Earth May Harbor a Shadow Biosphere of Alien Life 267
An anonymous reader sends us to Cosmos Magazine for a speculative article arguing that a 'shadow biosphere' may exist on Earth, unrelated to life as we know it. If such non-carbon-based life were found here at home, it would alter the odds for how common life is elsewhere in the universe, astrobiologists say. "The tools and experiments researchers use to look for new forms of life — such as those on missions to Mars — would not detect biochemistries different from our own, making it easy for scientists to miss alien life, even if [it] was under their noses. ... Scientists are looking in places where life isn't expected — for example, in areas of extreme heat, cold, salt, radiation, dryness, or contaminated streams and rivers. [One researcher] is particularly interested in places that are heavily contaminated with arsenic, which, he suggests, might support forms of life that use arsenic the way life as we know it uses phosphorus."
Obligatory (Score:5, Funny)
Re: (Score:2)
Why is it that I always think of this [youtube.com] whenever I hear that line?
(No, it isn't Rick Astley)
Re: (Score:2)
Not as we know it,
Not as we know it.
Jim? How about Captain. (Score:2)
Chief Science Officer Spock also had a close relationship with Kirk, but he would only call him "Jim" on rare occasions when he would let his Vulcan-logic show-no-emotion guard down for a a nanosecond. I am sure it would be "It's life, Captain, but not as we know it." Also, the determination of
Re: (Score:2)
I'll bet you're a lot of fun at parties. At the risk of some redundancy, I'll post this again [youtube.com] in case you missed it when dkleinsc posted it the first time.
Motives (Score:5, Funny)
Or the researcher is secretly needing arsenic to do his more brilliant colleague in the old Victorian-era way, having learnt from too many Agatha Christie novels.
Re: (Score:2)
Nah, he's just getting ready to ask for a defense research grant to look for life forms that use phosphorus the way we use arsenic ... "imagine the weaponizing possibilities."
If that fails, he's going to ask for a bailout and a "retention bonus."
So something which we can't define... (Score:3, Insightful)
Sounds pretty clear to me. Maybe rocks are intelligent. How would we know? Has anybody thought to ask?
Re: (Score:3, Insightful)
We can't communicate with rocks.
This reminds me of something I read a while back. Some scientists observed various metal molecules joining together into a helix structure.
They didn't do much beyond that, though... but it makes me wonder if carbon based life coming around on earth was just a fluke? It could've possibly gone another way, if we hadn't gotten there first?
Re: (Score:2)
And yet, they clearly rock!
3...
2...
1...
*bangs head to the music*
Re:So something which we can't define... (Score:4, Funny)
It could've possibly gone another way, if we hadn't gotten there first?
We would have just given the non-carbon lifeforms some blankets and hoped that they hadn't discovered gunpowder yet ;)
*ba-dum pssssh*
Re: (Score:2)
Why "if we hadn't gotten there first"? There's not much reason to suspect that if non-carbon-based life is possible on Earth, it won't remain possible long after we're gone
Organic life should be more common (Score:2)
Re: (Score:2)
*Throws rock at BikeHelmet.* ;)
There! Now doesn't that tell you something.
Re:So something which we can't define... (Score:5, Funny)
After a lengthy, one-sided dialogue with the nearest rock, I conclude that your theory is false.
Re:So something which we can't define... (Score:5, Funny)
After many zen practitioners' lengthy, two-way dialogues with rocks near and far, your test criteria seem to be flawed.
Re:So something which we can't define... (Score:5, Interesting)
You both have a point. The question is, where do you draw the line at what is life? Rocks may not have DNA or intelligence, but they do form, change, multiply and there's a recognisable process for destroying them. In a sense, rocks are a lot like the most basic forms of life that ever formed.
Let's be a little more serious now. Rocks around here probably won't ever advance beyond mimicking some very shaky comparisons to the most basic forms of life. But that doesn't stop us wondering if we're just seeing it on too small a scale to make that judgment. Perhaps it's safer to treat rocks as a failed attempt at life, one that happens too slowly to ever get beyond basic chemical reactions and simple molecular structures.
