NO Life IS Possible

[CraigS]

For all those who argue: "that if life arose on Earth, then life throughout the universe must be common", comes this one:

Astrophysicists apply new logic to downplay the probability of extraterrestrial life (http://www.physorg.com/news/2011-07-astrophysicists-logic-downplay-probability-extraterrestrial.html)

… at last ! … sensibility prevails ! …

Of course, my favourite perspective on all this, (Chaos Theory), already directly supports this new statistical approach, and goes even further by underwriting the non-predictability of it all !
Interesting that this stuff is now starting to come out .. hot on the tail of NASA's reduced funding outlook. :question:
Paper is here. (http://arxiv.org/abs/1107.3835)

Reality rules dudes … (& dudettes) ! :P :)

Cheers

[avandonk]

It is a bit like the old joke where a kid with a stick and a bit of line with a simple hook walks off the pier with a very large fish. A little old lady says 'thats a big fish you have there whart sort is it?'
The young boy replies 'all the blokes on the end of the pier with their fancy rods said it was an effin fluke!'

Both camps are deluded! We just do not know!

Bert

[CraigS]

Hang on a minute there Bert … haven't you said in the past that given all the same initial conditions as those which occurred on Earth in the past, life would still emerge, all be it different life ????

Cheers

[avandonk]

Yes it would. Given the correct conditions life is inevitable. Intelligent life is another matter. In my humble opinion intelligent life does not exist on Earth yet on average.
Have a look at any pond life and try to see the really intelligent sentient individuals.
Bert

[CraigS]

Well, their paper is a tricky read, but I think their argument is that the actual emergence of life, (abiogenetically), can be said to be so rare, that it means that the level of confidence of finding it elsewhere is extremely low ... to the point that one cannot predict the emergence (by the same means), elsewhere.

In other words, we can't extrapolate from what may have happened here ...



So, this model would seem to say that "given the same conditions, life is by no means inevitable" ??

However, as I mentioned, its a tricky read .. but I think this is what they're concluding in the paper … (happy to be corrected if I'm reading more into it than what it says).

Cheers

[renormalised]

Well, I can tell you right now that we won't see NASA or anyone else find life elsewhere in our lifetimes simply because of what's going on down here right at this minute. I doubt NASA will be going anywhere for a rather long time, in so far as manned (and even in some cases unmanned) missions go. In any case, as Bert said, there is no intelligent life present in this Universe. You couldn't call the so called sentient species dominating this planet, intelligent. If it was, we'd be in a much better position than what we are. So, both camps are wrong. They just don't know and it's rather pointless arguing about it. They're both coming at it from a system of belief and have the "evidence" and "science" to back their PoV's up.

You can make maths (and theory) predict anything you like and you can use it to back up any preconceived notion you want. Until you have proof to the contrary or to the affirmative, it's all just conjecture. Chaos theory or any other theory tells you nothing...until you have evidence to back it up (empirical, anecdotal or otherwise) it's nothing more than just reasonable (or wild, as the case may be) speculation.

However, given what we do know about life here on Earth and given what we know about how the Earth formed and the conditions which followed subsequently etc etc etc. And given what I know about these areas of science, it is my assertion that the same patterns that were found to be here, will also be found to be elsewhere. If there's life here, all things being equal, it will also be elsewhere. What that life might be, I haven't a clue, but there's nothing to say it won't follow similar patterns to what we have here. But it could equally be totally different altogether. That's the beauty of it all. The possibilities are endless.

[renormalised]

They have no way of proving that assertion at all. How do they know if abiogenesis is rare. What is the empirical basis for their assumption???. Their whole paper is not predicting anything....all it's doing is going over the same old, tired arguments for the Rare Earth Hypothesis. Hell, given their assumptions, we shouldn't even be here ourselves. Which just goes to show you how nonsensical their arguments actually are. It's quite simple to apply their reasoning and statistical methods on a global scale and that would mean no life should be present anywhere.

What it means is that they're going to have to explain our own presence and unless they have a very convincing and plausible explanation, then they're going to have to concede that they don't know at all and then the religious element will be bound to raise its "solution" to the problem eventually.

Back to square one.

[CraigS]

Ahhh … good ol' Julius-the-optimist at it again ?? :P :)

During my break, I had someone attempting to argue that if all the exo-planets out there had zero water, then you could say that the probability of exo-life was zero. (I agreed).

and then .. that if this were the case, (by the same logical premise), then if all the exo-planets out there DID have liquid water, then the chance of life as we know it, are increased. Everytime we find a planet with liquid water, then the chances of life as we know it, are increased.

I disagreed, as the 'life as we don't know it' component, may significantly swamp the proportion of 'life as we do know it' component, thereby swinging the chances back to even. (I decided that I started to sound too much like 'Sir Julius-the-renormalised' … so I went for another beer … :P

Cheers

[renormalised]

It's got nothing to do with optimism and everything to do with what we think to be the case. The laws of physics appear to be the same no matter where we look. Since we rely on those laws for our existence, all things being equal, the probability of life being elsewhere is just the same as it was (and is) for this planet.

Only one problem with the contention of all the exoplanets not having any water....they've detected water everywhere in the Universe. Given its ubiquitous nature and presence in all star forming regions, some of the planets which form in those regions must have water as a consequence of where they form. Even if they didn't, there's more than one substance around which can act as a medium and solvent for organic (or even non organic) life.

