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Colin Robinson
2013-Feb-13, 10:31 PM
George Gaylord Simpson wrote in 1964: "...exobiology a curious development in view of the fact that this 'science' has yet to demonstrate that its subject matter exists!" (from his article "The non-prevalence of humanoids" in the journal [I]Science.)

Simpson was writing at a time when exploration of the solar system by space probes was just beginning. Even though a lot has been done since then, and there is a lot more that can be done in the near future, still it has not been demonstrated that other planets/moons have life on them.

But is it conceivable that planetary exploration could be conducted at all, without considering astrobiological/exobiological issues?

E.g. Issues like whether it is important to sterilize a space probe to avoid contaminating a particular planet/moon with Earth microbes? If a sample-return mission is sent to a particular planet/moon, should precautions be taken to avoid contaminating Earth with exotic microbes?

These are actual issues that space agencies like NASA and ESA have to consider, and do consider, when exploring the solar system with space probes. How could they consider issues like that, without consulting scientists who take a professional interest in such questions?

The bottom line, for me, is this...

G. Gaylord Simpson's one-liner is relevant today only as a reminder that the existence of life beyond Earth, even microbial life, is still a question without an answer.

But it is not a cogent argument against the scientists who are working with space agencies to find the answer to this question and to related questions.

Selfsim
2013-Feb-13, 10:48 PM
No comment.

Except … a question … would you distinguish 'Astrobiology' from 'Earth-life Biological Sciences' for us?

If the two prove to be difficult to distinguish, (or even indistinguishable), then there is not much to discuss of scientific relevance for the term of your choosing (ie:'Astro' biology).

Rgds

Paul Wally
2013-Feb-13, 11:18 PM
No comment.

Except … a question … would you distinguish 'Astrobiology' from 'Earth-life Biological Sciences' for us?

If the two prove to be difficult to distinguish, (or even indistinguishable), then there is not much to discuss of scientific relevance for the term of your choosing (ie:'Astro' biology).

Rgds

Astrobiology deals with life in the universe at large. Earth biology deals only with life on an infinitesimal small part of that universe. It is of tremendous scientific importance because discoveries in Astrobiology will allow us to understand Earth biology within a larger context. We will be able to take a step back and see where Earth biology fits into the greater scheme of things, and that will actually help us to understand Earth biology much better than we would have otherwise.

Colin Robinson
2013-Feb-13, 11:23 PM
No comment.

Except … a question … would you distinguish 'Astrobiology' from 'Earth-life Biological Sciences' for us?

Well, one distinguishing criterion is that astrobiology involves astronomy, whereas Earth-life biological sciences generally don't.

Quoting from the first paragraph of NASA's Astrobiology Roadmap (2008):

"Astrobiology addresses three basic questions that have been asked in various ways for generations: how does life begin and evolve, does life exist elsewhere in the universe, and what is the future of life on Earth and beyond? ... Interdisciplinary research is required that combines molecular biology, ecology, planetary science, astronomy, information science, space exploration technologies, and related disciplines."

The complete Roadmap is quite detailed, and very worth reading IMO. You can download a copy (without charge) via the webpage
https://astrobiology.nasa.gov/roadmap/

Regards
Colin

BioSci
2013-Feb-13, 11:40 PM
But is it conceivable that planetary exploration could be conducted at all, without considering astrobiological/exobiological issues?


Perhaps conceivable as a plot for bad science fiction. But in our world it would be very bad science, bad public policy, bad politics, and short-sighted engineering.

One of the most scientifically important questions (and of great public interest) that could be answered by planetary exploration is whether or not life exists on other planets. As a biologist, I think that the discovery (and also non-discovery) of life would be of greater scientific (and social) impact than just an incremental increase in our understanding of the geology/chemistry/formation of other planets in our solar system.

neilzero
2013-Feb-13, 11:43 PM
Clearly there is little biology to study at present other than Earth biology, so the difference is in the goals and attitude of the student and electives such as astronomy and space craft design that might be taken. Neil

kzb
2013-Feb-14, 12:57 PM
We really should not wait for the existence of astrobiology to be proven before we take precautions.

Personnally I think the risk from xenobacteria colonising the Earth is virtually non existent. Any such microorganisms would be quickly out-competed by endogenous species, because they are the ones evolved to live on Earth. What's more, if there are Mars bacteria or Europan bacteria, they've landed on Earth already. But I still think we ought to be very cautious of things we do not fully understand.

The risk the other way, i.e contaminating other worlds with Earth bacteria, is serious. If the worlds are sterile to start with, there is the possibility that Earth bacteria will quickly take over and evolve to fill the environment. I am thinking here primarily of Europa and other worlds with sub-surface oceans.

The possibility of life on other worlds is one of the most important questions. Certainly it is discussed endlessly on here. If we contaminate Europa (say) with Earth bacteria, it will become impossible to answer one important facet of this question, that is abiogenesis. If there is the slightest possibility that positive results from Europa could be caused by Earthly contamination, the conclusions of the experiment will become muddied to say the least.

SkepticJ
2013-Feb-14, 06:32 PM
Personnally I think the risk from xenobacteria colonising the Earth is virtually non existent. Any such microorganisms would be quickly out-competed by endogenous species, because they are the ones evolved to live on Earth.

Sort of like how cane toads, fire ants, kudzu and water hyacinth are out-competed by native fauna and flora?

Selfsim
2013-Feb-15, 01:29 AM
Some comments (opinions maybe) on ‘the roadmap’ linked in post #4:

On ‘origins’ ...

How life begins remains a fundamental unsolved mystery. The origin of life on Earth may well represent only one pathway among many along which life can emerge. This belief forms the intellectual foundations for observations and missions aimed at searching for extant or extinct life elsewhere in the universe. Thus the universal principles must be understood that underlie not only the origins of life on Earth, but also its possible origins elsewhere.Beliefs don’t form ‘intellectual foundations for observations' in general science for any folk, other than those who adopt those beliefs in the first place!

This is how the ‘R’ word movements form, and is what distinguishes science, from ‘R’ movements.

If this is the fundamental tenet of NASA’s view Astrobiology, then it does in fact appear that Astrobiology does stem from a flawed basis, right from the very outset(??)
(IMNSHO).

That NASA has written these words, published them, and is funding research on this basis, does seem to be a central bone of contention as measured against the tenets of the scientific principle.

But so what?