If it weren't for carbon-based life, who knows?
Re:So something which we can't define... (Score:5, Interesting)
You both have a point. The question is, where do you draw the line at what is life? Rocks may not have DNA or intelligence, but they do form, change, multiply and there's a recognisable process for destroying them.
Rocks do not have gaseous exchange (breathing) nor reproduce (cracking a rock to make two is _not_ reprodction). However, there is no definition of life that fire cannot meet, which the mule can. In other words, any non-contrived definition of life that includes the mule must also include fire. Here is a very basic explanation: http://simple.wikipedia.org/wiki/Life [wikipedia.org]
Re:So something which we can't define... (Score:5, Funny)
Re: (Score:3, Informative)
http://en.wikipedia.org/wiki/Life [wikipedia.org]
Re: (Score:2)
I can't say I agree with the argument that Mules may not be alive because they cannot reproduce.
I may be sterile as well, I've never had children so I don't know. Does that mean I may not be alive? Of course not. I am made of cells, those cells are able to reproduce. I am a collection of living entities that happens to work in a symbiotic relationship to create a larger more complicated living entity. It's the same with a Mule.
Fire is a different argument. When I was at school I was taught that one the defi
Re: (Score:2)
The difference is that the cell splits into two that are of typical size for its species (or at least grow to typical size). The rock doesn't.
Re: (Score:2, Informative)
But rocks grow.
Re:So something which we can't define... (Score:5, Interesting)
Actually, a rock does grow, given the right conditions. Specifically, a rock exposed to supercooled rock vapour will have said vapour condense and freeze on its surface, resulting in a bigger rock.
Re: (Score:3, Insightful)
The discussion requires an open mind.
You must be very new here.
Re: (Score:2)
How about "Life is negative entropy" ?
Re: (Score:2, Interesting)
we're just seeing it on too small a scale to make that judgment.
specially time-scale.
perhaps they are intelligent, but if you talk to it for days, it can be just a split-second for the rock; and if the rock want's to tell you something, it won't finish the first word before you die of old age (or boredom).
tolkien's ents come to mind..
Re: (Score:2)
err.. the <quote> didn't work there on the first sentence
Re: (Score:2)
perhaps they are intelligent, but if you talk to it for days, it can be just a split-second for the rock; and if the rock want's to tell you something, it won't finish the first word before you die of old age (or boredom).
tolkien's ents come to mind..
This sooo reminds me of my boss...
Re: (Score:2)
It's called endurium.
Re: (Score:3, Insightful)
found it!
that is, this video this talk reminded me of:
http://video.google.com/videoplay?docid=-2966542393735208484&ei=I2eZSbSXA5OEqwKozYCgDg [google.com]
Re: (Score:2)
Rocks may not have DNA or intelligence, but they do form, change, multiply and there's a recognisable process for destroying them.
How many of these things happen without an outside force causing them ?
Re:So something which we can't define... (Score:5, Funny)
As the Zen practicioners are indistinguishable from day-dreamers such as my 9 year old son, your refutiation is meaningless.
Re:So something which we can't define... (Score:4, Interesting)
As the Zen practicioners are indistinguishable from day-dreamers such as my 9 year old son, your refutiation is meaningless.
Not really. They've studied the brains of Zen practitioners in meditation and have determined that Zen meditation actually increases brainwave significantly -- more so than even normal daydreaming.
Re: (Score:2, Interesting)
If your nine year old will, of his own volition, sit still for an hour at a time, you've either heavily medicated him, or have done an extraordinary job of parenting.
Anyway, the mental state of zazen is quite distinct from daydreaming, so Zen practitioners are distinguishable from daydreamers by the descriptions they give of their experiences.
Re: (Score:3, Funny)
By that criteria must we also conclude that girls are not intelligent?
Re: (Score:2)
It simply fell asleep because you're sooooo boring...
Re: (Score:2)
Please, try again, but now taking some LSD.
Re: (Score:2)
Perhaps it was simply not interested in communicating with an ugly bag of mostly water [slashdot.org].
