Not sure what I saw?

[Poita (Peter)]

The amount of planets etc. in the known universe sounds very big, but the chances of a DNA based software/hardware system developing so far hasn't been shown to be exactly likely, so even from a statistical viewpoint it may not be in favour of life existing elsewhere.

The stuff found in the Martian meteorites hasn't been proven to be bacteria, it looks a lot like it, but the size is way, way, way smaller than terrestrial bacteria, small enough that many scientists believe it would be too small to be able to exist, and that the deposits in the meteorite may be something else altogether. As far as I have read (and I could be totally wrong) the jury is still completely out on whether they represent life or not.

We certainly aren't unique or special amongst life on earth, we share nearly all of our genetic code with mice for instance, but the DNA/RNA system is incredibly unlikely and difficult to come up with from scratch, I believe it did happen here through a random chance (I don't believe in any kind of Skybully creator) but unless we find some as yet undiscovered laws, then the chance of it happening are almost infinitesimally small. Either that or the laws of physics are biased towards the creation of intelligent life, which is a pretty astounding claim.
Either way, we can't know unless we either
(a) find life elsewhere that didn't get there from here, or us from there (i.e. if we found life on Mars, it would mean nothing if life on Earth evolved from bacteria that arrived here in Martian meteorites)
(b) discover something in the laws of physics, or in a new law that biases molecules towards forming life.
We are all just speculating until some new discovery is made that tips the scales one way or the other.

Originally Posted by Amunous

It would be VERY VERY foolish and arrogant of us to believe that we are the only intelligent life in the universe, considering that we know the universe is at least 15 billion light years wide. (That we can see)

Consider all the galaxies and solar systems and planets that have the possibility of sustaining life. We have 2 in our solar system alone, and there are several within a few light years of us.

There is NO way we are alone in this massive universe.

Now whether they have visited us is another debate all together, but to turn around and say there is no life anywhere (without evidence to support your rant) just because you don't believe that if there was they wouldn't come here. Is naive and arrogant. We are NOT special, we are NOT unique (Look at how close we are in genetic make up to pigs and monkey's.)

There is too much evidence to suggest we are not alone.


Oh i forgot to add.. the fact that we have found bacteria on mars.. makes anyone who's argument that there is no life in the universe negated. We have FOUND life on other planets. Albeit not intelligent life but life none the less.

We are shaped by our knowledge of whats around us and what we have been taught (very very very very limited knowledge.) There quite frankly could very well be civilisations vastly more advanced than us. (millions of years more considering that we are considered and infant race.) Whats to say they cant travel millions of km at speeds we just don't understand. Them visiting us might be like us taking a trip to Sydney, or taking a trip to the shops. Purely because they are using technology that we just don't understand, and just because we don't understand it does not mean that it doesn't exist.

I could go on and on and on, and no im not some science fiction nut that goes out looking for UFO's spouting rhetoric about how were being visited by aliens so just stop before you accuse. I'm merely more open minded to something than to suggest that it doesn't exist without evidence, or because i was told it doesn't exist. (Like two people looking at a wall and one turns to the other and says that wall isn't there, and the first one nods and says yeah i agree, while a third walks up and paints it.)

[CraigS]

Greetings all !

In the hunt for exo-life discussion, I find three curious statements which can be stated with certainty:

1) the uniqueness of life to Earth can be instantly disproven with the first confirmed exo-life discovery;

2) the existence of exo-life in the universe, can never be disproven with multiple negative discoveries, no matter how vast in number these are;

3) purely mathematically speaking, the numbers of habitable environments throughout the universe, tells us nothing about the uniqueness or otherwise, of exo-life in the universe, until a single instance of exo-life is discovered in an exo-habitable zone.

Inference from beliefs taken from non-insular Earth modelled habitats, is what keeps the search going.

Cheers

[Poita (Peter)]

I'd agree with all of that, and would just add, that any exo life would have to be shown to not have originated from the same source.
e.g. If life was found on Mars, it would need to be proven that life on earth didn't begin and a result of life traveling to earth from the Martian surface (inside a meteorite or via some other method). We could find life within the solar system, but unless it also began from scratch it wouldn't tell us anything about whether life is likely to spontaneously erupt throughout the universe.

