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alien life possibility is pathetic

makaya325 said:
Bell, i may have exxagerated the 1000's of factors, my bad. However, the 200 plus factors still stand
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You have a tad of validity in your argument, but you've covered it up with so much muck it's buried. Recently some astronomer/biologists have suggested a lot more factors should be added to the Drake equation which have the effect of lowering the number of likely planets with life on them.

What you've missed however, is adding those to the equation still results in a positive number as a result. It's just less than initial estimates.

Modified Drake Equation

OTOH, we've also found with the Hubble telescope that Galaxies formed earlier than previously thought so that increased one variable in the Drake estimates. And, we've expanded our paradigm to include moons of large gas giants and other potential habitable zones as the discovery of extremophiles on this planet demonstrated.



The fact there is not just life on this planet, but life which has evolved past the microbial level suggests there is at least the likelihood of life elsewhere which has yet to evolve beyond microbes. I would think one needed a number of planets with microbes in order to get one that evolved into multi-cellular forms. And maybe you'd need a few planets with larger organisms before you'd get one that developed technology.
 
The drake equation is at best pseudoscience. Hes to nice to go in depth and add 200 needed factors that someone trained, like Peter Ward, would accept
 
makaya325 said:
Answer this: what are the chances 1000's of unique events happened again?
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Zero. 0.

By definition a unique event can only happen once. However, that does not mean that other events very similar or completely different cannot lead to the same conclusion. The eye evolved independently three (someone correct me if I'm wrong) times so why can't life be produced if there is sufficient chance to do so.


makaya325 said:
Do you not understand that, as of now, our solar system is pretty unique and our galaxy is alot safer and larger than most galaxies in the universe?
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Our solar system is unique but where is your evidence for "alot safer and larger than most galaxies in the universe"? You have provided none. How are you going to provide evidence of this?

There are 125 Billion galaxies in the observable universe. Even if you could check 1 galaxy every second do you know how long it would take you to check them all? That's a maths challenge btw - can you work it out?


3691 Years! - a billion seconds is approximately 31.7 years


You have absolutely no comprehension of the sort of numbers involved. Human beings are not very good with large numbers and statistics so it's not wise to bandy around such statements, they do nothing but make you look at best ignorant. Ignorance can be cure via learning.

No one here is saying that life definitely exists outside of Earth, however, what we are saying is that given the mind boggling number of galaxies that we can see, plus the huge numbers of stars that are to be found in these galaxies then the chances of life occurring is high.

Why on earth (pun intended) would you ever think that Earth is special? Why us? I don't see anything special in humans or dinosaurs.

Why do you assume that life has to be just like we see on our planet? Couldn't there be more than one way for life to come about? Couldn't there be life forms that operate on totally different (and maybe unknown to us) principles? If not, then tell us why not!
 
Those "factors" are nearly meaningless. There are no quantities involved. "If not enough x..." "If too much x..." But no indication of how many orders of magnitude exist between not enough and too much.

Just a ridiculous example, but not precluded by your data: If I have less than a microgram of something, it's not enough. But if I have more than 100 billion tons, it's too much. How could I ever find a quantity within that range?
 
Sun, if life wants to exist, carbon-based, which is the best bet, it will have to follow certain parameters. Life cant FORM on an icy planet or a hot planet, but a just right one
 
from wikipedia:

The Rare Earth hypothesis argues that the emergence of complex life requires a host of fortuitous circumstances. A number of such circumstances are set out below under the following headings: galactic habitable zone, a central star and planetary system having the requisite character, the circumstellar habitable zone, the size of the planet, the advantage of a large satellite, conditions needed to assure the planet has a magnetosphere and plate tectonics, the chemistry of the lithosphere, atmosphere, and oceans, the role of "evolutionary pumps" such as massive glaciation and rare bolide impacts, and whatever led to the still mysterious Cambrian explosion of animal phyla. The emergence of intelligent life may have required yet other rare events.

In order for a small rocky planet to support complex life, Ward and Brownlee argue, the values of several variables must fall within narrow ranges. The universe is so vast that it could contain multiple Earth-like planets. But if such planets exist, they are likely to be separated from each other by many thousands of light years. Such distances may preclude communication among any intelligent species evolving on such planets, which would solve the Fermi paradox.
 
TBONE, again: from wikipedia

Rare Earth suggests that much of the known universe, including large parts of our galaxy, cannot support complex life; Ward and Brownlee refer to such regions as "dead zones." Those parts of a galaxy where complex life is possible make up the galactic habitable zone. This zone is primarily a function of distance from the galactic center. As that distance increases:


Edited by Gaspode: 
Breach of Rule 4 removed. Text copied from http://en.wikipedia.org/wiki/Rare_Earth_hypothesis

Do not copy large sections of text from a copyrighted source. As a guideline, quote a paragraph or two and provide a link to the original.
 
