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Paul Beardsley
2012-May-11, 03:33 PM
In a now-locked thread which I am not trying to resurrect, I found myself arguing with a poster who believes that some large stone structures were built by aliens - or at least aliens helped with the building. This poster took the stance that it was his belief against mine. [Others were involved in the argument but I'm trying to keep it simple.]

I countered that that was not the issue - it was about belief versus evidence.

His parting shot was, "It's about belief because one person will believe something to be evidence while another person will not."

I was and am staggered at how wrong this assertion is. I suspect it's to do with the way different meanings of "belief" are used interchangeably, but that's by the way.

Evidence does not require belief, it requires only to be tested and shown to be reliable. Fingerprints, blood spatters, flecks of paint and fragments of glass often constitute valuable evidence at a crime scene. Dreams and hunches do not. Dreams and hunches might inspire somebody to successfully seek out evidence, but they are not themselves evidence.

Imagine if it were true that one person will believe something to be evidence while another person will not. "Well we've analysed the traces of skin and blood under the murder victim's fingernails, and the DNA matches that of the suspect, but unfortunately Judge Crystalgazer doesn't believe in DNA, so we can't use it as evidence."

Or, "You're a Leo, aren't you? That's unfortunate. Judge Crystalgazer believes astrology counts as evidence. You're going down!"

And it's not just in criminal cases. Spectroscopy has been shown to give reliable results when used on Earth. It seems reasonable to suppose that the results we get from analysing starlight is similarly reliable. Spectroscopic analysis is evidence; no belief is required. Anybody who claims otherwise has a massive burden of proof.

By contrast, my opponent in the argument appeared to be taking the stance of, "If something is difficult to explain, then all theoretical explanations are equally valid - including my own pet theory - and the very existence of the thing that is difficult to explain is evidence that supports my pet theory." [Incidentally, the thing in question is possibly not as difficult to explain as my opponent would like to think.]

The other problem, I think, is that "is consistent with" is sometimes mistaken to mean "is evidence for". Evidence can't just be, it has to point!

Can anyone see any flaws in my line of reasoning?

Perikles
2012-May-11, 04:22 PM
Surely is it not just the principle of Occam´s razor (http://en.wikipedia.org/wiki/Occam's_razor)which somebody is unable to apply?

profloater
2012-May-11, 04:28 PM
I think your line of reasoning is fine with an unstated starting assumption. Karl Popper discussed the nature of reality and said (in effect) let's remember we cannot tell if our reality is real but let's assume it is real because otherwise we get nowhere." I think you are assuming, quite reasonably and in common with most, that consensual reality is the background for evidence. If plenty of people indeed most people agree that a thing exists or a measurement is such, then we accept it is evidence. It gets worrying to see a stage hypnotist such as Darren Brown convince a load of people that something happened when it did not according to our TV view. Now when you get to belief the consensual reality argument gets into trouble because a very large group can believe something that another smaller group (perhaps) do not believe and how can this be resolved? Take stonehenge for example. We all agree it is there and evidence suggests it was there for thousands of years but then it gets tricky. I "believe" from the evidence of the 56 aubrey holes that it was used as a calculator and I "believe" that the blue stones originated in Wales but I do not "believe" aliens had anything to do with it> Now I have set out three beliefs that are not universally consensual.

antoniseb
2012-May-11, 04:51 PM
I don't have a problem with your reasoning. As you know, there are people in the world who want to imagine things to be true that a tedious series of details show to be unrealistic things. This topic about something being built or supervised by space aliens is a nice safe example to discuss.

To me, it seems like people taking such positions, and who assert contrary-to-scientific-method justifications for their position will not be led to reason. Your best position, once they've revealed that line of logic, is to state your reason for disagreeing with them peacefully to all observers, and then make a note that on this topic you shouldn't engage this person again until they have readopted reason. Pick your fights. Don't waste your energy where it will do no good.

grapes
2012-May-11, 04:57 PM
And it's not just in criminal cases. Spectroscopy has been shown to give reliable results when used on Earth. It seems reasonable to suppose that the results we get from analysing starlight is similarly reliable.
You're saying that spectroscopy results from stars is consistent with results here on earth. That seems reasonable.

The other problem, I think, is that "is consistent with" is sometimes mistaken to mean "is evidence for". Evidence can't just be, it has to point!

Can anyone see any flaws in my line of reasoning?I'm a little confused by that, what do you mean by it has to point?

Gillianren
2012-May-11, 05:17 PM
Your reasoning makes sense to me, Paul. However, I'm generally assumed to be closed-minded by those to whom it doesn't.

Paul Beardsley
2012-May-11, 05:22 PM
I'm a little confused by that, what do you mean by it has to point?

For something to qualify as evidence, it must actively support (or indeed refute) a theory or explanation rather than merely coexist with it. That's what I mean by point in this context.

For instance, if you find a dead body, possible explanations include next-door-neighbour Bill, ex-wife Susan, and suicide. The mere presence of a dead body does not point to any of these as being the correct explanation, so the dead body itself is not evidence.

However, if a bullet found in the brain matches a gun that is owned by Susan, then this counts as evidence and it points to Susan. This is not proof, of course - the truth might be more complicated - but it supports the "Susan did it" theory.

Swift
2012-May-11, 05:26 PM
Can anyone see any flaws in my line of reasoning?
No.

There seems to be a considerable percentage of people (maybe even a majority of people) who believe things, no matter what the evidence. They do not apply an analytical / logical approach to their assessment of the world. They make their judgments based on impressions, emotions, etc. I almost think it is actually an organic difference in their brains, though I suppose it could also be a learned behavior.

One of the things that surprises me the most is that some of these people actually manage to have successful careers in fields where the analytical approach is required: for example law or engineering. They seem to be able to apply enough of the logical approach to get by in those fields, but they do not apply that approach to all aspects of their lives, as if the rules of the universe apply different. For example, they will may be a great medical doctor, but they also believe in astrology. I have never understood that dichotomy.

Paul Beardsley
2012-May-11, 05:31 PM
For example, they will may be a great medical doctor, but they also believe in astrology. I have never understood that dichotomy.

Perhaps because there is not much of a conflict. It would be more surprising if a medical doctor believed in homeopahy, or an astronomer believed in astrology.

Nevertheless, I understand what you mean. You'd think the analytical approach would apply to both fields.

Gillianren
2012-May-11, 07:07 PM
The problem is an expectation that anything the human brain does is necessarily logical. It is in fact full of contradictions. My roommate and I have a lot of issues that we refer to as "conflicting crazies"--her mental illness operates in a different way from my mental illness, and sometimes, that causes problems in the household and the friendship. Sometimes, one of us is being completely logical from an outside perspective; often, neither of us are.

Swift
2012-May-11, 08:48 PM
Perhaps because there is not much of a conflict. It would be more surprising if a medical doctor believed in homeopahy, or an astronomer believed in astrology.

Nevertheless, I understand what you mean. You'd think the analytical approach would apply to both fields.
I think a related question came up in a thread where there was a discussion about medicine and evolution, and someone asked if people would use a medical doctor who did not "believe" in evolution. Personally, I would have trouble using such a doctor.

As you said, I think the analytical approach should apply across all these disciplines. I personally can't understand requiring evidence for your job as a chemist, but then believing in Invisible Elves (TM) because that's the belief your parents taught you growing up. But I come across people like that all the time, (though the belief part is usually about religion, not Elves).

Maybe it is actually a skill, to selective turn off one's need for proof, and just use faith for certain strongly held beliefs. I guess I never acquired that skill.

publiusr
2012-May-11, 09:11 PM
Evidence does not require belief, it requires only to be tested and shown to be reliable. Fingerprints, blood spatters, flecks of paint and fragments of glass often constitute valuable evidence at a crime scene

Ironically, that example might not be the best to make to woo-woo believers:
http://www.pbs.org/wgbh/pages/frontline/real-csi/

More chilling
http://www.pbs.org/wgbh/pages/frontline/vaccines/

Squink
2012-May-11, 09:33 PM
Evidence does not require belief, it requires only to be tested and shown to be reliable.Accepting evidence requires the belief that external reality is amenable to testing. If you get decent training in scientific method you'll come to accept that reality is testable as an axiom. However, the vast majority of people never get that hammered into them. Absent that, belief can seem more important than test results. Heck it's not uncommon on the internet to see people who take their defense of absurdity to the level of pointing out that we can never really prove that anything exists at all. Now that's hardly a winning argument, but that doesn't prevent the pilosophically challenged from believing they have unassailable wisdom on their side.

profloater
2012-May-11, 09:43 PM
But that is wrong. Reality is only testable if you accept the majority view that what seems, is. We should always accept the starting assumptions. The scientific method is a series of tests which fail to disprove an hypothesis. With each test the theory gets stronger. To believe in the reality of the method is a belief just like any other basic belief. To start to think you are somehow beyond belief is a mistake. You can get to the point of a dichotomy between belief and realism which is artificial. Physicists above all should appreciate the basic mystery of apparent reality!

HenrikOlsen
2012-May-11, 10:09 PM
As you said, I think the analytical approach should apply across all these disciplines. I personally can't understand requiring evidence for your job as a chemist, but then believing in Invisible Elves (TM) because that's the belief your parents taught you growing up. But I come across people like that all the time, (though the belief part is usually about religion, not Elves).
For some reason I read that as "Invisible Elvis" and found it a rather interesting belief to use as an example. :)

Selfsim
2012-May-11, 10:12 PM
Hi Paul (and all);

This is a topic very near and dear to my heart. I seem to be up against the same phenomenon myself, in the Life in Space Forum (albeit a much more rational and more open discussion - I'd like to express much respect for the folk I'm engaged with on those topics, by the way).

When it comes to the existence of exo-life topic, I find the choices believed by most folk are:
i) it exists and (ii) it doesn't exist. There is of course the third option, which is: (iii) it is unknown whether it exists or not.

What I find is that option (iii) is typically dismissed outright, and yet it is probably the most supportable view to adopt, as it is backed by the most evidence (or lack thereof) ! Adoption of such a position actually leads to more research .. what better way is there to set out on a scientific exploration activity ?

What I'm finding is that speculation and hypothesis is frequently being introduced to 'fill in the gaps' on what is unknown … to the point that the speculation itself, becomes real in the minds of the proponents of it. 'Reality by consensus' is still reality. It is not physical reality however, as measurements of it have no standard objective basis. It can easily have real flow-on effects in the physical universe. Individual reality also exists - eg: I'm hungry .. its real ! … but only I know its real. What I'm finding is that evidence is frequently cited, in order to support any specific one of these three domains, but the domains are rarely distinguished in the minds of those citing the 'evidence'.

The tools of science have been developed in order for us all to escape Individual and Collective Reality delusions. Using such tools in support of other than Physical Reality arguments, I find is a threat to a fundamentals of Science and I feel strongly about the importance of remaining vigilant about this in our communications.

Regards

profloater
2012-May-11, 10:14 PM
For some reason I read that as "Invisible Elvis" and found it a rather interesting belief to use as an example. :) Apparently invisible elves believe elvis is an anagram of lives but of course it's veils, silly elves.

Selfsim
2012-May-11, 10:35 PM
But that is wrong. Reality is only testable if you accept the majority view that what seems, is. We should always accept the starting assumptions. The scientific method is a series of tests which fail to disprove an hypothesis. With each test the theory gets stronger. To believe in the reality of the method is a belief just like any other basic belief. To start to think you are somehow beyond belief is a mistake. You can get to the point of a dichotomy between belief and realism which is artificial. Physicists above all should appreciate the basic mystery of apparent reality!Inside a discussion framed solely within 'Individual Reality' (ie: inside one's own mind), consensus involves convincing only one individual, (oneself). Being 'right' is pretty simple.

As soon as consensus is sought from others outside of that reality (ie: moving into the Consensus Reality domain, through means of communications), the distinctions of 'right' and 'wrong' become less certain. One must abandon one's own views of what is 'right' and what is 'wrong' .. that's why its called Reality by Consensus. If one succeeds in convincing others, one may then move forward with the assumpton that one is 'right' (or 'correct').

None of this yet involves the Physical Reality domain, however.

Regards

Selfsim
2012-May-12, 02:47 AM
There seems to be a considerable percentage of people (maybe even a majority of people) who believe things, no matter what the evidence. They do not apply an analytical / logical approach to their assessment of the world. They make their judgments based on impressions, emotions, etc. I almost think it is actually an organic difference in their brains, though I suppose it could also be a learned behavior.
Hmm ... very interesting ... I often wonder: "What purpose does a judgment serve, in the first place ?"
Frequently in research matters, it is better not to judge .. (but to go where the data leads) ...

Sometimes, in these fora, it seems that judgments are made solely for the purpose of expressing an opinion.
If one values all opinions lowly (including one's own) ... but one maintains a high regard for those expressing them ... then I find one can sometimes decouple the person from the opinion, and respect for the individual can still be maintained. If however, one chooses to spend one's entire life constituting oneself as a walking, talking judgment making/opinion expressing machine, then one is effectively subjecting oneself to a lifetime of being judged, (or avoiding being judged), by others ... and a lifetime of arguments !

What a miserable and unnecessary existence, eh ..(?).. especially considering that the individual can easily empower themselves to make the choice of simply abandoning the value they associate with judgments and opinions ... and, maybe, simply take up sifting new materials for additional knowledge ..?..
... (all in my opinion, that is ;) ).