What I find interesting is that astronomers and physicists generally seem to believe that life is likely if there is sunlight ,warmth and water, you hear it quite often when talking about bodies within the solar system that have some form of water for instance. Not many extrapolate what that belief entails. If water, certain chemicals and energy requirements = a high likelyhood of life appearing, then that would mean somewhere within the laws of physics that a tilt towards life is built into the laws. That is a pretty incredible concept.

[astroron (Ron)]

Isn't it amazing how far this thread as deviated from the original post of a couple of unexplained lights in the sky

[Poita (Peter)]

Mainly because we are all too dopey to work out what they were
I was hoping we would get an answer, but we never got enough detail as to the exact time, location etc. to be able to find out.

[CraigS]

Originally Posted by Poita

I'd agree with all of that, and would just add, that any exo life would have to be shown to not have originated from the same source.
e.g. If life was found on Mars, it would need to be proven that life on earth didn't begin and a result of life traveling to earth from the Martian surface (inside a meteorite or via some other method). We could find life within the solar system, but unless it also began from scratch it wouldn't tell us anything about whether life is likely to spontaneously erupt throughout the universe.

Sure .. good points .. it all depends on how one defines 'exo-life' and what one is looking to gain from the conversation.
Even if we did find life elsewhere that turned out to be indistinguishable from Earth's versions, then at least the panspermia theories would then have some evidence based support. (Which would also be a big step forward).
The conversation also needs to keep separate: 'Abiogenesis', 'Evolution' and 'Panspermia'.

Originally Posted by Poita

What I find interesting is that astronomers and physicists generally seem to believe that life is likely if there is sunlight ,warmth and water, you hear it quite often when talking about bodies within the solar system that have some form of water for instance. Not many extrapolate what that belief entails. If water, certain chemicals and energy requirements = a high likelyhood of life appearing, then that would mean somewhere within the laws of physics that a tilt towards life is built into the laws.

Do you think so ?
This doesn't quite work for me, but I can see how a belief might take them (or one) in that direction.
Extrapolation is only valid in deterministic systems (or sub-systems). There is no evidence that the occurrence of exo-life obeys such rules, or can be defined as such a system. As a matter of fact, Earth based life (ie: life as we know it), exhibits uniqueness of features at certain scales and dissimilarities on other scales. Elsewhere in nature (on Earth), this phenomenon constitutes firm evidence that life itself actually follows non-deterministic processes.

Abiogenesis is theorised as being the initial part of the life process. We can also infer from the evidence of similarity/non-similarity at different scales, that Abiogenesis may follow the same pattern .. but this would once again, be imposing our own penchant for determinism upon something we have no previous direct evidence for.

Extrapolation from no existing (past) evidence results in the problem … and this may come directly from our beliefs that everything in nature obeys the laws of determinism, despite plenty of hard evidence for and against (IMHO).

Maybe that's why the folk you mention, stop at the point you mention (over and above the obvious religious trajectory initially established). The instant that trajectory is established, the conversation can no longer be framed within the realm of the scientific process, as it has stepped beyond these boundaries.

Cheers
PS: We're just chatting here Ron … anyone else is more than welcome to bring this thread back onto the OP topic.

[Poita (Peter)]

I just meant that I find it interesting that the belief that life may be widespread throughout the universe seems to be more common amongst Astronomers and Physicists than amongst Biologists, I have to work with both crowds and most of the first type when engaged in conversation tend to believe that life is almost guaranteed given the right circumstances and the later think it unlikely. This is only from my personal experience of maybe a few hundred people, certainly not a big enough sample size to draw any real conclusions. I just find it interesting.

I do think that if you equate water and warmth = a likelyhood for life appearing that you are implicitly saying that the laws of physics are tilted towards the formation of life, and that that is pretty amazing if true. Or you are saying there is some other mechanism in the universe that is pro life.

I personally don't believe so, I think we are a freak accident, but I'd like to be wrong. I enjoy the quarantine thoery as well

[CraigS]

Interesting, Peter .. ie: the two different perspective you mention from biologists and physicist types … hmm.

