Water Not a Good Enough Guide To Find Alien Life 184
An anonymous reader noted an article in Cosmos that questions the conventional wisdom of the "follow the water" strategy of seeking extraterrestrial life, saying "There's an awful lot of places where water could exist — either on the surface of the Earth, or deep within it — yet life is largely concentrated in a small sliver of this."
Don't follow the water (Score:4, Funny)
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But without water, there's no life (as we know it) (Score:5, Insightful)
It seems to me that "follow the water" is better than seeking randomly -- if you find no water, then there can't be any life (as we know it) anyway.
Sure, if you find water, it's not a guarantee that there *is* life -- but it seems like a good way to weed out "definitely no" prospects.
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Re:But without water, there's no life (as we know (Score:5, Insightful)
Thats very possibly true (thus the appended "as we know it".) Unfortunately saying "Here are all the reasons you might be wrong" is a lot easier than determining new approaches and going out and looking, and you've got to start somewhere.
So until new evidence points us in another direction, "follow the water" is the best direction we have.
Re:But without water, there's no life (as we know (Score:5, Insightful)
I just want to reiterate what the parent said, as I'm becoming frustrated with all of the "why do we assume it can't exist if it is not like us" posts.
No one is claiming life cannot exist without water, we are only stating that life as we know it cannot. Since we have no idea what the hell we would be looking for otherwise, and since we have limited (and in the search for ET life, extremely limited) we have to determine some heuristic for our search. Since water is A) easily detected with telescopes, and B) a requirement for life as we are aware, it is so far our best means of refining our search. There may be some amazing form of X based or X requiring life out there, but since we do not know X, it is not at all helpful to acknowledge its possible existence. If, on the other hand, we happen upon X based/requiring life, we can then include X in our parameters.
Please stop assuming that this is some circa 1900AD Newtonian Physics style oversight.
Re:But without water, there's no life (as we know (Score:4, Interesting)
Well I am not saying it is impossible. But water has a lot of really unique chemical properties that makes randomly evolving life more likely. Being that it devolves a lot of chemicals, as well as it is sticky could come in handy in making life processes, Oh lets get rid of those pieces and glue these together while their bonds are week they stick together for a while then split. While silicon my have a lot of life giving properties for it to occur naturally/randomly you would need some medium to try to create random combination. Otherwise Sand/Silicon will be quite happy in sand like state.
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Ah, but you see, based on our sample size of ONE planet, we've determined the conditions for life on all planets.
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But since it's the only one we've ever found, I suppose your point more readily supports the view that we are alone in the universe.
Personally, thanks to Hawking's reasoning that's what I'm hoping for (paraphrased): There is probably life out there, but if they know where we are we're fucked.
The reasoning being that any form of life sufficiently advanced to detect us here on Earth has probably already consumed, or is close to consuming, the resources on their own home planet. Given that we will be little
Re:But without water, there's no life (as we know (Score:4, Insightful)
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Exactly, we should probably be looking for any form of liquid solvent, not just water. Of course, a completely arid and barren planet probably wouldn't have the necessary conditions for life to begin (primordial soup and all), so let's not focus there.
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It's unlikely enough to assemble genetic material (DNA/RNA on Earth) in a protective sheath (lipid bilayer here) in a liquid, how much more unlikely in a gas? It also means that unlike a small pool which could collect the necessary elements to create compounds in necessary quantities, these components disperse quickly in a gas. That same effect that would make life react quickly (chemically) once present would also reduce their likelyhood of appearing at all.
It's also possible extra-terrestrial intellige
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these components disperse quickly in a gas
in gas under sea level pressure on earth sure. not so much the case near the "surface" of a gas giant.
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Why is "a protective sheath" necessary (except for your lack of imagination) ?
There are a few reasons. First you need to understand why it is there - to control what can an cannot get in or out of the cell (for lack of a better word - without the membrane it wouldn't be a cell). If there is no membrane, all you have is chemicals which happen to be close together - there is nothing to hold them together so there is no reliable way to control reactions, so there is no life. Life is essentially just a set of self-controlling reactions which can self replicate.
The better for spreading the life to a large volume of an ecosystem, so that sparseness of "nutrition" / consumable energy, is not a problem.