Regards

Paul Beardsley
2012-May-12, 03:23 AM
Sometimes, in these fora, it seems that judgments are made solely for the purpose of expressing an opinion.
If one values all opinions lowly (including one's own) ... but one maintains a high regard for those expressing them ... then I find one can sometimes decouple the person from the opinion, and respect for the individual can still be maintained. If however, one chooses to spend one's entire life constituting oneself as a walking, talking judgment making/opinion expressing machine, then one is effectively subjecting oneself to a lifetime of being judged, (or avoiding being judged), by others ... and a lifetime of arguments !

Well I think it's relevant that if you only know somebody through a discussion board, and only in the more serious part of that discussion board, it's difficult to think of them as anything other than their opinion.

In real life most people probably have friends whom they'll meet down the pub or in the cafe once a week, look after each other's children, give each other emotional support in all manner of situation, or maybe even risked their life for the other... but there might be one area where they are strongly at odds. This area might be politics, or a belief/disbelief in some aspect of the supernatural, or even support for a different football team. Although it might be a fairly important area (to them), it's trivial compared with the other things their relationship is based on.

But on a board like this, it might be that the only thing you know about Bob is that he believes in astrology and can't even articulate why. This comes across as judgemental because we sometimes forget that these discussions are very different to more traditional forms of social interaction.

In general, though, the "judgements" referred to in the quoted section are no more than conclusions - sometimes tentative ones at that. I see nothing "miserable" in exchanging tentative conclusions and opinions.

Selfsim
2012-May-12, 04:32 AM
… Although it might be a fairly important area (to them), it's trivial compared with the other things their relationship is based on.

But on a board like this, it might be that the only thing you know about Bob is that he believes in astrology and can't even articulate why. This comes across as judgemental because we sometimes forget that these discussions are very different to more traditional forms of social interaction.

In general, though, the "judgements" referred to in the quoted section are no more than conclusions - sometimes tentative ones at that. I see nothing "miserable" in exchanging tentative conclusions and opinions.I appreciate what you say.
As far as I'm concerned, its fine to have an opinion (or 'tentative conclusion') .. I've got plenty myself … and the trick is to realise when one is expressing that opinion, (its not always straightforward .. and it may be buried quite deeply). I've found that the tools for distinguishing when a judgement/opinion is in operation, themselves, materialise by trying to keep 'present' (in mind), a very clear understanding of what a judgement/opinion/belief actually is, (and the relationships between them), when reading post responses. (Does that makes sense ?)

If someone declares something as opinion .. well that's fine by me .. I won't try to take it away from them.

Perhaps the real problem and its associated cost .. (eg: 'misery'), sets in when the opinion is held too closely, and behaviour becomes dogmatic and/or one of the parties seems determined to change the other's (??) … I'll bet I'm 'guilty' of this myself … (yep .. a self-judgement, right there !! :) )

Regards

PS: I'm also not trying to say that anyone should accept anything I'm saying, either. What I'd like to suggest is 'trying it on' .. to see if what I say fits the situation. If it does .. then go for it … if it doesn't … feel free to suggest or share some other method. :)

Gillianren
2012-May-12, 06:49 AM
Hmm ... very interesting ... I often wonder: "What purpose does a judgment serve, in the first place ?"

It enables us to exist in the world. We have to make judgements all the time.

Van Rijn
2012-May-12, 07:55 AM
For some reason I read that as "Invisible Elvis" and found it a rather interesting belief to use as an example. :)

Well, sure. Didn't you know? Elvis is alive and well and works as an elf impersonator.

profloater
2012-May-12, 08:51 AM
Inside a discussion framed solely within 'Individual Reality' (ie: inside one's own mind), consensus involves convincing only one individual, (oneself). Being 'right' is pretty simple.

As soon as consensus is sought from others outside of that reality (ie: moving into the Consensus Reality domain, through means of communications), the distinctions of 'right' and 'wrong' become less certain. One must abandon one's own views of what is 'right' and what is 'wrong' .. that's why its called Reality by Consensus. If one succeeds in convincing others, one may then move forward with the assumpton that one is 'right' (or 'correct').

None of this yet involves the Physical Reality domain, however.

Regards I think I understand what you say but I do not think I agree. The purpose of seeking consensus is in a way a direct test of personal reality. And it is not about convincing others, it is about sharing information and interpretation of those experiences in order to see if others agree. When they disagree it is like an experiment that gives an unexpected result, we learn more form that and we modify our theory (or our reality) to incorporate the new evidence. Evidence is not some kind of basic truth it is just "that which is evident" and the consensus about what is evident always goes beyond the personal. that is the point.

Strange
2012-May-12, 12:11 PM
Evidence does not require belief, it requires only to be tested and shown to be reliable. Fingerprints, blood spatters, flecks of paint and fragments of glass often constitute valuable evidence at a crime scene. Dreams and hunches do not. Dreams and hunches might inspire somebody to successfully seek out evidence, but they are not themselves evidence.

I agree, in general, with your argument. However, evidence - and een the existence of evidence - is not always black and white (is it ever). Real world data has error bars. Data can be contaminated (did that DNA really come from the crime scene). Data can be wrong (how fast were those neutrinos going).

So there can be arguments over the validity, relevance and accuracy of the evidence.

But we often see the argument: the data is uncertain; therefore science can't prove it is correct; therefore it may be wrong; therefore I am right (because you can't prove absolutely that I am wrong).

This chain of reasoning is so full of logical errors, I'm not sure how anyone can sustain it. But they do.

Strange
2012-May-12, 12:13 PM
The problem is an expectation that anything the human brain does is necessarily logical. It is in fact full of contradictions. My roommate and I have a lot of issues that we refer to as "conflicting crazies"--her mental illness operates in a different way from my mental illness, and sometimes, that causes problems in the household and the friendship. Sometimes, one of us is being completely logical from an outside perspective; often, neither of us are.

You don't have to be "crazy"; just have a different way of thinking/expressing things. I have seen (and taken part in) vigorous arguments between engineers who, in the end, turn out to agree 100% but (for some reason) just couldn't see the point the other was trying to make.

Strange
2012-May-12, 12:17 PM
When it comes to the existence of exo-life topic, I find the choices believed by most folk are:
i) it exists and (ii) it doesn't exist. There is of course the third option, which is: (iii) it is unknown whether it exists or not.

What I find is that option (iii) is typically dismissed outright, and yet it is probably the most supportable view to adopt, as it is backed by the most evidence (or lack thereof) ! Adoption of such a position actually leads to more research .. what better way is there to set out on a scientific exploration activity ?

This is also very common in UFO discussions. An attempt to explain that the U is for unidentified because we don't know what it was (because there is insufficient evidence) is frequently met with claims that the sighting is being dismissed as lies or swamp gas or Venus ... When all we are saying is that "we don't know".

People want an answer and if there isn't enough evidence will make one up (and think that is justified because there is no evidence)

mutleyeng
2012-May-12, 12:23 PM
i dont agree with everything here about evidence.
evidence itself does not need to point to something or refute anything...its just a bit of data.
the probolem you had with your (pesumably) ancient aliens friend was how he was applying that data to a hypothesis.
If you make a claim, you must demonstrate it to be true. those who do not agree merely have to refute the evidence as being supportive of the hypothesis put forward.

grapes
2012-May-12, 12:55 PM
You don't have to be "crazy"; just have a different way of thinking/expressing things. I have seen (and taken part in) vigorous arguments between engineers who, in the end, turn out to agree 100% but (for some reason) just couldn't see the point the other was trying to make.Yes, you have to participate. It does little good to just dismiss the argument.

Engineers will almost always agree, once they understand the problem. :)

profloater
2012-May-12, 01:06 PM
Yes, you have to participate. It does little good to just dismiss the argument.

Engineers will almost always agree, once they understand the problem. :) That is because we can agree that 25.4mm = one inch after that it's easy. (Oh and if it falls down the problem was stated incorrectly)

Paul Beardsley
2012-May-12, 03:14 PM
i dont agree with everything here about evidence.
evidence itself does not need to point to something or refute anything...its just a bit of data.

You'd have to give me an example.

As I see it, a suspect's fingerprint at a crime scene is evidence - it points to the suspect.

The fingerprint of someone who is not a suspect found somewhere unconnected to the crime scene is a piece of data, but it's not evidence.

Data that neither supports nor refutes a theory is merely data, not evidence. When you say, "I think Harry ran David down," and somebody responds, "What evidence do you have for that?" you say something like, "We found flecks of blue paint on David's body, the paint matches Harry's car, and there's a dent in the car too." These aren't just random items of data, they are items of data selected because they support the theory.


the probolem you had with your (pesumably) ancient aliens friend was how he was applying that data to a hypothesis.
If you make a claim, you must demonstrate it to be true. those who do not agree merely have to refute the evidence as being supportive of the hypothesis put forward.

There are ancient stone structures that were difficult to build - that's data, but it's not evidence of how they were built. If you find the remains of ropes, ramps and so on, that's evidence of how they were built by ancient people. If you find the remains of an alien spaceship, that would be evidence of alien assistance.

Attempting to redefine "evidence" is a poor substitute for producing the remains of the soaceship.

HenrikOlsen
2012-May-13, 09:59 AM
You'd have to give me an example.

As I see it, a suspect's fingerprint at a crime scene is evidence - it points to the suspect.
You just made the example yourself.

The fingerprint is still just data.

It's the combination of the fingerprint, and that the person it can be linked to (with all the large errors involved in fingerprints) is a suspect, that makes it evidence.

And, quite importantly, it's not evidence of the crime, but of, at some time, having been at the scene of the crime. It doesn't actually point to the suspect at all.

That was your belief that the suspect is involved that caused you to interpret the fingerprint to mean something it doesn't actually do.

Paul Beardsley
2012-May-13, 10:44 AM
The fingerprint is data, but it's not merely data.

A fingerprint at a crime scene is not proof that the suspect committed the crime, but it does link the suspect to the crime, which (AIUI) is the primary purpose of an investigation. This is what I mean by pointing to the suspect.

Having established a link between the suspect and the crime scene, the onus is on the suspect to account for his or her presence at the crime scene. If there is no link, there is no onus.

mutleyeng
2012-May-13, 11:02 AM
i really dont think these analogies help bring clarity paul.
when your talking of denying evidence, you could either be denying the data itself, or the interpretation of what the data means within a hypothesis.
if you really must use the fingerprint example, i might argue the data itself, and bring an expert to refute the identity of who it belonged, or the method by which the data was processed.
if you want to understand why your ancient alien friend accuses you of denying the evidence, then i would try to break it down to what data you agree on, and then where your opinions diverge.

Paul Beardsley
2012-May-13, 01:19 PM
i really dont think these analogies help bring clarity paul.

This is why I asked you to clarify.

I don't know why you used the word "analogies" here. I didn't give analogies, I gave solid examples of things that are (or are not) counted as evidence.


when your talking of denying evidence, you could either be denying the data itself, or the interpretation of what the data means within a hypothesis.

I was arguing that the data neither supported nor refuted the hypothesis and therefore didn't count as evidence.


if you really must use the fingerprint example, i might argue the data itself, and bring an expert to refute the identity of who it belonged, or the method by which the data was processed.

Yes of course. This is generally true with evidence, isn't it?


if you want to understand why your ancient alien friend accuses you of denying the evidence, then i would try to break it down to what data you agree on, and then where your opinions diverge.

He wasn't my friend, and he didn't appear to be interested in a two-way discussion. This was the reason for the frustration that prompted me to start this thread.

mutleyeng
2012-May-13, 03:26 PM
this is my problem with how you are using the defintion of the word evidence in relation to understanding a belief in something

http://en.wikipedia.org/wiki/Scientific_evidence#cite_note-philsci-0
that is the wiki article on "scientific evidence"

we agree evidence is made up of data, and it becomes evidence when it is applied to a hypothesis.
The problem is that it is that application of data to the theory that can, and often is subjective - this is what leads to disagreements, why we all believe different things.
Evidence isnt absolute, it can be dependent on the mind state that applied it.
So it might well be that you did indeed disregard his evidence...but that dosnt get you to the bottom of understanding just what the disagreement is.

this gets to the crux of why simply debunking a conspiracy theory will rarely, if ever, change a believers mind.
What can sometimes work is taking time to break down the reasons they have have for believing an evidence as legitimate.
But that takes a lot of time and effort - which is why debunking is far more common and almost entirely ineffective

Paul Beardsley
2012-May-13, 04:01 PM
The thing is, whenever fringe proponents - let's call them FPs - put forth non-mainstream ideas, BAUT regulars always ask, "Where is the evidence?"

And this is as it should be. You should have a reason to believe something.

In many cases, the FPs do not give any evidence at all. I don't just mean they don't provide data that they consider evidence but regular BAUTers would dismiss. They don't give anything.

It's not a case of dismissing something out of hand. It is a case of there not being anything to dismiss.

grapes
2012-May-13, 06:50 PM
The fingerprint is data, but it's not merely data.

A fingerprint at a crime scene is not proof that the suspect committed the crime, but it does link the suspect to the crime, which (AIUI) is the primary purpose of an investigation. This is what I mean by pointing to the suspect.
This is why I asked you about the "point to" thing. In the current example, an unknown fingerprint found at the crime scene may not be associated with anybody at all, but it would still be considered as "evidence", no? And it would probably induce investigators to search for possible matches. Same with DNA. So, how much pointing does evidence have to do? In the abstract.