I'm interested to understand why 'water + warmth = a likelyhood for life appearing' implies that the laws of physics are tilted towards the formation of life ? It sounds to me that from all of the environments possible, if you go looking specifically for (liquid) water + warmth, you might find life (ie: a habitable zone ?)

How is the other conclusion reached ? I'm being quite straight here .. I'm not pushing any agendas etc .. I'm just interested, because I can't follow the steps leading to the "tilted towards the formation of life" bit .. why should this be so?

Cheers

[Markvan]

The variables that have created life on Earth ( through accident or design) would have to be found elsewhere in the universe.

I hope I live long enough to see the universe understood in more detail.

[Poita (Peter)]

I have no agenda either, and this is really just the result of getting to pick the brains of highly trained people often, and a passion for hammering them about biogenesis. I am intrigued by the difference in belief between Biologists on one hand, and Astronomers & Physicists on the other (in general terms).

Originally Posted by CraigS

It sounds to me that from all of the environments possible, if you go looking specifically for (liquid) water + warmth, you might find life (ie: a habitable zone ?)

If you go looking for life on a planet that already has life on it somewhere, then yes, looking specifically for liquid water + warmth would give you a likely abode to find living organisms. If Panspermia works (i.e. that microbes drift around the universe and land on planets randomly) then that would be a place to look.

Originally Posted by CraigS

How is the other conclusion reached ? I'm being quite straight here .. I'm not pushing any agendas etc .. I'm just interested, because I can't follow the steps leading to the "tilted towards the formation of life" bit .. why should this be so?

I'm talking about biogenesis, or life being created from scratch.
When I talk to the biologists, we tend to talk about a super basic (or ancient) version of life as we know it, i.e. chemical based life with some form of replication system.

At the most basic level, such a system requires, at the very least, proteins that can act along with nucleic acids etc. Most of the people I speak to put the chance of the proteins occuring randomly (forgetting about the acids and other needed items for the most basic imaginable replicating organism, something far far cruder than a single cell bacterium) at about 10 to the power of 50,000.
People often claim that with the sheer amount of stars in the observable universe, that it would be insane not to think life was almost guaranteed, even by chance alone. But the latest estimate I saw of the amount of stars in the universe was about 10 to the power of 21 or something like that.
So although the universe is inconceivably large, to the biologists, the number of potentially habitable planets in the entire universe is almost trivial compared to the odds of even the proteins alone forming, let alone life taking off from there. It would be unlikely to happen even once, let alone many times. The universe seems big, but it is nowhere big enough.

So many biologists believe that to make the crudest raw materials for life (not functional RNA or even DNA, but just the basics to be able to let some crude replicator function) requires odds that are well beyond astronomical. If that is the case, then for life to be likely if you have water and warmth etc. then it requires something to push well against the odds. For protein chains to 'regularly' form against odds of 10^50,000 there would have to be something to make them do so.

This is what I mean about the laws of physics would need to be tilted towards life, there would have to be something in there to go so massively against the 2nd law of thermodynamics, it would require a law that led to greater complexity rather than chaos, the polar opposite of what is currently believed.
To say that life will appear given a basic set of conditions implies that we live in a universe that is inherently friendly to life appearing, that there are laws that govern the way molecules form etc. that inevitably lead to life, that is a massive statement, and one that goes against the little about physics that I know.

Originally Posted by CraigS

Interesting, Peter .. ie: the two different perspective you mention from biologists and physicist types … hmm.

I'm interested to understand why 'water + warmth = a likelyhood for life appearing' implies that the laws of physics are tilted towards the formation of life ? It sounds to me that from all of the environments possible, if you go looking specifically for (liquid) water + warmth, you might find life (ie: a habitable zone ?)

How is the other conclusion reached ? I'm being quite straight here .. I'm not pushing any agendas etc .. I'm just interested, because I can't follow the steps leading to the "tilted towards the formation of life" bit .. why should this be so? http://www.iceinspace.com.au/forum/....estionicon.gif
http://www.iceinspace.com.au/forum/....es/happy19.gif
Cheers

[Poita (Peter)]

Originally Posted by Markvan

The variables that have created life on Earth ( through accident or design) would have to be found elsewhere in the universe.