That only works if the life
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Because we are talking about where we should be looking for life. While it may well be possible for "life" to exist in any place imaginable, where we look is determined by what we define as life. The only life that we know exists is carbon based and relies on water. From that we can say firmly that life can possibly exist based on a different carbon-like molecule (silicon) and/or using a different solvent. That is as far as our knowledge of chemistry allows us to extrapolate.
This is much better said than my posts. We're just talking about probability of finding life, so we should look at locations that seem the most likely to be favorable (liquid solvent, atmosphere, relatively old star, etc) first. I think it's a waste of time either way, but from a purely intellectual standpoint, it's the only way that makes sense.
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Of course, a completely arid and barren planet probably wouldn't have the necessary conditions for life to begin (primordial soup and all), so let's not focus there.
But no, absolutely bullshit. I don't have the license to generalize. At this point, you must start talking about "probability" of finding life".
Right, my quote should have had the word "likely" or "expected". The point being, if we're going to look for life we might as well focus our search on life similar to the only other life we are aware of. At least we know that life can be based on carbon and water. If it's a crap shoot anyway, might as well bet on the one we know is possible.
Though I like your "waste of time either way". It is fun only as a purely intellectual pursuit.
Yup.
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But no, you must generalize - "Not water, but any liquid solvent ... blah blah ..". Unfortunately, this "any liquid solvent" does not have a particular spectral pattern from which it is simple to figure out if the planet consists of this "any liquid solvent".
Any liquid solvent does not work. Water is unique in the universe, it has hundreds of properties that, as far as we can tell, are absolutely essential.
For just one example, think about ice. Water is one of only five substances known to be less dense as a solid than a liquid. The others are gallium, bismuth, germanium, and silicon. Now imagine what would happen if ice didn't float in water, but instead sank, like most solids do when placed in their liquid counterpart. First a crust will form, held up by
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Re:But without water, there's no life (as we know (Score:5, Informative)
If life is just an evolved entity composed of randomly assembled machines, as some biologists claim, then it begs the question of wether or not there might be 'life' out there that is not water based, but based on say, sand -- or silicon.
That is not what "begs the question" means.
http://begthequestion.info/ [begthequestion.info]
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I doubt there's very many Biologists throwing around the word 'randomly' like that, since the standard model for evolution is that Mutation is generally random, but selection IS NOT. How complex silicon compounds may get has a lot of bearing on whether selection pressure can matter. (This assumes we are much less likely to find life as it has just begun, before there has been much if any time for selection pressure to affect it - as that's an awfully small window in time compared to the duration of a biome)
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"randomly assembled machines"
There's no professional serious biologist that says that. Darwinism and evolution is NOT "we somehow spontaneously fell together".
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'Some" biologists? Like pretty much all of them.
Name one, and you better have a quote where he says it's completely random like that.
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It's life Jim, but not as we know it!
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Hehe, the "ugly bags of water" episode was one of my favorites, and very fitting for the discussion.
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Yeah, because in all of the universe, life will only exist as we know it.
That is the epic logic failure of the whole thing.
And it’s incredibly arrogant.
Another milestone on the road of
- “The white male is the only one that really can think.”
- “The earth is obviously the center of the universe.”
- “Whites are the supreme human race.”
- “Men are superior to women.”
- “Humans are the only ones with emotions.”
- “Humans are the only ones who ca
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Actually, liquid methane, and methane ice, are looking like possible life supporting alternatives. maybe.
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Methane, and Ammonia, are problematic:
Pluses:
1. They are very common, like H2O, around the observed universe.
2. The could work with a Carbon based complex chemistry, at some temperature range.
3. They have solvent properties, also like H2O - you can get many other elements suspended in solutions.
Minuses:
1. They are non-polar, so the ices they form are heavier than the liquid, and sink to the bottom. Hence, Lakes of them freeze from the bottom up and seldom keep any liquid portions during typical models of wi
Life (as we know it) - Obligatory xkcd (Score:2)
Ultimately, the fact that we are looking for a small part (water-based) of the larger search-space (all life) relies on a certain anthrocentric bias.