Paul Beardsley
2012-May-13, 08:39 PM
This is why I asked you about the "point to" thing. In the current example, an unknown fingerprint found at the crime scene may not be associated with anybody at all, but it would still be considered as "evidence", no? And it would probably induce investigators to search for possible matches. Same with DNA. So, how much pointing does evidence have to do? In the abstract.

Hmm, interesting question.

In the abstract, I would argue that it is merely data, but it has the potential to become evidence. Once it has been matched with someone, it is evidence that that person was present at the crime scene. It now points at that person; it supports theories involving that person's involvement.

Or, if a suspect's fingerprints were found at the crime scene, and it was previously believed he was the only person present, then the discovery of this unknown fingerprint would point away from this theory. In other words, it would be evidence that he was not the only person present

I've just started a course in forensics (Open University S187: Elements of Forensic Science), and the glossary says this:

data Facts and figures that convey information.

evidence Something that is useful in helping to form or confirm a conclusion or judgement.

Paul Wally
2012-May-14, 03:33 AM
I countered that that was not the issue - it was about belief versus evidence.

His parting shot was, "It's about belief because one person will believe something to be evidence while another person will not."

I agree with you that his parting shot was wrong because evidence is factual.


Evidence does not require belief, it requires only to be tested and shown to be reliable. Fingerprints, blood spatters, flecks of paint and fragments of glass often constitute valuable evidence at a crime scene. Dreams and hunches do not. Dreams and hunches might inspire somebody to successfully seek out evidence, but they are not themselves evidence.

Here I disagree. Evidence is the test. It only requires to be discovered.


Imagine if it were true that one person will believe something to be evidence while another person will not. "Well we've analysed the traces of skin and blood under the murder victim's fingernails, and the DNA matches that of the suspect, but unfortunately Judge Crystalgazer doesn't believe in DNA, so we can't use it as evidence."

In this case "DNA matches that of the suspect" is a factual result of performing a DNA test correctly and Judge Crystalgazer has no choice but to accept it as evidence. However, Judge Crystalgazer might not believe in the theory that a DNA sequence is unique to each individual.


Or, "You're a Leo, aren't you? That's unfortunate. Judge Crystalgazer believes astrology counts as evidence. You're going down!"

In this case Judge Crystalgazer believes in the theory of astrology, but the evidence is that the accused is a Leo.


And it's not just in criminal cases. Spectroscopy has been shown to give reliable results when used on Earth. It seems reasonable to suppose that the results we get from analysing starlight is similarly reliable. Spectroscopic analysis is evidence; no belief is required. Anybody who claims otherwise has a massive burden of proof.

In this case the evidence is the actually measured spectrum and elemental composition will be a theoretical inference based on quantum physics.


By contrast, my opponent in the argument appeared to be taking the stance of, "If something is difficult to explain, then all theoretical explanations are equally valid - including my own pet theory - and the very existence of the thing that is difficult to explain is evidence that supports my pet theory." [Incidentally, the thing in question is possibly not as difficult to explain as my opponent would like to think.]

I don't know what he means by "equally valid" but there can be many possible explanations (theories) for the one and the same thing, but the problem is to find out which one is the correct one rather than picking one to believe. The scientific attitude is to seek the truth not to fix believes.


The other problem, I think, is that "is consistent with" is sometimes mistaken to mean "is evidence for". Evidence can't just be, it has to point!

I'd say that "evidence for" must be distinguishing evidence, i.e. evidence that is consistent with the proposed theory and not with other simpler theories, otherwise there would be no reason to accept the theory above any of the other simpler theories.

Perikles
2012-May-14, 07:31 AM
His parting shot was, "It's about belief because one person will believe something to be evidence while another person will not."


data Facts and figures that convey information.

evidence Something that is useful in helping to form or confirm a conclusion or judgement.I'm not so sure that these definitions stand up to detailed scrutiny. For a start, very often, it is a subjective opinion whether something is a fact or not. Something like a fingerprint has become to be recognized as a fact, despite a vanishingly small probability that somebody else might have the same fingerprint. But is a fuzzy CCTV camera shot of a suspect identified as person X count as a fact? And how do you define something as evidence, when the criteria for deciding whether something is useful or not are also subjective? Take for example stereotyping. If a suspect is of a group with a demonstrable history of dishonesty, does this fact count as evidence as defined above? The extent to which it matters is subjective.

I suppose the expression 'scientific' applied to facts and evidence is meant to convey objectivity rather than subjectivity.

The 'parting shot' might be might be better expressed as "It's about belief because one person will believe something to be fact while another person will not." I can't accept the statement universally, but I can see why he/she said it.

Gillianren
2012-May-14, 07:53 AM
In this case Judge Crystalgazer believes in the theory of astrology, but the evidence is that the accused is a Leo.

There is no theory of astrology. There is a falsified hypothesis of astrology.

Perikles
2012-May-14, 10:36 AM
I've just come across this concept of a fact, in connection which an allegedly exciting end to an English football match:


England cricketer Kevin Pietersen tweeted that it was why “there is NOTHING (his capitals not mine) better than sport. Fact”. And who could disagree? When it comes to delivering incredible drama, football and sport can conjure up heart-stopping, mind-boggling scripts.

There are clearly those who think that opinions count as facts because they know many people agree with them. It is perhaps worth pointing out that what constitutes a fact to a modern day scientist is a very small subset of what would be 'fact' to the general public. This has always been an issue since Galen (2nd century AD) can be seen struggling with the concept of fact applied to medicine, seen discussing what actually constitutes scientific evidence for, say, where thought processes occur in the body. He allocates a low value to consensus omnium, but still gives it some credit. People still do that today.

Paul Wally
2012-May-14, 11:26 AM
There is no theory of astrology. There is a falsified hypothesis of astrology.

I'm using "theory" in a very broad sense as in "being theoretical" as opposed to being factual. But fair enough, you can replace "theory" with "hypothesis" if you wish to draw a finer distinction between different kinds of theoretical assertions.

Paul Wally
2012-May-14, 12:28 PM
I'm not so sure that these definitions stand up to detailed scrutiny. For a start, very often, it is a subjective opinion whether something is a fact or not. Something like a fingerprint has become to be recognized as a fact, despite a vanishingly small probability that somebody else might have the same fingerprint. But is a fuzzy CCTV camera shot of a suspect identified as person X count as a fact? And how do you define something as evidence, when the criteria for deciding whether something is useful or not are also subjective? Take for example stereotyping. If a suspect is of a group with a demonstrable history of dishonesty, does this fact count as evidence as defined above? The extent to which it matters is subjective.


In the case of fingerprints the evidence would be that some fingerprint was found on the scene and that it matches that of the suspect. What remains to be determined is how and when the suspect's fingerprints got there. In the case of CCTV, the evidence would be the video-tape with certain data found in a video-machine connected to a CCTV camera. The actual inferences drawn from the evidence e.g. that the fuzzy image is that of the suspect doesn't count as part of the evidence that the tape was found in the machine.
In the case of expert witness testimony or eyewitness reports, I'd say that the evidence is the actual statement, i.e. the actual words uttered verbally or written in ink, but the inference or assumption that the statement is true or false does not count as part of the evidence.

Paul Beardsley
2012-May-14, 01:36 PM
I'm using "theory" in a very broad sense as in "being theoretical" as opposed to being factual. But fair enough, you can replace "theory" with "hypothesis" if you wish to draw a finer distinction between different kinds of theoretical assertions.

I think the key word in Gillian's post was "falsified". I don't think she was quibbling about the difference between "hypothesis" and "theory".

My own point was that no judge would consider astrological "data" as evidence (unless of course it played a role in the accused's motivation). He might privately believe "there's probably something in it" but he'd know it's not admissible as evidence.


In the case of fingerprints the evidence would be that some fingerprint was found on the scene and that it matches that of the suspect.

I can buy the idea that evidence is this complete package. Is this your personal definition, or a general dictionary definition, or a specialist (e.g. forensic) dictionary definition?

I would argue that the underlying theory must be generally accepted as correct, within clear limitations. For instance, we know that there's something like a one in three billion chance of two people having the same fingerprints, so they are not truly unique, but fingerprints still count as a very strong means of identifying a suspect.

On the other hand, the once-popular idea of phrenology is no longer held to be correct. We cannot say, "The evidence was that the suspect's skull was measured and it was found to correspond to that of the violent type of man."

grapes
2012-May-14, 01:43 PM
Hmm, interesting question.

In the abstract, I would argue that it is merely data, but it has the potential to become evidence. Once it has been matched with someone, it is evidence that that person was present at the crime scene. It now points at that person; it supports theories involving that person's involvement.

Or, if a suspect's fingerprints were found at the crime scene, and it was previously believed he was the only person present, then the discovery of this unknown fingerprint would point away from this theory. In other words, it would be evidence that he was not the only person present

Why not conclude that the unknown fingerprint is evidence that someone unknown was there?


I've just started a course in forensics (Open University S187: Elements of Forensic Science), and the glossary says this:

data Facts and figures that convey information.

evidence Something that is useful in helping to form or confirm a conclusion or judgement.Data can be evidence, and evidence can be data.

In the case of the OP, for some people, the existence of something so mind-bogglingly beyond human ken points to . . . aliens. :) Of course, if we didn't have the video, the Golden Gate bridge would be in that category. People just need to hear/learn what humans are capable of.

HenrikOlsen
2012-May-14, 01:54 PM
I would argue that the underlying theory must be generally accepted as correct, within clear limitations. For instance, we know that there's something like a one in three billion chance of two people having the same fingerprints, so they are not truly unique, but fingerprints still count as a very strong means of identifying a suspect.
That one in three billion number assumes perfect conditions though, in reality there are severe limits to how much fingerprints can be trusted because conditions are never perfect, so the 1 in 3 billion figure will be rather wrong on the vast majority of real life situations.

Paul Beardsley
2012-May-14, 02:52 PM
Why not conclude that the unknown fingerprint is evidence that someone unknown was there?

Is this in any way not saying exactly the same thing, other than with a slightly different emphasis?

If I was about to be convicted on the basis of being the only person present at the crime scene, I would be most interested in the weakening of the case against me.


Data can be evidence, and evidence can be data.

I don't think anybody disputes that data can be evidence, and I suspect that evidence is always data.


In the case of the OP, for some people, the existence of something so mind-bogglingly beyond human ken points to . . . aliens. :) Of course, if we didn't have the video, the Golden Gate bridge would be in that category. People just need to hear/learn what humans are capable of.

A state of mind-boggledness does not constitute evidence.

Paul Beardsley
2012-May-14, 03:00 PM
That one in three billion number assumes perfect conditions though, in reality there are severe limits to how much fingerprints can be trusted because conditions are never perfect, so the 1 in 3 billion figure will be rather wrong on the vast majority of real life situations.

(My bold.)

I understand what you're trying to say, but the bolded part is nonsense. It's like saying a piece of poetry is not as good as people claim because my photocopier was nearly out of toner when I copied it. It would make more sense to say that in real-life situations, the reliability is unlikely to approach this figure.

Gillianren
2012-May-14, 05:37 PM
I think the key word in Gillian's post was "falsified". I don't think she was quibbling about the difference between "hypothesis" and "theory".

Well, Gillian was kind of doing both. I am adamant that the word "theory" be used when scientifically appropriate; I have stopped using it in my personal life to mean "a vague idea." If I only use it in the scientific sense no matter what the context, no one who knows me is ever confused by which I mean. But "falsified" is also an awfully important word there.


My own point was that no judge would consider astrological "data" as evidence (unless of course it played a role in the accused's motivation). He might privately believe "there's probably something in it" but he'd know it's not admissible as evidence.

No competent judge. Certainly that would be grounds for appeal and, depending on what system you're in, probably removal from the bench as well.

grapes
2012-May-14, 06:46 PM
Is this in any way not saying exactly the same thing, other than with a slightly different emphasis?
It disagrees with "In the abstract, I would argue that it is merely data".

It is true that it agrees with your two examples, where it is considered evidence.

But I just noticed, re-reading that, that you conclude it is evidence based upon a previous (erroneous!) belief (" and it was previously believed he was the only person present"). How do you reconcile that with your OP?


I don't think anybody disputes that data can be evidence, and I suspect that evidence is always data.
Yes, and I suspect data is always evidence. :)

A state of mind-boggledness does not constitute evidence.
It doesn't even have to reach a state of mind-boggledness--just high improbability is good enough for statisticians.

But, to counter that, there are those videos of that guy who moves humongous stones by himself with primitive tools in a few hours--minutes even. I should find those, I'd like to watch them myself again.

grapes
2012-May-14, 06:54 PM
Well, Gillian was kind of doing both.
I am adamant that the word "theory" be used when scientifically appropriate; I have stopped using it in my personal life to mean "a vague idea."
Why couldn't astrology be a falsified theory? Is newton's a falsified theory, or a falsified hypothesis?

dgavin
2012-May-14, 07:24 PM
I tend to look at things in various ways.


Mainstream side of things:

Intuition = The minds ability to leap to a conclusion (surprisingly close to reality, or right at times) based on limited or no information, other then immediate external stimuli in ones environment, or from past events or stimuli.

Hypothesis = Take a conclusion and framing it into a reasonable structure, that matches already know facts, and allows for the proving or disproving of as of yet, undiscovered facts.

Research = The Ability to gather both supporting and non supporting facts about some conclusion.

Evidence = When the bulk of the facts obtained support or don't support a conclusion.

Theory = When the bulk of the Evidence is in support of a conclusion.

