My common sense tells me that out of the number of stars in the universe there has to be another intelligent lifeform. If they are advanced enough to travel that far then they are probably advanced enough to keep from being seen. So you may never see proof.

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"I'd buy that for a dollar."

Sure I believe there are Aliens out there somewhere, we can't possibly be the only forms of life in the endless space out there. I doubt there ever come to earth though.

Hy.

lilandpeter reminded me of a show on the Discovery Channel, where they showed a few "alien" creatures (from our own planet) that dind't need any oxigen. Think of those white crablike things that live on the edge on underwater geizers, there's no oxigen there, only sulphur, so that means that not all life needs oxigen.

Also, in another TV show they showed that most bacteria is not harmed by a meteor impact, i mean, if the bacteria would end up in space and crash into a planet, the heat and G forces alone would not destroy them, so it raises the question, did life start on our planet or this planet was simply "infested" by some sort of bacteria that in time evolved in all the living creatures you see (and some you don't see) that inhabit this world.

Anyway, the ideea is that there are so many misteries about life, that we can't be shure what is the definition of life, so who knowes how do alien lifeforms look like.

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There's no teacher who can teach us anything new
He can just help us to remember the things we always knew!
E N I G M A

Yes ----- well assume Man the sometimes Wise can know the answer !
Whilst I somehow know there are no KLigons or Vulcans in my immediate space everytime I dip into Star Trek ------ I know that complexity and scale of the Universe means Big Green "men" probably have evolved elsewhere!

And this can be and is so scary to the average educated human that he will need to say "NO!' to the proposal in case he or she may meet one ! Forget the perfectly acceptable argument as the real premises!! The person who says No here is really just afraid of the unknown when he already "just knows" there is intellegent life out there in the Cosmos.

Although I have been wrong often before - I suspect that I too an afraid of the Monsters ---- and someday soon human beings may meet some of these! And I am really saying I want to have the No position in my arsenal of response but I "just know" there are unknown intellegent living species somewhere right now !

The simple answer is yes.

If you want more see my post in the previous topic (Are we the only form of consious life?).

Life as we know it also needs carbon or silicon (because only carbon and silicon can form 4 covalent bonds). Carbon has a lot of advantages over silicon too. There also needs to be some kind of surface in order for there to be complex life forms. There must be a solvent of some kind (not neccessarily water, although it has many advantages over all others, such as melting/freezing/boiling temperature, and the fact that it expands as it approaches freezing point so that ice forms on the top of a body of water). There are a few others that I can't remember of the top of my head. I recommend reading a book called "worlds unnumbered" by Donald Goldsmith. It's about the search for extrasolar planets, and there is a whole chapter on the probability of intelligent life existing in the universe.

I don't think our galaxy is swarming with life. Perhaps there are another half a dozen civilisations our there.

Kashi

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Climate Change Australia

My answer is yes, I mean the thought that we are the only ones in the universe is quite scary.

I believe there is alien life out there, it doesn't have to be the klingons or vulcans. I would be even suprised if they found green slime on europa or other places in the solarsystem than earth.
Our world may not be technically advanced to travel to other worlds or prove there is alien life out there, but that doesn't stop me from believing.

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Always has time for the stars

Stephen Hawking gave a speach at the end of the cold war saying how the greatest single danger humanity faces is the threat of nuclear war (which is fair enough considering that Russia and America still have enough nukes pointed at each other to kill every living organism on the planet several hundred times). He said that there's a sick joke going around that says maybe the reason why we haven't been contacted by alien civilisations is that most civilisations tend to destroy themselves when the reach our stage!

Scary stuff.

Kashi

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Climate Change Australia

That is a scary thought, but I sure would like to believe that there are some advanced races out there with enough wherewithal to survive this stage and advance to the next, which hopefully is some form of planetary peace.

maybe they are as small as viruses out there
but we couldnt have been the only creation. i dont think they will reach us cuz the cozmos is so incredibly spacious and we are spread out evenly with lotsa space between.
i dont think aliens are like those i horror fiction alien movies.
dwarf-like, maybe.
thats why they cant reach us fast.
theyre puny

There is no way that earth is the only planet with "intelligent life". I think that some people’s religious beliefs are getting in the way of this question. Yes there is life on other planets. Yes some are intelligent and yes some are not. All in time we will finally prove this. I only wish to die knowing that we are not alone.