We want to be the only ones... because otherwise, we wouldn't be special anymore (especially important to the religious crowd)
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Nobody is saying there can't be life without water.
They're saying that since we have no idea of what it would look like, or how to look for it, there is simply no point in trying to look for it.
Tell me, how would you undertake to look for the conditions of life that we don't e
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It seems to me like the thing to do is to look for anomalies and patterns... and especially anomalous patterns.
But looking in places that look familiar is a pretty obvious start.
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Well, it wasn't long ago that we were finding the first exoplanets. Now, we've found a whole lot of them.
However, damned near everything is anomalous since some of these planets are pretty extreme in terms of temperature, proximity to sun, what have you.
I think we're going to need to catalog lots more planets before we start seeing patterns that might point us to lifeforms we can't fathom yet.
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but any planet in an appropriate place makes at least a bit of sense to check.
And what exactly are you checking for? We can't exactly get surface resolution on the majority of the Earth-sized satellites in our own solar system, and we've yet to come up with any other set of substances that are conducive to life other than water and carbon. Most planets outside our solar system we can't even detect directly. You have to have something broad to look for, otherwise what you see in a planet will tell you absolutely nothing about whether or not there is life there, yet you want us to
Does Not Change Anything (Score:4, Insightful)
We cannot measure the water beneath the surface (to my knowledge) so the example of the earth's composition of water is moot. If you were to take the surface of earth covered by water and then that amount of water that contains life, I think the percentage would be much higher. The microbes and small organisms that our oceans are teaming with alone would be a scientific goldmine on another planet. Of course the deep trenches of the Atlantic and Pacific will throw off your rates but we can't measure them anyway on another planet or even water in the mantle
If water isn't good enough, what is better?
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If water isn't good enough, what is better?
Oxygen? Extremely long chained hydrocarbons?
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Oxygen? Extremely long chained hydrocarbons?
Yeah. And trees.
If you find trees, there's most probably life.
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I don't know... There's trees in Cleveland.
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And how do you suggest we find trees?
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There are other compounds similar to O2 that would also be good indicators for the presence of life. In the absence of life, most planetary systems will have atmospheres where the chemical reactions have all occurred so as to result in the chemical compounds with th
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If water isn't good enough, what is better?
Gin and Tonic
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Not really, we've learned more recently that there is a fair amount of life there as well.
There are MASSIVE amounts of deep water coral for instance that we never really knew existed until very recently.
The problem is ... we say 'life can't exist in that environment' ... then we go find out ... life does actually exist in that environment, using methods to survive that we never even considered.
Theres nothing wrong with assu
Tiny sliver??? (Score:5, Insightful)
You know, the earth has bacteria and fungi floating around high in the atmosphere and deep undersea -- probably even under the deep ocean, though we haven't looked there yet.
Tiny sliver... HA!
-l
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Their point is that there is almost definitely liquid water on several moons of Jupiter and Saturn and in limited amounts on Mars. In gaseous form it can be found in the atmospheres of all the gas giants and in solid form it can be found on our own moon, comets, asteroids, and probably a dozen other objects in our solar system. Of all the objects with water in our solar system, only a single one is believed to have life and even that is skewed by the anthropomorphic principle.
Saying 'follow the water' cas
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People have known that water is very common for decades. You're not saying anything meaningful. I think you're getting ahead of yourself making statements about which you know nothing.
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You didn't follow Mozee Toby's argument at all, and frankly you are the one who's making wrong claims here. People simply did not, for example have close up evidence of erosion on Mars 'for decades'. It's been within the last few years, both that we got much better evidence for occasional liquid water on Mars and that we got some of our best evidence against life on Mars. Mozee Toby referenced that, it IS meaningful, and if you didn't get any meaning from that, that's YOUR problem.
(Lit
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should have been corrected by the time you got out of a public high school level
Pfft, not if he came from most high schools.
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Everywhere we have found liquid water, we've found life, including in a lot of places we thought no life could survive. We've found suggestions that there might be liquid water in some other places, but we haven't confirmed that, except for one place, and we certainly haven't shown that there isn't life in that water.
