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Scientific testing (split from goal of science)


Reg Prescott

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Since you found discourse with Strange and Swansont so distasteful, why did you put so much effort into it thereby claiming you had no time to discourse with others and in particular that you had no interest in extending your knowledge if you could not address the questions others proposed.

You only had to ask.

 

I have learned much from through forum by asking, and, in turn, answered others to the best of my own knowledge.

Edited by studiot
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No mention was made of an observation vs theory distinction.

 

You have been repeatedly told that science is about comparing the predictions of theory against observation (because, as you admit, it is impossible to compare it against truth).

 

I am not going to go back and point out the many times this has been explained to you, only to be ignored or dismissed.

 

You raised the question of how we can tell which of two theories is true, when they both match observations. When it was pointed out that this completely undermines your claim that science is about truth, you quickly changed the subject. Then produced some waffle about it being a matter of personal taste, completely abandoning the idea of science at that point.

 

My position has not changed. Science is about what we can know (observations of the natural world). Truth is unknowable (as you would know if you had studied philosophy as you claim). Therefore, science is not about truth. It is about creating models that match, and predict, what we observe.

 

Your childish argument that this means that all scientific theories are therefore false does not reflect well on you.

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@ Studiot

 

It's a fair question. Ans: Hoping for a modicum of justice, perhaps. Wondering if just one among you might have the decency to overcome your collective affiliations and judge impartially.

Edited by Reg Prescott
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Well, pardon my confusion, but here's my recollection of events:

 

1. The original claims made by Strange were :

 

(i) "Remember, science is not about "truth" but about models that work;" (post # 5)

(ii) "Science has (almost) nothing to do with "truth", whatever that is". (post #10)

 

(and similar claims - see post #66 for a selection)

 

I cried bs. He requested evidence. I produced it. Seeing his position was indefensible, he adjusted his claim (moved the goalposts) to: "Science is not about truth these days". (see posts 52 & 55)

 

No mention was made of an observation vs theory distinction. Would you now like to adjust the claim (move the goalposts) once more to: "Science is not about truth, at least not in the domain of theory, these days"?

 

And you talk about ME moving the goalposts? *bangshead*

That the discussion was in the domain of theory was established in the first few posts, and reconfirmed by you in post #29 (emphasis added)

 

"Instrumentalism is contrasted with realism; the position that scientific theories purport to describe reality; the way things really are out there - truth! Black holes, quarks, species, fields, forces, genes, etc, etc really do exist. It's true!"

 

So, no, the goalposts were not moved. This has always been about theory. You equated "true" with "describing reality" and have been given many examples where this is not the case.

 

Now, even if we do grant this latest embarrassing shuffle of position, I still challenge your claim. It's often said, unless I'm badly mistaken, that the cause of global warming is at least partly human. Causes are not observable. So you'd better not catch yourself telling anyone it's true that we're responsible for global warming. Or that there are good reasons to believe that it's true. Or that we have good reasons to believe that smoking causes cancer. Or... ad infinitum.

 

After all, you guys just deal in models and abstractions. *bangshead again* Ouch!

Another straw man. "Abstractions exist" ≠ "everything is an abstraction"

 

Global warming models use discrete step sizes in time and discrete areas; these have gotten smaller as computing power has gotten better, but that's baked in to them because they are done iteratively on a computer. Does nature *actually* work like that?

 

The statement that "global warming is true" is one that deals with the results and effects, but not the reality of the model.

 

No mention was made of an observation vs theory distinction.

 

Oh for crying out loud. Do I have to go back and document this? My guess is this being mentioned a dozen times, at least.

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No mention was made of an observation vs theory distinction.

This was explained in the very first response to you. These are just from the first page of this thread:

 

In physics we construct models and make predictions that are, or at least can be in principle, tested against nature.

GR matches the observed data. That is what we expect scientific theories to do.

A theory is a mathematical model. The question is not one of right and wrong, but good and bad. A theory is 'good' if it matches nature well and 'bad' otherwise.

GR produces results that are consistent with observation (while Newtonian gravity doesn't.)