If Astrobiology is not a science, but represents the focal point of knowledge distilled from multiple diverse streams of empirical science, in order to gain a perspective on the belief at its core, then it should live and die by its own rules (as I’m now sure, it will). That’s the net outcome of hypotheses which go on to result in empirical tests isn’t it?


We must move beyond the circumstances of our own particular origins in order to develop a broader
discipline, “Universal Biology.” Although this discipline will benefit from an understanding of the origins and limits of terrestrial life, it also requires that we define the environmental conditions and the chemical structures and processes that could support life on other habitable planets. Thus we need to exploit universal laws of physics and chemistry to understand polymer formation, self-organization processes, energy utilization, information transfer, and Darwinian evolution that might lead to the emergence of life in planetary environments other than Earth. Clearly an inventory of molecules must exist that is capable of gaining chemical, structural, and functional complexity and eventually assembling into living systems.How does ‘exploitation of Physical Laws’ do anything other than reinforce a belief that something might or might not exist? So far this looks to be a topic looking to suck justification out of knowledge coming from other sources, in order to justify its own existence. Gaylord Simpson's ‘joke’ is no ‘joke’, after all!

…. and then, on ‘bio-signatures’ and their detection (my favourite) ...


Astrobiological exploration is founded upon the premise that signatures of life (biosignatures) will be recognizable in the context of their environments. A biosignature is an object, substance and/or pattern whose origin specifically requires a biological agent. The usefulness of a biosignature is determined, not only by the probability of life creating it, but also by the improbability of nonbiological processes producing it. An example of such a biosignature might be complex organic molecules and/or structures whose formation is virtually unachievable in the absence of life. A potential biosignature is a feature that is consistent with biological processes and that, when it is encountered, challenges the researcher to attribute it either to inanimate or to biological processes.I certainly recognise the underlined terms, (they are strangely similar with the language of this forum). But how can they be justified other than by basing the whole idea on what is already known (from Earth-life studies)? In other words, the study of terrestrial Biology is the source of ‘authority’ .. not ‘Astrobiology’. Astrobiology has brought nothing original of its own, because it has no evidence of its field of interest. I have deep concerns with this paper, (from a scientific perspective). Although, I am not particularly surprised about what it says. At the very least, it is up front about the flawed basis on which the topic proceeds.

I trust I’m still on topic though, and not running contrary to any customised agendas here am I? ;)

I'm not saying that Astrobiology adds no value at all. But like SETI, the emphasis on its central beliefs is subjective, until it has something of its own to study. Sterilisation of spacecraft came from the ideals of 'planetary protection' following from the Outer Space Treaty ratification by most countries of the UN, in 1967. I'm not sure I'd attribute that initiative to NASA's Astrobiology Department (or its predecessors)(??)

Rgds
PS: This post is not aimed at obstructing any discussion on the topic. (Quite the opposite, actually .. it seems to have gone a little quiet, and I do think its a good topic for some 'rigourous' discussion .. but it may not be 'nice' for some). :)

Colin Robinson
2013-Feb-15, 03:39 AM
Some comments (opinions maybe) on ‘the roadmap’ linked in post #4:
On ‘origins’ ...

How life begins remains a fundamental unsolved mystery. The origin of life on Earth may well represent only one pathway among many along which life can emerge. This belief forms the intellectual foundations for observations and missions aimed at searching for extant or extinct life elsewhere in the universe. Thus the universal principles must be understood that underlie not only the origins of life on Earth, but also its possible origins elsewhere.

Beliefs don’t form ‘intellectual foundations for observations' in general science for any folk, other than those who adopt those beliefs in the first place!

This is how the ‘R’ word movements form, and is what distinguishes science, from ‘R’ movements.

If this is the fundamental tenet of NASA’s view Astrobiology, then it does in fact appear that Astrobiology does stem from a flawed basis, right from the very outset(??)
(IMNSHO).

IYNSHO?

After all, it's scarcely possible to talk about anything without expressing an opinion of some sort...

Question: If the authors of the Roadmap had used the word "opinion" instead of "belief" in the passage you've quoted, would that change the substance of what they are saying here?

What would be a non-flawed basis of scientific observation? Does it require having no opinions at all?

Or is it about developing opinions which are consistent with what is known, yet which take a step beyond what is known –– opinions which can then be tested (either verified or falsified) as the results come in?

Paul Wally
2013-Feb-15, 10:46 AM
Beliefs don’t form ‘intellectual foundations for observations' in general science for any folk, other than those who adopt those beliefs in the first place!



Well, that belief stems from a much more fundamental belief of science in general, and that is that the universe is intelligible. Let's look at that proposition:


How life begins remains a fundamental unsolved mystery. The origin of life on Earth may well represent only one pathway among many along which life can emerge.

"Unsolved mystery" means that we don't understand how life begins. The search for understanding stems from the belief that the universe is intelligible, in other words, if the universe was unintelligible then there would be no point in seeking understanding. I can now proceed to explain how the proposition that there may be many possible pathways, follows from the intelligibility of the universe: If physics and chemistry is the basis of the abiogenesis process then it is understandable how several different pathways within physical and chemical processes can exist, it is also understandable how many of these pathways can have the same general outcome of life. It is however not understandable, by me and I'm sure astrobiologists too, why or how only one possible pathway would lead to life. Understanding abiogenesis would mean seeing it as an instance of a general law, just like seeing an apple fall is an instance of the general law of gravity. I cannot understand or explain why an apple falls without the larger context of gravity, and in the same way, we cannot understand abiogenesis without the larger, more general context of how life in general can follow from the laws of physics and chemistry.

Selfsim
2013-Feb-15, 10:55 AM
Question: If the authors of the Roadmap had used the word "opinion" instead of "belief" in the passage you've quoted, would that change the substance of what they are saying here?That would depend on how much the reader values an opinion/belief. (I consider both opinions and beliefs to be pretty well interchangeable generally speaking ... they are both formed from past experiences, and thus aren't necessarily contingently related to the unknown future, until demonstrated to be so ... a philosophical perspective here).

I cannot deny that someone has valued the belief they mention ... is that the only reason we should all follow suit? If so, I choose not to, (as it looks to me like a pure choice).


