The Search for Extraterrestrial Life: Are we Going About It Wrong?

[Ultimate Paragon]

You know, I've been thinking.  In the search for life in outer space, why are we assuming they'd fit in on Earth?  For all we know, the rules of life on other planets could be completely different.  Even on Earth, we have bacteria that hate oxygen, and deep sea organisms that don't rely on the Sun for anything.  For all we know, life on other planets could breathe sulfur and drink mercury.

Any thoughts?

[Katsuro]

I thought they only prerequisit scientists used for where life is likely to be is wherever water is, due to the fact that seems to be the only common connecting feature of life on Earth - the need for water. Even where there appears to be none; I seem to remember a documentary talking about a species of bacteria that is able to get water from rocks, as mental as that sounds.

But anyway, I'm guessing the main reason is because, due to the vastness of space, they have to narrow the search down somehow and this is as good a palce to start as any, ie places that have the same conditions as other places we know for certain life exists.  You have to start somewhere.  Once we eliminate the places that have the conditions deemed more likely to contain life as we know it we can then move on to the other palces that, if they had life, contain life in a form that we do not know about and therefore cannot reasonably predict.

So basically, it's coz we know life can exist in certain conditions so it makes more logical sense to start the search where those conditions are met and where we know that life definately could exist rather than in places where we've no idea if it's even possible for life to exist there.

[mellenORL]

I thought at first this would be about SETI.

But yes, the more we learn about "extreme-ophile" life forms here, the more likely it is that life elsewhere is various and versatile.

But, about SETI, anyway, maybe we have not found evidence of intelligent life yet because of the deep time factor; perhaps sentient life capable of technology does not develop all that often, does not last all that long...and within context of a 13 billion year old universe, perhaps we have just missed 'em, or happen to be isolated by enough space time distance that we won't know of extant ET's.

[Askold]

I think that the main reason scientists look for earthlike-conditions and similar signs of life is that they know the signs that earthlike life has.

There might be planets with intellegent weather patterns or energy creatures or something but it is pretty difficult to know what kind of telltale signs a truly alien form of life would have. On the other hand, methane for example is produced by animals on earth so signs of methane is a pretty good chance of earthlike life.

[Random Gal]

I thought they only prerequisit scientists used for where life is likely to be is wherever water is, due to the fact that seems to be the only common connecting feature of life on Earth - the need for water. Even where there appears to be none; I seem to remember a documentary talking about a species of bacteria that is able to get water from rocks, as mental as that sounds.

Even liquid water is not necessarily a requirement for life. Just because it's common to life on Earth, that's no guarantee another kind of life doesn't exist elsewhere.

Before we can really search for alien life, we first need to know what "life" really means, and that's a lot harder than it might sound.

[Katsuro]

I thought they only prerequisit scientists used for where life is likely to be is wherever water is, due to the fact that seems to be the only common connecting feature of life on Earth - the need for water. Even where there appears to be none; I seem to remember a documentary talking about a species of bacteria that is able to get water from rocks, as mental as that sounds.

Even liquid water is not necessarily a requirement for life. Just because it's common to life on Earth, that's no guarantee another kind of life doesn't exist elsewhere.

That's not what I said.  I said I thought it was the only prequisit scientists use for looking for places to start looking for life as they now know everything else is definately irrelevant (which has actually widened their search criteria by quite a lot).

I never said it's a requirment for life, I said it's a requirment scientists use to pick places they think are good places to start looking; you have to start with what you know can happen before moving to what you don't know might happen, that's how logic and sanity work.  When you lose something in your house the first places you look are where you know for sure you've had it before, not where you could have had it before but you don't really know for certain.  You move on to those places once the search in the first category of places is unsuccessful.  And you don't start searching by just going from one random point to the next, unless you're panicking.  When I'm ging out and need my shoes I don't start my off by looking for them in oven, even though there is a small chance they could be there as I don't live alone and someone could be playing silly buggers.

I never said there is zero chance life could exist without water and there's any guarantee that another kind of life doesn't exist elsewhere.

[Random Gal]

I thought they only prerequisit scientists used for where life is likely to be is wherever water is, due to the fact that seems to be the only common connecting feature of life on Earth - the need for water. Even where there appears to be none; I seem to remember a documentary talking about a species of bacteria that is able to get water from rocks, as mental as that sounds.

Even liquid water is not necessarily a requirement for life. Just because it's common to life on Earth, that's no guarantee another kind of life doesn't exist elsewhere.

That's not what I said.  I said I thought it was the only prequisit scientists use for looking for places to start looking for life as they now know everything else is definately irrelevant (which has actually widened their search criteria by quite a lot).

I never said it's a requirment for life, I said it's a requirment scientists use to pick places they think are good places to start looking; you have to start with what you know can happen before moving to what you don't know might happen, that's how logic and sanity work.  When you lose something in your house the first places you look are where you know for sure you've had it before, not where you could have had it before but you don't really know for certain.  You move on to those places once the search in the first category of places is unsuccessful.  And you don't start searching by just going from one random point to the next, unless you're panicking.  When I'm ging out and need my shoes I don't start my off by looking for them in oven, even though there is a small chance they could be there as I don't live alone and someone could be playing silly buggers.

I never said there is zero chance life could exist without water and there's any guarantee that another kind of life doesn't exist elsewhere.

Sorry, I must have misinterpreted your post.

[Old Viking]

Aliens could be very human-like in appearance.  You know, like Republicans.

[Vypernight]

Aliens could be very human-like in appearance.  You know, like Republicans.

Or it could be something less evil, like Cthulhu.