Maybe Rocks ARE Intelligent (Score:2)
Maybe rocks are intelligent. How would we know? Has anybody thought to ask?
The creative forces behind this video [youtube.com] have put some thought into it.
Re: (Score:2)
Heh! That was fun.
Re:So something which we can't define... (Score:4, Funny)
I'm pretty sure Spock talked to rocks - and Kirk may have made love to one
Re: (Score:2)
Re: (Score:2)
My personal POV is that the whole universe is alive, is synonymous to God, full of love, and that all living beings share a collective super-consciousness, which is the only "place" where the "reality" actually happens. The only reason for which my theory could be any less valid than any other, could be that less people perceive the world this way.
The Minbari happen to agree with you. It's a very interesting philosophy.
Re: (Score:3, Interesting)
Have you read some of the recent stuff about the Universe being a hologram? The Universe would not be God, but merely a thought of God, or the interaction of two separate beings. One becomes two. Two become many.
Re: (Score:3, Funny)
Terry Pratchett, Equal Rites
Re: (Score:2)
"Has anybody thought to ask?"
You find me a university that will give me tenure and a paid ten-year sabbatical to find out, and I'll give it a shot.
Re: (Score:2)
You know... (Score:2)
On behalf of all trekkies from Boomer to Gen X, it's about damn time.
Re: (Score:3, Funny)
the silicone-based rock creature that Spock mind melds with to share its emo about being a rock
Silicone? OMG smart breasts!
(I think you mean silicon).
Re: (Score:2)
Re: (Score:3, Informative)
Re: (Score:2)
silicone based life forms are a much better possibility.
They have already been shown to exist in Southern California.
Re:You know... (Score:4, Funny)
Or Red Dwarf, "The End".
Captain Hollister: Just one thing before the disco. Holly tells me that he has sensed a non-human life form aboard.
Lister: Sir, it's Rimmer
Re: (Score:2)
Re: (Score:2)
Silicon based life is pretty far fetched, the temperature requirements for chemical reactions are pretty high compared to carbon based polymers. Even the silicone we commercially are primarily carbon chains with as silane [wikipedia.org] base or two attached.
Personally I'd look to Archea for examples of possible hidden biospheres; theose guys are turning up all over the place and not too many years ago we we thought they were just a few fringe niche creatures.
Re: (Score:2)
Re: (Score:3, Funny)
Kirk will lay anything.
Re: (Score:2)
You've just given me an incredible idea for a SF/porn movie!
"The woman with two brains!"
Re:You know... (Score:4, Funny)
Oh yeah...
Carbon-based for a reason (Score:5, Insightful)
On planets with radcially different environments there's probably a lot of potential for life that's totally different from ours, but I think it's fairly unlikely for us to discover it here.
Re: (Score:2)
"Davies is particularly interested in places that are heavily contaminated with arsenic, which, he suggests, might support forms of life that use arsenic the way life as we know it uses phosphorus."
Re: (Score:3, Informative)
Yes, and both phosphorus and arsenic are Group V, with 5 electrons in their outer shell so they can be expected to have chemical properties that are similar. But the main material of living things, carbon, will more than likely be the same, for reasons of carbon's unique abilities to form complex compounds.
Silicon-based life with phosphor or arsenic? Apart from this sounding very much like the list of main ingreidents for N-type semiconductor material; silicon, while in Group IV like carbon, with 4 electr
Re:Carbon-based for a reason (Score:5, Interesting)
You can form chains or rings of around 6 sulphurs (with oxygen), but carbon can be found in chains of 30+ atoms and in multiple ring systems.
It's very difficult to grasp how large the isomer spaces are - and how quickly they grow, but a recent guestimate I made was that if a program (molgen) can enumerate all possible C10H16 molecules in 2 seconds, and all C13H22 in 2 minutes, then it would take 2 days for C18H36 and 1 billion years for C36H72...
Also, there are 25,000 C10s and 9 million C15s. So the sheer number of possible carbon compounds argues that carbon is the only likely candidate.