What would be a non-flawed basis of scientific observation? Does it require having no opinions at all? Observations have uncertainties. But in this case, their tenet has a flaw in scientific principle. To start out on the right track, it should contain things which are objectifiable, independently verifiable, and be interpretable via already tested, internally consistent physical theory (or Law) ... Y'know ...stuff we know we can do, we know what the results mean, and we know the process works. These guys aren't even attempting that. They seem to be starting out from the 'belief' that what they're trying to detect is already there, and looks and responds like earth-life, therefore when they see those signs, they will by definition, confirm the existence of their belief, and that's how certain measurements, used in confirming their belief, become 'bio-signs'!

Or is it about developing opinions which are consistent with what is known, yet which take a step beyond what is known –– opinions which can then be tested (either verified or falsified) as the results come in?Why not just go out and find the sample?
I don't see a lot of point in trying to formulate theories based on opinions, when all it takes is going for the sample itself.
Rgds

kzb
2013-Feb-15, 12:39 PM
Sort of like how cane toads, fire ants, kudzu and water hyacinth are out-competed by native fauna and flora?



Yep good example. These are species which grow vigorously on Earth ,when transferred into similar habitats to where they came from (but lacking the predators/pests/diseases which kept them in check there).

If transferred to Mars or Europa they wouldn't stand a chance.

Colin Robinson
2013-Feb-15, 06:58 PM
Why not just go out and find the sample?
I don't see a lot of point in trying to formulate theories based on opinions, when all it takes is going for the sample itself.
Rgds

That may be all it takes... but how do you do that?

Which planetary bodies do you study, how do you study them, what sort of locations do you send robot probes to, what sort of gear do you equip them with?

The Roadmap does it best to answer questions like these, with its lists of "example investigations". And yes, these "example investigations" are based on opinions about what might be out there...

Are there other sorts of investigations, not in their lists, which are more likely to result in finding a sample?

SkepticJ
2013-Feb-15, 11:29 PM
Yep good example. These are species which grow vigorously on Earth ,when transferred into similar habitats to where they came from (but lacking the predators/pests/diseases which kept them in check there).

If transferred to Mars or Europa they wouldn't stand a chance.

But Europan bacteria could conceivably stand a chance here, at least around deep sea vents. Maybe even in arctic waters, if Europa's ice stains really are photosynthetic organisms.

Also, if they aren't actually bacteria, but we just use that word because they're small and kind of look like them. If they are based on different organic chemicals, Earth life couldn't eat them, anymore than you can chow down on plastic.

Selfsim
2013-Feb-16, 04:49 AM
That may be all it takes... but how do you do that?Build probes. Send them.

Which planetary bodies do you study,The ones you can reach.
how do you study them,With instruments like Curiosity's.

what sort of locations do you send robot probes to,Ones where they can land safely, so they can achieve their goals.

what sort of gear do you equip them with?Whatever fits on the probe. (Like Curiosity's).

The Roadmap does it best to answer questions like these, with its lists of "example investigations". And yes, these "example investigations" are based on opinions about what might be out there…We don't need the roadmap. We already know what's in the roadmap (from other areas of study).

Are there other sorts of investigations, not in their lists, which are more likely to result in finding a sample?The lists don't make a difference. We'll know what to sample, once its been spotted.

Rgds

Colin Robinson
2013-Feb-16, 08:15 AM
Build probes. Send them.
The ones you can reach.With instruments like Curiosity's.
Ones where they can land safely, so they can achieve their goals.
Whatever fits on the probe. (Like Curiosity's).
We don't need the roadmap. We already know what's in the roadmap (from other areas of study).
The lists don't make a difference. We'll know what to sample, once its been spotted.

I've just been reading an interview (here's the link (http://www.astrobio.net/interview/5063/curious-about-life-interview-with-pan-conrad)) with one of scientific team running the Curiosity project -- astrobiologist Pan Conrad, deputy principal investigator of the SAM (Sample Analysis at Mars) team.

Pan says that that Curiosity is "trying to understand the habitability potential of another planet" which is "straight out of the Astrobiology Roadmap".

Selfsim
2013-Feb-16, 08:50 AM
What is this supposed to mean? (Can someone please translate for me?) I haven't a clue as to what this is supposed to mean, (it seems to be speculative speak):

As we do that, we begin to get a feel for what might be too dynamic, what might be insufficient raw material, and what might be indicative of the probability for those requirements that at least the life we know about would place on an environment.It seems as though it might have something to do with this(?):

When sedimentary rocks are made, they record the environment at the time they are deposited, so it’s important to remember that record can be altered over time. So the preservation potential of various environments affects the accuracy with which we can interpret the rock record. To top it off, we have to infer habitability for an environment that isn't Earth and the potential of habitability for life that may not be like life on Earth. We have to keep a very open mind. It's a really tough problem.

Surely if there are no signs of preserved (fossilised) life, or present-day life, what's the point of trying to infer a habitable environment? I mean if there's no evidence of past or present life, doesn't that mean the environment wasn't and isn't habitable, (for Mars life)? Who cares about definitions of 'habitability' then?

Man, this thing is messed up!

Paul Wally
2013-Feb-16, 09:53 AM
Build probes. Send them.
The ones you can reach.With instruments like Curiosity's.
Ones where they can land safely, so they can achieve their goals.
Whatever fits on the probe. (Like Curiosity's).
We don't need the roadmap. We already know what's in the roadmap (from other areas of study).
The lists don't make a difference. We'll know what to sample, once its been spotted.


So, you can't answer Colin's questions then. That's fine, you're not required to, but why didn't you just say you don't know instead of replying with such meaningless tautologies?




Surely if there are no signs of preserved (fossilised) life, or present-day life, what's the point of trying to infer a habitable environment? I mean if there's no evidence of past or present life, doesn't that mean the environment wasn't and isn't habitable, (for Mars life)?

The question of past or present habitability of Mars is still unanswered. I think that's why Curiosity is there in the first place.


Who cares about definitions of 'habitability' then?

Without a definition of habitability we cannot conclude whether Mars is/was habitable or not.


Man, this thing is messed up!

That's your perception, based on the fallacious thinking I pointed out above.

Colin Robinson
2013-Feb-16, 06:00 PM
Surely if there are no signs of preserved (fossilised) life, or present-day life, what's the point of trying to infer a habitable environment? I mean if there's no evidence of past or present life, doesn't that mean the environment wasn't and isn't habitable, (for Mars life)? Who cares about definitions of 'habitability' then?