By correctly he means that the theory now matches the observations, taking into account experimental errors...

And then the same point has been made repeatedly throughout the thread. Pretending that it is a new revelation doesn't look good.

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Global warming models use discrete step sizes in time and discrete areas; these have gotten smaller as computing power has gotten better, but that's baked in to them because they are done iteratively on a computer. Does nature *actually* work like that?

 

To take this a step further: let's say someone had established that time actually was discrete, at let's say the 10^-40 sec level (for sake of argument). Does that mean scientists will abandon using continuous functions of time for analytic solutions in favor of numerical integrations using the correct time interval? I think the obvious answer is "no". They would not be concerned that their method reflects the reality of discrete time, only that the answer they get is correct, and that it's faster to do it the wrong way. The only motivation to change in this regard is if the results disagreed with experiment as a result of the method chosen.

 

Similarly, the choice to use discrete time steps is not driven by any desire to reflect reality, but by the computing power one has and how well the model gives results that agree with what we observe. How many scientist would say that their choice of models is driven by an underlying desire to represent time as really being discrete or really being continuous? Unless that's the point of the model — to test that particular hypothesis — I doubt any of them would care.

 

There are plenty of instances in science where the theory involves discrete objects, but the math used to describe them are continuous functions. It works because the numbers are large, but that does not reflect reality, and as above, there is no motivation to reflect reality unless the results end up being wrong.

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Throughout the thread several posters have asked the question, "How would we ever know [that out hypothesis/theory is true]?"


"Everyone is trying to tell you that we may never know the 'truth' " - Studiot (post 150)


"If you cannot test "the way things really are" then how does anyone know?" - Klaynos (post 158)


etc., etc.


Given that certainty seems beyond our grasp, more realistic, I think, would be to ask: How can we ever have good reasons for believing that our theories are true? One possible solution to this important conundrum is offered by "Inference To The Best Explanation" (IBE), known to some as abduction.


We haven't adverted to the relevance of explanation at all in the thread, except very briefly at the bottom of my post # 160, however it seems a matter of course that scientists, at least in some cases, infer from the goodness of an explanation to its truth. That is, from a set of two or more competing hypotheses, all of which are consistent with the data or evidence, the scientist infers that the hypothesis among them which best explains the data is likely to be the true one -- just as we all do routinely and mundanely on a day to day basis!


This, of course, is a form of inductive inference, and thus can yield no logical certainty; only some degree of epistemic justification -- good reasons for believing the hypothesis/theory is true -- or so the realist would argue anyway.


It's regrettable that the thread seems to have degenerated into petty squabbling; nonetheless, I offer the following link ("Inference to the Best Explanation" - Peter Lipton), and two excerpts, for any members genuinely interested in these matters:




"The model of Inference to the Best Explanation is designed to give a partial account of many inductive inferences, both in science and in ordinary life. One version of the model was developed under the name `abduction' by Charles Sanders PIERCE early in this century, and the model has been considerably developed and discussed over the last twenty five years. Its governing idea is that explanatory considerations are a guide to inference, that scientists infer from the available evidence to the hypothesis which would, if correct, best explain that evidence. Many inferences are naturally described in this way. Darwin inferred the hypothesis of natural selection because, although it was not entailed by his biological evidence, natural selection would provide the best explanation of that evidence. When an astronomer infers that a star is receding from the earth with a specified velocity, she does this because the recession would be the best explanation of the observed red-shift of the star's characteristic spectrum. When a detective infers that it was Moriarty who committed the crime, he does so because this hypothesis would best explain the fingerprints, blood stains and other forensic evidence. Sherlock Holmes to the contrary, this is not a matter of deduction. The evidence will not entail that Moriarty is to blame, since it always remains possible that someone else was the perpetrator. Nevertheless, Holmes is right to make his inference, since Moriarty's guilt would provide a better explanation of the evidence than would anyone else's."


[...]


