Is there life out there?

[thestoat]

"... and pray that there's intelligent life somewhere out in space 'cos there's bugger all down here on earth".

Do you think life (intelligent or not) exists outside of our planet / solar system? There are over 100 billion stars in our galaxy, and something like 140 billion galaxies in the known universe. Would those who believe there is life and also believe in a god also believe that their god looks after those lifeforms too?

[Sub Human]

Oh it's likely there is life out there. If life can form one place what would hold it back elsewhere? I worry about the fact that all life on earth seems to follow exactly the same amino acid DNA plan and nothing is working with a different schematic. That seems to indicate either that only one plan is possible or only one plan is tolerated. There might be a better way to form life, more efficient say, but intolerant DNA managed to assemble first and blocks any newcomers.

[tyro]

That seems to indicate either that only one plan is possible or only one plan is tolerate

d.

Or it could mean that the initial jump from lifeless to something capable of reproduction is a big hurdle. Then, once life as we know it took hold, the competitiveness of survival was in our favour.

[Rick]

Well at the very least the next plan will have to be c.

b is taken...

[Gob]

I think it would be highly egocentric of us to think we are alone and unique in this universe.

[loCAtek]

"... and pray that there's intelligent life somewhere out in space 'cos there's bugger all down here on earth".

Do you think life (intelligent or not) exists outside of our planet / solar system? There are over 100 billion stars in our galaxy, and something like 140 billion galaxies in the known universe. Would those who believe there is life and also believe in a god also believe that their god looks after those lifeforms too?

The scientists say that at the microscopic level, there is probably plenty of that sort of life. Developing past that is the tricky part, and takes so many ideal conditions that almost seem guided by a divine force.

[dales]

Mathmatically, it's very probable :ugeek:

[thestoat]

Developing past that is the tricky part, and takes so many ideal conditions that almost seem guided by a divine force

If we assume the "known universe" is all there is, then let's do some maths. Assume only 1 in 100 stars have one or more planets (current thinking is that the number is way more than that) and assume only 1 in 1000 of those planet systems have conditions that could form life.

We know there are around 100 billion galaxies, each containing very roughly 100 billion stars.
Then in the known universe, we'd have something like 10^22/(100*1000) planets that could in theory contain life.

That's a billion billion star systems out there that could contain life. And we're the only one that has evolved beyond the microscopic level? I think not.

[Andrew D]

The problem is that even if we correctly calculate the number of "planets that could in theory contain life," we still don't know the odds -- the likelihood that a planet which could have life on it actually does have life on it. For all we know, those odds are one out of a billion billion.

Likewise, we do not the the odds that even a planet which does have life on it does (or, for that matter, even will eventually) have intelligent life on it. For all we know, those odds are also one out of a billion billion.

If only the first of those is true, then for our planet to be the only one with life on it is perfectly in line with those odds. If only the second of those is true, then for our planet to be the only one with life on it is perfectly in line with those odds. And if both of those are true, for our planet to have life on it at all represents the occurrence of a mind-staggeringly unlikely event.

[thestoat]

And if both of those are true, for our planet to have life on it at all represents the occurrence of a mind-staggeringly unlikely event.

Absolutely. This is why we cannot say for sure that there is life on other planets. You simply have to draw reasonable conclusions from what you observe. Your statements - for me - have too many ifs. We have seen life grow on this planet in unexpected and highly inhospitable places and thrive in very very hot or cold conditions. This suggests that the goldilocks principle (that a planet can't be too far to too close to its sun, but just right) provides for a much bigger range of potentially habitable planets than previously expected. Obviously, if it were found that there were 7 bagooglion planets out there, someone could always say "but maybe the odds of life forming is 1 in 7 bagooglion", and maybe that statement is true. I just don't believe so personally.

Further, of course, most scientists talk of "life as we know it", which I assume means carbon based (I am not a biologist so forgive any inaccuracies here). Maybe elsewhere life is based on Boron or Nitrogen? The universe is a big place (I think Douglas Adams may have coined that phrase) - I find the possibilities hugely exciting, even though they are likely to remain academic.

[loCAtek]

Well, the known life (that is on Earth) is carbon-based because carbon is such a simple molecule.


Wiki;

Carbon forms the backbone of biology for all life on Earth. Complex molecules are made up of carbon bonded with other elements, especially oxygen, hydrogen and nitrogen, and carbon is able to bond with all of these because of its four valence electrons. It is often assumed in astrobiology that if life exists somewhere else in the universe, it will also be carbon based. This assumption is referred to by critics as carbon chauvinism.

The other elemental molecule that is speculate to able to bond with other element to create life is perhaps silicon.

[thestoat]

Carbon chauvinism. Love it

[Crackpot]

All hail the Horta!

[Miles]

My mind boggles trying to comprehend an unending space. That black void that has no boundries that expands in all directions into infinity. Do I believe there is intelligent life out there, certainly. Only those who are stanch believers in God as our creator would say we are truely alone in the universe. On the other hand if earth and life as we know it are just an experiment of God perhaps we are one of many. You know like some giant petry [sp] dish. Just one of many.

[Gob]

If we are an experiment in a Petri dish, I want more tentacles please!

[Gob]

[Grim Reaper]

I worry about the fact that all life on earth seems to follow exactly the same amino acid DNA plan and nothing is working with a different schematic.

Alien life may already be among us for all we know.

Discover and Scientific American both have articles about how different forms of life may still be around.

Only about 1% of all bacteria have been cataloged, so there's still a lot to learn about Earth.

[loCAtek]

Mostly Harmless

[thestoat]

Alien life may already be among us for all we know.

Gordon Brown springs to mind ...

[Gob]

LOL!!