================================================== ============================


the 'Believer' side of things:

Imagination - The minds ability to invent conclusions.

Belief = The ability to hold fast to a conclusion, not matter how right or wrong it is later found to be.

Stubbornness = The ability to hold fast to a conclusion, not matter how right or wrong it is later found to be.

"Conspiracy Theory" = What becomes of your conclusions after the bulk of evidence has proved it wrong, and you still insist in believing in it.

Gillianren
2012-May-14, 07:28 PM
Why couldn't astrology be a falsified theory? Is newton's a falsified theory, or a falsified hypothesis?

Because astrology was never entirely about science. I'm not sure there were any scientific theories before Newton, though I'd be willing to be convinced otherwise. Astrology began as religion and hung on as tradition, and it was never about the weight of evidence. It doesn't take much evidence to prove astrology wrong, and no one put in the work to try for a very long time. Astrology never stood up to the testing it would take to be a theory. It can't.

Paul Beardsley
2012-May-14, 08:41 PM
It disagrees with "In the abstract, I would argue that it is merely data".

Yes. That's why I put the word "Or" in front of it, to describe a scenario where it's not merely data. I will grant that this might not have been clear.

If a murder takes place in a location where it's expected that a lot of people will have left fingerprints - for instance, a bus shelter - then the various unknown fingerprints will constitute data but not evidence.


But I just noticed, re-reading that, that you conclude it is evidence based upon a previous (erroneous!) belief (" and it was previously believed he was the only person present"). How do you reconcile that with your OP?

As I said in another post, there are different meanings to "belief". I was using it in the sense of "suppose" - assuming something is the case because someone with no obvious reason to lie told you it was so, or because it is usually so. I define this kind of "belief" as "taking things on face value because it would be impractical to check everything out". I believe there is a Great Wall in China, for instance - the likelihood of the accounts, documentaries and pictures in books being faked is too insignificant to be worth considering.

There are other kinds of belief - in Tarot, reading tea leaves and so on - which require believers to switch off mental faculties. No sane person would ever regard them as evidence.

The things that we do regard as evidence are based on principles that are verified. There is no leap of faith involved.

grapes
2012-May-14, 10:30 PM
Yes. That's why I put the word "Or" in front of it, to describe a scenario where it's not merely data. I will grant that this might not have been clear.
To be clear, we were talking about my sentence, not yours. :)

You thought my sentence was a re-statement of yours, but I don't think it is. You qualified yours with a belief, but I didn't.


If a murder takes place in a location where it's expected that a lot of people will have left fingerprints - for instance, a bus shelter - then the various unknown fingerprints will constitute data but not evidence.
That would be an interesting question for your forensics class. What is the professional standard there? Is it to take fingerprints off everything, knowing how contaminated they will be, or do they just not bother. If they do collect them, do they save everything? Does it all go into storage in the white file boxes?


As I said in another post, there are different meanings to "belief". I was using it in the sense of "suppose" - assuming something is the case because someone with no obvious reason to lie told you it was so, or because it is usually so. I define this kind of "belief" as "taking things on face value because it would be impractical to check everything out".
But which of those would possibly apply in this case? If discounting the fingerprint as evidence hinges on that belief, where does that belief arise? Probably from more data.

grapes
2012-May-14, 10:51 PM
Because astrology was never entirely about science. I'm not sure there were any scientific theories before Newton, though I'd be willing to be convinced otherwise.
If everything before Newton is non-science, astrology would definitely pre-date that. I think someone (Sagan?) mentioned Heraclitis as one of the first scientists. Or did Sagan talk about the Ephesians? (Heraclitis was an Ephesian) Anyway, Copernicus, Gilbert, Galileo pre-date Newton, and translations of Galileo's Two New Sciences is worth a read. Gilbert's On Magnetism was published before Newton was born, and very influential.


Astrology began as religion and hung on as tradition, and it was never about the weight of evidence.The origins of astrology are pre-history I think. We are so used to modern charlatans that produce incredible fantasies that it's easy to assume that everything begins that way (even moon landings!). It's possible that it started as a simple observations related to seasonal nutrition in the embryo. It's easy to assume that all of the ancients were totally gullible but even some of the people who made their living with astrology were skeptics.

mike alexander
2012-May-15, 04:39 PM
Kepler's great work is titled

A NEW ASTRONOMY Based on Causation
or A PHYSICS OF THE SKY
derived from Investigations of the
MOTIONS OF THE STAR MARS
Founded on Observations of
THE NOBLE TYCHO BRAHE

Those six lines describe, in compact form, the birth of modern scientific inquiry.

grapes
2012-May-15, 08:00 PM
Kepler! I don't know why I didn't include Kepler in that list.

Just a stupid mistake :)

mike alexander
2012-May-15, 08:16 PM
In terms of great titles, A Physics of the Sky is one of those that gives me a bit of a shiver. The sheer audacity of the man!

Definitions of 'belief' and 'evidence' depend, like all words, on context. 'Limit' in mathematics is similar to, but not quite the same as, the meaning in common parlance.

I offer the thought that in scientific use, 'trust' might be better than 'belief'. If the experimenter has controlled his variables, if the observer has kept his eye and pencil sharp, if the theoretician has considered limiting cases, infinities and zeroes, black swans, then we develop trust in the outcome. We believe it to be true (more or less conditionally) because we trust those who have proposed it and those who have critiqued it. It is not blind.

headrush
2012-May-20, 09:07 AM
Hi,
I think that the two terms could be distinguished by how much work is required to acquire or sustain them. I can believe in the Great Wall of China, but that belief is ultimately not worth very much unless I travel to China and poke the wall with a stick and travel along its length. Then I would have evidence of its existence. Belief requires no evidence, simply acceptance.

Of course there are always shades of grey, so that you may be said to believe an eminent scientist when they announce some results but that belief is based on past achievements and results, not blind "faith". Opinion and belief are also hard to separate in that while one is entitled to ones own opinion, it does not follow that the opinion is valid in the real world. Modern media and to some extent political correctness have to take a lot of blame for that situation.

But of course, all of this is my own opinion! But by posting I hope to gather supporting evidence (or not) :)

Alan

Gillianren
2012-May-20, 05:55 PM
Your analogy only works if personal experience is the only kind of evidence. If that's the case, almost all of science and history collapses. I don't believe in the Great Wall of China. I know it's real unless literally millions of people through history have conspired to convince me that it's fake, which seems a bit unlikely. This may be the third category, "trust," coming into play. I trust that all those photographs, films, drawings, and writings are not a hoax. It's possible that they are but silly to believe it.

headrush
2012-May-20, 08:55 PM
Your analogy only works if personal experience is the only kind of evidence. If that's the case, almost all of science and history collapses. I don't believe in the Great Wall of China. I know it's real unless literally millions of people through history have conspired to convince me that it's fake, which seems a bit unlikely.
I wasn't aiming for an analogy but taking your point : perhaps an adjustment is in order ;
"I can believe in the Great Wall of China, but that belief is ultimately not worth very much unless I or someone I trust travels to China and pokes the wall with a stick and travels along its length.Then I would have evidence of its existence. Belief requires no evidence, simply acceptance."
Is that better ?

Alan

ETA: Of course the tense matters, This visitation may have happened before I was aware of the Wall, but if somebody trustworthy says it is so, them I'm likely to accept their judgement. But still, basic belief has no threshhold of evidence.

headrush
2012-May-20, 10:57 PM
Actually, after some reflection, I would like to retract the last post and revert to my original idea.
There is one added proviso which I think gets to the heart of the matter (for me)

"I can believe in the Great Wall of China, but that belief is ultimately not worth very much unless I or a reliable proxy travels to China and pokes the wall with a stick and travels along its length.Then I would have evidence of its existence. Belief requires no evidence, simply acceptance."

My reasoning is thus : The whole point about evidence is that it is derived from data, and that derivation is repeatable. If no-one were to ever repeat the experiment, then nothing could be certain. Somebody [several people] has to poke it with a stick ! If I think the person doing the poking is doing the job at least as good as me then I'll accept their findings. You could call it trust but it's a bit more than that.
Belief almost requires you NOT to poke anything, but instead to go with the received wisdom.

Alan

Perikles
2012-May-21, 08:27 AM
Belief almost requires you NOT to poke anything, but instead to go with the received wisdom.But where exactly are the boundaries between evidence and belief? Your basic requirement is that you poke the Great Wall of China with a stick. This provides evidence to your bodily senses. Surely this requires a belief in the reliability of your senses? Then the proxy. That requires a belief that the proxy is trustworthy. Next, the photographs, requiring a belief that they are genuine. And so on.

By the way, the Ancient Greek word for I know is actually the perfect tense of the verb to see. (I know, OIDA = I have seen.) They felt that the only way to know something was to confirm with your own physical senses.

HenrikOlsen
2012-May-21, 10:40 AM
By the way, the Ancient Greek word for I know is actually the perfect tense of the verb to see. (I know, OIDA = I have seen.) They felt that the only way to know something was to confirm with your own physical senses.
Which as we know is a horribly bad was of gathering evidence because our senses lie to us constantly.

Paul Beardsley
2012-May-21, 12:03 PM
There is a consensus that holds that the Great Wall of China exists. It's a fact that we can assume to be true unless and until somebody provides evidence that it does not.

I prefer to say that I accept that the Wall exists rather than that I believe it exists.

Similarly, it is reasonable to accept that a given scientific theory fits the evidence better than any other. A better one might come along tomorrow, or someone might uncover some counter-evidence or a logical flaw tomorrow. But until then, we stick with what we've got.

Furthermore, I accept that scientists are being honest about their findings. There might be a massive conspiracy among scientists to withhold the truth about something from the public, but unless there is a compelling reason to think this is so, it is not a thought worth pursuing.

Is it actually constructive to avoid using the word "belief"? I think it is. I don't believe there is life on other planets; I do accept that life on other planets is likely, although we have no idea how likely.

Robert Tulip
2012-May-21, 12:30 PM
the Ancient Greek(s) felt that the only way to know something was to confirm with your own physical senses.
Maybe some thought that, but not Plato. The Analogy of the Divided Line (http://en.wikipedia.org/wiki/Analogy_of_the_divided_line) explains that "Plato holds a very strict notion of knowledge. For example, he does not accept expertise about a subject (the Gorgias,482d), nor direct perception (the Theatetus), nor true belief about the physical world (the Meno) as knowledge. For knowledge, he also requires philosophical understanding of the relevant Ideas (Forms), as a basis for proper justification at all other levels of the Divided Line."

In the Sophist, Plato compares the effort to make sense of the world to an imaginary battle between giants and Gods, in which the difficulties of philosophy are discussed in terms of the quarrel between materialism and idealism. The giants "define reality as the same thing as body, and as soon as one of the opposite party asserts that anything without a body is real, they are utterly contemptuous and will not listen to another word", while on the other side the Gods "are very wary in defending their position somewhere in the heights of the unseen, maintaining with all their force that true reality consists in certain intelligible and bodiless Ideas" (246b). What the giants "allege to be true reality, the Gods do not call real being, but a sort of moving process of becoming" (246c). Plato believed that both these ways of thought had something important to offer, but he attacked the materialists for being violent and uncivilised (246d) and for thinking that "whatever they cannot squeeze between their hands is just nothing at all" (247c). He says, "it is quite enough for our purposes if they consent to admit that even a small part of reality is bodiless", arguing that this must be admitted in the case of qualities of the soul like "justice and wisdom or any other sort of goodness or badness" (247b).

The logic of evidence requires acceptance of simple axioms, such as that the universe exists, and that abundantly corroborated observation is reliable. We have to assume these ideal foundations for logic in order to build systematic and consistent frameworks of knowledge.

Paul Wally
2012-May-21, 01:20 PM
I would define "a belief" as a proposition accepted as true without evidence of its truth value. So in this sense evidence and belief are indeed two different concepts, because evidence is defined relative to belief as that which is required to verify the truth value of a belief. Science, however, has a more critical approach: We have suppositions not beliefs and beliefs never need to come into the picture.

A supposition is a different kind of thing than a belief, and I think the one can often be confused for the other. In science we say: Suppose X, Y, and Z is true then what does that mean? It means that such and such evidence must be observed, but if such evidence is not observed then we say, let's make a different supposition. Belief doesn't come into the picture. Even if science reaches some point in the future where it begins to look like a firmly established and well supported body of doctrine, the job of science would be to find holes in that system and to make new discoveries etc. That is the critical nature of science and it's never about establishing beliefs. As long as scientific theories are based on empirical evidence only, the possibility will always exist that they are wrong and thus the critical attitude must always prevail.

NEOWatcher
2012-May-21, 01:36 PM
From what I've seen, "belief" is far too broad of a word to really have any meaning when it comes to science and evidence.
I think the real issue is that belief also covers "dogma", and people don't want to accept that thier (dogma)belief is not based on evidence.

HenrikOlsen
2012-May-21, 02:11 PM
I agree that people in this thread have had a tendency to say belief when they meant dogma.

There is belief in science too, a belief that there is a universe and that it's consistent.
There's normally also a belief that the scientific method in whichever variation has a very strong tendency to be the best tool at hand for devising useful descriptions of this universe.
There's also a belief that all humans (without any exceptions) are fallible.

headrush
2012-May-21, 04:15 PM
Just to make clear that when I talk about poking the wall with a stick I'm actually referring to a scientific investigation being carried out. That is what provides evidence, facts and real understanding. I agree somebody's senses are involved but only to record data. The reproducable part of the scientific method relies on more than one person/group doing the investigation, which firms up (or disproves) tthe evidence or theory. And I also agree that dogma is probably a better term for what I meant by "belief".