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makaya325 said:
from wikipedia:

The Rare Earth hypothesis argues that the emergence of complex life requires a host of fortuitous circumstances.[...snip...]The emergence of intelligent life may have required yet other rare events.

In order for a small rocky planet to support complex life, Ward and Brownlee argue, the values of several variables must fall within narrow ranges. The universe is so vast that it could contain multiple Earth-like planets. But if such planets exist, they are likely to be separated from each other by many thousands of light years. Such distances may preclude communication among any intelligent species evolving on such planets, which would solve the Fermi paradox.
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According to this, other Earth like planets could have formed. Statistically they may be a small percentage, but a small percent of potential billions is still a large number. So far in this thread you seem to be saying the opposite--that we should not find other Earth like planets. Can you clarify your position compared to the source you quoted?

Or is your premise that if life arises elsewhere we will never find it?

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PS--I am aware I am new in this forum, but not to online bulletin boards. Copy and pasting is generally considered bad form elsewhere, and I would imagine it is here too. Quote one or two sentences at a time and comment as needed, but don't lift entire entries. Post a link and some of your comments on its contents--be specific. The more specific you are in your argument, the better we can determine what you are saying. This will result in less pages of "what do you mean" and "well someone told me once" type posts.

Oh, and when you do copy/paste a quote(s), provide a link to the source. Wikipedia is well known, but it is still a big place and a pain to search through.

ETA: Emphasis and snipping mine
 
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With my very limited knowledge on the topic, I would think it more likely that abiogenesis would occur in more than one place, than only ever in a single location in the whole universe.

I also think assumptions for the set of requirements for abiogenesis will widen with time. The previous assumptions of requirements that many had on temperature and access to the dependency on the suns energy were changed with the discovery of life on hydrothermal vents. Just because life on Earth requires liquid water does that mean that something else could not form which could be classified as life without it.
 
Ok, I went on a little hunt. Of course, someone may post between my viewing the page and my posting this, in which case I will look a little silly. Hopefully not too much.

I hunted down two things, one is the link to mayataks reference, the other is some more information on the Deep Field photo posted earlier.

The long Wikipedia quote directly above my last post is from The Rare Earth hypothesis entry, it is the entirety of the first subsection The galactic habitable zone, slightly edited. It appears shortly after the introduction to the page.

The Hubble Deep Field. If I'm not mistaken, the photo referred to is this one at hubblesite.org. That link points to the intro page, there is a fair amount of other information there as well if you follow the pink tabs. Information includes size of the image in the sky, location, etc. If this is not the exact image, the image in question should be somewhere on that site--if someone really wants to take the time feel free to poke around. (Or poke around anyway, those pictures are pretty sweet!).

Some pertinent information:
Position (J2000): R.A. 3h 32m 40s.0
Dec. -27° 48' 00"

Constellation: Fornax

Dimensions: The image is 3 arc minutes square
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Hubblesite.org looks legitimate, but because I am not familiar with them, I looked up the NASA page as well. A general discussion can be found here. The image and links related to it can be found here. To note, I just realized the bottom-most link on the page I link to IS to the hubblesite.org page I link to above.

Note: Makaya325, the moderators have snipped at least one of your posts due to lengthy quoting. Please fix your post 190 in some fashion (shorter quotes, more comments, or even just a link to point). If you are not familiar with this 'rule', a good rule of thumb is three to four sentences/quote from an external site. It is much easier on you and is more respectable to fix such things yourself than to have action taken against an offending post.
 
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makaya325 said:
Sun, if life wants to exist, carbon-based, which is the best bet, it will have to follow certain parameters. Life cant FORM on an icy planet or a hot planet, but a just right one
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As for an icy planet, Methane could be the solvent used by the biochemistry, in which case a very cold planet or moon would be suitable. Further study of Titan in our solar system may give us insight into this. IIRC, such life could be carbon based. I bet someone could come up with a potential hot weather solvent...
 
The article link by skeptigirl is interesting, but I had two problems with the article (but not related to the point that skeptigirl was making)

"If evolution is the correct theory for the emergence of life on Earth,..."
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Evolution is not the theory for the emergence of life, abiogenesis is.

"Evolution results in species that are conditioned for survival at the expense of others."
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I don't think that "at the expense of others" is accurate. Some species evolve mutually beneficial arrangements over time. Humans actively attempt to prevent extinction of species (although it was often humans that made them endangered in the first place). The article suggests that an encounter with extra terrestrial intelligence would be dangerous due to natural selection (section 7 of the article).