I hope I live long enough to see the universe understood in more detail.

That is what the biologists have a problem with, if they are right about the chance of the materials forming being so incredibly rare ( e.g. 10^50000 or even 10^30000) then the universe isn't big enough for it to be likely that the same variables would exist anywhere else that created life on Earth.

Their argument is that you could have 10 billion "earthlike" planets, and the chances would still be infinitesimally small that life would appear.

The conditions during a lotto draw are basically the same each time, the balls start off in the same order, and are dropped from the same height into a barrel that rotates in the same way each time. Yet the sequence of numbers that come out are basically always different.

Imagine a lotto draw with a few billion balls in it, and the chances of a particular number sequence appearing, even though the starting conditions are basically the same each time.
You could do a draw a day for the entire age of the universe and never see your sequence once.
Yet this is billions of times more likely to happen than the proteins required for life appearing even on a single 'earthlike' planet.

If they are wrong, and the formation of life *is* likely, then what is the mechanism that drives molecules to form non-randomly into long complex chains that are non-periodic and specific enough to lead to life?

If they are right, then we are a collosal fluke, and unless panspermia works then we are most likely alone in the universe.

That is the big question for me. Is there an as-yet undiscovered law, perhaps something will come from information theory or whatever it is called these days, that means life is likely in our universe, or are we truly alone?

[CraigS]

Hi Peter and others;

Peter: Thanks for your answer (in post #50), to my question. I think the matters you've raised are very interesting and are worthy of a separate thread. If you'd like to continue the discussion, I'd like to suggest we do it in the Science Forum, as a few folk who inhabit that region have biochemistry backgrounds and it'd be great to have their contribution to the discussion.. I'll raise a thread (I think I might call it "Abiogenesis") and perhaps, if you'll join me .. we can take it from there. There's lots of other dimensions which your colleagues might like to consider .. (and that's not to say they haven't already).

As far as the statistical points you raise:

Originally Posted by Poita

That is what the biologists have a problem with, if they are right about the chance of the materials forming being so incredibly rare ( e.g. 10^50000 or even 10^30000) then the universe isn't big enough for it to be likely that the same variables would exist anywhere else that created life on Earth.

Their argument is that you could have 10 billion "earthlike" planets, and the chances would still be infinitesimally small that life would appear.

And those 'chances' no matter how small, are not zero, thus it is still possible that life can arise in a universe of infinite dimensions .. and this is a valid point, (even though there is no reason, other than optimism and inference, for believing that a specific life combination might arise).

Interestingly, I think the differences between the infinitesimally small probability you mention, and the offsetting, perhaps infinite size of the universe, depends entirely on which life model one chooses, also. Our modern DNA is almost certainly not how it started out. Pre-biotic ‘life’ was most likely much simpler than modern DNA. Evolution and natural selection modified it to what we see today and its effects should not be underestimated. (Purely theoretically speaking, now). We should look into this in the new 'Abiogenesis' thread. (When I get the chance to start it)

Originally Posted by Poita

The conditions during a lotto draw are basically the same each time, the balls start off in the same order, and are dropped from the same height into a barrel that rotates in the same way each time. Yet the sequence of numbers that come out are basically always different.

Imagine a lotto draw with a few billion balls in it, and the chances of a particular number sequence appearing, even though the starting conditions are basically the same each time.
You could do a draw a day for the entire age of the universe and never see your sequence once.
Yet this is billions of times more likely to happen than the proteins required for life appearing even on a single 'earthlike' planet.

This argument depends on one's belief of what the probability is that life could arise by random chance, in the first place. (Ie: it also most likely assumes a normal probability distribution, random chance selection, etc .. and there is no evidence underpinning any these assumptions, remember).

See also, my above comment on impact of assumptions of what might constitute ‘life’, as these are of primary importance and dominate the conclusion reached.

Originally Posted by Poita

If they are wrong, and the formation of life *is* likely, then what is the mechanism that drives molecules to form non-randomly into long complex chains that are non-periodic and specific enough to lead to life?