Interesting discussion :)

Alan

Gillianren
2012-May-21, 06:17 PM
My point is that I don't have to personally be the one with the stick. I don't have the wherewithal to be the one with the stick; I barely have the funds to get to Seattle, much less China. But many, many others have used many, many sticks, and I can trust their methodology and accept their results, and I still think that's different from "belief."

HenrikOlsen
2012-May-21, 06:53 PM
And, given enough money, you actually could go there and have a poke.
There's nothing intrinsic in the argument of "it exists because it can be poked with a stick" that would prevent you from doing so.

Whereas an argument such as "it exists because big-beard man in the sky told his chosen one" is intrinsically unrepeatable.

Gillianren
2012-May-21, 07:29 PM
Absolutely. I'm just saying that I do not myself have to perform the experiment to accept that it would hold true if I did, and that's different from faith.

Selfsim
2012-May-21, 09:54 PM
Is it actually constructive to avoid using the word "belief"? I think it is. I don't believe there is life on other planets; I do accept that life on other planets is likely, although we have no idea how likely.Hi Paul;
Well, I think you've hit the nail on the head here (in your first two sentences).

Should there be any importance associated with what anyone believes when it comes to scientific matters ? How many times in the past, has such a close association with an individual's beliefs, led to dogma ? One of the distinguishing features of science, is to maintain deliberately, an as unbiased approach as is possible, when exploring the unknown. Belief actually thus undermines one of the key principles of the scientific approach.

Sure, hypotheses (or ideas) provide the spark for pursuing specific avenues of investigation .. but fairly soon into that process, one should abandon attachment to those ideas and attempt to falsify them. This is actually where the real value of hypothesisation becomes realised.

Its a little hard-hitting, and many take offence to the saying: "It doesn't matter what you believe (or even think)" … but this is actually mainstream scientific process in action .. and offence may not necessarily be intended.

Also, I question, (in your example), the need to: 'accept that life on other planets is likely'. Other than demonstrating support for: (i) the consensus view and, (ii) the exo-life investigation activity, I can see no reasons for acceptance of the physical reality of such a thing. The investigation can still be supported, without a need for accepting the physical existence of exo-life (especially when there is no physical evidence. ;) )

Regards

Paul Beardsley
2012-May-22, 05:22 PM
Also, I question, (in your example), the need to: 'accept that life on other planets is likely'. Other than demonstrating support for: (i) the consensus view and, (ii) the exo-life investigation activity, I can see no reasons for acceptance of the physical reality of such a thing. The investigation can still be supported, without a need for accepting the physical existence of exo-life (especially when there is no physical evidence. ;) )

Well, first of all I didn't express a "need" to accept anything. Second, as I stated, I don't accept the physical existence of exo-life, I accept the likelihood of exo-life. Third, I am speaking as a layman, not a scientist, but expressing the sort of answer I would give to someone who asked if I believed in aliens.

Besides demonstrating support for the consensus view and the exo-life investigation activity, I am also emphasising that the possibility of alien life is something founded on reason. By way of contrast, I can point out that I do not accept that centaurs and Romero-style zombies are likely to exist.

Selfsim
2012-May-22, 09:45 PM
Well, first of all I didn't express a "need" to accept anything. Second, as I stated, I don't accept the physical existence of exo-life, I accept the likelihood of exo-life. Third, I am speaking as a layman, not a scientist, but expressing the sort of answer I would give to someone who asked if I believed in aliens.
Ok .. thanks for that .. got it, now.
Personally, I find the use of the term 'likelihood' to be technically improper, as for me, it refers to the state of being 'probable', which has extremely specific constraints in theory. It also requires prior assumptions which frequently have some kind of biased assumptions underpinning them. I do agree that its use amongst exo-lifers is very common, but this seems to be being used in the common language sense .. which differs from the formal definition.
When I'm asked about my beliefs, I generally respond by disqualifying my beliefs as being irrelevant to where I'm coming from … (they should be irrelevant ... but I can also make mistakes about this, also. :) ).

Interesting.


Besides demonstrating support for the consensus view and the exo-life investigation activity, I am also emphasising that the possibility of alien life is something founded on reason. By way of contrast, I can point out that I do not accept that centaurs and Romero-style zombies are likely to exist.Whilst I appreciate that such extremists views exist, (ie: that centaurs and zombies are likely to exist), I have a sneeking suspicion that the term 'likely' is the main issue. As expressed above, the conditions for the assumed 'likelihood' might be more interesting than the conclusion.

Cheers

djellison
2012-May-22, 09:50 PM
but [I]it does link the suspect to the crime, .

It links them to a location. Not necessarily the crime.

R.A.F.
2012-May-22, 10:05 PM
...I do not accept that...snip...Romero-style zombies are likely to exist.

The heck you say.


I've been driving all over Dead Island, and i can tell ya that the Zombies are everywhere.

...and they're really fun to run over, too...:)

mutleyeng
2012-May-22, 10:51 PM
I cant for the life of me see how you can use an argument that something you think likely is reasoned just because the possibility of it is founded on reason.
To go from possible to likely, without sufficient evidence, absolutley is a belief.
you cant have your cake and eat it im affraid.

djellison
2012-May-22, 10:56 PM
And indeed the difference between possible and likely was the very crux of the rapid decay of the alien life on exoplanets thread.

Paul Beardsley
2012-May-23, 06:41 PM
I cant for the life of me see how you can use an argument that something you think likely is reasoned just because the possibility of it is founded on reason.
To go from possible to likely, without sufficient evidence, absolutley is a belief.
you cant have your cake and eat it im affraid.

This sounds to me like quibbling-for-the-sake-of-quibbling, and I'm not interested in that at all.

If ET life was found, its discovery would not overturn our understanding of the universe. Given what we do know, the discovery of ET life would be a lot less surprising than the discovery that life never emerged anywhere beyond Earth (assuming that negative could be proved). That is what I mean by "likely".

mutleyeng
2012-May-23, 10:43 PM
well, you say its quibbling - i say its fundamental
to say that ET life is more likely than no ET life, given what we know, nicely side steps the issue that its the stuff we dont know that is most relevant to holding a view one way or the other.

HenrikOlsen
2012-May-23, 11:28 PM
We know life exists in the universe at least one place. To expect that it only started once in the universe seems frankly ludicrous given the size of the universe, the prevalence of Earth-like planets and how early in its age life started on Earth.
In terms of astronomical time it happened nearly instantaneous once conditions allowed the type of chemistry needed.

mutleyeng
2012-May-24, 09:57 AM
which is fine, when you present it as your opinion.
Its when you try to use science to claim that belief is more than an opinion where we have a disagreement.
It also illustrates the subjective nature of evidence, which is where it ties into the theme of the thread.

Paul Wally
2012-May-24, 10:34 AM
well, you say its quibbling - i say its fundamental
to say that ET life is more likely than no ET life, given what we know, nicely side steps the issue that its the stuff we dont know that is most relevant to holding a view one way or the other.

So, what more are we suppose to know before we can say it is likely?

Selfsim
2012-May-24, 10:38 AM
We know life exists in the universe at least one place.Err .. I beg to differ.
We know of extant life on one planet only.

To expect that it only started once in the universe seems frankly ludicrous given the size of the universe, the prevalence of Earth-like planets and how early in its age life started on Earth.To the best of my knowledge, the only theoretical basis under which we can say that life has (or can) theoretically recur, requires the assumptions referred to under the "Infinite Universe" paradigm, (infinite spatial expanse and infinite age (time)). And I use the term 'infinite' in the formal mathematical sense. This is the only theoretical basis I'm aware of, where assertions of the existence of other instances are theoretically legitimate and demonstrable ... (ludicrous or not) !
The rest of your above assertion is inferred only ... unless you can produce physical evidence of another instance of independently emerged life of course, (of which I'm presently unaware).

In terms of astronomical time it happened nearly instantaneous once conditions allowed the type of chemistry needed.And what isn't mentioned here, also speak volumes ... ie: what we don't know about what else was required for life to emerge.
If chemistry was all that was needed, then reproducing the chemistry you reference, would result in another emergence of new life ... and evidently, it hasn't ! :confused:

Regards

mutleyeng
2012-May-24, 10:48 AM
So, what more are we suppose to know before we can say it is likely?

In my opinion, a sound theory of Abiogenesis or a test tube containing ET which you are sure is not related to us (to be Alien).
To be honest, i would share the opinion that ET life is likely with less than this.. perhaps from signitures which have no explanation we know of other than life... but I would still be aware that it was just my opinion and i may be wrong.
But again, anyone is free to say they think its likely - theres no issue with that at all

agingjb
2012-May-24, 10:51 AM
Some interesting questions arise about the usage of the word "believe", in particular how it is negated.

"I do not believe that X is true" implies, for me, that the writer is saying: "I do not seriously entertain the possibility that X is true", rather than "I am neutral about the possibility that X is true". Put it another way, the "not" seems to transfer from "believe" to "true".

It's clear that others use the word in a different way.

Robert Tulip
2012-May-24, 11:44 AM
I don't believe there is life on other planets; I do accept that life on other planets is likely, although we have no idea how likely.


I cant for the life of me see how you can use an argument that something you think likely is reasoned just because the possibility of it is founded on reason. To go from possible to likely, without sufficient evidence, absolutley is a belief.

Mutleyeng, Paul's statement is a reasonable case of probabilistic reasoning. We accept that statements that are probably true are likely, as Paul said. I accept, somewhat grudgingly, that Queensland will probably win the State of Origin Rugby League series over New South Wales this year. That does not mean I have some faithful certainty or belief about this prediction in the absence of corroborated evidence (which is impossible for any future event).

Things get muddier when the probability approaches certainty. I believe that Venus will transit the sun on 6 June because of the weight of corroborated evidence from celestial mechanics and the expectation that the future will conform to the past. Some scientists would say they know Venus will transit the sun, defining knowledge as justified true belief based on firm evidence.

For Paul's example, acceptance that life elsewhere in the universe is probable, some may consider this has similar near-certain probability, given the size of the universe and what we know of the conditions for the emergence of microbial life. However, without conclusive evidence we can only accept it is likely, as beliefs that lack evidence are merely statements of faith.

mutleyeng
2012-May-24, 12:10 PM
but i dont accept that it is probably true, because i have seen nothing to substantiate it. Its a leap of faith whether he has used probablistic reasoning or not.
with a rugby game you have statistical records of all the relevant data to make a call.
I suspect the ancient alien believers are using probablistic reasoning too...its just not good probablistic reasoning.
Again, it shows the value on evidence is subjective.

if you had quoted the whole of pauls post, he went on to tie possible with likely, and it was the conflation of those terms i was replying

the reason i am quibbling about this is because i believe it gets to the core of why people believe strange stuff, and claim it rational. That is, the subjective way we appraise the value of pieces of evidence.
It also is how people rationise things to themselves. They interchange and conflate words with different meanings to attempt to give the illusion of being rational- either to themselves or to others. You see this from conspiracy theorist types all the time, and we are probably all guilty of it to a greater or lesser degree

Perikles
2012-May-24, 12:32 PM
We know life exists in the universe at least one place.


Err .. I beg to differ.
We know of extant life on one planet only.

How can you beg to differ, when this is exactly what @Henrik (presumably) meant?

NEOWatcher
2012-May-24, 01:52 PM
And what isn't mentioned here, also speak volumes ... ie: what we don't know about what else was required for life to emerge.
So; some pieces of missing information means that the whole idea is not possible?


If chemistry was all that was needed, then reproducing the chemistry you reference, would result in another emergence of new life ... and evidently, it hasn't ! :confused:
Yet.
Just because Jamie and Adam haven't been able to recreate certain myths doesn't mean they automatically say "busted". If they get close, they they say "plausible".

Cougar
2012-May-24, 07:44 PM
And what isn't mentioned here, also speak volumes ... ie: what we don't know about what else was required for life to emerge...

According to Stuart Kauffman, it's just molecular diversity. Unproven, but scientifically developed and supported.

Selfsim
2012-May-24, 09:15 PM
How can you beg to differ, when this is exactly what @Henrik (presumably) meant?I can only go on what Henrik actually said .. not what I presume he said.
If he meant what I said .. then our two statements would have identical meaning .. and they don't.
Regards

Paul Wally
2012-May-24, 09:44 PM
I can only go on what Henrik actually said .. not what I presume he said.
If he meant what I said .. then our two statements would have identical meaning .. and they don't.
Regards

So what is the difference between what Henrik meant and what you meant? I see only pedantic differences.

Selfsim
2012-May-24, 09:46 PM
So; some pieces of missing information means that the whole idea is not possible? In a critical system, any small changes, (particularly in initial conditions), can result in different outcomes. As far as I'm concerned, as long as this 'possibility' is not ruled out, the inevitability of the emergence of exo-life remains indeterminate (in theory).
('Infinite Universe' assumptions excepted).

Yet.
Just because Jamie and Adam haven't been able to recreate certain myths doesn't mean they automatically say "busted". If they get close, they they say "plausible".The term 'plausible' denotes speculation .. or opinion.
Inferences drawn from speculation are still speculative.
Speculation is distinct from physical reality (and established theory).

What Jamie and Adam say, and what is physical reality, are two different things.