I think that an intelligent species would require large scale cooperation to become technologically advanced. I would think that cooperation requires some sense of fairness (I can not directly back up that assumption, but I think Dawkins book “The Selfish Gene” covered a similar topic, but I read that a long time ago).

I would not be worried by the fact the extra terrestrial intelligent life evolved by natural selection. I would be worried that they may be so advanced compared to us, that they could see us as most humans see Chimps and stick us in a zoo or experiment on us.

But I think it unlikely that we will contact intelligent life for an extremely long time, if ever. Sorry if this post is a little off topic.
 
makaya325 said:
Sun, if life wants to exist, carbon-based, which is the best bet, it will have to follow certain parameters. Life cant FORM on an icy planet or a hot planet, but a just right one
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X knows only of Y to exist and Y only knows of Z to exist.
And Z knows nothing he is still looking the other way.
So X settled on just Y and Y is happy with only knowing Z.
Z gave up and went home.
All just my Hypothetical assumptions of course.
I'll avoid math right now, sometimes I just look at the Universe.
 
jasonlpsmith said:
I think that an intelligent species would require large scale cooperation to become technologically advanced. I would think that cooperation requires some sense of fairness (I can not directly back up that assumption, but I think Dawkins book “The Selfish Gene” covered a similar topic, but I read that a long time ago).
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Well, as far as I recall, Dawkins wrote spent an entire chapter (named "Nice Guys Finish First") discussing exactly why co-operation is such a strong evolutionary advantage in many cases, particularly in any situation that's not a zero-sum situation, such as the famous prisoner's dilemma, which he analysed in splendid detail.

Or as Pratchett summed it up in "Feet of Clay" (paraphrased): "Lord Vetinari stayed Patrician by making the guild leaders realise that it's OK to get a smaller slice of the pie, but ensure the pie is bigger."

Of course, that still doesn't rule out the possibility of a society advancing through a ruthless dictatorship, but I'd like to think that such a society at least has less of a shot of gaining continous technological advances to the point of interstellar space travel, without there ever being a political upheaval at some point. (I'm also making a guess that interstellar space travel most likely won't give rise to a dictatorship either, in case anyone wants to point out that this too is an option.)
 
Makaya, even if we accepted your parameters about galaxy cluster size and restricted zones of galaxies where life is possible, that doesn't help your case at all. Look at that deep field photo again. Count how many spiral galaxies you can see. Those are just the spiral galaxies in a tiny, tiny subsection of the visible universe.
 
Hello,

i'd like to add a few point to this discussion as well.

First, one has to be aware that all the images of the visible universe we have actually show how it was millions to billions of years ago. It would be pretty stupid to look at them and then conclude that there could or could not be any life out there. Things there have changed since, so we don't even know the actual state. All we see is the past, not the present.

Imagine someone would look at a photo of the earth, from 500 million years ago. There would be no way to conclude from it that there could be humans on it at one point in time.

Next, as has been pointed out by others as well, it is patently absurd to judge what defines life based on what we know from earth. It happened here in this way, but that does mean that it is the only way it could happen. That would be like putting a kettle over a fire, see the water boil, and then conclude that only fire can make water boil. Just plain wrong.

Another point is that there also is a very slim chance that biological matter could be brought onto some planet to start things there. We know of extremophile organisms on earth that could very well survive a trip through space. While i must admit that this is a really, really slim chance, it is one nonetheless.

Then, as to the lottery argument. Yes, it looks like a big win in a lottery that there is life on earth. But then, many people won a lottery, not only one person. Using that analogy somewhat automatically implies that life can be possible elsewhere. Again, assuming that life must be something similar to what we know from earth sounds just wrong. Even more so if we recognize that we don't know every life-form on earth either. Deep sea exploration is a hot topic, where constantly new stuff is discovered. So, we don't even have a complete picture of life on earth, who are we then to judge what can be possible and what not?

Finally, as others already pointed out as well, the visible universe is so big that there is no way to rule out life elsewhere. And that is only the visible part. Heck, we don't even now everything and every place about our galaxy, let alone what places in there could be "life friendly". As someone said, to really make sure that there is no other life in the universe one has to comb the whole universe to make sure. Unless that happens, the probability for life somewhere else besides the earth is just really high, imho.

Greetings,

Chris
 
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Christian, Do you realize that extremophiles here on earth would die if put on another planet due to the extremer conditions that make earths extreme conditions look laughable? Even if it is possible to survive on a deadly planet, What are the chances if something like bacteria, which couldnt even survive on most planets, could even ARISE on them?
 
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