Astrobiology--for real!

[JadziaKathryn]

Actually if I remember correctly the idea that any intelligent civilization out there would be millions or billions of years ahead of us was put forward by Dr. Frank Donald Drake(I may be wrong but I think he said it in some documentary on Discovery Channel). I agree with the idea and it makes sense.

Why?

You know, we're kind of assuming that all theoretical alien civilizations would want to explore space. What if they didn't? (Consider China in the late Middle Ages - neverminding that the term Middle Ages is European: they had the capability to explore the oceans, but except for a few years under one emperor they didn't. The next emperor even burned most of the records, but historians mostly agree that they reached Africa anyhow.) What if they weren't as curious as most of us humans now are?

ANOTHER QUICK THAN I'LL SHUT UP RELIGIONS PERSPECTIVE...ONCE AGAIN IF YOU ARE OFFENDED BY THIS KINDA THING JUST IGNORE THISIf I remember correctly there are other religions out there that mention visitors from "other worlds", but for the life of me I can't remember which ones do at the moment....I'll have to look around and see.

Mormonism is based on it. That's all I'm saying because my views will inevitably color my opinion. If anyone really cares they can PM me.

I seem to remember some UFO stuff from the Bible being on the History Channel too. Like that guy that was taken to heaven without having to die (forget his name).

Enoch.

[blacknblue]

Why does everyone seem to think that aliens would want to vist us? I think it's a cultural hubris of a most revealing type. Really, if there are aliens coming close to Earth, they've got to be pretty advanced to have long-distance space travel. What if they took a few scans or caught some satellite signals and said, "These people are pumping out pollutants and can't stop killing each other. We're outta here!" (This assuming they could translate our satellite signals, which could be extremely difficult as well.)

***WARNING. THE FOLLOWING IS A RELIGIOUS DISCUSSION BASED ON A CHRISTIAN PERSPECTIVE. IF THIS OFFENDS YOU, GO AWAY AND DON'T READ IT. ***

Actually, I have seen at least two (2) references in the King James Bible that support the idea of life on other worlds. One more than the other.

In one place in the New Testament, one of the disciples describes Jesus as the means "by which he (God) made the worlds" (emphasis added). It think it was Saint John, but not positive on that.

In another place, just before ascending to heaven, after rising from the tomb, Jesus told his disciples that he had to leave them for a time. "And other sheep I have, that are not of this fold. Them also must I gather in..." or something like that. You can look up the exact language. I think I am quoting it correctly, but you better double check me. It is always better to double check me. Anyway, the way I read it, it hit me that it could be interpreted to mean that he was going to go visit other people in another place to teach them, just as he had here on Earth.

Anyway. There may be other places in the Bible that could be interpreted that way.

Well, my Bible is New International Version, but I've never even heard of anything like this second verse. And I checked the end of all four gospels plus the beginning of Acts. *shakes head* Verrrry skeptical of that.

I was referring mainly to Genesis 1:6-8. Like I said, though, I find it highly unlikely. But I don't rule it out because one never knows.

John 10:16

<quote>

And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.

</quote>

I may have mis-remembered the placement however. Re-reading it, it seems that the statement was made earlier. So he could have been referring to Gentiles. But you never know.

BTW, The first reference I mentioned is in Hebrews 1:2 and 11:3.

[blacknblue]

If life develops independently on various worlds, why wouldn't it be at various points of development all over the place? Right now, if I remember correctly (please correct me if wrong) our sun represents the most common type in the galaxy. There are lots of stars older than ours, and lots of them younger too.

[Entilzha]

Life may be out there in various stages of development but any intelligent life would most likely be far ahead of us but not behind because humans haven't been on this level of intelligence for very long and the odds that a civilization is at the same level or similar to us is astronomical(again not my idea but I agree with it).

[Rigil Kent]

To which I have to wonder, why is it automatically presumed that any other alien species are more advanced? It seems kind of silly to expect that any such intelligent life is so much more advanced than we are. It seems, to me, just as likely that any such alien life is going to be less advanced than we are, not more advanced. Evolution is a slow process, so presuming that it'd move along faster for some other species doesn't really make much sense...

The insistence on a much more advanced race seems almost like a religious belief, as in "only the advanced, evolved aliens can come here to save us stupid, backwards monkeys from ourselves."

JMHO.

[Entilzha]

If there is intelligent life out there they would have evolved long time ago and in order to be alive at the moment they would have to be very technologically advanced.

[Rigil Kent]

And you know this for certain how?

ETA: Until we actually meet intelligent alien lifeforms or discover actual proof of their existence, automatically presuming that they are both highly advanced and much more intelligent than humanity doesn't make much sense to me.

[johndo22]

To which I have to wonder, why is it automatically presumed that any other alien species are more advanced. It seems kind of silly to expect that any such intelligent life is so much more advanced than we are. It seems, to me, just as likely that any such alien life is going to be less advanced than we are, not more advanced. Evolution is a slow process, so presuming that it'd move along faster for some other species doesn't really make much sense...

any civilazation that will be behind us by more then several decades will not have radio technology or computers so it wont be able to communicate with us or made its existence known I assume that the presumptions made about alien civilazations who able to at least communicate with us for this kind of operation you need an huge transmitter (at least several hundreds KHW for 5 light years assuming the other sing have very large reciever and its direct on your position or very close to it for real comm you need hundreds of MHW) any civilazation who can build it is more advanced than us beacause we didnt do it yet (the SETI is listening not transmitting)

[Entilzha]

In order for a civilization to survive for a long time they would have to overcome a lot of difficulties. Most of it are related to survival in the universe which isn't very friendly.

