Arthyron said:
No, at least not life resembling human complexity. There are 100's of reasons why earth was and is ideal for the generation of life (whether or not you believe it was spontaneous or "designed"). The fact of the matter is that life as we understand life can only arise based on certain elements and combinations of elements, and as far as we know, the processes that were the origins of these elements are likely to produce the same elements elsewhere. We've never seen a star form, only stars die. So since the Big Bang, it's not likely that there have been any new formulations of planets or stars. So "life" would have to generate during that time period.
This is wrong, too-wrong. Stars have been forming ever since the big bang (if the big bang even existed; i'm having more and more doubts about its existence lately) and still do. Their birthplaces are called nebulae (yes, i'm aware that those are also huge clouds of dust and whatnot, but stars are "born" there). Second, i'm sure there are many planets that are the "right" distance from their sun (and that distance would also vary with the sun's heat and size, so there are many "right" distances). Third, i highly-doubt you have a right sense of proportion (this isn't personal; i don't believe
anybody does, since the universe is bigger than anything we can possibly comprehend or imagine); there are many-more stars and planets out there than you think there are (i'm not mindlessly repeating the whole "there's billions of planets blah blah blah" thing you so despise, i'm implying that if there are so many then there must be more than one with characteristics similar to those on this planet (and they don't necessarily have to be similar, as stated before and mentioned somewhere below)). Fourth, see below.
Edit: Blowtus beat me to the star-formation thing, shit...
Arthyron said:
Now given all these things (especially specifically the elements issue), life can only arise under certain conditions as far as we know, and can only be comprised of certain elements as far as we know. And as I said, earth is very very VERY ideally suited to both generate and support life. For some good texts on the issue check out "The Privileged Planet" by Dr. Guillermo Gonzalez and Dr. Jay Richards, as well as "Rare Earth: Why Complex Life Is Uncommon in the Universe" by Dr. Peter Ward and Dr. Donald Brownlee. Earth is in just the right place within our solar system, near the right kind of sun, in the right place in our galaxy, etc etc to sustain life as we're aware life can take place.
Given the incomprehensibly unlikely odds it would take for life to spontaneously generate on earth (a planet well suited for life), I simply don't see it as occurring to any great extent elsewhere.
Life is overrated. A living being is nothing but a chemical system which is a) stable under certain conditions, b) able to multiply itself provided it has the necessary elements (and this goes as far as photons, subatomic particles and temperature, not just your standard organic molecules), and c) in a state of constant matter/energy exchange with its environment. You can throw in "d) is formed by proteins which are coded by either dna or rna" in there if you want, but that's just life as we know it and possibly not all life in the universe.
That said, i'm sure there are many stable chemical systems that constantly exchange energy and matter with their environment (easy: everything is constantly being bombarded by subatomic particles, photons and so on, and, as everything that happens has a consequence, molecules change or atoms move or particles split into different particles; now you just have to make sure the system doesn't consume completely as in combustion or change considerably as in simple chemical reactions (what we know as "life" is more-or-less-constant in that an organism retains at least some of its characteristics throughout its "life")). The hard part is the self-replicating one, but i'm sure rna/dna-based cells as we know them aren't the only possible ones.
Now, given that there are all kinds of planets and that there's a vast multitude of them "out there", i can easily think of a scenario in which several atoms join into a molecule which then joins with other (different or similar (or, more-likely, a combination of both)) molecules to eventually form more-or-less-complex self-replicating systems (a strong theory about the origin of life on Earth suggests that this happened many times and that for one or other reason some of them "died" or were consumed or reacted with something else and one (or more) of those systems was/were enclosed in a lipid sphere and became the first cell(s), so if it happened many times on Earth why can't it happen on other planets?). They don't even have to be carbon-based. And if one survives and finds that it is fit to multiply and keep surviving in its environment for long-enough without consuming it too-quickly then the logical consequence is evolution/speciation.
Edit: a moogle beat me to the not–carbon-based thing, SHIT...
As everybody has probably realized by now, i believe that the possibility that there is "life" (read: relatively-stable relatively-constant self-replicating chemical systems) in other parts of the universe is a huge one. As for the possibilities of finding them, no, i don't believe in
Alien or StarCraft or
Independence day.
Edit: That was going to be my post originally, but reading more of Arthryon's stuff (which reeks of mindless anthropocentrism and even contradicts itself) moved me to write further:
Arthryon said:
However we're not sure where this bacteria came from, and last I heard it wasn't native to Mars, but came from a meteor or comet or something (it's been several years since that discovery, I dont' remember exactly).
You just shot yourself in the foot: if that bacterium/bacteria (whichever the correct term is) came from a meteor or comet or something, then it means that life exists at least in one other place (the meteor couldn't have come from Earth for many reasons), which instantly makes you wonder why two and not a million. Mars or another solar system, it doesn't matter, what matters is that there's life outside Earth (and i don't mean astronauts).
Arthryon said:
The only data we know of indicates that it is not possible, so it's more likely that there are not sulfur based lifeforms somewhere.
The only data the ancient egyptians had (note how i'm not saying "ancient greeks") indicated that Earth was flat, but, last i heard, it was a spheroid blue-green object that was orbiting the sun between Mars and Venus, not a giant rectangle.