As far as life as we know it, or don't know it, is concerned, we have no way of knowing anything about the proportions of either. Until we go out there and look for ourselves. The likelihood of either is an unknown quantity.

[xelasnave]

I cant understand why the Drake equation it given any time at all...it merely tries to quantify something with no evidence ... you may as well pick a number out of the air or calculate the probability of unicorns.. it is useless.
alex

[renormalised]

It's just an equation Frank came up with as a theoretical exercise in trying to get a handle on what might be the case. Some of the numbers are known to a reasonable degree, but the majority of the equation's variables are pure guesswork.

[avandonk]

All I know that 13.7 billion years of evolution means I can cuddle my lady loves large bottom. She has a minor thought of my muscular body. The resulting children are us. And so the cycle goes on.

I wonder if these blokes could work out the chances of a root without the contradictions.

Bert

[CraigS]

Didn't John Forbes Nash Jr win the Nobel Prize for working that one out ?

(I think Sir Russ also did it in "A Beautiful Mind" …??…)

Cheers

[CraigS]

The laws of physics also apply for earthquakes ..
Where and when an earthquake will next occur, is not predictable ...

The laws of physics (presumably) applied when life emerged …
Where and when a second occurrence will occur, is also not predictable (for the same reasons as above … all things being equal, of course … ;) ).

Cheers

[renormalised]

Yes, they do.

It's not a matter of predicting when and where anything will occur. It's a matter of if something happens once, given that everything is equal, it will occur again, elsewhere.

[CraigS]

Yep .. I'd say that's a prediction …

.. and yet, its not predictable …

:)

Cheers

[Ray?]

Sorry, alien life does exist. Every time I go to one of our local shopping centres, the evidence is irrefutable.:rolleyes:

Cheers

Ray

[renormalised]

I totally agree....there you go, Craig. And so much for the government conspiracies.......THEY'RE HERE!!!!!!:):P

[supernova1965]

Hi Craig,

I mean this with all respect to you and your views but every post you do on life it comes across that you believe life isn't out there you say your mind is open but that is not how it comes across. I have no problems with you infact I admire your arguments in all except when it comes to the subject of life in the universe it comes across as something that you have already made up your mind on which is not a very scientific way of looking at things.


Just an observation not a critisism I believe that you generally add a positive foward looking improvement to scientific debate.:thumbsup:

[renormalised]

Warren, it's because he's on a bandwagon with a certain subject. No matter how applicable it might be to any situation, if you start to believe it's a panacea to all problems and situations then it becomes a problem itself. What then is seemingly logical and reasonable becomes illogical and unreasonable by dint of its supposed universality. Belief in something that becomes too good a thing is where most people (and many scientist sometimes) go wrong.

It's a wise thing to remember the old adage "there's more than one way to skin a cat". Especially when it comes to science and philosophy.

[CraigS]

Hi Warren;

The only thing I'm firm about when it comes to this topic, is the unpredictability of finding another instance of emerged life. This particular research paper comes to that same conclusion.

"How it comes across": The only feeling (or 'belief') I have ever expressed in this matter has been that I really don't care whether exo-life exists, or not. How it comes across, is as much a function of how you might be reading what I'm actually saying … but 'thank you', for allowing me the opportunity of restating my position (which remains unchanged on this matter).

Both of the majority perspectives on the topic, are purely products of optimism or pessimism, neither of which carry any weight in science.

My beliefs are also completely irrelevant, and I encourage you to dismiss them, whenever you like, and wherever you see them.

Cheers

[renormalised]

But to use that unpredictability to then deny that the opposite assumption is equally true is rather disingenuous, Craig. Which is what you've done on numerous occasions. You've basically said that saying all things being equal and given what we know, we can't say life has appeared elsewhere. No, we can't categorically say that with 100% certainty, but to deny that it can (appear elsewhere, given the conditions and fundamental processes) and that chaos theory somehow is the overarching arbiter of the subject is presumptuous in the least.




That being the case, it would be wise to choose your words and the way you express them rather carefully.



I agree, but you can't divorce them from what science is being done. Humans are not robots.



Yet it's abundantly clear your beliefs about the subject cloud your opinions and what you write. Dismiss them and you dismiss what you write.

[CraigS]

Carl;

This has nothing to do with my 'beliefs' or anything else you have dreamed up.

The 'bandwagon' you allude to, is a perfectly legitimate, supportable branch of mainstream science and has found many areas of diverse applicability.

My role in discussing it, has been purely one of 'carrier-pigeon'.

An understanding of Chaos Theory does not in any way, eliminate or compromise, any other scientific principles, theorisation, conjecture, principles, etc, etc, (as I have pointed out many times already).

Also, kindly do not speak on my behalf again … I am perfectly capable of expressing myself, when posts are directed at me.

Cheers

[supernova1965]

The title of the thread is where I base my statement that you don't believe life is out there it is hard to argue that you are not firm in the fact that you don't believe.

[supernova1965]

No we don't know when an earthquake will occur but we do know that one will

[renormalised]

Yes it has. You have expressed an opinion on the complete and overarching veracity of a subject that despite its applicability in certain areas is still a matter of controversy in others. Not because it's wrong or anything of the sort, but because it has not been found to be applicable.