Gillianren
2012-May-24, 09:47 PM
Yeah. We don't know of more than one, but we do know of one. Ergo, at least one. That is the smallest number of planets in the universe on which there is life according to our direct experience.

Selfsim
2012-May-24, 09:49 PM
Yeah. We don't know of more than one, but we do know of one. Ergo, at least one. That is the smallest number of planets in the universe on which there is life according to our direct experience.Agreed - thanks for the assistance .. (I have a feeling I won't be able to keep up with the impending barrage, here. :) )
Regards

Selfsim
2012-May-24, 10:01 PM
So what is the difference between what Henrik meant and what you meant? I see only pedantic differences.Henrik cited the size of the universe and comparative elapsed age of the Earth for emergence to occur:

To expect that it only started once in the universe seems frankly ludicrous given the size of the universe, the prevalence of Earth-like planets and how early in its age life started on Earth.… the size of the universe is extreme. The argument calls for exploration of extremes. Meticulous exploration of the extremes is thus, basically the grounds he invoked for discussion .. just trying to stay within that paradigm.

Constraining discussion to the large scales, without recognising the realm of the microscopic, or even molecular/atomic scales would result in an unbalanced discussion.

We need to consider very broad areas and all extremes, including the unpredictability inherent in non-deterministic systems, when discussing life emergence and speculated distributions of the unknown.

Selfsim
2012-May-24, 10:11 PM
According to Stuart Kauffman, it's just molecular diversity. Unproven, but scientifically developed and supported.Whilst Kauffman has certainly spent much of his life exploring the highly relevant topics in this area (and I very much respect his contributions), I also find that he rarely spends much time dwelling on falsification (or the other side of the coin).
If one reads what he has to say from this perspective, there remains a lot of scope for for critical thinking.

Regards

Paul Wally
2012-May-24, 10:48 PM
In a critical system, any small changes, (particularly in initial conditions), can result in different outcomes. As far as I'm concerned, as long as this 'possibility' is not ruled out, the inevitability of the emergence of exo-life remains indeterminate (in theory).
('Infinite Universe' assumptions excepted).
The term 'plausible' denotes speculation .. or opinion.
Inferences drawn from speculation are still speculative.
Speculation is distinct from physical reality (and established theory).

What Jamie and Adam say, and what is physical reality, are two different things.

Do you have any proof/evidence supporting the idea that life can be a single "critical outcome"?

Selfsim
2012-May-25, 12:06 AM
In a critical system, any small changes, (particularly in initial conditions), can result in different outcomes. As far as I'm concerned, as long as this 'possibility' is not ruled out, the inevitability of the emergence of exo-life remains indeterminate (in theory).

Do you have any proof/evidence supporting the idea that life can be a single "critical outcome"?
Ha … I expressed my view only .. "as far as I'm concerned". Like many others, I make no affirmative claims in respect of the physical reality of this (as expressed above, and elsewhere in discussion of the thread topic).

That aside, there is plenty of evidence that complex dynamic biological systems frequently organise themselves at, or close to criticality. Whilst this may not specifically address the presently unknown .. (ie: in this case; the emergence of life), it does demonstrate that living systems, behave fundamentally differently from the deterministically predictable systems at scales of say, a planet's orbit around a relatively massive star. The evolution of planetary environmental eco-systems, are also the subject of the same complex behaviours, and the influence on this on planetary bio-systems, is also evident.

Orbital mechanics, eco- and bio- systems also behave within the bounds of the known Laws of Physics (and Chemistry).

The 'possibility', (a term of familiarity), thus resides alongside a seeming plethora of others, and like all the others, evidence-based inference is easily able to be drawn. So what is the purpose of such a line of query, other than the communal sharing of views?

Wonderfully complex, wouldn't you say ? :)

Gillianren
2012-May-25, 02:09 AM
Agreed - thanks for the assistance .. (I have a feeling I won't be able to keep up with the impending barrage, here. :) )

Actually, I'm agreeing with Henrik. "At least one" is a perfectly legitimate way of stating the number of planets in the universe with life on them.

NEOWatcher
2012-May-25, 11:50 AM
The 'possibility', (a term of familiarity), thus resides alongside a seeming plethora of others, and like all the others, evidence-based inference is easily able to be drawn. So what is the purpose of such a line of query, other than the communal sharing of views?
Please explain this "seeming plethora of others". What I see in the rest of the post are "factors" in "possible".
I see 3 options:
"Yes" is provable.
"Possible" has levels based on evidence.
"Never" is not provable.

HenrikOlsen
2012-May-25, 01:10 PM
Henrik cited the size of the universe and comparative elapsed age of the Earth for emergence to occur:
… the size of the universe is extreme. The argument calls for exploration of extremes. Meticulous exploration of the extremes is thus, basically the grounds he invoked for discussion .. just trying to stay within that paradigm.
The point I was trying to make is that "one" is less likely than "none" or "some", exactly because the likelihood needs to be extremely small while not being impossible, in order for "one" to be the result.

I have no trouble with impossible, I have trouble with possible but unlikely enough to only happen once in the history and span of the universe.

And to go to the microscopic: . . . especially given the prevalence for self-organization easily demonstrable in organic soups.

HenrikOlsen
2012-May-25, 01:15 PM
How can you beg to differ, when this is exactly what @Henrik (presumably) meant?
Logically they're equivalent statements as they give exactly the same information: n\geq 1, though selfsim's statement is stated without acknowledging how many planets we don't have information about yet.


"We know of one" and "at least one" are logically identical until you've inspected every other.

Perikles
2012-May-25, 02:55 PM
"We know of one" and "at least one" are logically identical until you've inspected every other.Your precise statement reminds me of the joke about a physicist and a mathematician reporting after having been for a walk in the country. The physicist reports he saw a flock of sheep with one black sheep in it, whilst the mathematician reports that he saw a flock which included at least one sheep which was black on at least one side.

Selfsim
2012-May-26, 02:56 AM
Please explain this "seeming plethora of others". What I see in the rest of the post are "factors" in "possible".
I see 3 options:
"Yes" is provable.
"Possible" has levels based on evidence.
"Never" is not provable.The seeming 'plethora of other possibilities' I'm referring to, are life emergence possibilities. Chaotic origins, evolving towards biologically complex adaptive systems, can lead to a different interpretation of 'likelihood', as classical determinism plays a less influential role in Chaos. Slight differences in conditions at a particular scale, would lead to different (unpredictable) outcomes when comparing different origin events. Such outcomes could quite easily lead to non-viable end-products on astronomical scales, (as measured by our known life tolerance criteria). Any one stage of progress towards life, may become critical for progress towards the next stage, or what we ultimately call 'living', and yet, these may not even necessarily occur, let alone meet the criteria for successful progress towards the next dependent stage. And there might be lots of them, or there may be very few .. we just don't know.

There are many variants which become visible with considerations from this field of study, as Chaos continues to influence self-organsation of natural systems at multiple interdependent scale levels. The vision of 'likely', (when inferred from the rock-solid foundations of determinism, inherent Classical Physical and Chemical Systems), shifts substantially when viewed from this equivalently valid, mainstream theoretical, largely Biological Sciences perspective. Whilst Astrophysical studies are recognised as being directly influenced by Chaotic processes, strangely, considerations of the emergence of life from the same chaotic Astrophysical phenomena, seems largely absent in these discussions.

Once again, I am making no claims of assertion that this perspective is any more valid than any other mainstream speculative life emergence ideas, but it is certainly worthy of consideration when debating 'likelihood' assertions (inferred from mathematically dubious bases) and claims of 'ludicrosity' directed at undermining seemingly valid, and perhaps unconsidered (?), mainstream science, theoretically based ideas.

'Evidence' comes in many forms, and supports many different domains of science. 'Belief' in this case, about the 'likelihood' of exo-life, relies on indirect inferences drawn from the size of the observable universe, which so far, has presented us with no direct evidence demonstrating direct causal relationships, between the environments it creates, and the emergence of life. By excluding these aspects, it may be reasonably inferred that it takes a universe of the size we observe, in order for one, (or more), life instance(s) to appear. The likelihood of the prevalence of those instances, is as dependent on the amount of visibility we have about how complex natural systems behave and interact, as much as it does on the size of the observable universe .. and those systems, aren't all necessarily predictable, nor are we able to estimate with any degree of reliable precision, the distributions of their outcomes.

We simply do not know as much as we need, to in order make bold assertions (and predictions) such as 'likely', or 'unlikely', without reliance on belief.

Regards

Selfsim
2012-May-26, 03:08 AM
Logically they're equivalent statements as they give exactly the same information: n\geq 1, though selfsim's statement is stated without acknowledging how many planets we don't have information about yet.

"We know of one" and "at least one" are logically identical until you've inspected every other.Hi Henrik;

The mathematical equivalency is not in question.

The logic presented, is based purely on a numbers game.

Such logic requires extension to reasoning beyond this.

The existence of life on Earth, does not imply life exists elsewhere.

Regards

Gillianren
2012-May-26, 03:19 AM
It doesn't have to for the statement to be true. "At least one" doesn't mean there must be any other, just that it might. That it is possible but unknown.

Van Rijn
2012-May-26, 05:46 AM
The existence of life on Earth, does not imply life exists elsewhere.

Regards

I'd say that the existence of life on Earth doesn't require or prove that life exists elsewhere. Implication, though . . .

I think exoplanets provide an analogous situation. Before exoplanets were directly detected, you could make the argument that perhaps they didn't exist. Perhaps there was some unique property to our solar system that only allowed planets to exist here, or perhaps there was something that made planet formation extraordinarily improbable. We had ideas about how planets could form, but they were far from certain or complete. We had never witnessed planets form, and we obviously couldn't build them in the lab. However, we could look at planets, learn what materials would be required for their formation, and look for evidence that those materials existed elsewhere in the universe. When we found evidence for similar material, for instance, a star surrounded with a disk of gas and dust, we could create simulations using known physics, and see what might result. I think it is clear that, while we didn't know exoplanets existed until direct detection, there had long been abundant implications that they existed.

Similarly, while I certainly am willing to consider the possibility that life might only exist on Earth, there are things we know about life, and these things do have implications for the existence of life elsewhere.

Selfsim
2012-May-26, 07:33 AM
The existence of life on Earth, does not imply life exists elsewhere.I'd say that the existence of life on Earth doesn't require or prove that life exists elsewhere. Implication, though . . .
... {snip}...
Similarly, while I certainly am willing to consider the possibility that life might only exist on Earth, there are things we know about life, and these things do have implications for the existence of life elsewhere.Hi Van Rijn;
Well, in the absence of direct evidence, the speaker is in control of those implications. In my statement, I exercised that control, and resolved the implication explicitly, because of the lack of causal evidence.

For example, the speaker of the statement: "Earth has water, so Earth has life" implies that life and water are intrinsically linked, no matter where in the universe either occurs, without explicitly stating this.
A listener might well feel justified by inferring, (or making a guess), that where there is water, there is life, but there could still be no evidence of casuality between water and the emergence life. As a matter of fact, the presence of surface liquids other than water, is now considered to be sufficient for raising expectations about the possible emergence of exo-life on say, Titan, for instance.

I'm hoping you might agree that there's a quantum leap of physical complexity between what causes a planet to form, where Classical Laws of deterministic Physics and Chemistry dominate .. and the added layers of complexity which distinguish life, from a planet. From this distinction, I could infer a separate, more complex origin process for life, but I'd like to be upfront about this, by acknowledging this as being merely inference, with no further implications intended.

Regards

Van Rijn
2012-May-26, 09:01 AM
I'm hoping you might agree that there's a quantum leap of physical complexity between what causes a planet to form, where Classical Laws of deterministic Physics and Chemistry dominate .. and the added layers of complexity which distinguish life, from a planet.

From this distinction, I could infer a separate, more complex origin process for life, but I'd like to be upfront about this, by acknowledging this as being merely inference, with no further implications intended.

Regards

I'm not entirely sure what you mean by "quantum leap" but no, I don't think we agree. Yes, there are additional complications, but I don't see how it applies to the argument. Certainly it could suggest that lifeless planets would be much more common than planets with life. But by mentioning complexity, you haven't demonstrated anything that points to a conclusion that only Earth has life. The existence of life on Earth still does imply life exists elsewhere.

mutleyeng
2012-May-26, 09:39 AM
No one is claiming that only life on earth exists.
The argument, i think, is simply that we have such a gapping great hole in our understanding of how the spark of life emmerged, and the conditions required for it, that we do not have the ability to make an informed estimate of likelihood. Without this, the numbers of worlds that could support life is meaningless.
The same was not true for planetary formation.

The moment you can put on the table a complete theory of Abiogenesis, then sure, you can start talking about likely...and claim science supports you.
You dont need to see something to think that it is there, but you need need to understand how it could be there.

caveman1917
2012-May-26, 06:29 PM
Logically they're equivalent statements as they give exactly the same information: n\geq 1, though selfsim's statement is stated without acknowledging how many planets we don't have information about yet.


"We know of one" and "at least one" are logically identical until you've inspected every other.

They're not logically equivalent, "at least one" doesn't imply "we know of (exactly) one".

There's a difference between two statements that are equivalent and two statements that just happen to be true at the same time.

Gillianren
2012-May-26, 06:33 PM
They're not logically equivalent, "at least one" doesn't imply "we know of (exactly) one".

No, it implies "we know of only one." However, it takes the stance that we cannot know about the others, so they may or may not. It is open-ended, not assumptive.

caveman1917
2012-May-26, 06:47 PM
No, it implies "we know of only one."