But can we say a place the size of Mars has "no signs of preserved (fossilised) life, or present-day life", when we're only beginning to study the place?

As I understand it, NASA's strategy is to first assess present and past habitability, and afterwards, if they conclude that Mars is or was ever habitable, they will then look for signs of present or past life (e.g. fossils), concentrating on the regions they've assessed as the most habitable.

Selfsim
2013-Feb-16, 06:52 PM
But can we say a place the size of Mars has "no signs of preserved (fossilised) life, or present-day life", when we're only beginning to study the place?

As I understand it, NASA's strategy is to first assess present and past habitability, and afterwards, if they conclude that Mars is or was ever habitable, they will then look for signs of present or past life (e.g. fossils), concentrating on the regions they've assessed as the most habitable.Well I agree with you say! (!!!) :)

And therein lies the problem again.

Let me try & explain (I might have at least some chance in this forum .. ;) :)).

So, we've defined 'Habitable Environment' from what we know from Earth, (ie: life is here .. in this environment).

We take that definition to Mars.

There are no obvious signs of life on Mars.

We search for our definition of 'Habitable Environment'. We find signs of 'Habitable Environment', but no signs of life.

The tenets of Astrobiology (as outlined in the 'Roadmap') result in a demand for an explanation … if there existed a 'Habitable Environment' (defined on the basis of Earth) on Mars, then why is there no life there? (Notice the 'why' is a philosophical question .. not one science typically attempts to answer, (go for it Paul .. it'll 'make no difference' to the scientific perspective on this, though)).

An answer is concocted, (although science calls for questions which can be tested .. which actually exacerbates the problem caused by originally flawed question) … 'Oh .. it must be underground' or 'it must be someplace we didn't look' and 'oh its also microscopic'. 'We'll have to keep looking'.

The search is endless .. meanwhile Colin's favourite moon, Titan, never gets explored, because every effort and resource continues to be poured into pursuing an answer on Mars that has no exit criteria.

And that's why Astrobiology's tenet is flawed. Gaylord Simson's joke has become real.

Not all questions are good scientific ones, but if the tenet wasn't a scientifically sound one in the first place, then all subsequent questions of the same type will be allowed .. that's how 'Rs' start. They can probably all be turned into scientific ones at some lower level of detail, but that conveniently obscures the original flawed tenet.
(A bit like being 'nice').

Cheers

Paul Wally
2013-Feb-16, 07:59 PM
The tenets of Astrobiology (as outlined in the 'Roadmap') result in a demand for an explanation … if there existed a 'Habitable Environment' (defined on the basis of Earth) on Mars, then why is there no life there? (Notice the 'why' is a philosophical question .. not one science typically attempts to answer, (go for it Paul .. it'll 'make no difference' to the scientific perspective on this, though)).


You see, you're jumping ahead of the process. You're trying to predict the scientific process on Mars, but you can't, because the whole point is to investigate the question of habitability on Mars. We cannot predict and that's why we investigate. You also cannot predict how scientists will behave if they found out that Mars was never habitable, because it depends on what they will actually discover on Mars. There could be degrees of habitability, there might be differences of opinion on the matter. We cannot predict what they'll find and therefore we cannot predict their response.



An answer is concocted, (although science calls for questions which can be tested .. which actually exacerbates the problem caused by originally flawed question) … 'Oh .. it must be underground' or 'it must be someplace we didn't look' and 'oh its also microscopic'. 'We'll have to keep looking'.

Seriously? An answer is concocted? Why would they send probes to search for answers and then 'concoct' an answer. Doesn't make sense.



The search is endless .. meanwhile Colin's favourite moon, Titan, never gets explored, because every effort and resource continues to be poured into pursuing an answer on Mars[U] that has no exit criteria.

The search doesn't look endless. Mars is a finite world. Eventually we'll have our questions about Mars answered. But in the mean while, what's wrong with looking for answers to questions about Mars? Exit criterion should be to have our questions answered, don't you think?



And that's why Astrobiology's tenet is flawed. Gaylord Simson's joke has become [I]real.

Not all questions are good scientific ones, but if the tenet wasn't a scientifically sound one in the first place, then all subsequent questions of the same type will be allowed .. that's how 'Rs' start. They can probably all be turned into scientific ones at some lower level of detail, but that conveniently obscures the original flawed tenet.
(A bit like being 'nice').


Just calling something real, as to convince yourself, doesn't make it real you know. Are you sure that your understanding of what "scientific" means is indeed how science works? I mean, where have you learned that science is the way you think it is, and how do you know that is actually how science works?

eburacum45
2013-Feb-16, 08:37 PM
The idea that extraterrestrial life may differ from Earth life in some, or many, characteristics is an important one. This idea lays open three possibilities, as far as I can see;
1/ There is no lfe on any other world that we are likely to be able to examine in detail.
2/ there is life on other worlds, but it resembles Earth life in most ways, allowing us to use our experience of life on Earth to develop ways of detecting this life.
3/ there is life on other worlds, but at least some of it differs in character substantially from life that can be found on Earth.

This third category presents a lot of difficulty for anyone attempting to do astrobiology; but that doesn't mean that we should abandon all hope of ever detecting life that is substantially different to Earth life.

I think that a lot of very useful data about alternative forms of self-replicating system will become available in the next century or two, as the technology of self-replication becomes better understood. But this development will be driven mostly by economic factors, rather than by astrobiological speculation. In due course this (not-yet developed) technology could help us understand the science of (not-yet discovered) alien biologies; but this sort of thing is a long way in the future. I suppose it is possible that the speculations of astrobiology might also assist the development of self-replicating technology, but that remains to be seen.

Colin Robinson
2013-Feb-17, 01:35 AM
More information about relationship between the Curiosity mission and astrobiologists.

Curiosity's program scientist, i.e. the person giving overall leadership to the scientific side of the mission is Michael Meyer. He is also the lead scientist for NASA's Mars program as a whole. Meyer used to run NASA's exobiology program (before it became astrobiology), was also NASA's planetary protection officer, and was one of the founders of the astrobiology team.

Michael Meyer describes Curiosity as "the first astrobiology mission since Viking in 1976" and says it is carrying out one of the steps envisaged in NASA 1995 publication, "An Exobiology Strategy for Mars Exploration".