If they are right, then we are a collosal fluke, and unless panspermia works then we are most likely alone in the universe.

Just the pessimistic flip-side of the coin.
The optimistic argument carries the same weight.

Originally Posted by Poita

That is the big question for me. Is there an as-yet undiscovered law, perhaps something will come from information theory or whatever it is called these days, that means life is likely in our universe, or are we truly alone?

We won't know until an instance of exo-life is found.
And another 'certainty' … if we don't look .. we'll never find it !

Cheers

[Poita (Peter)]

Our modern DNA is almost certainly not how it started out. Pre-biotic ‘life’ was most likely much simpler than modern DNA. Evolution and natural selection modified it to what we see today and its effects should not be underestimated.

The odds I was quoting was assuming just the creation of a single protein. Even the simplest pre-DNA organism would need lots of proteins and other complex items. Even just an RNA replicator would require more than this.

I don't think people properly understand what a chance of 1 in 10 ^ 30,000 means.

The number of *atoms* in the observable universe is only around 10^80.

So unless the universe was truly infinite then the chance of it happening even twice is below consideration.
And that is just the chance of a single protein occurring, it would take much much more than that for even a pre-DNA super basic ancestor organism to occur.

I'll head over to the other thread, I'm keen to hear what folk far more knowledgeable than myself think on this stuff.

[Markvan]

Hey Poita,

Thanks for your posts... do the scientists have theories on how our DNA took the big jump?

[CraigS]

Originally Posted by Markvan

Hey Poita,

Thanks for your posts... do the scientists have theories on how our DNA took the big jump?

Hi Mark;

Over billions of years … and constant environmental interactions:

Mutation + Natural Selection = Increased Information.

As pointed out by Szostack's Abiogenesis Theory, no complex protein machinery is needed to get the process started .. and for life functions to commence. This dramatically alters the 1 in 10^30,000 figure argued by Peter's colleagues.

Cheers

[Poita (Peter)]

Originally Posted by Markvan

Hey Poita,

Thanks for your posts... do the scientists have theories on how our DNA took the big jump?

Once we have DNA then natural selection kicks in as the mechanism that moves us 'against the odds' so to speak.

CraigS, even for Szostack's simplest proposed original replicators, it would require multiple self-replicating genetic polymers whose odds are also of the 10^30,000 variety, making the actual odds even worse.
Szostack is attempting to make and then combine two self-replicating systems: a nucleic acid (such as RNA or DNA) that can transmit genetic information and a simple membrane-bound vesicle that keeps the nucleic acid chains from drifting apart. He hasn't actually managed even that yet, and that is in highly contrived and controlled lab experiments. He is working on "the development of a self-replicating genetic polymer." as he says himself " Despite many years of effort, complete cycles of chemical (i.e., nonenzymatic) replication of RNA have not been achieved."

http://www.hhmi.org/research/investigators/szostak.html

His work is interesting, it looks for far simpler organism models than exist today, but even the simplest of them still have odds that are greater than the number of atoms that exist in the universe. There is the problem.

If someone comes up with a way that life can form that is not unlikely given a set of pretty basic starting conditions (i.e. a chemical soup and some energy input) then that will mean that life forms simply and spontaneously according to the basic laws of physics, that would cause a greater rethink of how the universe works than anything Newton or Copernicus or Einstein came up with. It would break the 2nd law of thermodynamics and mean that we can create non-random, information rich systems by the application of simple laws. It would mean a total re-write of what physicists currently believe (of any macro-level physics theories).
It may be right, but it will take a new branch of science or a total shake-up of physics to be so. That is why the search for *true* exolife (not transpermia) is so important, if found, then we have a fundamental mis-understanding of the way the universe works, and that would lead to a whole new area of scientific enquiry, plus would be very cool.

[Amunous (Michael)]

I'm glad this has evolved into an intellectual debate. I'm sick of people's only arguments being;

Me: So i think there is life somewhere in the universe.
Random person: No there isn't.
Me: How so?
Random person: Because i said so.!! (or only idiots believe in that crap.)
Me: Well what about (insert several points here)
Random person: Uh ahhhh your WRONG!!
Me: /facepalm.