Re: (Score:2)
No, it just means it's a likely candidate, but it's not the only candidate by a long shot.
Re:Carbon-based for a reason (Score:5, Informative)
Without carbon-based life, such an atmosphere would not exist on Earth.
Of course the whole problem with all this is we do not have a good definition for "life" or "intelligence". For example an ants nest can be considered as a single intelligent organisim or a swarm of mindless individuals. The same concept applied on a global scale is what Lovelock's [wikipedia.org] much maligned Gaia hypothesis [wikipedia.org] was all about.
Silicon-based life of a sort... (Score:5, Informative)
You can't swap silicon for carbon in DNA. Silicon doesn't have the same talent for directionally bonding to itself. You can get get multiple bonds if you stick an oxygen in between, but the oxygen always has electron pairs that make it open to attack. There is no equivalent of the stable and inert paraffin chain.
If you were to have silicon-based life, then it would probably not use chain molecules. Suppose you had a planar silicate structure that catalysed the formation of a similar layer on top of it. The layers might then separate or exfoliate and then catalyse other copies of themselves. Some formations would be more stable, or would come out of solution at lower concentrations, and thereby 'predating' on less successful conformations by lowering the conentration of valuable components, and causing the other to go back into solution.
This is pretty dull sort of life - it isn't really much more than crystallization. No antennae, no ray-guns, no 'greetings earthlings, we come in peace'. However, carbon-based life was probably a pretty dull affair before the cell wall. It would have relied on random variations in ambient chemistry and temperature to do anything, and a lot of time must have been spent waiting for the right conditions for the next move. The simpler viruses are more like big chemicals than small creatures.
I remember a Scientific American article from about 1983 where it was argued that some of the lamellar structures that you can get in pre-cambrian clays may have been just such a system. No easy way of telling now, of course, because carbon based life would probably have killed it off. If it could be said to have been alive in the first place.
Re: (Score:2, Interesting)
There is an excellent book by Alexander Graham Cairns-Smith called "Seven Clues to the Origin of Life" that talks about such self-replicating clay
The main feature of his argument is that the clay surfaces could serve as templates for catalysis of polynucleotides (RNA, probably). These, then would form the first RNA world.
He uses the metaphor of a rope, where no strand goes from one end to the other - the rope is time, and strands within it are clayworld, rna world, dna world...
Carbon is like Lego blocks (Score:5, Interesting)
I think you are absolutely right. It seems that many people cannot understand how special the carbon atom is. They assume that our life being based on carbon wouldn't exclude life based on other atoms somewhere else.
Not true. There's a special, unique property in the carbon atom orbital structure that allows very complex structures. No other atom has that quality, unless some basic constants of the universe were changed. It's like comparing a set of Lego blocks with a box of marbles.
The same goes for temperature, to get life one needs a liquid solution that lets molecules interact. With a solid there's no interaction, with a gas the molecules don't stick together, so one needs a liquid for transporting the elements of life. If a planet is too cold or too hot life will not appear. These are some basic limits on the physics and chemistry that will allow for complex chemistry to gradually evolve.
And the funny thing is that we have both theory and experiment telling us that life isn't very common in the universe. We haven't found any sign of life in either Mars or Venus, which a hundred years ago many people thought would certainly have life. If planets like Venus and Mars, that are very close to the Earth in their characteristics, didn't create life, then one should assume that our position is very special.
Re: (Score:3, Interesting)
You can't swap silicon for carbon in DNA. Silicon doesn't have the same talent for directionally bonding to itself.
I'm not a chemist and I'm not really sure where to look, but does carbon only have this unique talent for directionally bonding to itself at ANY temperature and pressure? Is it conceivable for another element to develop this property at radically different environments?
Great googa-mooga! (Score:2, Funny)
Alternative biochemistries and definition of life (Score:5, Interesting)
Not an expert in biology, but unless these contaminated areas have been contaminated for a very long time (read tens of thousands of years), and are quite large, the chances for life to have sprung up seem very, very slim. Current life needed millions of years to gain a firm foothold and start building up complexity. Lucky meteorites aside, starting from zero is bound to be hard.