Interview with Michael Meyer about Curiosity (http://www.astrobio.net/interview/5076/curious-about-life-interview-with-michael-meyer)

So I think it is a big mistake to contrast Curiosity's empirical work with the theoretical considerations in the strategy papers, or to argue that you don't need strategy papers when you have space-probes like Curiosity. Because without that patient work developing strategies for research, Curiosity would never have been built.

kzb
2013-Feb-18, 01:08 PM
But Europan bacteria could conceivably stand a chance here, at least around deep sea vents. Maybe even in arctic waters, if Europa's ice stains really are photosynthetic organisms.

Also, if they aren't actually bacteria, but we just use that word because they're small and kind of look like them. If they are based on different organic chemicals, Earth life couldn't eat them, anymore than you can chow down on plastic.

Well I did say we should be very cautious about things we don't fully understand. I was just commenting on the balance of probabilities.

Say you have two strains of microbes growing in a culture. The generation time is usually very short with bacteria. It only takes one strain to have a small per cent advantage over the other before it completely takes over the culture. It's like compound interest.

So in theory, any Europan sea vent microbes transferred to an Earth sea vent are quickly outgrown by the existing bacteria, who are more fine-tuned to their environment. It does not mean one is eating the other.

If Europan life is fundamentally stronger than Earth life, then I guess we have problems.

eburacum45
2013-Feb-19, 04:54 PM
The fact that all life on Earth shares a common origin might be a clue to the outcome of any contest between different biota. If there have been multiple abiogenesis events on this planet, only the result of one such even appears to exist today; this means that the biota resulting from all the other abiogenesis events have died out. This may be the result of pure chance, or it might be the result of competition between different biota which has caused one to become dominant and at some point to become the only surviving example.

Of course if the results of a different abiogenesis event were ever discovered on Earth, a so-called shadow biosphere, then this idea would need to be revised.

AstroRockHunter
2013-Feb-19, 07:27 PM
I’m sorry that I’m so late to this discussion.



And therein lies the problem again.

Let me try & explain (I might have at least some chance in this forum .. ;) :)).

So, we've defined 'Habitable Environment' from what we know from Earth, (ie: life is here .. in this environment).

We take that definition to Mars.

There are no obvious signs of life on Mars.

We search for our definition of 'Habitable Environment'. We find signs of 'Habitable Environment', but no signs of life.

The tenets of Astrobiology (as outlined in the 'Roadmap') result in a demand for an explanation … if there existed a 'Habitable Environment' (defined on the basis of Earth) on Mars, then why is there no life there? (Notice the 'why' is a philosophical question .. not one science typically attempts to answer, (go for it Paul .. it'll 'make no difference' to the scientific perspective on this, though)).The tenets of Astrobiology (as outlined) would also result in a demand for an explanation if Mars were found to not to have a ‘Habitable Environment’ but signs of life were discovered.

‘Why’ is not strictly a philosophical question. ‘Why’ also serves to stimulate a series of inquiries that (hopefully) lead to an explanation of an observation or event.

As an aside, ALL tenets demand an explanation. Whether science can supply that explanation is sometimes debatable


An answer is concocted, (although science calls for questions which can be tested .. which actually exacerbates the problem caused by originally flawed question)
I disagree that the original tenet is flawed. Remember, the original tenet is:

The origin of life on Earth may well represent only one pathway among many along which life can emerge.I also disagree with your observation that
Beliefs don’t form ‘intellectual foundations for observations' in general science for any folk, other than those who adopt those beliefs in the first place!It is belief in a tenet that stimulates the intellectual pursuit of observations. If the original tenet is flawed, then the only reason would be that the origin of life on Earth is the only pathway in which life can emerge. Either tenet requires inquery.


… 'Oh .. it must be underground' or 'it must be someplace we didn't look' and 'oh its also microscopic'. 'We'll have to keep looking'.

The search is endless .. meanwhile Colin's favourite moon, Titan, never gets explored, because every effort and resource continues to be poured into pursuing an answer on Mars that has no exit criteria.I would like to see your evidence that NASA ‘has no exit criteria’. You assume to know the inner workings of the NASA decision making process that we others are not privy too.

And that's why Astrobiology's tenet is flawed. Gaylord Simson's joke has become real.

Not all questions are good scientific ones, but if the tenet wasn't a scientifically sound one in the first place, then all subsequent questions of the same type will be allowed .. that's how 'Rs' start. They can probably all be turned into scientific ones at some lower level of detail, but that conveniently obscures the original flawed tenet.
(A bit like being 'nice').

Cheers

I agree that not all questions are good scientific ones, but I believe that Astrobiology’s tenet is flawed only in your very narrow viewpoint.

BTW, you say
… that’s how ‘Rs’ start.What is ‘Rs’?

agingjb
2013-Feb-19, 08:53 PM
Well I can't follow all the ideas about what attitudes we should take to the possibility of some phenomena analogous to life elsewhere, but I do think that our priorities for exploration of planetary bodies (including large moons) in the solar system should ignore the possibilities of life entirely.

I'd set the order according to resemblance of planetary surfaces (as far as it goes) to Earth - Mars, Titan, Venus, large airless moons, Mercury - although given its proximity I'd put the Moon in the list following Titan.

Actually I'd be happy to say: Mars, Titan, the rest.

Colin Robinson
2013-Feb-19, 10:01 PM
Well I can't follow all the ideas about what attitudes we should take to the possibility of some phenomena analogous to life elsewhere, but I do think that our priorities for exploration of planetary bodies (including large moons) in the solar system should ignore the possibilities of life entirely.

Why do you think that?


I'd set the order according to resemblance of planetary surfaces (as far as it goes) to Earth - Mars, Titan, Venus, large airless moons, Mercury - although given its proximity I'd put the Moon in the list following Titan.

Actually I'd be happy to say: Mars, Titan, the rest.

Your list seems to leave out Enceladus, the small airless moon with water geysering out...

agingjb
2013-Feb-19, 10:30 PM
Well, perhaps I should put it another way. What would our priorities be if we knew there was nothing we could call "life" elsewhere in the solar system? I'd say they would be different, and I'd say that we should be careful to respect that difference in drawing up our plans.

If it lay with me I'd send missions everywhere. It doesn't lie with me though, and I'm actually more interested in Mars (the surface most closely resembling Earth, although with many differences) and Titan (a surface unlike Earth but with so many interesting parallels), even if they did turn out to be sterile, than in speculations about water under the ices of the various moons.

Life? A splendid bonus if it turns up.

