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Post by Wycco on Apr 5, 2002 8:43:30 GMT -5
Well- following a few years ago when scientists thought they found fossill evidence (I read the book they published afterwards- seemed kinda sketchy to me)...
Now Scientists claim they might have discovered chlorophyll on Mars... chlorophyll being what plants use to convert sunlight to energy (only living things contain chlorophyll)...
I would DEARLY love for them to find signs of life on Mars, if for no other reason, than to shush the creationists...
But to me- for life on two different planets to have evolved the same exact mechanism for converting sunlight to energy (chlorophyll) seems highly unlikely to me...
I also think its nuts people always assume liquid water is necessary (never eat cake...) for life to exist... what we are doing is assuming all life that could be found in the galaxy will be composed of the same matter as our planet...
Anyhow- any S.E.T.I buffs out there?
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Post by pabs on Apr 5, 2002 12:29:12 GMT -5
I think you are on the wrong track Wycco.
Scientists don't claim that life can ONLY exist where there's water or oxigen. The only thing they say is that if there is water and oxygen, then there is a high probability that life will exist in that planet. Same thing with chlorophyll (that's the stuff that makes plants green and it is produced during photosynthesis).
That's the reason that we look for water and other signs of life that are familiar to us. Simply stated, we don't know any better. All we know/are familiar with is carbon-based life.
I agree with you. I think there are other ways that life can develop. Even know reading National Geographic (last issue I think), astrobiologists are relaxing a little the requirements for life.
The problem is that nobody has come up with any other theories for the origin of life, so if we don't know how else can life start, apart from the usual aminoacid theory, then how do we know what to look for?
I think you see where I'm going with this.
Interestingly enough, we may in fact be the results of an "alien" invasion ;D For many years we have known that some of the meteorites that hit the earth contain aminoacids (which are the base for proteins and life as we know it). The latest issue of Nature magazine contains an article that reproduces some of those results in a laboratory environment, thus strengthening the possibility that at least some life here in this planet may have come from outer space. Neat no?
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Post by Wycco on Apr 5, 2002 15:49:28 GMT -5
Actually, the problem I have with this is,
Most astrobiologists DO tend to argue that life requires liquid water. Or at least- they base their searches on where water is. Oxygen isn't even a prequesite for life on earth though. Plenty of anaerobic bacteria are alive on earth.
Just last month- Discover magazine had an article based upon how there might be life on Europa because there is liquid water under the ice crust... This is just one article... over the years I've read how they think life could exist in liquid water pockets under the Martian surface... on this moon of such planet- or that moon of such planet...
They always base their findings on water... which I understand IS essential for life on Earth. But I consider it highly egocentric of astrobiologists to believe ALL life forms are just like us... (meaning Earth based lifeforms)
Regarding the theory that Earth was pollunated by bacteria spores. So far the only bacteria discovered on Earth capable of remaining dormant- but alive- through extreme heat and cold- for an extended period of time (required for a space flight) are only really simple primative forms of bacteria- certainly nothing as complicated as a cell that can produce chlorophyll.
I'm not sure if I subscribe to the Earth Bacteria-Spore pollunation theory- there is no proof... although I certainly conceed it IS very possible.
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Post by pabs on Apr 5, 2002 16:36:35 GMT -5
Just got done reading the Discover article actually. Very interesting stuff how the bacteria can live in those tiny pockets in the ice.
But going back to what you say...I don't think you understand what I am saying. The reason we are looking for traces of H2O, CO2, O2, etc (yes, there are plenty of anaerobic bacteria but...) is because these are strong indicators that life could exist in those remote places.
The point is not that water is a requirement. The point is that we simply don't know what else to look for because we don't know how else life could be formed. So we look for the things that we do know.
Perhaps one day we'll come up with other theories. If say, someone came up with a theory that metallic life-forms could exist, then we'd be looking for traces of Hg or something. But we can't even begin to speculate on that because we know so little about how life began.
Do you see my point?
As for the bacteria-spores, well, we have found traces of aminoacids, not bacterias, in asteroids. And the latest findings indicate that they can form from basic compounds under intense heat or even at room temperature. This opens up the possibility that at least some life forms could have originated from asteroids during re-entry into our atmosphere. I doubt that any lifeform, even bacteria, could survive the vacuum of space. But I do believe that certain aminoacids could have been brought by asteroids.
And even then Wycco, the first life forms were indoubtly simple bacteria that then evolved into more complex multi-cellular organisms, so I wouldn't dismiss those theories just yet.
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Post by JWK on Apr 5, 2002 19:07:57 GMT -5
"The mountains are but stone, yet seeking eyes grow blind" -James K Baxter
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Post by beefburger on Apr 5, 2002 21:31:26 GMT -5
Scientists are increasingly amazed at just where life is found and how durable and persistent life gnerically is proving to be.
Whilst they previously belived that life could only really exist (as we know it) under conditions somewhat similar to those that exists on earth, life has been found in areas previously thought incapable of supporting any life forms!