[Kevin Thomas Riley]

I think that in the past few years, the chances of extra-terrestrial life has risen by a significant amount. Why? Because we've found that there exists numerous planets (100+ or something) around other stars. When we eventually learn to detect smaller, rocky planets in the habitable zone, then the chances get even higher.

Still, all we can now talk about is qualified guesses based on the limited knowledge we do have. We know that there is a high probability that stars have planets. We also know that if the conditions are right, organic molecules will form and probably simple life forms as well. Whether or not this means that more advanced life forms, not to mention sentient life forms, will be found out there is an open question.

Personally I believe that with the billions and billions of stars out there, that there is life out there, even intelligent. Considering the age of the universe, there are probably some extinct intelligent life forms that have left artifacts. And there are probably some currently living.

However, due to the vast distances out there, I think that the likelihood of us ever meeting other intelligent beings are remote (unless we invent FTL drive, which I don't think we will, even if I really, really would want that). Radio communication is probably what we're stuck with and that would also be a constraint due to the time it would take for the signals to travel (unless we invent subspace communications, which I don't think we will, even if I really, really would want that).

[Rigil Kent]

In order for a civilization to survive for a long time they would have to overcome a lot of difficulties. Most of it are related to survival in the universe which isn't very friendly.

But, again, you're making blanket assertions without any proof. We have no idea what the universe is like beyond what little we can see from this planet. Automatically assuming that any species that exists beyond humanity are more evolved and more technically adept doesn't make sense. For all we know, a species could develop on a planet where the conditions are even better than Earth's, so they aren't as smart, or as fast, or as capable, yet they've been around for eons longer.

Now, if you're talking about a species that can communicate with us now, that's a whole new ballgame...

[Entilzha]

I am referring to the present time frame in my assumptions. If a species doesn't evolve technologically and sociologically far enough they would not survive for long because there are enough things that can destroy them(on the surface of the planet or from space).

[JadziaKathryn]

Now, if you're talking about a species that can communicate with us now, that's a whole new ballgame...

I also think a lot depends on how you picture life. If there are plants but nothing else, you can say that there's life on the planet, but it won't be sending us radio signals.

BTW, The first reference I mentioned is in Hebrews 1:2 and 11:3.

Hmm, my translation has 'universe' instead of 'worlds.' I wish I knew ancient Greek! It's an interesting thought, all of this, but still, my life goes on the same.

[Elessar]

What it depends on - Drake's idea - is whether or not there is a functional relationship between how old the star systems in a galaxy are (2nd, 3rd generation, etc) and the chances of complex life developing on them. We can only argue that humans are likely to be ahead of the other races in the galaxy if it can be shown that complex life is less likely to develop in the first few billion years of a galaxy's formation than in the later stages. In other words, our galaxy has been around for awhile -- if there is some property of an early, developing galaxy which prohibits or impedes the development of complex life inside the first 5 or 7 or 9 billion years, THEN there's no reason to believe that there should be other more intelligent life forms than ourselves which have been developing for the past 2 billion years or more. However, if there's no evidence to suggest that the habitibility of stars in a galaxy vary with the age of the galaxy in such a way that habitability peaks around the age we are currently at, then it is logical to assume that an arbitrary star system in our galaxy was just as likely to birth new life in the preceeding 13 billion years as it is today, i.e., that those civilizations could be still around.

The other possibility which yields a situation in which we are more advanced than most other races is if there is a peak level of technological development after which a society ceases to grow and begins to decline, eventually falling and no longer advancing, and that we are just prior to that peak. Then we would be more advanced than most or all other races in the galaxy, if none have been able to survive much further beyond where we are at. I'm not suggesting this is the case, just playing devil's advocate to Rigil and Ent's points...

Personally, I avoid making concrete statements of fact with respect to astrobiology because there are so many holes in our knowledge of stellar development and ... the entire field of astrobiology. It is in the same stage as particle physics was in 1900.

[justTripn]

Ooo . . . I wish I really had time to recheck my facts since this discussion is getting good.

Basically, I'm about as pessimistic/optimistic (is the glass half full or empty?) as KTR, Asso, and maybe Elessar. I think that simple, nonsentient bacteria-type life should be common in the universe. Why? Because it evolved on this planet pretty much instantly as soon as the era of heavy bombardment (astroids hitting and melting the Earth) ended. That is as soon as the world cooled there was simple life. It may have taken only 10,000 years, which is nothing in astronomical terms.

I just checked my facts. The Earth is 4.5 to 4.6 billion years old, but for most of the first half billion years it was molten.The age of heavy bombardment ended 3.9 billion years ago. The first fossils are from rocks 3.6 billion years ago and they show identical to bacteria on earth today.

People are beginning to consider the evolution of simple life to be inevitable, whereever conditions permit. They suspect that simple life may have evolved and been wiped out several times--by astroids that boiled away the ocens. Very recently, scientists are suggesting that life on this planet may not have evolved once but TWICE. That viruses and DNA-based life are in fact two separate coexisting lines of life! (viruses have not typically been considered life, but maybe they should be.)

As for complex, sentient, and intellegent life, I am somewhat pessimistic. I think they are out there of course (or have been or will be out there--and given the distances involved, the distinction between "now" and "then" is kind of ridiculous and irrelevant (much of the light reaching us is billions of years old). It makes me happy just to figure that somewhere, long, long ago, in a galaxy far, far away . . . . yes a whole different civiliation from ours took place.