Selfsim
2013-Feb-19, 10:41 PM
The tenets of Astrobiology (as outlined) would also result in a demand for an explanation if Mars were found to not to have a ‘Habitable Environment’ but signs of life were discovered.If signs of life were discovered, then Astrobiology would have its subject matter, which would then provide the evidence for its existence. Astrobiology has no such evidence other than Earth-life, and only appears to action its beliefs on that basis.


‘Why’ is not strictly a philosophical question. ‘Why’ also serves to stimulate a series of inquiries that (hopefully) lead to an explanation of an observation or event.Whereas the scientific method makes use of verifiable evidence, physical law and evidence-based theory, to prompt its enquiries. Not beliefs.


As an aside, ALL tenets demand an explanation. Whether science can supply that explanation is sometimes debatableScience's evidence provides the basis for its enquiries, which then allows for consideration of broader possibilities .. Belief based questions don't (IMO).
The difference is: what we don't know, that we don't know, (DKDK). Astrobiology is blind to that, because of its belief basis. (IMO).



I disagree that the original tenet is flawed. Remember, the original tenet is:The origin of life on Earth may well represent only one pathway among many along which life can emerge.… and the way to broaden the search is to investigate the DKDK by simply exploring where we can afford to go, and go for achievable targets/goals … ie: 'snoop' local things out (IMO). The priority becomes what is reachable, rather than what is desired by belief.
Astrobiology is attempting to direct that exploration, on the basis of what it believes and therein lies the difference between it, and science, (IMO).




I also disagree with your observation that:Beliefs don’t form ‘intellectual foundations for observations' in general science for any folk, other than those who adopt those beliefs in the first place! It is belief in a tenet that stimulates the intellectual pursuit of observations. If the original tenet is flawed, then the only reason would be that the origin of life on Earth is the only pathway in which life can emerge. Either tenet requires inquery.And we don’t know whether either is a valid reason, one way or the other, so why proceed on one path whilst ignoring the other?

The differences between the scientific approach and Astrobiology’s belief based approach, would manifest themselves in the different priorities of investigation. Astrobiology also appears to make no distinctions about exit criteria for its searches, because its beliefs do not action those possibilities, (other than by tacit lip-service), IMO.

If an 'Earth-like', water bearing planet was discovered say, 5 light years away, would Astrobiology's beliefs dominate the space based research and development portfolio, to the exclusion of more achievable local targets, (I wonder)?
(Ie: similar to the Webb telescope experience … with the distinction that the Webb actually addresses a far broader scope of research, than just the narrower hunt for exo-life).


I would like to see your evidence that NASA ‘has no exit criteria’. You assume to know the inner workings of the NASA decision making process that we others are not privy too.Well, the evidence is there that NASA has difficulties in terminating programs driven by beliefs about what it takes to bring some projects to fruition (eg: the Webb).
Astrobiology seems to be another excursion down the same pathway, (IMO).


I agree that not all questions are good scientific ones, but I believe that Astrobiology’s tenet is flawed only in your very narrow viewpoint.My viewpoint addresses the DKDK. How exactly does Astrobiology address this?


BTW, you say What is ‘Rs’?R.eligions.

PS: I may not be able to respond further in this discussion on opinion-based science .. I have other priorities now. Cheers.

Selfsim
2013-Feb-19, 10:45 PM
Well, perhaps I should put it another way. What would our priorities be if we knew there was nothing we could call "life" elsewhere in the solar system? I'd say they would be different, and I'd say that we should be careful to respect that difference in drawing up our plans.:clap:




Life? A splendid bonus if it turns up.[/U][/B] :rimshot:

:clap:

AstroRockHunter
2013-Feb-20, 12:19 AM
If signs of life were discovered, then Astrobiology would have its subject matter, which would then provide the evidence for its existence. Astrobiology has no such evidence other than Earth-life, and only appears to action its beliefs on that basis.I must disagree. There is ample evidence for Astrobiology. It's called life on Earth.


Whereas the scientific method makes use of verifiable evidence, physical law and evidence-based theory, to prompt its enquiries. Not beliefs.Yes, the scientific method makes use of verifiable evidence, physical law and evidence-based theory which was obtained because of (WFI) belief in a tenet, or if you prefer, a hypothesis.


Science's evidence provides the basis for its enquiries, which then allows for consideration of broader possibilities .. Belief based questions don't (IMO).Evidence collected because someone, somewhere had a question and decided to seek the answer. I get the feeling that you are confusing Astrobiologys tenet with dogma.


The difference is: what we don't know, that we don't know, (DKDK). Astrobiology is blind to that, because of its belief basis. (IMO).The problem is that without belief based questions, scientists would have no reason to make enquiries. In other words, why look if you have no reason?


… and the way to broaden the search is to investigate the DKDK by simply exploring where we can afford to go, and go for achievable targets/goals … ie: 'snoop' local things out (IMO).What things, and why?

The priority becomes what is reachable, rather than what is desired by belief.
Astrobiology is attempting to direct that exploration, on the basis of what it believes and therein lies the difference between it, and science, (IMO).Not on what it believes, on finding the answer to the question (does)the origin of life on Earth represent the only pathway along which life can emerge?


And we don’t know whether either is a valid reason, one way or the other, so why proceed on one path whilst ignoring the other?Exploring either one would provide an answer to both.


The differences between the scientific approach and Astrobiology’s belief based approach, would manifest themselves in the different priorities of investigation.
So far, Astrobiology’s ‘belief based approach’ is only belief based in you very narrow viewpoint.


Astrobiology also appears to make no distinctions about exit criteria for its searches, because its beliefs do not action those possibilities, (other than by tacit lip-service), IMO.That’s a very broad brush you’re using. Are you sure of this?






If an 'Earth-like', water bearing planet was discovered say, 5 light years away, would Astrobiology's beliefs dominate the space based research and development portfolio, to the exclusion of more achievable local targets, (I wonder)?
(Ie: similar to the Webb telescope experience … with the distinction that the Webb actually addresses a far broader scope of research, than just the narrower hunt for exo-life).This is a straw man argument.


Well, the evidence is there that NASA has difficulties in terminating programs driven by beliefs about what it takes to bring some projects to fruition (eg: the Webb).
Astrobiology seems to be another excursion down the same pathway, (IMO).

My viewpoint addresses the DKDK. How exactly does Astrobiology address this?

