantee that they have life on them. Admittedly we are only just beginning our search and the possibilities are wide of range however I think we may just be getting ahead of ourselves with regards to the probability of alien life. We need more information and more research to find the data that will point us in the right direction.

Surely we need more information and more research to be able to say that it seems to be a rare occurrence? How can we draw that conlusion, tentative as it may be?

[S2F]

Surely we need more information and more research to be able to say that it seems to be a rare occurrence? How can we draw that conlusion, tentative as it may be?

With the qualifier of observable evidence. It is the culmination of what we have seen so far. We can guess, even take an educated stab at it with things like the Drake Equation however that won't change the evidence. That is the point, I think, of the article. To stray too far from what the evidence shows runs the risk of promoting opinion and speculation as fact. Even when you consider the Drake Equation, it is just a formula with several key components being nothing but variables at this point. It is a good starting point but without defining some of those variables with factual data then the formula is incomplete and unsolvable.

[preacherman76]

I read the linked article through. The argument of the scientists strikes me as weak. To get to a position that advanced life in space is rare, one must assume that Earth is not typical; that we occupy a 'special' place in cosmos. Such thinking was common in the past, at various times, and in different forms. The Earth was once held to be at the center of the universe, and the only world to exist. Later we placed ourselves at the hub of the solar system, with even the Sun revolving around us. Still later , it was assumed that our solar system stood at the center of the galaxy. Not that long ago, it was seriously suggested that planet formation was a fluke, and would very seldom occur at other stars. In each instance, improvements in knowledge destroyed the former conviction of uniqueness, Today, the contrary position, that we are, on this planet, quite a typical example of what the universe holds in abundance, is close to being a scientific working principle. It's called ' Non-uniqueness of viewpoint'.

Im in no way saying the earth is at the center of the universe. In fact its my argument that anyone who claims to know whether we are or are not at the center of the universe is full of it. Truth is we have no way to know our position in the universe. We have no idea where it begins, or where it ends, or if it ends, or begins at all. In order to know that, you would have to be able to see and measure the very ends of the universe in all directions. Impossible to know, or see.

To me, if life can really create its self outta raw material, then this universe must be full of life. Though we have yet to even come close to proving that is possible, so Id have to agree with the article and say at this point its wishfull thinking.