Whether it's legitimate, mainstream or not is not the issue. The bandwagon is the belief that chaos theory has some magical "uber-influence" and applicability to everything. It's a theory, nothing more or nothing less. It could just as easily be replaced by something else tomorrow and it's not an universally agreed upon subject, despite what you might feel about it.



You do know, they became extinct:):P:P



That might be what you write here, but from everything else you've written about it, it would seem to indicate otherwise.



I wasn't speaking on your behalf. I was speaking on my own and on what I have read of what you've written. You're only peeved because I am having a go at your position and you don't like it. I'm not doing it to upset you intentionally. I'm doing it to make you think but you seem to have not realised this. Chaos theory is not universally accepted amongst the scientific community, nor is it the last word on anything. Although from some of things you've written here, it's quite reasonable to think that this is what you feel about it. All it is, is just one approach to explaining how things work in those certain areas where it can be applied. If it's to be applied as an universal law/theory, then there has to be evidence saying as much. There isn't, so, the only thing that can be said is that where it's applicable use it. And, until it's found to apply to those previously inapplicable areas, leave it be.

Chaos theory is just a cog in a much larger system and should be applied/viewed as such.

[marki]

This is totally irrelevent. We cannot possibly know if life has evolved elsewhere in the universe equations or otherwise until we have searched the entire universe. You can calculate or believe what you want but right now we have no evidence for life elsewhere but that does not mean it cannot exist, just that we have not found any other examples at this point in time. All this seems to be doing is generating angst amongst members.

Mark

[renormalised]

Ultimately, that is correct. All the equations in the world will mean nothing if you can't find or don't know the value of the variables to enter into them. It's much the same with philosophising about it. It's the age old question..."how many angels can dance on the head of a pin??". The answer being however many you wish. Saying that because chaos theory makes any determinations impossible and therefore life is rare or non existent elsewhere is just as irrelevant as saying every single rock out there has life on it and there's a gadzillion number of civilisations. They're moot points unless you have the rock solid evidence in your hands.

I'm not going to argue anymore with this or some of the other threads here. It's becoming not only tedious but rather fractious and non productive.

[Zaps]

It's an excellent paper, and the qualified conclusions are valid.

There is no reason to assume that ET life does or doesn't exist, and the authors have been careful to avoid baseless conclusions. The only thing anyone can say for sure is that humanity has yet to discover any reliable evidence of the existence of ET life.

[renormalised]

Yes it is, and it's well thought out. But the danger is when people read too much into it.

However, it's also equally correct to say that the authors themselves should be careful not to be so sure of their own conclusions, based on their mathematics and their assumptions. Maths can be made to say and prove anything. Your last sentence is the only one we can truly be sure about....it all boils down to evidence.

[CraigS]

The title is not my opinion ! It is a mathematically legitimate outcome from the analysis. It carries no more weight than the optimistic "Life IS Possible" statement !

The quote in my orginal post also points this out .. here it is again ..

If the same occurrence doesn't happen elsewhere, then a "null" outcome, ie: "NO life(forms)", is just as legitimate as either "different life(forms)" permutations. Neither of these is ruled out and at the same time, neither is directly supported (according to their analysis). The same occurrence elsewhere, is also not supported by the analysis.


.. and this point asserts the emotional/opinion/belief motivations underpinning either optimistic or pessimistic statements.

Cheers

[Zaps]

No, it's not.



No, it can't. Not when it's correct. People who do not know what they are doing often think they can make incorrect maths somehow correct.



It all boils down to falsifiability.

[CraigS]

The only rational reason you can make this statement is because there is a history of earthquakes. If this history were absent, as is the case for previous exo-life discoveries, then you could not even predict that "there will be one" (earthquake, that is).

Earthquakes are functions of Complex Systems. Chaotic Systems can be viewed as a subset of Complex Systems, and may be distinguished by their initial conditions and lack of historical dependence.

Cheers

[supernova1965]

Yes there is a history of earthquakes as well as moonquakes and planetquakes throughout the Solar system. Going by this evidence I am confident in saying that quakes happen throughout the Universe.

I can't prove that life exists or doesn't I can't prove that quakes happen in the universe or not but you haven't provided any proof to say that either don't exist and until you can do that they both exist and don't exist as with Schrödinger's cat.

Unlike you I do care whether life exists or not and if scientists didn't care whether something was true or not they wouldn't bother to try to prove it one way or the other.

[CraigS]

Ie: there is a history of past quakes … so there is a basis to extrapolate from.


I'm not arguing that these things don't exist ! You seem to keep pinning this on me .. you've got the wrong target !
There is simply no evidence of exo-life to base rational statements about probabilities of their existence upon.
It is thus unpredictable.


I have no problems in acknowledging the human motivations for scientific investigation. Curiosity and belief clearly provides the impetus and probably the momentum. I don't consider this to be particularly earth-shattering news, though …

Cheers

[CDKPhil]

What an interesting thread. I am no scientist but to say there is no life any where in the universe is about the same as saying the world is flat.
Science is in it's infancy we are only just beginning to understand some of the mechanisms that rule our universe. I would dare to say in a few hundred years time that scientists will look back on this part of history and laugh, and wonder how the hell did we get through it.