R.eligions.

PS: I may not be able to respond further in this discussion on opinion-based science .. I have other priorities now. Cheers.

Gee, that's too bad.

You make many allusions to ‘more achievable local targets’ and ‘achievable goals’ without bother to enlighten us as to what those might be. Please do so.

eburacum45
2013-Feb-20, 10:59 AM
The 'belief' that life elsewhere than the Earth may be different to llife on the Earth is not a religious belief, but rather a philosophical challenge to the 'belief' that any life in the Universe outside the Earth would be essentially the same as Earth life. In many ways it is an antidote to a belief-based set of preconceptions, rather than a preconception itself.

There are three options, as I've pointed out before; as long as astrobiologists continue to consider not only Earth-similar life but also Earth-dissimilar life and the null case, no life, then they have all the possibilities covered and belief doesn't come into the equation.

Only if prejudices start to form, favoring Earth-similar life or either of the other two options, does the problem of belief enter the picture. It is useful to reject all forms of belief in the consideration of exobiology, including any idea that we can anticipate the outcome of a search by simply modelling it in advance.

Selfsim
2013-Feb-20, 08:56 PM
Only if prejudices start to form, favoring Earth-similar life or either of the other two options, does the problem of belief enter the picture. It is useful to reject all forms of belief in the consideration of exobiology, including any idea that we can anticipate the outcome of a search by simply modelling it in advance.{Aside: (& IMO): … and yet this concept is almost always seen as obstructionist around these parts. It is met with cries of "that's wrong" and strong disagreement, from that point onwards. (I expect someone will now call that a 'straw-man' argument, too .. there is plenty of evidence for it however .. and that doesn't necessarily come from the discussions with my usual 'partners-in-conversation', I might add}.

Eburacum: I am pleasantly surprised, and I warmly welcome the above view.

When a belief is cited as the central tenet in a strategy document of a so-called evolving "Science", my warning bells go off loud and clear. The subtleties of what you mention, requires way more attention in such a document, in order for it to demonstrate its authenticity, and to distinguish the bias potential flowing from non-consideration of such subtleties. I don't find this present in the document, other than its citing that 'its hard' to look for what we don't know. (Once again the emphasis is on looking for it .. inferring that its assumed to be realistic, that we can in the first place .. ie: more belief-based rationale, yet again ..).

I accept that the search for exo-life is the test for the hypothesis that: "What we recognise as 'life', might be universal". I'm not going to believe it though, until we have some results from that test ... and we don't have any yet.

IMO, investment in directed searches of exo-life 'biosigns', on planets light years distant, should be commensurate with a motivation of what I'd call 'anecdotal scientific curiosity' (only) .. (like SETI). I don't see any evidence that 'anecdotal curiosity' might be that motivation at all, however. Investment in development of ways of supposedly detecting already known, very specific types of Earth-like-life, (like intelligent life), would represent going way beyond 'anecdotal scientific curiosity'. (Watch this space).

Noclevername
2013-Feb-20, 09:13 PM
IMO, investment in directed searches of exo-life 'biosigns', on planets light years distant, should be commensurate with a motivation of what I'd call 'anecdotal scientific curiosity' (only) .. (like SETI). I don't see any evidence that 'anecdotal curiosity' might be that motivation at all, however. Investment in development of ways of supposedly detecting already known, very specific types of Earth-like-life, (like intelligent life), would represent going way beyond 'anecdotal scientific curiosity'. (Watch this space).

What methods would you propose for detecting extrasolar life that does not transmit signals over interstellar distances?

Colin Robinson
2013-Feb-20, 11:23 PM
Well, perhaps I should put it another way. What would our priorities be if we knew there was nothing we could call "life" elsewhere in the solar system? I'd say they would be different, and I'd say that we should be careful to respect that difference in drawing up our plans.

If it lay with me I'd send missions everywhere. It doesn't lie with me though, and I'm actually more interested in Mars (the surface most closely resembling Earth, although with many differences) and Titan (a surface unlike Earth but with so many interesting parallels), even if they did turn out to be sterile, than in speculations about water under the ices of the various moons.

Life? A splendid bonus if it turns up.

I'd agree that when drawing up plans for exploring the solar system we need to take into account the possibility (which may one day become something known) that there is no life in the solar system beyond Earth. We should also take into account the possibility (which may one day become something known) that there is life in the solar system beyond Earth.

Both possibilities are mentioned in NASA's Astrobiology Roadmap:

"Key questions include the following: If life ever arose elsewhere, is it related to terrrestrial life, or did other bodies in the Solar System sustain independent origins of life? If life never developed elsewhere in the Solar System, is there a prebiotic chemical record preserved in ancient rocks that might contain clues about how life began on Earth?" (page 719)

I also strongly agree that Titan should be near the top of the list for exploration: not just because of its surface geography and meteorology, but also because of its complex carbon chemistry. As the roadmap says:

"Titan can be viewed as a natural laboratory... The existence of lakes of liquid hydrocarbons on Titan opens up the possibility for solvents and energy sources that are alternatives to those in our biosphere and that might support novel life forms altogether different from those on Earth." (page 718)

The fountain of water on Enceladus is a scientific fact, not a speculation, and is definitely worth a closer look too, IMO...

Wherever we send probes in the Solar System, life is less likely to "turn up" if we don't equip the probes with tools that can detect life-like morphologies (i.e. microscopes) as well as tools that can detect life-like chemistries (i.e. mass spectrometers).

Noclevername
2013-Feb-23, 12:09 PM
Let me generalize my question to Selfsim: What would you have us do differently?

Selfsim
2013-Feb-23, 10:06 PM
Let me generalize my question to Selfsim: What would you have us do differently?Develop a deeper understanding of the things which do interact with us … (and how we relate to those interactions).

… As opposed to trying to conjure up things which don't interact with us.

Noclevername
2013-Feb-23, 11:39 PM
Develop a deeper understanding of the things which do interact with us … (and how we relate to those interactions).

… As opposed to trying to conjure up things which don't interact with us.

So you're saying that until and unless we find ET life, we shouldn't look for ET life?

And based on your previous comments we shouldn't speculate about it either...

Selfsim
2013-Feb-24, 01:31 AM
So you're saying that until and unless we find ET life, we shouldn't look for ET life?
And based on your previous comments we shouldn't speculate about it either...If our exploration strategy prioritises noticing things which interact with us, ET life, if it is present elsewhere, will be noticed. Like recognises like .. that's what we are, that's what we do.