So far, based on what we actually know, liquid water is a very good (perfect, actually) indicator of life. It's possible that 100% accuracy won't hold, but it's awfully early to start critici
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So we've found life on Mars? That's news to me. Apparently that they have observed even indirect evidence for liquid water on Mars is news to you. You do realise that your second sentence contradicts your first, and it's special pleading for your claim, on a level with "maybe God does miracles but makes them look so natural we can't use them for proof he exists".
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All that is true, but, as replies above have pointed out, our best heuristic so far is water. Without water, we have no criteria to narrow the search.
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It's still a tiny sliver. Even if we assume that there are bacteria living and reproducing at 200 km above the surface of the earth and 10 km under the surface, that still only makes it a 210 km zone on a sphere with a radius of 6,578 km (6378 + 200 km atmosphere). That's 3.2% of the Earth - which, to my mind, qualifies as a sliver.
That's not the sliver we're talking about (Score:2)
The author wasn't talking about how life only occupies a tiny sliver of the planet as a whole. Duh, most of the planet is molten iron.
The author was talking about how life only occupies a tiny sliver of the areas of the planet that do or could contain significant amounts of water.
And the O.P. was saying, rightly I think, that this isn't true. Everywhere there's water on this planet, there's life. There might be a tiny sliver that doesn't have life, but that's okay, because astronomers aren't assuming tha
Stupid... (Score:4, Insightful)
He's an idiot. Nothing to see here, move along.
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Everywhere on Earth we find water, we find life.
The argument seems to be that for your statement, everywhere on Earth's surface is true. However, for everywhere above or below Earth's surface your statement does not hold.
He's an idiot.
Not quite an idiot but certainly shortsighted. The real confusing thing for me is that his "sliver" -- 12% -- would still be scientifically revolutionary if we hit up a planet and 12% of the water on it contained life. Can he produce any other chemical or indicator we can detect light years away that produces some percentage greater t
Re: Stupid... (Score:2)
The real confusing thing for me is that his "sliver" -- 12%
Is the 12% even accurate?
What percentage of the earth's water is in the oceans, and how much of the oceans are devoid of life?
Re: Stupid... (Score:5, Funny)
and how much of the oceans are devoid of life?
The black, oily, part.
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That's why they're so worried about the oil munching bacteria getting out of control and using up all the oxygen in the water.
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0%
There has yet to be a part of the ocean that life has not been found in. We may not notice it right away, and it may be a little less common or recognizable, but there is no part of the ocean devoid of life.
From the Marianas trench to the 400 degree volcanic vents to the coldest parts of the world ... we've found some form of life in all of them.
There is really no place on this planet where we haven't found life.
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the 400 degree volcanic vents
That was the most amazing part of the ocean that I've seen recently - microbes flourishing in temperatures hot enough to melt lead on the surface, which create food for creatures sitting on the outside of these vents which just absolutely thrive in waters over 150 degrees Fahrenheit. Some of the tube worms were ancient, too. I may be miss-speaking but I believe some were said to be around 100 years old or older.
The next most amazing thing to me was the underwater brine lake they found, which another littl
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Everywhere on Earth we find water, we find life.
The argument seems to be that for your statement, everywhere on Earth's surface is true. However, for everywhere above or below Earth's surface your statement does not hold.
No, you're wrong. On Earth, everywhere there is water, there is life. From the bottom of the Marianas Trench, to the top of the troposphere. Everywhere. Unless you don't consider bacteria life.
By extrapolation, water means there's a pretty good chance of life on a planet. No guarantees, but more probable than a methane filled planet.
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No, you're wrong. On Earth, everywhere there is water, there is life. From the bottom of the Marianas Trench, to the top of the troposphere. Everywhere. Unless you don't consider bacteria life.
So you're telling me that deep within the black smokers [wikipedia.org] on the ocean floor, where water comes in contact with 1200 C magma ... that down in there underneath the ocean floor that water has bacteria and life living in it? Where the pressure is so great that the water can't even boil?
News to me.
And what is the deal with people moderating me over rated lately? It's non-stop. Jesus, the biologist who wrote this article was short sighted, his figure of 12% might have been off but he was not wrong abo
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As some ACs have noted there are Hyperthermophile (extemeophiles) that can thrive at temperatures between 80–122 C, such as those found in hydrothermal systems.