There are some great theory's out there but we must remember that they are just that. It always puzzles me to see all these theory's and people thinking or presenting them as fact, I don't know why that is, I guess it is just another form of belief.

For the record I think that there is plenty of life out there but we are to far away and we at this present time are to unintelligent to see it.
Thats my theory.:)


Cheers
Phil

[marki]

I would say the opposite is true here. It's people who do know what they are doing that make it correct, just check out any of the latest political fights, both sides always seem to be backed by irrefutable stats based on in depth studies by proffessional bodies. How can they both be right when they directly oppose each other? The old saying lies, dam lies and statistics still holds true. Mathematics like any piece of written work is always open to bias and manipulation.

Mark

[Ray?]

Meanwhile, on the other side of the galaxy, the same argument continues. ;)

Cheers

Ray

[supernova1965]

:D:thumbsup:

[renormalised]

Yeah, but they have starships, particle beam weapons, antimatter torpedoes and such. Their arguments are rather nasty:):P

Until they find us. Then they decide to band together and wipe us out!!!:):P

That last GRB we observed......well, you get the story:):P

[CraigS]

The entire point of this paper, is to provide an analysis to highlight the sensitivity of the outcome to the initial assumptions. The conclusion is, necessarily, that choice of initial assumptions, (in this case the probability parameter of relatively short-span abiogenesis), has the dominant influence on the outcome.

Further, they restate the commonly held fact, (made so by abundant empirical evidence), that life began on this planet fairly soon after the Earth became habitable. This is then, is entirely consistent with a low probability of abiogenesis. Using this as a basis for another iteration of the Bayesian calculation, necessarily drives the conclusion of life being arbitrarily rare in the Universe.

I find the application of the cliches like "lies, dam lies and statistics", and inferences of "mathematics being manipulated for a particular outcome", as small-valued opinions, adding little weight to a meaningful scientific discussion.

Bayesian inference (http://en.wikipedia.org/wiki/Bayesian_analysis) in statistics is specifically used to estimate if a hypothesis is true. It makes use of iterations when fresh evidence (raw data) appears, to repeatedly modify the initial hypothesis. This technique carries a lot of weight in scientific probability estimation circles, as it is clearly designed to expose the dependency of outcomes on initial assumptions, for all to see. (Ie: falsifiability incarnate).

The authors specifically make the point that a discovery of exo-life would alter the outcome of future iterations of the Bayesian Inference (due to the sensitivity to initial assumptions). Like it or not, this is exactly the butterfly effect in action.

I for one, choose to not dismiss outright, a value-laden analysis, purely because of prior opinionated bias, coming form some prior belief system.

[sjastro]

Garbage in=Garbage out isn't a mathematical formula.
The mathematical tools themselves are not open to bias and manipulation.

Regards

Steven

[renormalised]

That's true Steven....the mathematical formulae are what they are. It's the data entered into the equations which is the problem and that's where the bias and manipulation arises from.

That's why any statistical analysis of this subject is flawed right from the beginning. How can you know the probability of any particular outcome when you don't have any prior knowledge of any of the variables of the analysis. What little knowledge we do have is only based on one example and quite frankly that would be rejected in any objective statistical analysis...of any subject let alone this one. Bayesian analysis requires that the calculations are based on a prior distribution of the parameters that are being looked at, in order to arrive at the answers sort. That means if you use a different set of priors, you get a different set of answers. It's loaded straight from the get go. You could make any inference as to what the initial prior was going to be. It could just be based on a hunch and you would be able to plug it into the equations and get any answer you wanted. Science prides itself on its objectivity and yet it could be hardly said that Bayesian analysis is truly objective. That's why you see Frequency Inference statistics being used for the most part, because many scientists are uncomfortable with the subjectivity of Bayesian analysis. That, and you need a powerful computer to do complicated Bayesian because the calculations can become onerous.

In any case, this particular study is moot straight from the start simply because we really have no idea of what the initial conditions were to begin with and the calculations could be made to go either way, just based on your initial set of assumptions. As I have mentioned previously. Meaning it's inherently biased right at the beginning, whether intentional or not.

[xelasnave]

Craig that link was excellent.

When I fully understand it I will become a professional gambler.

I am not strong in math as you all know but in reading about it if there is one thing that becomes apparent it is that math is uncorruptable. I was fascinated by the extent of various proofs and the unbelievable work behind the seemingly most simple statement.
If two sides offer different numbers that is about politics and as Steven said the math tools are not open for manipulation etc. in any event I doubt if those working on the subject of Craig,s post were out to prove a view they had arrived at before doing their work.

Thanks Craig

alex

[renormalised]

That is a fallacy you should very quickly forget. It's not the equations that are the problem, Alex, it's the data that is used to derive an answer which can be the problem. If the data is false/faulty to begin with, then you will get a false/faulty answer. If your assumptions are false/faulty to begin with, then likewise.

The politics comes from belief and the taking of positions....that comes after the fact w.r.t. the maths. The maths is only a tool used to bolster one's position or belief.

[SkyViking]

Interesting thread. The title was "NO life IS possible", which is a perfectly valid statement that some scientists have now evaluated using some fancy math. There is really nothing more to it that that.
If anyone thinks that statement is false then I'd certainly like to see the proof of the opposite ie. that ET life does exist. Otherwise I can't see how anyone can disagree that it is a possibility that ET life does not exist. Just as well as it being a possibility that it does exist.