Relatively recently they found thriving fish populations that lives at the bottom of the ocean whose nourishment is deadly (to us) volcanic emissions of boiling sulphur.
I'm not sure how they do it, but I think I'm going to try myself!
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Post by Cine_Man on Apr 6, 2002 0:11:49 GMT -5
Well if you check the Hitchhikers Guide, you'll realize that we're the descendants of the Golgofrinchin "B" Ark that crashed here on Earth (what a boring name) because they all were a bunch of sponging middlemen that had been "sent ahead" to prepare a proper planet for settlement once the home planet was destroyed by a marauding space-goat.
On another topic.... there is a wonderful crackpot theory that the "whoe planet" is 'alive'. The Biosphere extends inward as deep as you like... and extremely primitive an d exotic organisms are metabolizing the mantle of the planet.... into.... hey presto... hydrocarbon. Which percolates upwards into collection pockets which become strategic oilfields. Wouldn't this be an interesting development if it were true? That petroleum is actually a "renewable" resource, rather than a "fossil fuel" as is currently accepted as gospel?
Already there is anecdotal evidence of supposedly exhausted oilfields mysteriously "re-filling"...what IF the planet is continuously generating fuel? How bloody convenient, I say.
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Post by pabs on Apr 6, 2002 1:19:34 GMT -5
[Sarcasm On] Hurray!! More COx and pollution, more people driving SUVs, more oil money in politics ;D [Sarcasm Off] I don't mean to be an a$$ Cine ;D, I do think that's pretty cool. But from a practical perspective, I am entirely anti-hydrocarbon fuels. I really hope that these guys that are developing fuel cells get it right. Nearly entropy and pollution free. Now how cool is that? ;D ;D hmmmmm...please don't get the impression that I am a tree-hugger  I realize I can sound like that sometimes, but only recently I have become more environmentally-aware. Blame my sister the environmental engineer |
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Post by hearing_aide on Apr 6, 2002 14:30:39 GMT -5
Welll lets see. Beef- What you are talking about in deep ocean trenches is called "Chemosynthesis". That single discover changed the entire view of life on other planets. Until that discover we assumed that life could only exist with sunlight and water. Now virtually any planet can sustain life. But that leads to several problems... First of all Space is big...really big, not even comprehensible to most people on how big big is. Now with that out of the way.... Space is old really old...like OT is No comparison to how old old is. Those 2 things create alot of problems. The universe is probably teaming with life, but it's so far away that we don't know about each other. Or their society hasn't develpoed to the point where we can communicate with them, Or they did develop but they developed millions or billions of years before us. Lastly, if you were an intelligent society with the means to travel the great distances of space and you happened to be doing this around this time here on Earth...would you stop for a chat?  After intercepting our communications that are beamed out into space constantly, and if I may add reading "T3's" post would you come down here for a few cold ones? We are probably looked at the same way you look at a 2 yeard old in the middle of a temper tantrum, except we have Nuclear weapons. Mars could have life, could of had life, or may have life in the future. Someday I think we will know. If they "had" life...look at how quickly things breakdown here...buildings, historical records, new intelligent threads on F1-Live, in the matter of a few centurys we can lose track or trace of things. Imagine what would happen in a few millenium. As Carl Sagan said "If we are the only life in the Universe, what a waste of space." Any references to "The Hitchhikers guide to the Galaxy" in this post are completely stolen and have been used with out permission... hearing aide |
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Post by hearing_aide on Apr 6, 2002 19:18:15 GMT -5
Or maybe I'm wrong.
hearing aide
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Post by thajavaman on Apr 6, 2002 23:44:14 GMT -5
[Sarcasm very on]
...
no need to steal 'pabs' style... shutting it off and in the deepest, most sincere way:
WE ARE ALL GOING TO DIE
;D
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Post by thajavaman on Apr 7, 2002 0:10:42 GMT -5
Now, being a little -just a little- more serious;
I do believe there is live out there, Carbon-based, 'metalic', and in many other ways we haven't and cannot yet think or believe of.
And I do see the necesity of searching for different life forms, to learn from them, because some day sooner than we expect, the enviroment we take for granted will exist no more, and some radical meassure must be taken. luckily (and I say this with out glee), I wont be here for that.
But going back to the subject, finding extraterrestrial life scares the .... out of me. All of our lives we've 'owned' this magical, untangible, inexplicable and SEDUCTIVE vision and 'understanding' of these creatures, and well, big green heads, microscopic fearsome gastropods, morphing-3 eyed monsters, etc... well there is some gleaming magic on that. magic that I wish not to understand.
Without wanting to sound chauvinistic (he he, who'll believe that!) it is like with women, the moment one understands the one that's by your side, the moment you can predict her, is the moment you get bored of her. Well I dont want to get bored of science-ficiton.
Hey, keep all those space biologists at work, after all there's a hunger for such literature here on earth, just make sure that they eternaly get closer and closer to nothing, so that the ppl that want to have 'contact' are happy, and the ppl like me are too.
'closer and closer to nothing' keep that in mind you all.
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