No, it doesn't imply that. "At least one" can be true when "we know of only/exactly one" can be false. There is only an implication in the other direction, "we know of only/exactly one" implies "at least one", not the other way around. Ergo the statements are not equivalent.

It is akin to the statements "it rains" and "i'm getting wet". The implication also only works in one direction, "it rains" implies that "i'm getting wet", but not the other way around. Therefor they are not equivalent statements.

Gillianren
2012-May-26, 07:54 PM
You're not getting wet if it rains when you're inside; likewise, there are ways of getting wet that don't involve rain. I'm not sure which was your point. But how can we know of at least one when we don't know of exactly one? In this instance, remember, we have no way of knowing the number out there. We do know of one. Ergo, we know that the lowest amount of X possible in the subject under discussion is one. That is the least.

Paul Wally
2012-May-26, 07:55 PM
The seeming 'plethora of other possibilities' I'm referring to, are life emergence possibilities. Chaotic origins, evolving towards biologically complex adaptive systems, can lead to a different interpretation of 'likelihood', as classical determinism plays a less influential role in Chaos.

Chaos,at least in the way its discovery originated and in the way it developed, is a classical deterministic phenomenon. It is precisely because chaos can be deterministic that it is possible to study it with simple nonlinear equations and algorithms on a computer, and it's from such computer simulations that we've learned the bulk of chaos phenomena. I think you assume that "deterministic" and "predictable" is the same... it's not.


Whilst Astrophysical studies are recognised as being directly influenced by Chaotic processes, strangely, considerations of the emergence of life from the same chaotic Astrophysical phenomena, seems largely absent in these discussions.

Whatever you mean by "chaotic astrophysical phenomena", that too can be modeled and simulated as classical deterministic processes in a computer.


'Evidence' comes in many forms, and supports many different domains of science. 'Belief' in this case, about the 'likelihood' of exo-life, relies on indirect inferences drawn from the size of the observable universe, which so far, has presented us with no direct evidence demonstrating direct causal relationships, between the environments it creates, and the emergence of life. By excluding these aspects, it may be reasonably inferred that it takes a universe of the size we observe, in order for one, (or more), life instance(s) to appear. The likelihood of the prevalence of those instances, is as dependent on the amount of visibility we have about how complex natural systems behave and interact, as much as it does on the size of the observable universe .. and those systems, aren't all necessarily predictable, nor are we able to estimate with any degree of reliable precision, the distributions of their outcomes.

But in your view of chaos, causality doesn't even have any meaning and therefore any attempt at causal explanation is considered futile from the start. With causality out the way, we could know of a hundred planets with life, and we would still have no basis for inferring the existence of more than just that hundred planets. "We know of extant life on 100 planets only" will be all you could say in such a "chaotic universe".

caveman1917
2012-May-26, 08:10 PM
You're not getting wet if it rains when you're inside; likewise, there are ways of getting wet that don't involve rain. I'm not sure which was your point.

It was meant in the sense of being outside. But try the following ones, they're less ambiguous: "I am writing an english text" and "I am using the latin alphabet". These statements are also not logically equivalent even though there exists a unidirectional implication and both can be true at the same time.


But how can we know of at least one when we don't know of exactly one?

By knowing of exactly 20, or any other number really. If we know of 20 then the statement "we know of only/exactly one" is false yet "we know of at least one" is true, therefor "at least one" does not imply "we know of exactly one", and Henrik's statement that they are logically equivalent/identical is incorrect, which was what i was responding to.


In this instance, remember, we have no way of knowing the number out there. We do know of one. Ergo, we know that the lowest amount of X possible in the subject under discussion is one. That is the least.

Yes, but the implication is only in that direction, not the other direction, so there is no equivalence. They just happen to be both true at this time, but that doesn't make them equivalent. Just like "I am writing an english text" and "I am using the latin alphabet" may very well both be true at some time, but that doesn't make them equivalent.

"We know of exactly one" implies "we know of at least one" (as you have said), but "we know of at least one" does not imply "we know of exactly one". For equivalence you need bidirectional implication, not unidirectional.

Gillianren
2012-May-26, 09:33 PM
Well, it's certainly true that you cannot write an English text without using the Latin alphabet. But the fact is, while we only currently know of one planet with life, we do not know if that is the total of planets with life in the universe. We know the universe supports at least one, but we cannot know if it supports more than one until we either find another one or examine every planet. Of course, assuming there is no life elsewhere in our solar system, it's entirely possible we will never be able to do either, though I like to hope we will be able to reach planets outside our solar system at some point. Therefore, I have no problem with phrasing it as "we know there is at least one planet with life on it in the universe" and in fact have a serious problem with "we know there is one planet with life on it in the universe" because of its implications.

pogono
2012-May-26, 11:14 PM
I have read your discussion and I suppose the problem is much more deeper then just one or two way implication issue. You discuss essence of scientific approach here, so let me express my point of view in few lines of drama.

Mr Evidence (ME): Scientific approach is based on data and criticism. We cannot use assertion or belief as part of reasoning. Science is based on facts. Data and predictions have to fit to each other.

Mr Belief (MB): I agree, that science may explain the past. But what will be the result when I roll of the dice?

ME: We may deduce future from the past. If we know the force, air density and so on, we may predict the result. Mechanics is well described and there is no enigma in it.

MB: You have already denied above. Moreover, the prove is done by science.
- We are not able to measure all factors, at least because by measuring we change these factors (QM).
- We have to accept error bars, what may drive to unpredictable results (Chaos theory).
All we can say, is the probability of the options, but we are not even sure if we calculate it right.

Enough to recall axioms of probability. We know, there is nothing on the world what may have 0 or 1 probability. We cannot even be sure of our axioms since there is nothing with probability 1 (if someone disagree, please refer to Godel's theorem (http://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorems))

By pressing the elevator button we just increase the probability of its arrival. We cannot be sure if it will arrive. There are waves of the probability of events around us. All we can do is to curve this waves.

ME: Ok, my last sentence was mind shortcut. There is no complete certainty of anything. But if we gather data and make theories we are closer and closer to the right answer. Saying that Venus cross the Sun at well calculated day we indeed say, there is very high probability of it, based on available evidences.

MB: So, how do you know that by science you come to better results. You cannot be sure.

ME: I believe there is some order. By scientific approach I get closer to understand it.

MB: So, you are believer, just like me. Then, who is not true believer? I recognize two sorts of them:

1. People who have some ATM idea or conspiracy theory. They are SO SURE they are right, that even if all known data says something different, it must be some problem with the data.

2. People who have been learning for long time, so sometimes some of them think they know something for sure. Scientists who went this way may be found f.e. here: http://amasci.com/weird/end.html

Present days, both of above may be often found lost in fight on Internet forums.

Selfsim
2012-May-27, 12:11 AM
I have read your discussion and I suppose the problem is much more deeper then just one or two way implication issue. You discuss essence of scientific approach here, so let me express my point of view in few lines of drama.
…{snip} ...
1. People who have some ATM idea or conspiracy theory. They are SO SURE they are right, that even if all known data says something different, it must be some problem with the data.

2. People who have been learning for long time, so sometimes some of them think they know something for sure. Scientists who went this way may be found f.e. here: (http://amasci.com/weird/end.html)

Present days, both of above may be often found lost in fight on Internet forums.Hi Pogono;
With respect, the discussion is well within the 'norms' of mainstream science, and is well clear of ATM.

MB: I agree, that science may explain the past. But what will be the result when I roll of the dice?
ME: We may deduce future from the past. If we know the force, air density and so on, we may predict the result. Mechanics is well described and there is no enigma in it.
You mention 'throwing dice'. A dice is specifically designed such that it can only produce six possible outputs .. no more … no less. This is why betting on dices is rational. The probabilities can be computed and the risk can be evaluated. The randomness is 'measurable' and is given by probability theory in a pre-given possibility space.

The outcomes can be calculated, because of the geometrical symmetry of the dice .. or: the relative probabilities are defined by the symmetries with respect to the observable, in a pre-stated phase space.

Randomness in biology, doesn't work this way. We cannot apply a normal probability measure to biological unpredictability because of the absence of of this pre-given phase space, which is provided by the geometrical symmetry of the dice, in the dice example.

Biological randomness leading to variation, cannot be measured by probabilities. Whilst this really is another topic for discussion, the point of raising this, and attempting to reduce the emergence of life discussion to precisely what we know, is that this is the point we have to go back to, in order to view the emergence question under the Biological paradigm, which stands distinct from the Astronomical 'numbers game' one.

You touched on this point in your discourse, but the point I'd like to make is a different one from the one your characters made.

Out of courtesy to Paul (the OP), I'm hoping to start a new thread on this shortly … I think we really are beyond the scope of evidence and belief at this point.

Regards

caveman1917
2012-May-27, 02:04 AM
Well, it's certainly true that you cannot write an English text without using the Latin alphabet.

But you can certainly be using the latin alphabet without writing an english text.


But the fact is, while we only currently know of one planet with life, we do not know if that is the total of planets with life in the universe. We know the universe supports at least one, but we cannot know if it supports more than one until we either find another one or examine every planet. Of course, assuming there is no life elsewhere in our solar system, it's entirely possible we will never be able to do either, though I like to hope we will be able to reach planets outside our solar system at some point. Therefore, I have no problem with phrasing it as "we know there is at least one planet with life on it in the universe" and in fact have a serious problem with "we know there is one planet with life on it in the universe" because of its implications.

I mostly agree, though i do think there is a difference between "we know there is one planet with life" and "we know of only one planet with life" which is what was said, the latter is not restrictive about future discoveries. The former would be false, at least interpreted as "we know there is only one planet with life".

In any case my remark was merely towards the statement of logical equivalence, not much else besides that. As i recall you once said you disapproved of people incorrectly using the term "literally" all the time, i suppose for me the same goes towards the term "logically". To each his own :)

Van Rijn
2012-May-27, 06:24 AM
No one is claiming that only life on earth exists.


Then life on Earth does imply life elsewhere?



The argument, i think, is simply that we have such a gapping great hole in our understanding of how the spark of life emmerged, and the conditions required for it, that we do not have the ability to make an informed estimate of likelihood. Without this, the numbers of worlds that could support life is meaningless.


I am not attempting to estimate the number of worlds that support life. The argument that I had an issue was, "The existence of life on Earth, does not imply life exists elsewhere." While there are certainly gaps in our understanding of life, there is much we do understand, and those do have implications for the existence of life elsewhere.



The same was not true for planetary formation.


I disagree. There ware a variety of ideas about planetary formation, partial models, and so forth, but while it was generally expected there would be exoplanets, there was no solid way to estimate how common they would be (and in fact there were many surprises when we did start detecting exoplanets).


The moment you can put on the table a complete theory of Abiogenesis, then sure, you can start talking about likely...and claim science supports you.


If I were trying to draw any specific conclusions about how common life is, I would agree. But just as we didn't need a complete theory about planetary formation to discuss some implications for exoplanets, we don't need a complete theory of Abiogenesis to discuss some implications for life elsewhere.

Selfsim
2012-May-27, 08:07 AM
The seeming 'plethora of other possibilities' I'm referring to, are life emergence possibilities. Chaotic origins, evolving towards biologically complex adaptive systems, can lead to a different interpretation of 'likelihood', as classical determinism plays a less influential role in Chaos.Chaos,at least in the way its discovery originated and in the way it developed, is a classical deterministic phenomenon. It is precisely because chaos can be deterministic that it is possible to study it with simple nonlinear equations and algorithms on a computer, and it's from such computer simulations that we've learned the bulk of chaos phenomena. I think you assume that "deterministic" and "predictable" is the same... it's not.Paul .. as usual, we seem to be discussing different points (??) ... and I agree with what you say ... its just that this wasn't what I was trying to say.
I was using the term 'classical determinism' in a different sense from mathematical formalism. In the context of my statement above, I was attempting to encapsulate the effect of perturbation on a Complex Adaptive Biological System in nature (as distinct from a computer model making use of deterministic formulae, to study chaos).
A perturbation follows all the available paths of influence which in turn, influences all parts of the complex whole. Describing such an effect when this happens, is close to pure randomness (stochastic) and is non-deterministic in nature.



Whilst Astrophysical studies are recognised as being directly influenced by Chaotic processes, strangely, considerations of the emergence of life from the same chaotic Astrophysical phenomena, seems largely absent in these discussions.
Whatever you mean by "chaotic astrophysical phenomena", that too can be modeled and simulated as classical deterministic processes in a computer. Yep ... and so ? (See my reply above).