How we personally choose to weigh those possibilities doesn't really have anything to do with the topic of the thread I'd say. Personally I tend to think there must be ET life out there, but that is pure speculation and irrelevant for the topic of the thread.

[CraigS]

Poppycock !

Data is data .. data says nothing … data interpreted within hypothesis or theory, is a different matter.

The design of an experiment might be driven by theory, but the data which that experiment generates is purely data. Interpretation of that data depends on theory or hypothesis and is subject to assumptions. All data is subject to falsification by criteria laid out in the experiment (or theory).



This statement is so devoid of any semblance of scientific principles, that I'm too flabbergasted to attempt to refute !

[xelasnave]

I think we are on the same page Carl:thumbsup:. I am aware of how one can manipulate figures but my point is many think manipulation points to a flaw in the math. Math is a tool and I suppose it could be abused in an evil world by folk to prove whatever...but what are the chances of that:D.
alex:):):)

[supernova1965]

I will repeat what I said before until and only then that it is proven one way or the other EXO LIFE both does and doesn't exist at the same time. Again I draw your attention to Schrödinger's cat (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat)


Until the proof is found one way or the other this discussion is useless unless you have said proof. We can't prove it here if you want to prove it get out there and do the science yourself.:thumbsup:

[xelasnave]

Why dont we ask someone who knows..one of the many folk who have been abducted by et;)... how could you assign a probability that maybe one in a thousand had been abducted unless it is certain that at least one person had been abducted:shrug:..however a Bayer approach could assign a probability ..who is lieing, who is deluded and maybe even if someone is telling the truth....the researchers Craig reported upon at least work from what little "is known as fact" and that is the point I would think. Bayer offers a mechanism that is scientific from what I can understand and would seem a most useful tool with various applications...read Craig's link and my point may be clearer.

alex:):):)

[SkyViking]

That exactly is my point. Nobody has tried to prove anything. I'm only saying that the statement "no life is possible" is true. And an opposite statement such as "life is possible" is also true. I don't think anyone said otherwise?
I was really just wondering why this seemed to cause such a debate? :) :shrug:
The paper from the original post merely deals with a mathematical exercise to acknowledge that it is a possibility that no ET life exists. How likely that might be is another matter entirely and that is pure guesswork at this stage, which is also one of the points of that paper.

[supernova1965]

Because several people in the debate want to prove it one way or the other which cant be done until Schrödinger's (http://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat) box is open and it isn't open which is why I said the debate is a waste of time until we have proof:shrug:

[renormalised]

You were a systems analyst, you should be very well aware of the acronym GIGO. Enter garbage or nonsense into an equation or an assumption and you get the same out. Data can be just as false as a hypothesis or a theory. It depends on its source and when/where/how it was collected.



True, but my first point is as applicable to this paragraph as it was to the first, so I won't repeat myself.



That's only because you know that I'm right. Maths is a tool. A tool can be used for any reason whatsoever....whether that be to bolster one's position or belief, or to prove/disprove a hypothesis. If your position as a scientist is that "x=true" and "y=false", then it's very easy to use maths to bolster that assumption, or its counterpoint. Especially since both x and y maybe theories held by different scientists or might be competing theories within the scientific community. Proving or disproving either is the purview of mathematics and data can be manipulated to say whatever you want because your assumptions will dictate how that data is used.

If you think belief is totally absent from scientific research and discussion then you're sadly mistaken.

[marki]

No Steven just the interpretation.

Mark

[renormalised]

It's all guesswork, Rolf. But being dogmatic about either answer because it fits in with what you believe to be the case...i.e. pushing a particular line of belief, is a waste of time when you try to justify that through theory/mathematics. Simply because you either don't have the full monty as far as the variables/data goes, or you have a particular line to push and will intentionally look for those things that will back you up. That is purely subjective thinking. People shouldn't kid themselves, otherwise.

I'm just as subjective as the next person here, w.r..t this subject. But I don't try to justify any claims by backing them with maths, simply because I know for a fact that the numbers could be manipulated to say anything. Trying to come to a conclusion when you don't have all the facts, or hardly any at all will always result in a subjective outcome, regardless of what is said or believed about the subject.

[CraigS]

Incorrect !

The two essential characteristics of Science is objectivity and independent verifiability.

Without both of these, its not Science .. its nonsense !

Pure and simple.

[CraigS]

Incorrect !
Or you also know that it will expose flaws in nonsense logic !

That depends on exactly what, and how, it is worded.

I can make a conclusion that:
"further research is required, as this particular research has returned a null result, in the context of the initial objectives".

.. and this could easily be an objective conclusion.

[xelasnave]

Craig why do you post such contraversial material;)
but keep up the good work:thumbsup:

AND for a very reliable view of whats out there we have........

http://www.dailygalaxy.com/my_weblog/2009/11/the-vatican-embracing-the-possibility-of-advanced-extraterrestrial-life.html

So any discussion on et life can be considered religious and therefore beyond discussion:rolleyes:.

alex:):):)

[renormalised]

No Craig.....



In which case, that particular paper is nonsense, because it is neither objective or independently verifiable. Pure and simple, as you say.