N=R*fs*fp*ne*fl*fi*fc*L

R is the average rate of star formation in the galaxy, equal to about 20 stars per year (i.e. recent HST observations of M16 showing star formation sites).

fs is the fraction of stars that are suitable suns for planetary systems, approximately 0.1 (most stars belong to spectral type M and are probably too small, whereas a few, such as O and B stars, are too short-lived). The circumstellar disk around Beta Pictoris is evidence of planetary formation.


fp is the number of suitable suns with planetary systems, now thought to be around 1/2 (i.e. 51 Pegasus discovery), a value that has made scientists optimistic about the possibility of intelligent life elsewhere in the galaxy


ne is the mean number of planets that are located within the Continuously Habitable Zone (assuming liquid water is necessary for life)

fl is the fraction of such planets on which life actually originates (given enough time primative organic substances will be synthesized into DNA and RNA, recent detection of the amino acid Glycene in the ISM by radio observations)

fi represents the fraction of such planets on which, after the origin of life, some form of intelligence arises (evolution probably occurs wherever life arises, and intelligence has survival value

fc is the fraction of such intelligent species that develop the ability and desire to communicate with other civilizations (they construct radio telescopes or laser systems)

L is the mean lifetime (in years) of a communicative civilization (because it depends on the NATURE of the race of intelligent beings it is the most uncertain factor in Drake's Equation)

WWW.seds.org/~rme/drake.htm

This page will allow you to enter your own numbers.

As far as religious beliefs go, I think God could make any creature live anywhere in the universe. The human race is nothing special.

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Insanity: doing the same thing over and over again and expecting different results.
Albert Einstein

Maybe we humans are not the most highly evolved beings on this planet in the sense that there are species' with greater endurance (eg. bacteria might out-survive us in the event of an asteroid impact, and bacteria are less likely to destroy themselves in a nuclear war).

Going on what Professor Hawking said, perhaps humans are an evolutionary dead-end, and that all we can hope to find "out there" are microscopic organisms.

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Climate Change Australia

Yes, why not keep our options as widely open as possible. I was looking at the night sky over the last few nights here in NZ and I've never seen so many stars and planets. The nebula array is simply breathtaking... and I can see only a flyspeck of the Universe.
While I do respect the opinions of those who can use scientific theories to 'prove' the optimists 'wrong', I recall Pasteur's 'germ theory' (still used by pharmaceutical companies to push all sorts of noxious crud) being shown to be false a few years ago. It may take a few years, a few million years, or maybe tomorrow even, but I think we'll make verifiable contact sometime (if we don't wipe ourselves out first).
One last thing; someone mentioned bananas being 'strange fruit' without seeds... bananas are actually herbs and they do have seeds, some non-commercial varieties are still grown this way as opposed to the commercial practice of grafting and so on.

Another Kiwi here with more on Bananas. The edable variety is a genetic mutation and has no seeds because mutations are invaribly sterile, they only survive because people find them so tasty.





Oh and on life in the universe. The potentiality for life is so varied there must be some somewhere, why not?

Evil (It's life Jim but not as we know it)

come on someone had to.

Welcome to the Universe Today forums Evil Steve and 4stix. Keep on postin' :-)

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Publisher
Universe Today - Free space news delivered by email every weekday.

I think that there is life in the universe, due to two reasons :

(1) Firstly, I is simply idiotic to suppose that we are the only form of life in a universe with a billion galaxies , each with a billion stars.

(2) Secondly, that WE are made up of carbon and oxygen doesn't imply that
life forms cannot be made up of other things (silicon, maybe ,we are close to doing it on our own planet)

I hope you agree with me.

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Limericks, written by me: http://limericker.blogspot.com

Yes, i do, and will leave it at that =)

. ..-={A}=-.. .

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. ..-={A}=-.. .