There is a dead zone in the Gulf of Mexico caused by fertilizer runoff from the Mississippi where there is no oxygen in the water and many kinds of life cannot exist. Hurricanes come along during storm season and froth up the water which aerates it, and reduces the size of the zone.
There are 'exceptions' where no life as we know it lives, but f
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When they first did the "build amino acids from methane and ammonia with electric current and UV in a big glass ball" experiments, 'they' also confidently predicted that the next stages, getting more and more complex compounds would follow soon and would be surprisingly easy. There were people on record as claiming that they would have actual life within a few weeks. Life Magazine published Nobel Laureates 'predicting' we would synthesise artificial life by New Years day. Nothing has come of these claims
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Seriously, black smokers are your argument? And life doesn't live *inside* them, but does just outside. Yeah, life does live just fine there. And all over the bottom of *every* ocean. Even 25,000 feet down:
http://www.extremescience.com/zoom/index.php/life-in-the-deep-ocean/44-deepest-fish [extremescience.com]
And to prove my point, life at the bottom of the Mariana Trench:
http://news.nationalgeographic.com/news/2005/02/0203_050203_deepest.html [nationalgeographic.com]
Even radiation doesn't seem a real problem for life, bacteria live ON radiation rod
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There is certainly life in the water around black smokers, where the water is very hot and the pressure is so great the water can't even boil. As for right down where it hits lava, we don't know.
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Any life that was happy in 1200C water wouldn't last too long when exposed to 4C sea water so you'd have a hard time finding it even if you looked. You might find some dead organic material but that would be about it.
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So long as you change the statement to liquid water, the argument is incorrect as well. Everywhere on Earth we find liquid water, we find life, including above and below the surface. As for water that is not on Earth, we simply don't know if it has life in it or not.
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Everywhere we look for life on earth we find it .... ...even the places that have been dismissed in the past as lifeless, we have since found life ....
the only requirement is water, but sometimes in such minute amounts that it was found *after* we found the life that depends on it ....
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<your style>
Yeah, and every planet in the universe that has life on it, is EXACTLY like earth, just as every life in the universe looks like the “aliens” on Star Trek, and at least EXACTLY like something from earth.
You’re an arrogant simple-minded dick. Nothing to see here. Move along.
</your style>
Do the people that submit these articles (Score:5, Insightful)
ever bother to read them? I haven't had an article accepted in over 10 years and I suspect it's because I read the link I am referring to and write an appropriate headline.
It simple states that water can exists in environments that is hostile to life as we know it.
No shit, Sherlock.
I do take issue with the idea that only 12% of the water on earth has life. AFAIK, a cup of water from any natural source in or in the ground has some sort of life in it.
Re:Do the people that submit these articles (Score:4, Interesting)
It simple states that water can exists in environments that is hostile to life as we know it.
No shit, Sherlock.
Yeah, seriously. The "conventional wisdom" is not that water implies life, but rather that the absence of water implies the absence of life.
We search for water on other worlds not because we're sure that's where there will be life, but rather because it's the first, most basic indicator of the possibility of the only kind of life we know can exist.
Water alone is not sufficient? Duh! Nobody ever thought it was.
I do take issue with the idea that only 12% of the water on earth has life. AFAIK, a cup of water from any natural source in or in the ground has some sort of life in it.
Yeah, like the very first look we took 600 feet under the Anarctic ice sheet showed complex life [sfgate.com]. Sounds fishy. Or shrimpy as the case may be.
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Uhm, so, I believe a lot of the ocean depths are supposed to be sterile, because of a lack of oxygen, and extreme cold (cold enough to freeze methane). But every time scientists send an exploratory vehicle to the deepest bottom of the ocean, they find large, multicellular life crawling around and swimming around. So I think maybe the problem of some scientists saying 12% or whatever is actually a misunderstanding of science and statistics on their part, not a lack of life. I do not believe we can find large
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I haven't had an article accepted in over 10 years and I suspect it's because I read the link I am referring to and write an appropriate headline.