'Evidence' comes in many forms, and supports many different domains of science. 'Belief' in this case, about the 'likelihood' of exo-life, relies on indirect inferences drawn from the size of the observable universe, which so far, has presented us with no direct evidence demonstrating direct causal relationships, between the environments it creates, and the emergence of life. By excluding these aspects, it may be reasonably inferred that it takes a universe of the size we observe, in order for one, (or more), life instance(s) to appear. The likelihood of the prevalence of those instances, is as dependent on the amount of visibility we have about how complex natural systems behave and interact, as much as it does on the size of the observable universe .. and those systems, aren't all necessarily predictable, nor are we able to estimate with any degree of reliable precision, the distributions of their outcomes. But in your view of chaos, causality doesn't even have any meaning and therefore any attempt at causal explanation is considered futile from the start. With causality out the way, we could know of a hundred planets with life, and we would still have no basis for inferring the existence of more than just that hundred planets. "We know of extant life on 100 planets only" will be all you could say in such a "chaotic universe".Well, it appears that this very issue is presently up for debate within evolutionary biology circles. The idea of the evolutionary process being 'at cause', seems to be being replaced with more of a view of it 'facilitating enablement'. The same goes for environmental influences on evolution.
This is definitely a key point.
I think we're all pretty well aware that Astronomy, (specifically, Astrophysics), holds causality as a fundamental which, I think, perhaps, is why so many view that life is inevitable (or determinable), from an adequate 'supply' of specific habitable environments (??) This would seem to be at odds with where evolutionary biology is currently headed ..
As mentioned previously, we really should set up another thread to discuss further, (if further discussion is desired).

headrush
2012-May-27, 09:47 AM
I don't understand the issue with Henrik's use of "at least one".
AFAIK "at least" is synonymous with "a minimum of", so regarding the earth in relation to the wider universe, we do in fact know of at least one planet where life exists. We might only know of one life bearing planet, but that still satisfies the meaning of "at least" and " a minimum of".

mutleyeng
2012-May-27, 11:24 AM
[QUOTE=Van Rijn;2021644]Then life on Earth does imply life elsewhere?

why does it have to. Why untill we have more information can it not just be a piece of data.
For me, so far life on earth neither implies there will be life on other worlds or there wont.




I am not attempting to estimate the number of worlds that support life. The argument that I had an issue was, "The existence of life on Earth, does not imply life exists elsewhere." While there are certainly gaps in our understanding of life, there is much we do understand, and those do have implications for the existence of life elsewhere.

To me, the fact that we have life on earth makes the idea of life on other worlds possible. I do not consider i have sufficient information to make a guess at how likely it might be. Although i guess we could get into a quibble about what the word likely means too - i would generally assume it to mean the more likely of the two options.
The part about our understanding of life is where this side issue gets back to the topic of the thread.
My assesment of what we know does not provide me with sufficient confidence to come to a conclussion of likely. You'res possibly does.
We look at the evidence and subjectively assign significance to it.
For me, you are woefully under estimating the significance of the parts we do not know. Sure, people have ideas, but no one can say they understand how life started.
With planetary formation we had known mechanism that would allow for the formation of planets. They dont even have to be right - they just have to show you have mechanics that would work. How common they might be wasnt important.
While you can argue they had gaps in their knowledge of planetary formation too, the reason we dont see eye to eye is the scale and significance of those gaps when it is compared to a theory of life.
My possition is that you can apply probablistic reason and come to a conclusion that it is likley, but you are not in a possition to assert it as a truth with the weight of science behind it.

Paul Wally
2012-May-27, 01:18 PM
A perturbation follows all the available paths of influence which in turn, influences all parts of the complex whole. Describing such an effect when this happens, is close to pure randomness (stochastic) and is non-deterministic in nature.


I don't have a problem with "randomness" as long as you define what exactly the random variables are and what their distribution density functions look like. Vague notions like "pure randomness" seem more like an attempt to argue for unknowability, i.e. "it's purely random, so we cannot know".



I think we're all pretty well aware that Astronomy, (specifically, Astrophysics), holds causality as a fundamental which, I think, perhaps, is why so many view that life is inevitable (or determinable), from an adequate 'supply' of specific habitable environments (??) This would seem to be at odds with where evolutionary biology is currently headed ..

I see a linear time-line view of causality here. The way I see it, life is a natural phenomenon like tornadoes, hurricanes and lightning storms, we cannot predict these phenomena on a linear timeline but we can tell whether the environment is conducive to their occurrence.




As mentioned previously, we really should set up another thread to discuss further, (if further discussion is desired).

Yeah, we should.

pogono
2012-May-27, 01:38 PM
Can anyone explain me why we are so interested in other life in space?

We have a lot of life here, on Earth, and it is commonly known what people do with other forms of life: we eat them.

If we find other forms of non-intelligent life in space, with a high probability (close to certainty) it will end as a dish. Maybe very rare and expensive, but dish.

If we find some much more intelligent form of life, they will probably do the same with us.

The only interesting possibility I see is if we find some life on our intelligence level. Then we will probably also do what we do on Earth (politics, wars, exploring local resources, and so on...). So, I do not see anything interesting in it.

To be honest, I hope we are alone. However, I suppose we are not.

mutleyeng
2012-May-27, 02:10 PM
because other life in the universe is one of those fundamental motivators for the quest of exploring our wider enviroment.
I dont think we would have robots on Mars now if we didnt care about that question.
We have a compulsion to understand how we came to be, and where we fit in the universe.
It is so important because it is about us, and we have a fascination with ourselves

I might add, that while as a species we have our faults, fortunately the sciences are largely occupied by the best of our species, people with benevolent ideals.

Paul Wally
2012-May-27, 02:41 PM
Why until we have more information can it not just be a piece of data.

Even if we had more information we will just have more pieces of data.


For me, so far life on earth neither implies there will be life on other worlds or there wont.
... nor would any amount of evidence imply anything beyond the evidence itself. What is always needed is a theory, because theories imply. But scientific theories
are falsifiable in principle. So if someone (not me) proposes a theory that has the implication that "all planets (and moons) with liquid water should have detectable amounts of microbial life" then that would be a falsifiable scientific theory. But theories are not about belief, because it would be rational to hold multiple conflicting theories in my mind but it's not rational to have contradictory beliefs. My main point, and this is an important point, is that to have a theory and to have a belief is not the same thing. I find that sometimes when I make a theoretical supposition it is misinterpreted as an expression of belief. Then, instead of discussing actual ideas the discussion degenerates into one of what can be said and what cannot be said.

And those who now want to get into the differences between hypotheses, models and theories ... yes I acknowledge there are these finer distinctions between different kinds of theoretical forms but those distinctions are simply not relevant to my main point that the principle of falsifiability applies to scientific theoretical assertions in general. One difference between hypothesis and theory is that theory is well supported by evidence where hypothesis is not, but they are both falsifiable in principle, and that is my main point.

HenrikOlsen
2012-May-27, 03:41 PM
No, it doesn't imply that. "At least one" can be true when "we know of only/exactly one" can be false. There is only an implication in the other direction, "we know of only/exactly one" implies "at least one", not the other way around. Ergo the statements are not equivalent.
The thing is though, that we already know that "we know of only/exactly one" is true, so quibbling about whether there is equivalence when "we know of only/exactly one" is false is meaningless.

We know of one, we haven't inspected everything else to determine that it's unique and the only information that can be determined given those two statements is that there is at least one.

I'll admit that if you ignore the "and we haven't inspected everything else" because it wasn't stated explicitly, then the statements are not equivalent, but that's again self evident enough to not really warranting mention except that this apparently once again degenerated because of some people who think arguing minuta of semantics while ignoring the main subject matter are the way to discuss.
Sorry, not playing with you anymore.

Gillianren
2012-May-27, 06:35 PM
If we find other forms of non-intelligent life in space, with a high probability (close to certainty) it will end as a dish. Maybe very rare and expensive, but dish.

Not necessarily. It might turn out to be completely indigestible to us. Or poison.

As to why we care . . . well, I have to admit that I don't think about it much in my day-to-day life. But as a species, we are fascinated with the unknown and always have been. For now, life or not on other planets is unknown.

caveman1917
2012-May-27, 09:27 PM
I'll admit that if you ignore the "and we haven't inspected everything else" because it wasn't stated explicitly, then the statements are not equivalent

They're not equivalent even if you don't ignore "we haven't inspected everything else" and interpret things in the self evident manner. Logical equivalence requires two sentences to be both true or both false under every interpretation (and yes, "interpretation" is a technical term here).


this apparently once again degenerated because of some people who think arguing minuta of semantics while ignoring the main subject matter are the way to discuss.
Sorry, not playing with you anymore.

That's your decision. But i will note that making a statement as to the logical equivalence of two sentences said in a discussion is making a statement about minuta of semantics, so replying when that statement is challenged that the discussion degenerates because people argue minuta of semantics rather than the main subject matter seems rather weak.

You've made an erroneous statement about logic. It was challenged. That's all there is to it.

glappkaeft
2012-May-27, 10:16 PM
Not necessarily. It might turn out to be completely indigestible to us. Or poison.
Or have a disgusting taste or smell. Of course that might not stop someone to consider it a delicacy, I occasionally eat fermented herring and that certainly tastes foul, but it should decrease the odds at least.

Colin Robinson
2012-May-28, 01:46 AM
Well, it appears that this very issue is presently up for debate within evolutionary biology circles. The idea of the evolutionary process being 'at cause', seems to be being replaced with more of a view of it 'facilitating enablement'. The same goes for environmental influences on evolution.
This is definitely a key point.
I think we're all pretty well aware that Astronomy, (specifically, Astrophysics), holds causality as a fundamental which, I think, perhaps, is why so many view that life is inevitable (or determinable), from an adequate 'supply' of specific habitable environments (??) This would seem to be at odds with where evolutionary biology is currently headed ..
As mentioned previously, we really should set up another thread to discuss further, (if further discussion is desired).

I think there are two very different questions here:

1 What is the probability of some form of life emerging on a habitable planet?
2 What is the probability that evolution on two different planets will result in similar life-forms? (E.g. "humanoids")

On question 2, it may be true that biological thinking is currently heading (or has recently been heading) in a direction that emphasizes chance and contingency. A direction that would lead us not to expect other planets to have beings that look anything like us. Good-bye, Mr Spock.

On question 1, the questions of abiogenesis, I really don't think biology is currently heading in the direction you say. There are some well-known statements about low probability of abiogenesis by biologists several decades ago -- I'm thinking of Monod and Horowitz -- but where is the recent work that points the same way? On the contrary, work by Kauffman and de Duve, and James Trefil all points in the direction of abiogenesis as a process less random than previously thought.

On both these questions, it's important to remember that chance versus determinacy is not necessarily a black and white issue... E.g. as Trefil and his friends argue, the laws of thermodynamics favor the emergence of catalysts that allow banked-up chemical energy to be released, but that doesn't necessarily mean that the emergence of any particular catalyst is predetermined.

Hlafordlaes
2012-May-28, 02:17 AM
How did it go again? Justified true belief depends on:

1. "A" is factually correct
2. I subscribe to "A" being true
3. My reasons for subscribing to "A" are also correct

So, not good enough if I believe the Earth is round (OK, whatever it is exactly) if that belief is based on thinking the Earth is a hollow ping pong ball (slightly misshapen). One has to be right about being right, right?

As for evidence, facts become evidence depending on context. What gets me on this point is that somewhere along the line I need a sort of rationalist hunch to look for the evidence before I become an empiricist and measure it as fact. Whereas I have a great deal of sympathy for the "shut-up and calculate" crowd, how to choose what to calculate?

(It's late on Sunday and I am merely musing in the raw, so I did not wiki and arm myself with pretend knowledge to sound good. It's rather frightening to find how much one forgets.)

Colin Robinson
2012-May-28, 04:23 AM
Can anyone explain me why we are so interested in other life in space?

Perhaps it has to do with questions like: What is life? What sort of place is space? What do life and space have to do with one another?


We have a lot of life here, on Earth, and it is commonly known what people do with other forms of life: we eat them.

If we find other forms of non-intelligent life in space, with a high probability (close to certainty) it will end as a dish. Maybe very rare and expensive, but dish.

If we find some much more intelligent form of life, they will probably do the same with us.

I think it will a long time before we earthlings send spacecraft to Mars or Europa or Titan just for something to eat. Non-intelligent life on another world will be valued more as a source of information than as a source of nutrition... So no, I don't think they'll go into the kitchen. On the other hand, biologists will be keen to get specimens into laboratories, which might be equally bad news for the organisms!

As for a much more intelligent form of life, it's difficult to guess how they might deal with us. The idea that they would see us as a food source was explored long ago by H.G.Wells in War of the Worlds... Whatever they did or didn't do, meeting them would be a blow to human pride. Instead of thinking of ourselves as the smartest things around, we'd have to get used to the idea of being smarter than the apes but not nearly as smart as the aliens. Would such a rethink be a bad thing or a good thing? I'm not sure...


The only interesting possibility I see is if we find some life on our intelligence level. Then we will probably also do what we do on Earth (politics, wars, exploring local resources, and so on...). So, I do not see anything interesting in it.

To be honest, I hope we are alone. However, I suppose we are not.

I think it is unlikely we are alone. Space is too big a place to be alone in. We would rattle.

Selfsim
2012-May-28, 07:03 AM
Folks;

As we are now drifting away from the more generalised topic of 'Evidence and Belief', and heading down the more specific exo-life path, I propose we head back to the Life in Space Forum to discuss further.

I have set up a new thread called: "Is Life Inevitable ?" (http://www.bautforum.com/showthread.php/133485-Is-Life-Inevitable?p=2021964#post2021964)

I suggest we take the life discussions there.

Regards

NEOWatcher
2012-May-29, 03:44 PM
As we are now drifting away from the more generalised topic of 'Evidence and Belief', and heading down the more specific exo-life path, I propose we head back to the Life in Space Forum to discuss further.

I have set up a new thread called: "Is Life Inevitable ?" (http://www.bautforum.com/showthread.php/133485-Is-Life-Inevitable?p=2021964#post2021964)

I suggest we take the life discussions there.

Regards
I will take that suggestion. But; I did want to point out that this "specific path" is a perfect example of where are disconnects are. By; understanding this one specific, it could help with the bigger picture.