Perhaps life isn't as abundant as we might have thought. Great article:

http://www.sciam.com/article.cfm?articleID...B81809EC588EF21

Also rahuldandekar, I think that silicon based life would be much less likely to exist than carbon based life, as carbon atoms form more compounds and share much stronger bonds, making carbon based substances more resistant to temperature etc.

Kashi

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Climate Change Australia

Yes, that's a good article. BUT, there are a few things Campbell either glosses over or doesn't mention in his short overview.

On the negative side, though he does point out that the fact that it took so long to get beyond unicellular life on Earth indicates that multicellular life may be hard to do and uncommon, we can also see that we are obviously the only technological species. There seem to be several other species with some degree of intelligence and self-awareness on Earth, but none of them, not even our extinct hominid ancestors, have developed the ability to use abstract symbols and language anywhere close to homo sapiens. This may indicate that this particular type of intelligence, presumably necessary to technology, may be uncommon even where otherwise intelligent, self-aware life is common.

On the positive side, though Campbell does point out that if there were other civilizations, Earth would almost certainly have been visited by now, he seems to neglect to consider that :
1. Such a civilization would necessarily be very advanced compared to where we are now (likely measured in hundreds of thousands, if not millions of years), and
2. We have not really considered how such a very advanced civilization might behave, or even how we could recognize it if it was right in front of our faces.

We can only wildly speculate on behavior, but we can place some rough limitations on recognition. For instance, if you were to hand a chimpanzee a banana and a digital watch, which would the chimp likely find more interesting? Maybe if the "digital banana" could do something like make more bananas if manipulated correctly you could get the chimp's attention, but if it just told you the exact date, time in all zones, etc., and didn't look edible, I doubt it. Carl Sagan made much of a lack of artifacts of an advanced civilization, but to my knowledge never considered that we may not be able to recognize one if it were handed to us. In other words, it would have to fit into our pre-existing concept of an artifact.

And even though we can only speculate on a very advanced civilization's behavior, that does NOT mean we should assume it would behave like ours (land, pave the place, and open a Starbucks) or set rules for itself that resemble ours.

I dig your analogy about a chimpanzee's priorities!

Can someone answer a question for me? I want to know whether there is actual evidence (i.e. fossils) of more than a handful of species at different stages along the evolutionary path towards modern humans. If we evolved from the apes, why do they till exist, but no "in between species" remain?

Maybe we ARE one of the "space colonies" Campbell mentions in the Scientific American article!

Kashi

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Climate Change Australia

That is an interesting idea. I think it was the premise of Battlestar Galactica (if you are old enough to remember the '70s!). Douglas Adams also used it in THHGTTG. It's kind of a cool idea.

There is this quote I love. I don't remember where it is from, but I think of it often:

"The surest sign that there is intelligent life in the universe is that it hasn't contacted us yet."

If anyone knows where that is from, I would like to know!

A couple of people have mentioned the carbon-based issue. Who's to say that all life out there is so similar to us? Maybe there are critters out there that enjoy a leisurely stroll on a 200'F (or -200'F) day; or that need to breath methane fumes; or that consider pasteurized cheese food product to be a rare and tasty delicacy? (I know that last one is a bit of a stetch!)

Maybe we are looking for the wrong type of planet? Maybe there is life out there that is not so close to a star. Maybe photosynthesis isn't the be all and end all we think it is.

Then there is this: There is a lot of space out there, but there is also a lot of time. Maybe that elusive life we are hoping is there (or hoping isn't there) has already come and gone a very long time ago. Or maybe they are still in the "primordial ooze" stage of development; by the time they are able to wonder about us, we'll have long since come and gone. Timing is everything, my friends.

SETI is listening for signals. Ok, but maybe the life that may (or may not) be out there has no desire to be heard or found. Maybe they consider us the wierd neighbor that they avoid making eye contact with. Maybe they are watching our late night infomercials and think we are just the type of neighbor that is best kept in their own yard. Maybe our broadcasts are messing up their radio reception so they're going to come over, knock on the door, and insist we turn down the music or they'll call the cops.

Well, my answer to the yes or no question is: Maybe.