If the experiment succeeds (here or elsewhere), and something "life-ish" is found, the results will still be tricky to classify. Can a given chemistry lead to increasing complexity, or is it just a dead end? Without hindsight, this seems like a very difficult question.
Re: (Score:2)
Actually area available for life to live in is not really what we should be comparing. Most scientific theories regarding the creation of a life are based upon a very particular requirements, life will not for example simply spring up in the middle of your back yard. If these 'contaminated
Re: (Score:2)
Re:Alternative biochemistries and definition of li (Score:2)
Can a given chemistry lead to increasing complexity, or is it just a dead end?
Why is "increasing complexity" a requirement for life? It's clearly a requirement for evolution, but I don't see any reason why something "lifelike" but alien might not have a very simple "maximum complexity" compared to standard carbon-based earthly life forms.
Re: (Score:2)
In the sense of the article volcanic areas on our planet can typically be classed as contaminated and have been so for millions of years.
Especially sub sea volcanic vents are known to harbour life forms that are really special and studies have only just started.
..use arsenic the way we know it uses phosphorus (Score:4, Informative)
Re: (Score:2)
not buying it. (Score:3, Insightful)
Re:not buying it. (Score:5, Interesting)
The most likely alternate chemistry for life though, is carbon based, but using ammonia instead of water. At above about 70 psi, and somewhere below zero celsius it has a liquid range and chemistry similar to water. Given a larger, colder planet than earth with a thick atmosphere, life in liquid ammonia is the most probable option.
Maybe very different but still carbon based (Score:2)
I can easily believe that much of the fundamental chemistry of this "alien" life could be different. I'm sure there are plenty of ways to chemically move energy around that don't require phosphorous. One thing I think we will find is a constant though is that life will be carbon based*. It's just not possible to make a wide enough range of complex molecules with any element other than carbon. Even if we look at the next best atom for making complex molecules, silicon, and the simplest lifeforms we know abou
Perhaps they should read this (Score:5, Interesting)
Re:Perhaps they should read this (Score:4, Informative)
Just look up Extremophiles....
They live practically everywhere including in boiling acid, semi liquid rocks, extreme cold, and on black smokers as above ... it seems that everytime discounts an environment for carbon/DNA based life someone else finds life there ...
I doubt there are many niches for non-carbon based life around for them to exploit on Earth.... other planets may have different forms of life ...
They're Made of Meat (Score:5, Insightful)
"They're made of meat."
"Meat?"
http://home.earthlink.net/~paulrack/id82.html [earthlink.net]
Re:They're Made of Meat (Score:4, Interesting)
My favorite thing about that story is thinking about what sort of world these creatures came from. The fact that they know what meat is means that they have seen it (or something close to what we call meat), and obviously anything that is similar enough to be recognizable as meat, would be living tissue of sort. But the fact that they are repulsed by the fact that a sentient life form is made of this stuff, would make me think that they have never seen it in any sort of animate life whatsoever
So on their world muscle tissue must be some sort of inanimate life form like plants, or coral. This is somewhat weird as the whole purpose of muscle tissue is to move. Most of the inanimate life forms that we know on earth are designed to (more or less) passively absorb what they need to survive from the environment through photosynthesis and mineral absorption, whereas meat-based animals can rarely passively absorb what they need and rely on hunting to survive. Furthermore, meat required more nutrients and energy to support than the tissues needed for passive energy collection. But apparently the meat they have seen in the past has been "dumb" or passive enough that they were surprised when they saw it in something that they recognized as life.
So what would this alien meat be moving? Maybe it is more like heart or lung muscle than limb muscle and was pumping surrounding liquid into itself so it could absorb all the nutrients and then spit it back out - might be more efficient than passively collecting whatever liquid happened to flow near it. What would be controlling the meat - most of the muscle-bound creatures I can think of have a central nervous system to control them, but these must be more like a simple pacemaker or very simple chemical sensor/response mechanism.