Simply because....

1. Bayesian analysis is not objective by design. It's wholly based on a priori premises which dictate the outcomes of the equations used. As a matter of fact, you can use the same equations and data as another person and come up with a completely different answer to theirs. What does that say about the objectivity of the maths.

2. How are you going to verify the outcome, either way, to this analysis??. At present, it's impossible. We have no way whatsoever of saying yes or no to the question of life elsewhere and its probability of existence, except in purely subjective terms. The math used was nothing more than an exercise in subjectivity. In the final analysis, it really only meant what it was set out to prove....a possibility that there is no life elsewhere. But because that possibility, at present, is impossible to uphold/prove or reject/disprove, then it was really just a time filler. Nothing more than a gedankenexperiment to fill in the time between actual work which would've been productive (or at least we hope so).

[renormalised]

Come of the grass, Craig, now you're starting to sound facetious. And more like those guys over at T'bolts.



No, I don't back them up with the maths because the maths themselves are not applicable to the question at hand because of its subjectivity.



No, the wording has nothing exactly to do with it at all. If the question is subjective to begin with and you don't have all of the facts to prove or disprove it otherwise, you will always end up with an incomplete and subjective answer (as a matter of consequence). If the question is objective, and you don't have all the facts, and/or your maths is initially based on a priori assumptions, then your answer will be subjective also.



However, there is no null result in this case. A null result would require that no definitive answer, either way, was forthcoming. Which in this case would mean the heading of this thread should've read "We don't know the probability of life existing elsewhere in the universe" because the answer you got from the maths was inconclusive....a 50/50 chance either way.

If the initial objectives of the study made no prior mention of, or were biased either way to the conclusions of the study, then that could count as an objective conclusion. But only where their methodology of the study was also objective in its application and the subsequent analysis reflected this.

[sjastro]

I'm curious Mark.
How does one interpret mathematics?

Regards

Steven

[marki]

If assumptions are put in place in the abscence of evidence however you wish Steven.


Mark

[CraigS]

Ok .. Science in general can be distinguished into:
(i) theory and;
(ii)observation/experiment (observation, for short).

For observations (ie: the data), tests to assess whether the data is independently verifiable could be split into two parts:
i) Test #1 (Pass/Fail): say, a hard-copy printout, or release of raw electronic data giving unmanipulated access to others;
ii) Test #2 (Pass/Fail): a thorough description of (a) how to set up the instruments, tune them, and; (b) how to recreate the events leading to the generation of the data.

For theory (or hypothesis), tests to assess whether the theory is independently verifiable might simply be:
iii) Test #3 (Pass/Fail): Publication of the idea .. ie: everyone gets to the ability to check the details of the theory, until they can replicate those details with precision.

Self-consistency of a theory is also vital:
Determination of a theory's self-consistency has to be based on a "Pass" result to test #3. It's entirely possible to have a theory which is objective and independently verifiable, and for that theory to be internally inconsistent. But, unless it is both objective and independently verifiable, it might be impossible to work out that it is internally inconsistent.

Mathematics thus performs the function of assessing the self-consistency of propositional outcomes, outlined as results.
=================================== ================

In the case of Speigel's paper:

i) Test#1 result is a 'Pass', as the empirical data underpinning the assumption that abiogenetic life arose rapidly on Earth, is readily available for review by anybody (they have tabulated it);
ii) Test#2 result is a 'Pass' as the conditions for recreation of the measurements of the evidence that abiogentic life arose rapidly on Earth is readily available to everyone;
ii) Test#3 result is a 'Pass' because I found their paper ... I could read it, and I could educate myself sufficiently to understand what Bayesian Inference is, (I thus understand their methodology). More importantly, the paper has been submitted to Proceedings of the National Academy of Sciences, USA and will undergo rigorous peer-scrutiny.

Self-consistency
Each step in the Bayesian process has been clearly outlined in the paper. The mathematical steps in their analysis is open for all to scrutinise. They have tabulated their model parameters and provided sensitivity analyses applicable to pessimistic and optimistic values. They have published the algorithms used and provided results so they can be checked. The results have been bounded into upper and lower categories.

The conclusion is that their analysis is self-consistent.

None of the authors has made any assertions as to whether the analysis results in TRUTH. The assumption that this analysis attempts to portray TRUTH, lies entirely with those attempting to decry this work as 'subjective'.

These 'decriers' have provided no scientific basis whatsoever for their 'opinions' and are thus not practising Science.

Cheers

[sjastro]

Mark,

Scientific theory makes predictions not assumptions.
A theory stands or falls on the basis of evidence. A theory can be supported but not proved by evidence. Evidence however can disprove a theory.

There seems to an issue here regarding where mathematics ends and science begins.

When a theoretical physicist uses mathematics to develop a theory, the maths he uses is proven. This is what distinguishes maths from science. This doesn't however "prove" the theory.
The theory still has to be self consistent, and falsifiable (subject to observational and/or experimental evidence).

This puts it in the realm of physics not mathematics.

Regards

Steven

[renormalised]

You can write all you like, Craig, it makes no difference to the outcome of the argument, either way.

Let me tell you why your rant here has failed....