Arthryon said:
Perhaps there is some random process that has successfully created sulfur based lifeforms elsewhere and they're very plentiful, but in our current knowledge this is not possible, so I'm inclined to believe that it's very unlikely that this occurs, rather than that it does.
Why not, in a more–open-minded attitude, be inclined to believe that we do not have the necessary information (not counting the Mars meteorite that was mentioned earlier) to make any respectable assertions as to whether life exists elsewhere in the universe or not?
Just to avoid misunderstandings: i never said "i'm sure that life exists in other planets because there's evidence of it", i merely suggested that it's likely that it does and that i think (but am not sure) that it does. As infoterror said:
infoterror said:
Why believe/disbelieve, since we have no data? Just say: It's possible, and would make sense given what I've seen so far.
And no, it's not the same as believing, it's being open to the possibility.
some dictionary said:
3. (of natural phenomena) arising from internal forces or causes; independent of external agencies; self-acting.
I'm sure everybody here would agree that the appearance of life was / is / will_be a "natural phenomenon". That said, the appearance of something cannot possibly be spontaneous because it cannot possibly be dependent only on "internal agencies" (need i say why?).
a moogle said:
I'm pretty sure there isn't enough bandwidth on this forum for the amount of zero's that would go after just how many chances there are for a situation that could develop into life on some other planet in the universe, most likely thousands of other planets, millions of other planets; and if the universe is infinite (which seems sorta likely), INFINITE other forms of life.
Just write it as a percentage and it won't go above 100.
Dawkins said:
On the other hand, if you look at what's actually happened on this planet, it probably took less than a billion years from the origin of the planet, under fairly unfavorable initial conditions, to produce life.
This made me think of another thing: If our calculations are correct, the universe is fifteen-thousand-million years old, Earth is some five-thousand-million years old or so and life on Earth is a little less than four-thousand-million-years old. Taking into account that scale of time (thousands of millions of years) and not our everyday one (barely a hundred years), 1x10^9 years isn't that much, it's only one-fifth of Earth's life. So if "life" was that quick to appear here (take into account that the early conditions of Earth weren't the same as the current ones, so we could say that it was "another planet") and has survived for all this time (throughout the whole transition from burning planet with unbreathable atmosphere and zero liquid water to nice comfy planet with blue sky and 70%water-30%land, so we could say that we live in a "different planet" than the one terran life appeared on) then it doesn't look like it's all that unlikely, does it?
a moogle said:
Not just bacteria on mars, but foreign organic matter found in a meteor. The meteor was dated to before our own solar system, hence the organic matter could not have been from earth or mars.
Wrong. It could and it most-likely is. It could have gotten there when somebody started dating or examining the meteor (or it could have just bloody gotten there on its own; some bacteria do move, you know).
Furthermore, what the hell does it matter whether the meteor comes from Mars or from another solar system? Since we haven't set foot on Mars, it's not like if the bacteria was already there before it fell down on Earth then we could still have contaminated it but if it came from another system then we didn't, duh...
judas69 said:
At some point I'll read through this thread ..but I want get your opinion on the SETI project (
http://setiathome.berkeley.edu/) if it hasn't already been raised. I personally think it's a clear waste of time more on the side of method.
I agree that it's a waste of time. Intelligent life does not exist in our solar system, and we are light-years away from the nearest system and, if the expanding-universe theory is true, getting farther all the time at great speeds. Considering that the force we'd need to accelerate something to an important fraction of the speed of light (say, a speed greater than the one we're getting farther from other systems at) would exceed the whole production of every country on Earth put together BY FAR (the words 'by' and 'far' are there so that nobody starts going "oh, but maybe aliens have more-effective machines and/or more countries"; it is simply TOO MUCH FORCE), we'll never be able to get to another system, let alone find a system with intelligent life. So, while i believe in and am in favor of the colonization of all of the rocky bodies in this system and the terraformation of some, i don't believe we'll ever set foot on anything outside the Oort cloud. As the same holds true for the other systems (if we can't build something fast-enough to reach another system, the beings in that system can't build something fast-enough to reach ours), nobody will ever find us either.
Furthermore, how likely is it that, supposing an alien civilization received our signals and whatnot, they would a) have the necessary technology to capture the information in it, b) not be tricked by some stupid fanaticism into believing that it's a message from God(dess(es)), c) interpret the information and make some sense out of it, d) have developed space travel (and i'm forgetting my previous paragraph here) and e) be able to track down exactly where the signal comes from?
I take back what i said: it's not a waste of time, it's a waste of time, resources, credibility and interest-in-space (i.e. they could use the time, the resources, the propaganda and whatever credibility they still have in the scientific community to support the colonizations of Mars, Phobos, Deimos, the moon and Venus, not to mention the moons of the outer planets and the dark side of Mercury, instead of wasting it all on futile attempts at establishing communication with a presumed alien civilization.
Edit: I hadn't thought of what Uladyne said about the aliens responding. They'd have to respond, and we'd have to be here when the signal gets here, be looking out for the response and have the technology to understand / track_down / etc the signal.
We are alone in the universe not because of lack of aliens but because of our impossibility to reach or be reached by them if they exist.