"A good illustration of this is provided by Ignaz Semmelweis's nineteenth-century investigation into the causes of childbed fever, an often fatal disease contracted by women who gave birth in the hospital where Semmelweis did his research. Semmelweis considered many possible explanations. Perhaps the fever was caused by `epidemic influences' affecting the districts around the hospital, or perhaps it was caused by some condition in the hospital itself, such as overcrowding, poor diet, or rough treatment. What Semmelweis noticed, however, was that almost all of the women who contracted the fever were in one of the hospital's two maternity wards, and this led him to ask the obvious contrastive question and then to rule out those hypotheses which, though logically compatible with his evidence, did not mark a difference between the wards. It also lead him to infer an explanation that would explain the contrast between the wards, namely that women were inadvertently being infected by medical students who went directly from performing autopsies to obstetrical examinations, but only examined women in the first ward. This hypothesis was confirmed by a further contrastive procedure, when Semmelweis had the medics disinfect their hands before entering the ward: the infection hypothesis was now seen also to explain not just why women in the first rather than in the second ward contracted childbed fever, but also why women in the first ward contracted the fever before but not after the regime of disinfection was introduced. This general pattern of argument, which seeks explanations that not only would account for a given effect, but also for particular contrasts between cases where the effect occurs and cases where it is absent, is very common in science, for example wherever use is made of controlled experiments."

Edited by Reg Prescott
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That is, from a set of two or more competing hypotheses, all of which are consistent with the data or evidence, the scientist infers that the hypothesis among them which best explains the data is likely to be the true one -- just as we all do routinely and mundanely on a day to day basis!

 

This is a subjective judgement and therefore not science.

 

It is also not very helpful because when there are competing theories that cannot be distinguished on the evidence then, not surprisingly, different scientists will favour different theories on the basis of taste, religion or personal preference.

 

How does that help determine which is more likely to be true? Do you go on the basis of popularity? Is testing for truth then just a beauty contest?

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SillyBilly

 

Given that certainty seems beyond our grasp, more realistic

 

Studiot

Everyone is trying to tell you that we may never know the 'truth'

 

 

You respond little enough to my posts as it so so please don't mistake what I said or draw false conclusions from it.

 

I said, "...may never know the truth.... "

No conclusion as to certainty can be drawn from such phraseology.

 

On occasion, we may also know the truth in hindsight.

 

Non bayesian statistics is about this as is some of the other aspects of scientific testing I offered and you have refused to discuss.

Edited by studiot
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On occasion, we may also know the truth in hindsight.

 

Can you explain what you mean, please?

Non bayesian statistics is about this as is some of the other aspects of scientific testing I offered and you have refused to discuss.

 

It's not so much refusal to discuss than inability to discuss that of which I know nothing.

 

I've read a little on Bayesian confirmation with respect to scientific methodology, but I'm not quite sure what "Non bayesian statistics" refers to in this context. I'm all ears if you'd care to explain. Thanks.

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Can you explain what you mean, please?

 

studiot, on 07 Oct 2015 - 09:34 AM, said:snapback.png

Non bayesian statistics is about this as is some of the other aspects of scientific testing I offered and you have refused to discuss.

 

It's not so much refusal to discuss than inability to discuss that of which I know nothing.

 

I've read a little on Bayesian confirmation with respect to scientific methodology, but I'm not quite sure what "Non bayesian statistics" refers to in this context. I'm all ears if you'd care to explain. Thanks.

 

 

Hindsight:

 

The probability of RedRum winning the 2015 Derby is precisely and exactly zero.

 

That is a mathematical statement, also applicable in that other silly thread curently running about applying mathematics to reality, of non bayesian statistics.

 

It uses after the event knowledge (hindsight) to make a statistical statement.

 

I could make another mathematical statement in simialr vein.

 

The probability of Dettori winning the 2015 Derby is precisely and exactly 1.

 

I have chosen examples as simple as I can make them, a good technique when testing a theory or methodology.

This line of thinking has enormous implications in the field of testing and can be developed much further.

 

Oh and +1 for a sensible response at last.

Edited by studiot
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@ Studiot - Thanks for explaining.

 

Now, would you mind answering for me what you make of a claim such as "science has nothing (or almost nothing) to do with truth", please?