Your dataset, for a start, is based totally on assumptions made in the past that are only what scientists believe to be the case based on what scant evidence they actually have. I should know a bit about this, Craig, considering it's what I studied at Uni. I'm not coming at this from some completely different field or without any prior knowledge in this, you know. Unlike yourself. Getting back to the matter at hand, those tabulated values are nothing more than guesses/assumptions of what might have been the case. The models are based on this because they have no hard evidence to go by. Most of those early trace fossils have been argued over for years as to whether they're actually real fossils of algae/bacteria that are present in those early rocks. In any case, those rocks have been so heavily metamorphosed, it's almost impossible to tell what's what from possible biogenic or purely abiogenic sources. The only thing that can be said for certain is that it happened, and probably rather early on.

Their data is subjective right from the start.

My own position on this is that life did arise early on this planet after its formation. Most likely after the first 100-200 million years or so. Despite their results and whatever you might think, there is a good chance that given the right conditions and all things being equal, life will arise elsewhere in a similar manner. Though, there is no evidence either way to prove/disprove this. It is a subjective answer based on subjective data.

As for your second test, they fail this miserably. They have not gone and collected their own data. All they have done was used previously published data (where it could be found) and entered that into their own analysis. The data was based on rather fluid assumptions to begin with, so their own conclusions will be affected by this. In other words, their conclusions will be nothing more than guesstimated opinions, not rigorous results that you would expect otherwise from a scientific paper. It was nothing more than a gedankenexperiment...a thought exercise, with only marginal applicability. More a topic for conversation and further discussion and maybe a pointer to some further research.

Independent verification does come via publication, because that is where others get to see their paper and then to mull over it and try to replicate the results. So in that regard they pass the third test. However, any scientist worth their salt would see this paper for what it is and not even try to verify the results. Because, that is not what this paper is about. Scientists know the ins and outs of the various methods of statistical analysis and know that some are better than others for the jobs they perform. I've already stated in earlier posts the pitfalls of Bayesian analysis and why it's not seen by many as being an ideal method for some areas of scientific data analysis. To reiterate the main reasons as to why this form of statistics, in this particular case, is not ideal....

1. Quantifying prior beliefs into probability distributions is not simple. First, we haven’t all thought much about our prior beliefs about most things, and, even if we have some beliefs, those aren’t usually condensed into a probability distribution on a parameter.

2. We might not agree with colleagues on the prior distribution.

3. Even if we can find a formula for the distribution describing our prior beliefs about the parameter, actually doing the probability calculations to find the posterior distribution using Bayes Theorem maybe more complex than we can do in closed form.

....basically, in order to find the posterior calculations (the answers), a prior knowledge or belief about the distribution of the data is required. If that prior distribution is already based on tenuous assumptions, then the answer you get will be the same. You can even get completely different answers from the same set of data, using the exact same equations. All depending on what prior parameters we care to use at the time. They don't even have to vary that widely to get different results. Many scientists don't like Bayesian analysis for these reasons as it's not an objective method of analysis.

Just because anyone can pickup a paper and read it doesn't mean it automatically passes independent verification, and it hardly means it will just because someone thinks they understand what it says because they've read up a bit on it. You have to actually have done the science before, in order to verify it, or at least have studied in the field and then understood the implications of that science in the paper being read. You wouldn't get a neuroscientists writing an in depth critique of a journal paper written by a nuclear physicist, simply because he hasn't the required learning, or experience, under his belt to be able to do so...and vice versa. Even if they do understand some of what's being written.

If a theory or hypothesis is plagued by subjectivity in its methods of analysis because its underlying maths is this way itself, then self consistency is moot.

As far as truth is concerned, at no time at all did any of us here arguing the counterpoint to your position, Craig, ever say that we had a handle on the truth. It's you, in fact, that have brought this point up. I don't know what the truth is and most likely will never get the chance to find out. All I have argued is that given the universality of the physical laws governing the universe and the fact that life evolved on this planet, that all things being equal, life should evolve elsewhere in the universe and especially on planets where the conditions are similar to what they were on the early Earth. Not that it did or has, or that it exists at present. But that given all the circumstances etc, it most likely will be.

The ridiculous thing about all of this is that the paper itself even said this. However, they took the negative stance on the matter where it concerned their results. And they're entitled to do so. However, I and many others, would beg to differ despite conceding that their conclusions might be correct.

[marki]

Yes Steven I agree we are moving towards that grey area. I should make myself clear here. My objection is not towards the mathematics involved far from it but rather the thin grey line itself. In my opinion and it is only my opinion for what its worth, too much emphasis is being placed on theories with little or no real evidence to back them up...to the point where people are starting to proclaim them irrefutable truths (and they will argue with gusto and venom against any other possibility). The universe is far too complex for such nonsence. We try to simplify everything so our feeble minds can attain some sense of comfort in knowing what is going on and back it up with "the maths tells us so". We as a species have so much to learn that we have yet to scratch the surface. The title of this thread states "No Life Is Possible" and how you decode that is a matter of semantics I guess. Sure Earth may be the only place in the Universe that life has evolved but then it may very well not be. No mathematical work no matter how elegant can give us an answer to that question. We simply need to get off our RS's and explore the universe which is easier said then done.


Mark

[avandonk]

I watched a program on SBS on Infinity last night. One result is if the Universe is infinite there are an infinite number of Earths and equally an infinite number of each of us. Somewhere a monkey has typed all of Shakespears works. In fact this random monkey has typed all the books ever published! In an infinite Universe every possible thing has happened!