None of that requires any beliefs (or tenets) as to whether ET life exists, or not.
What advantage does such a belief and its associated home, (Astrobiology), actually offer as a result of that belief, then?

What disadvantages also come with such beliefs?

Noclevername
2013-Feb-24, 02:16 AM
Why do you assume astrobiology is a belief? Their methods consist of observation and hypothesis based on observation, just like any other science.

Solfe
2013-Feb-24, 02:51 AM
If our exploration strategy prioritises noticing things which interact with us, ET life, if it is present elsewhere, will be noticed. Like recognises like .. that's what we are, that's what we do.

None of that requires any beliefs (or tenets) as to whether ET life exists, or not.
What advantage does such a belief and its associated home, (Astrobiology), actually offer as a result of that belief, then?

What disadvantages also come with such beliefs?

As a result of belief: greater creativity, team building, project building, interest, funding, greater understanding of systems, greater understanding of life on Earth, public support, creative chemistry, etc.

Disadvantages? There are only so many funds available, and sometimes doing something that has little return will waste money. But then again, not wasting money and time may actually cause the reduction of funds to either specific sciences or all sciences collectively.

Look at this way, I can pay a dollar to send a kid to the circus. That kid has some fun and hopefully some of that dollar goes to support medical treatment for another child. How much help is in it for the kid in the hospital? Maybe $0.05.

Exactly how helpful is that? Nada. Do I stop donating?

Nope. I donate 20 bucks to "send a Shriner to the circus".

Why? Because when people within earshot hear that I am willing drop 20 bucks to do the ridiculous or maybe $40 to do the extremely ridiculous, they pony up some cash too. Funding complete, job well done. Is 100% of the funding going to aid children in hospitals? Nope, not a chance. But it provides me momentary entertainment, it entertains children, and maybe, just maybe someone who is on hard times gets a laugh and a little financial help.

Science is not a democracy. Citizens are purchasing skill and talent and this exchange is a give and take.

Is it reasonable to put hi-def video camera on a rover? No. Can you build hi-def videos from science data? Yes. Is it reasonable? No. Does it do science? No. Does it make the public willing to pay for rovers? Yes. Does shaving your head do science? No. Does it generate publicity for science projects? Yes. Do spoof music videos count as science? No. Does it create interest? Yes.

What you do today creates the talent and impetuous for science tomorrow. It all doesn't have to make sense.

Noclevername
2013-Feb-24, 03:01 AM
If our exploration strategy prioritises noticing things which interact with us, ET life, if it is present elsewhere, will be noticed. Like recognises like .. that's what we are, that's what we do.

None of that requires any beliefs (or tenets) as to whether ET life exists, or not.
What advantage does such a belief and its associated home, (Astrobiology), actually offer as a result of that belief, then?

What disadvantages also come with such beliefs?

But what I asked was what should we DO differently. Not "what attitute towards science do you think we should all have".

Should we aim our telescopes at different stars? Should we stop searching for radio signals? Should we allocate funds differently?

Colin Robinson
2013-Feb-24, 04:34 AM
If our exploration strategy prioritises noticing things which interact with us,

Whatever scientific instruments you put on a space-probe, if they work at all, won't they notice things which interact with them?


ET life, if it is present elsewhere, will be noticed.

If it interacts in some way with the instruments we've sent, then yes, the interaction will be noticed. Otherwise nothing will be noticed.


Like recognises like .. that's what we are, that's what we do.

Not sure what you mean by this. Would you like to elaborate?


None of that requires any beliefs (or tenets) as to whether ET life exists, or not.
What advantage does such a belief and its associated home, (Astrobiology), actually offer as a result of that belief, then?

Astrobiology provides hypotheses to test, and strategies for testing them. Strategies more specific than your strategy of noticing things which interact...

Noclevername
2013-Feb-24, 07:10 AM
I don't guess at people's beliefs or motivations, I care about what they do, and the results of those actions. While I disagree that it is a belief, I'll still say IMO the advantages and disadvantages of searching for life:

Advantage: It gives us parameters to spend finite resources. It gives a sense of purpose. It is not mere random flailing that can be dismissed by those who ask "why bother?"

Disadvantage: None known. If life is not out there, we miss nothing, as we are still gathering data which tells us a lot about the universe, and fuelling the search for knowledge, which is the point of any branch of science. The more we learn, the more accurate our models are.

Selfsim
2013-Feb-24, 09:08 AM
Like recognises like .. that's what we are, that's what we do.Not sure what you mean by this. Would you like to elaborate?Perception (http://en.wikipedia.org/wiki/Perception) .. a fundamental, inescapable characteristic which distinguishes 'human'.

Noclevername
2013-Feb-24, 10:37 AM
Perception (http://en.wikipedia.org/wiki/Perception) .. a fundamental, inescapable characteristic which distinguishes 'human'.

And what is your purpose in mentioning it?

ADDED: Here I'm asking for you to explain and clarify your argument, not define the terms. I'm trying to be as clear as possible.

Selfsim
2013-Feb-25, 12:48 AM
And what is your purpose in mentioning it?

ADDED: Here I'm asking for you to explain and clarify your argument, not define the terms. I'm trying to be as clear as possible.I recommend reading (i) the NASA Astrobiology Roadmap and then (ii) my posts from post #9 onwards. My purpose is articulated in those posts. You may not agree with them .. that's fine, but I feel I have already explained my position in this thread.

Noclevername
2013-Feb-25, 05:11 AM
I recommend reading (i) the NASA Astrobiology Roadmap and then (ii) my posts from post #9 onwards. My purpose is articulated in those posts. You may not agree with them .. that's fine, but I feel I have already explained my position in this thread.

Very well then. As written, I find our disagreements irreconcilable. We simply see the subject in different terms. From this point forward I'll speculate on the potential for ET life without regard to objections other than science-based ones.

(If someone tells me a certain chemical formula can't work, and explains why, that's an example of a valid scientific argument. If someone objects on the basis of what they think I "believe" or my "attitude" towards the subject, that is an example of an irrelevant argument; and possibly an Ad Hom if it gets too personal.)

At no time will I make statements assuming the actual existence of ET life, just as I have not in the past. I will continue to express personal opinions as to the existence of ET life, clearly labeled as such.