And more importantly where can I get this amorphous meat to put into my garden/aquarium/floating gas clouds :)
have they checked... (Score:3, Funny)
The odds don't alter ... (Score:3, Insightful)
I don't know what the original article said (the site is thoroughly slashdotted), but finding life based on alternative chemistry won't "alter the odds" - it will just alter our computation of the odds. That immediately raises my suspicions since it suggests that the article was written by a journalist rather than a scientist, and consequently that it might be severely distorted.
Having said that, there are a lot of possible alternative chemistries that don't involve non-carbon-based life: substituting arsenic for phosphorus as mentioned here need not also substitute something else for carbon, so the most likely possibility is that such life would be carbon based but still "alien." As far as we know now, at Earthly temperatures and pressures carbon is a far more plausible basis for life than anything else, and so far we haven't even found much that's very promising at other temperatures and pressures. But I'm not at all sure that we have sufficiently explored alternative temperatures and pressures to rule them out as possible habitats.
Deep Ocean (Score:5, Interesting)
I didn't find it on Google, but about 30 years ago I read an account of a creature like a giant sand dollar that was dislodged from the deep ocean by an undersea earthquake. I can't verify it until I find a reference, but I recall that the scientist examining it found that it was largely silicon, hydrogen, and sulphur (and decayed rapidly giving off H2S). His theory was that it was silicon based life - and that its chemistry required deep ocean temperature and pressure to remain stable. (Note that there are carbon based ocean creatures able to process silicon to create SiO2 structures.)
Not only in the ocean, grasses (Score:3, Insightful)
"Alien"? (Score:5, Insightful)
This raises the more important question... (Score:2)
The full version of the alien life story (Score:4, Informative)
Scientific American Nov '07 (Score:4, Informative)
How about H2 feeders? (Score:4, Interesting)
The article suggests that the hydrogen was produced only when rocks crack, meaning that the microbes' food supply was meager and sporadic. Now Freund has discovered a chemical process in Earth's crust that may produce enough hydrogen to feed a mass of underground life larger than the mass of all living things at the surface. "[T]he rocks around them will replenish the hydrogen supplyÃÂ--indefinitely, over eons of time," said Freund.
Talk about a shadow life form.
Wouldn't alter all that much (Score:2)
Actually I don't think it would alter all that much really. It's probably true that there are simple organisms on this planet that are not carbon-based, or that survive without DNA, but simply haven't been discovered.
On the other hand, if we've lived with them all this time, and not noticed, how important can they be? A cause of many diseases, perhaps. A cure for many diseases, perhaps. None of that would be earth-shattering; we know there are new species, new causes and cures for diseases in rain fores
Re: (Score:3, Insightful)
Two flaws in your argument. First, if such life forms exist in a remote but abundant environment--for example, deep underground--they could be having a significant effect--for example, on geology--that we don't yet recognize. Second, even if such organisms are extremely rare on earth, studying their biology could help us find similar life forms elsewhere. We already know what signatures to look for in the atmospheres of other planets to indicate the presence of carbon-based life, but not necessarily for oth
Re: (Score:2)
On the other hand, if we've lived with them all this time, and not noticed, how important can they be? A cause of many diseases, perhaps. A cure for many diseases, perhaps. None of that would be earth-shattering;
Jaded, much? A cause of and cure for many diseases which operates through a heretofore unseen mechanism would most certainly be a major event for science.
When most people speak of alien life, they're talking about advanced, sentient alien life. A lot of this "life on mars" or "shadow biosphere" stuff is nothing more than sensationalism.
Unless you're a creationist, life has to go through another stage before it can reach sentience. Finding that other stage on this planet would have potential repercussions for the rest of the galaxy.
In other words, you do not know what you're talking about, and are just typing out silly words which don't really go together. Would you please go away?
Re: (Score:2)
You obviously haven't had any good LSD.
Re: (Score:2)
Can you start posting ones which aren't all conjecture?
I don't know, can I ?
Re: (Score:2)
Can you start posting ones which aren't all conjecture?
I don't know, can I ?
Perhaps. But maybe not.