I gave up trying to submit articles after realizing my mistake: I was trying to do a good job, which slowed me down. The secret to getting your articles selected isn't doing a good job, the secret it submitting lots and lots of them.
I became especially discouraged since 1/2 my articles were later accepted, after someone else submitted them, with a much crappier write-up. *sigh*
not good enough (Score:2)
I always thought of "water litmus test" as a criterion of where NOT to find life (no water, no life), rather than where to FIND it.
It's just one of many requisites of life as we know it and since there has been many instances of observations of any of them, finding water seems rather exciting.
Re:not good enough:CORRECTION (Score:2)
"since there has NOT been many instances "
I hope people got it.
Dumbest thread in months (Score:5, Funny)
I don't caim having read every single one, but I think this is the dumbest news item in Slashdot in months.
Maybe intelligence is just concentrated in a small sliver of it!
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The presence of intelligent life on this planet is greatly exaggerated.
Is this new? (Score:4, Informative)
It's not clear what Lineweaver is trying to say, here. Even when I took graduate astrobiology nearly 10 years ago, we were taught that you needed three things for life: raw elements (CHON, in particular), water, and an energy source. From the article, it sounds like he thinks he's had this revelatory notion just now.
Of the three ingredients, water does seem to be the hardest to find in sufficient abundance for a good likelihood of life arising anywhere. There are certain the raw materials and often energy sources available in many places, but water seems to be the missing factor in most of the solar system. So it's not a sufficient condition, it does seem like the smart thing to look for first.
(Also, his 12% figure confuses me. Is he including the entire mantle, for example? Because there isn't a lot of water there, as I recall, so you wouldn't expect to find a lot of life there. That alone would pretty easily throw the calculation in favor of his result. However, we have found life in deep rocks under the Earth, which is still pretty amazing and suggests that it's danged hardy.)
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The article is just a nice discussion about looking for life. It's pretty handy for people who only hear news about looking for life occasionally. Especially when the news always involves finding water, then looking for life.
This person who submitted this article and wrote the headlines is an idiot and just taking a casual article and getting it wrong. I would say the poster misread it, but that would imply that attempts to read it; which is doubtful.
Maybe slashdot should stop allowing anon. article submiss
For example, the earth has a lot of water on it (Score:2)
But due to a shitload of oil in that water, we can't reliably say that if there's water, there's life. Lots of dead things, though.
And some oil-eating microbes. Hey look, we found life!
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Yes, there is life. They're polluting the oil
Necessary and Sufficient Conditions (Score:2)
So water is a necessary, but not sufficient condition for life (as far as we know). This really isn't new knowledge. We still want to look for water. We just have to pair that with other necessary conditions to increase our odds. Of course, we probably only have a small subset of necessary conditions for life here on Earth, so we don't entirely know what to be looking for.
Retarded (Score:2)
have estimated the volume of the Earth where liquid water can exist, and calculated that life inhabits as little as 12% of it.
And what about the volume of Earth where liquid water can not exist, what percentage of that is inhabited by life?
12% is applied the wrong way (Score:2)
12% of the water on this planet supports life. This does not imply that only 12% of the planets that have water will have life as he claims. You'd have to assume that all other planets are completely uniform, with none of the variation in environment that our planet has, and apply a single potential water bearing environment to each planet for that to be the case. I don't think we've found a single uniform planet yet, applying that to every planet is ridiculous.
Only 12% of my car can support a working en
jumped the shark (Score:2, Insightful)
I remember a few years ago many were saying that slashdot jumped the shark, to the point where saying it jumped the shark had jumped the shark.
this story submission is sharks jumping sharks jumping sharks {...} sharks all the way down
Author Also Says 99% of Earth H2O Has Life (Score:4, Informative)
Looking up some of the author's actual publications on this issue shows some very interesting details that greatly modify this picture. See: http://www.mso.anu.edu.au/~charley/papers/Jones&LineweaverProceedingsv7color.pdf [anu.edu.au].
Most remarkably he calculates that 99% of the Earth's ACTUAL liquid water contains life!!
This 12% business is the volume of the Earth where liquid water can physically exist due to its pressure-temperature phase diagram - whether or not there is actually much (or any water) there.