So to boil this down. In an infinite Universe everybody is correct somewhere with an on line argument!

Hope that makes you feel better.

Bert

[CraigS]

Found this guy … right here on Earth, Bert !

Cheers

[marki]

LOL I saw that to . Better go and find that dam monkey, wonder if copyright will be valid :P.

Mark

[Zaps]

What I've seen, and continue to see, are scientists erring on the side of caution. On the other hand, "enthusiasts" claim a lack of evidence is all but proof of their own pet conjecture.

[Alchemy]

Trying to prove the unprovable. Waste of time worrying about it.

We are here........we haven't found life elsewhere, given our situation it's highly unlikely so the question will never be answered.....

[Poita]

My own personal take on this is that I find it hard to support the theory that if you get a warm planet with water on it, and a Sun at the right distance, that life will naturally follow.

We haven't found anything as far as I know to support the idea that life forming on earth is not a colossal one off event. There are theories all over the place, but unless we find life on one of the squishier solar system moons, or on the other planets, and then prove that life on earth didn't just come from that planet anyway (or vice-versa) then we can't really know.

Resorting to infinities doesn't float my boat, as that just means that everything is happening somewhere, which doesn't tell us anything really.

The whole DNA/RNA combination seems so tricky to get going, that the odds are quite possibly, literally beyond astronomical of it happening again.

Until we can trace our own life history back to the source, or create life in the lab, I'm assuming that life is pretty damn rare, but I hope I'm wrong.

[big_dav_2001]

Hi all, extremely interesting thread...

Ive gotta say I agree with warrens Schrödingers cat reference. Until we 'open the box' and find undeniable evidence of life, we can safely assume that it both does and does not exist, regardless of mathematical formulae which supports either side of the arguemet.

Mathematical theory is just as the term implies: THEORY, until it can be proven (which at this point it can't), it's nothing more than a mathematical crystal ball which can make predictions (some quite accurate), but contains no real evidence to back up the predictions. Like any crystal ball, the predictions made are open to interpretation and can be taken several ways.

Just my 2¢ worth, I'll get back in my hole now :)

Davin
:cheers:

[xelasnave]

At this point the answer to the question is there life elsewhere can only be answered by the expression of an opinion... It is a matter of belief and opinions can have no greater basis than belief irrespective of the foundation for that belief.

We could say we have observed 3 objects in the Universe first hand and that observation tells us there is life on one of those objects (Earth) the others (Moon and Mars) show no evidence of life to date.

That does not mean we are entitled to rate the odds at one in three for other objects having life. Our observation is meaningless because the Universe is made up of billions and billions of objects and we have first hand observations for three only...

However as an opinion (unsuppoted) it would seem inconceivable that in a Universe of a size beyond the comprehension of a human that there is no other life. Are we the center of "life", are we the first and the only... I doubt it...but that is mere opinion. There are others who believe the Earth was built for humans etc...thats OK because it is only belief.

Our literate monkey in an infinite universe is only a belief..has anyone read anything this monkey has written to form such a belief..no..however such ideas flow from the concept of an infinite universe..reasonable maybe but pure unsupported speculation...


Further our understanding of life is that it started here whereas it may be like pollen in the wind at a cosmic level such that if conditions are favorable life can flourish having been delivered to a new home via the flow of cosmic dust...AND before you laugh I suggest that all such is possible when we speculate with reality racing forward with no facts but preconceptions.

AND although that is specualtive we have little else but speculation and equations like the Drake equation only allow answers using inputs unestablished in reality ..it turns on placing some number on the probability when we can not say if any number can be placed there at all.

Given the size of the Universe such an approach means we can have life elsewhere the moment we suggest there is some life out there..the equation can only deliver a positive once a number has been assigned... the number of objects in the universe in human terms is seemingly infinite so even if we say one object in a trillion may have life we have moved out of reality..we dont know that...so we introduce fiction into our sums.

It is like saying all those folk who claim abduction by aliens cant be wrong at least one must be correct...no!!!! we dont know that so any probability is meaningless.

One in a trillion seems conservative but it has no bearing on our reality which is ... so far we have no justification for attributing any number for "other life" we just dont know that yet.

As Craig says however Bayer approach allows for adjustment... if we find life on Europa or not the readjustment gives us a new probability etc but using the Bayer approach at the moment means we only input what we know and what we know is at the moment limited to Earth really (on the basis that Mars and the Moon still require further exploration to eliminate all possibilities of life).

Also probability points to a possible future not a certain future.

It is interesting to read all the views on the other life issue or non other life issue:thumbsup:

alex:):):)

.

[Rob_K]

Sorry guys, just catching up after an IIS-less month! Not such a productive thread, but I do take issue with this statement Craig.

The only scenario in which the thread title might be 'legitimate' is where a different set of physical laws operated in the emergence of life in our own solar system - essentially a Creation scenario.

Ignoring that, we already know that the operation of natural physical processes on star stuff in our Universe has produced life, and life as we know it. :P We are an example of it. Therefore we can be utterly certain that it is possible elsewhere in the Universe, regardless of the processes involved.

This of course has no bearing on the likelihood of it, which is a different issue.

Cheers -