And don't forget people... anyone referencing physics and thermodynamics and such. All those papers and theories were derived from experiences or experiments that occurred on earth. Therefore the laws can only be applied to anything on earth. Once you move to another planet with different mass, rotation speeds etc etc all those theories and practices get thrown out the window.
You only have to look at how gravity behaved on the moon to see how stupid it would be to apply the same principles to every planet in the universe. Different gasses on planets would also interrupt the way thermodynamics would work on different planets, unless of course EVERY planet in the known universe is identical and the same distance from their sun, rotating at the same speed, and covered in the same gasses, and has the same mass...

Like i said we are limited to what we know and understand. Once we start exploring space all our laws and rules will be null and void. We are already learning that just by stepping into the inner reaches of space.

Just because a set of biological rules works here doesn't mean that it will work elsewhere. If that was the case we wouldn't need space suits to walk on the moon, but in saying that, just because we cannot survive on the moon does not instantly mean that nothing can survive on the moon. So saying that the only way life can evolve is, this way, because that's how it happened here. Is pure folly, and just shows how narrow minded our species is.

But until we find evidence of Intelligent life elsewhere that we can exchange ideas with and learn about, its all really theories and conjecture.

[CraigS]

Originally Posted by Amunous

I'm glad this has evolved into an intellectual debate. I'm sick of people's only arguments being;

Me: So i think there is life somewhere in the universe.
Random person: No there isn't.
Me: How so?
Random person: Because i said so.!! (or only idiots believe in that crap.)
Me: Well what about (insert several points here)
Random person: Uh ahhhh your WRONG!!
Me: /facepalm.

Good onya Michael !
I whole-heartedly agree.

Its a very interesting topic .. with so much potential for learning .. and so many self-imposed thinking obstacles to break down.

Gotta love the challenge .. and at the end of the day, we all know that no-one can be right either way … otherwise, there would be no point in talking about it, eh ?

(Chuckle, chuckle) ..

Cheers

[Amunous (Michael)]

Yeah lol i usually never speak to people like that again. I try to surround myself with people of varying degrees of intelligence. Regardless of whether they agree with me or not so long as they can debate the matter in any context instead of flat out denial then im all for it.

[Poita (Peter)]

I'm pretty sure the theories of thermodynamics work the same way whatever planet you are on.
The whole point of physics is to explain the way the universe works and to be able to then model and predict outcomes with different variables. Different planets would just have different variables, the equations stay the same.

Originally Posted by Amunous

I'm glad this has evolved into an intellectual debate. I'm sick of people's only arguments being;

Me: So i think there is life somewhere in the universe.
Random person: No there isn't.
Me: How so?
Random person: Because i said so.!! (or only idiots believe in that crap.)
Me: Well what about (insert several points here)
Random person: Uh ahhhh your WRONG!!
Me: /facepalm.



And don't forget people... anyone referencing physics and thermodynamics and such. All those papers and theories were derived from experiences or experiments that occurred on earth. Therefore the laws can only be applied to anything on earth. Once you move to another planet with different mass, rotation speeds etc etc all those theories and practices get thrown out the window.
You only have to look at how gravity behaved on the moon to see how stupid it would be to apply the same principles to every planet in the universe. Different gasses on planets would also interrupt the way thermodynamics would work on different planets, unless of course EVERY planet in the known universe is identical and the same distance from their sun, rotating at the same speed, and covered in the same gasses, and has the same mass...

Like i said we are limited to what we know and understand. Once we start exploring space all our laws and rules will be null and void. We are already learning that just by stepping into the inner reaches of space.

Just because a set of biological rules works here doesn't mean that it will work elsewhere. If that was the case we wouldn't need space suits to walk on the moon, but in saying that, just because we cannot survive on the moon does not instantly mean that nothing can survive on the moon. So saying that the only way life can evolve is, this way, because that's how it happened here. Is pure folly, and just shows how narrow minded our species is.

But until we find evidence of Intelligent life elsewhere that we can exchange ideas with and learn about, its all really theories and conjecture.