advanced life

[dannyday5821]

ya know how the popular belief is that if we ever find any other life existing anywhere in the universe - that its likley to be more advanced that us...

what if it isnt? what if we are the advanced life in comparison to them? all these films and stories and tv series about finding other life thats so much more advanced than us - why havent i seen anything before that says actually, us humans, as the most advanced?!

why not eh? no seriously, am curious!

[jake-the-peg]

We only know one example of what you'd probably call advanced life forms (and that's us).

It's therefore very difficult to estimate what the average lifespan of an advanced civilisation is.

That's important because it's the last term in the Drake equation

http://en.wikipedia.org/wiki/Drake_equation

That equation seeks to estimate how many detectable (in other words advanced) civilisations there are in the Universe/Galaxy/local area.

Now if the estimates you come up with gives you a high value for that there are lots of advanced civilisations and it's therefore unlikely that we are the most advanced.

If however you get a low value then we might very well be the most advanced.

I would think it's unlikely that we are the most advanced if you're looking at the entire Universe because there are an awful lot of stars out there! Life started very quickly on Earth so it's probably quite common.

But the Sun is not all that old so there's probably a lot of planets that have a bit of a head start on us

[heathfield]

To paraphrase 'The Hitchhiker's Guide...' - ''A big hello to all intelligent life everywhere in the universe, and for the rest of you, just keep banging those rocks together.''

[R1Geezer]

The only other life we are ever going to see will probably be microbial and certainly local. Mars hasn't been ruled out entirely, other candiadates include Europa and Titan.

However as I've said countless times the Universe teems with life, unfortunately the scale is so vast that we will never comminucate with it.

Cue the start trek Stuff! I'm ready! Even at warp 100, communaction with even the closest star is impractical.

[Clanad]

An important (at least to me) fact in this discussion centers on the determination by most astronomers that Population I stars (such as our Sol) are all either the same age (relatively speaking) or are or will reach the same metallicity component. Population I stars are further classified as "Extreme" or "Intermediate" depending on metal content. Our own Sun is an "Intermediate", all of which are just a few billion years old.
Presently, it doesn't seem feasible that any life could develop on Population II or "Extreme" Population I stars.
This seems to me to have huge implications for any life, much less advanced life "out there" since it's believed and pretty well confirmed that no Population II stars can support life even if planetoids or planets orbit them and, of course no Population III (the oldest) stars are known to exist.
Since out own star and our own planetary system are the same age (roughly 4.5 billions of years old) and, as jake alludes, the earliest life appeared on earth early at 3.8 bya, then, by reference no other solar system could be expected to have developed life much earlier, hence a major factor in the lack of supposed "advanced life" systems...

[jake-the-peg]

No Clanad there's a major flaw in that argument

You're assuming that our Sun is the oldest population 1 star capable of supporting life and you have no evidence for that.

Pop 1 stars can be up to 10 billion years old.

Even if there was only a small variation of say 10 million years you could have an advanced civillisation that much older than ours (assuming they survive that long see my above point)

If your point is that it's unlikely to find advance life form billions of years older I'd agree but in the same way that a week is a long time in politics a million years is a long time for a civilisation.

[beso]

We only went beyond microbes just 600 million years ago. The rate of rise of complex organisms was spectacular once it got underway.

This step could happen at any time in in the history of life so it is quite possible that some Population I systems could have developed complex life very early while other never moved beyond microbes.

We really have no way of knowing where we stand in comparision to other possible civilisations.

However like any very successful population we are already threatening our environment and depleting our resources. I expect that many an advanced population has wiped themselves out.

[heathfield]

Drake assumes that where planetary conditions would permit the creation of lifeforms, then they will be created. (fe=1, or 100%). That's a big assumption. In the case of our solar system, this would include both the Earth and Mars, (ne=2) . If we find that no life ever existed on Mars, then fe becomes an unknown quantity, and the equation becomes invalid.

[Clanad]

Well stated jake... except that the Intermediate Pop I stars must also be in the main sequence class... which dramatically reduces the quantitiy. Additionally, according to Henden and Kaitchuck (1982), "...More specifically, upper main sequence stars are not found among population II stars, while though they are rare among population I stars, they are among the brightest population I stars..."
Development of any planetary life is highly dependant on the metalicity of the parent star and greatly narrows the age range for such a favorable condition.
Lastly, the number of characteristics required of a galaxy, star and solar system for any life to emerge is staggering... but at the very least, the only star (so far) observed to achieve this is our own Sun, classified as a G2 which strongly infers all other suitable stars capable of supporting life in it's planetary system(s) must be similar...

[joko]

i think the main reason it is assumed they will be advanced is because in order for us to ever meet them they will have had to have travelled from a massive distance away - much much further than we could manage - we know there is nothing within our immediate vicinity...therefore their technology would have to be hugely advanced to cope with it....and presumably they would have to know we were here already somehow otherwise the chances of them just so happening to come to this galaxy must be millions to one...

that is unless of course, being aliens, they dont need oxygen perhaps, or can grow sustenance extremely easily, and their fuel is self regenerating or something...so their crafts can easily go wherever they want, with little extra special engineering...

[wildwood]

There are 2 million+ species of life on Earth, and certainly many more as yet unclassified. Why do we presume anything like Humans (described as intelligent?) on other worlds.

[LazyGun]

@Wildwood - I am not sure that those who speculate scientfically as it were about life originating elsewhere other than earth assume it will be human-like; Mostly, the only ones who speculate that it will be are producers of popular science fiction programmes, and the reason is blindingly obvious - far more dramatic narratives available if aliens were human like.

Pragmatically speaking though - It might well be true to say that there would be precious little grounds for interaction between say a hyper -intelligent gas cloud used to the atmospheres of Jupiter like planets, and ourselves - Not many points of common need when discussing trade, or art, or even science and medicine really.For us to have any meaningful interaction with an alien civilisation, it probably needs to have arisen from similar roots.............

[jomifl]

It is possible that the sun is one or more intelligent beings , there is no shortage of energy and the strange magnetic fields may have more to them than we suppose.

[heathfield]

http://www.newscienti...-in-the-universe.html