There are yet more limitations on this claim: it is based on the presumption that there is no life below 5 km in the Earth's crust. This is a region very slightly explored, so it can hardly be said that this claim is based on extensive direct observation. The assumption is really that the temperatures below this depth are too high life to exist (the assumed limit is 150 C). But organisms known to survive this temperature dormantly (tardigrades) are actually complex organisms (not simple extremophiles), and it was only recently that organisms were discovered that actually thrive above 121 C (the temperature of an autoclave), so the assumption that this is really the upper limit seems weak.
And the claims get even weaker. Why have we only recently discovered thermophiles above 121 C? Because there are very few accessible locations where liquid water can exist above this temp in which to observe it! Concentrated salts can raise boiling points only so far, beyond which only considerable pressure will keep it liquid. Probably the only environments we can access currently to investigate the >150 C regime are the black smoker vents on the sea floor, where emerging water hits 400 C (before rapidly cooling due to mixing).
And by this same token, the high pressure high temperature liquid water regime will be impossible for astronomers to directly observe anyway (its buried under kilometers of rock, or deep, dense atmospheres, don't ya know).
So if it is an environment where we can actually hope to OBSERVE liquid water (rather than simply postulate its existence) then yes indeed, it is almost certain to be one where life-as-we-know-it can exist.
Forget water. Look for Chaos! (Score:2, Interesting)
In looking our global ecosystem it seems to me that it is extremely fragile. There are myriad of unique characteristics of our planet that come together to support life.
Earth is just the right size to allow for a decent atmosphere.
It is just the right distance from the sun which allows for water in liquid form.
The iron core creates a magnetic field that protects us from solar radiation.
Also consider that we have just recently been able to find exoplanets, and most of what we have found are large jupiter-lik
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Yeah. "Questioning the conventional wisdom" has become a worthy pursuit for its own sake. The part of questioning the conventional wisdom where you first understand the conventional wisdom, and then come up with an informed question, seems to have fallen by the wayside. But if you point out this distinction, then you're apparently attacking the idea of questioning in the first place.
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And where do people go when "conventional wisdom" tells them "do NOT question conventional wisdom, you are an uninformed fool" ?
In some parts of the world, 1500 years of conventional wisdom says that mutilating a girl's sex organs is the proper thing to do. Does that mean it should never be questioned, even by the uninformed ?
You, like the current crop of AGW crazies, would have us all believe that questioning (by the informed OR uninformed) is verboten, and only the high-priests are allowed to hold the "ho
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And where do people go when "conventional wisdom" tells them "do NOT question conventional wisdom, you are an uninformed fool" ?
You go someplace to get your ignorant ass informed, then come back with the capability of making a useful contribution.
In some parts of the world, 1500 years of conventional wisdom says that mutilating a girl's sex organs is the proper thing to do. Does that mean it should never be questioned, even by the uninformed ?
Nope, go right ahead. Part of the extremely subtle distinction I
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"...which haven't changed much for the past 50 years declaring water is impossible to exist on the moon for example or on mercury."
It's not the same people, and based on the knowledge of the time, that was a reasonable thought. Through the collection of data, and logical thinking(Science!) the data indicated that water is far more abundant then we thought.
Guess what? new measurable data came in(thanks Science!) and things changed.
There isn't 'correction' there is new data that give minor and incremental cha
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I'm now wondering, what portion of Slashdot cranks drive Geo Metros?
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"What? so the thousands of accurate predictions through experimentation don't indicate anything? the fact that planets have been predicted before we could see them means nothing?"
Well, science doesn't work that way and I think your confusing what I said about conclusions and theory.
No where did I say that thousands of experiments do not indicate anything and what I was speaking about was conclusions. Many of which are far fetched when it came to water.
Given what we know about water, it was determined that
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SETI really works out to the search for Extraterrestrial Information Bearing Radio Sources. We still would need a separate way to search for everything that metabolises, gets irritable, or reproduces but can't craft a decent vacuum tube yet. (Or has converted totally to tight-casting, fiber-optic, or something we haven't thought of yet but which we will have a hard time distinguishing from 'magic' or 'psionics', if we ever find it.).