 

It seems certain other members -- invested with an authority known only to themselves -- are quite content to blithely stipulate, in no uncertain terms, that all scientists, in all disciplines, in all times, and in all places are quite unconcerned with getting the world right; i.e., in producing theories that are true or approximately so.

 

It's a claim I took to be preposterous in the extreme when I first heard it, and I still do so (and I get accused of insensibility. Sigh!).

 

What's your position on this?

Edited by Reg Prescott
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It seems certain other members -- invested with an authority known only to themselves -- are quite content to blithely stipulate, in no uncertain terms, that all scientists, in all disciplines, in all times, and in all places are quite unconcerned with getting the world right; i.e., in producing theories that are true or approximately so.

 

Please back up the bolded part with actual quotes. That anyone has made this an absolute, rather than rebutting the other case, that it's the primary driver.

 

All this straw is giving me an allergic reaction.

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It seems certain other members -- invested with an authority known only to themselves -- are quite content to blithely stipulate, in no uncertain terms, that all scientists, in all disciplines, in all times, and in all places are quite unconcerned with getting the world right; i.e., in producing theories that are true or approximately so.

 

As far as I can tell, no one other than you has said that. I think that is a classic example of a strawman argument.

 

Edit: cross-posted!

 

 

It's a claim I took to be preposterous in the extreme when I first heard it, and I still do so

 

You will be pleased to know that I also find it as preposterous now as I did when you first came up with it.

Edited by Strange
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@ Studiot - Thanks for explaining.

 

Now, would you mind answering for me what you make of a claim such as "science has nothing (or almost nothing) to do with truth", please?

 

It seems certain other members -- invested with an authority known only to themselves -- are quite content to blithely stipulate, in no uncertain terms, that all scientists, in all disciplines, in all times, and in all places are quite unconcerned with getting the world right; i.e., in producing theories that are true or approximately so.

 

It's a claim I took to be preposterous in the extreme when I first heard it, and I still do so (and I get accused of insensibility. Sigh!).

 

What's your position on this?

 

You are almost doing it again.

 

That is extrapolating from the qualified to the definite.

 

It would be helpful if you could include the post number in references to older posts, I cannot remember who said those exact words.

Then the context can be checked.

 

Without this, I would make of it that the originator qualified his or her statement.

 

This actually ties in with the discussion I have been trying to promote, about statistics in relation to scientific testing.

 

The instances where science can actually state the unequivocal truth are few and far between, and most of these are in hindsight as in my examples.

Of course much of science takes place in the present or future and we can find even less certainty there.

 

It is not impossible to make a certain mathematical statement about the future, for example

 

The probability of RedRum winning the 2016 Derby is precisely and exactly zero.

 

I can be certain about this because RedRum died a few years ago.

 

But I cannot correctly make any certain statement about the other horse.

 

Moving on to wider applications, suppose I wish to build a house.

 

So I test the bearing capacity of the soil.

Obviously I perform scientific testing to be of any use.

But the result that I measure will not be the certain 'truth'.

I will never know the exact bearing capacity, and my figure will be reported as a range, say between 75 and 150 kN/m2

My report may even include a statistical probability that the 'true value' lies between these limits.

 

Much, if not most, scientific testing is of this nature.

Edited by studiot
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Can you explain what you mean, please?

 

Another example, related to one of your first examples, is the existence of Neptune. This was purely hypothetical (i.e. a model) as an explanation for the perturbations in the orbit of Uranus. There could have been alternative models to explain the data.

 

Now, with hindsight, we know that Neptune exists and is the cause of the observations.

 

(I am assuming that we can agree that Neptune does exist. And we are not going to get into a debate about how we can really ever know anything, the unfalsifiability of solipsism, the nature of knowledge, etc.)

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It would be helpful if you could include the post number in references to older posts, I cannot remember who said those exact words.

Then the context can be checked.

 

Without this, I would make of it that the originator qualified his or her statement.

 

As requested:

 

(i) "Remember, science is not about "truth" but about models that work;" (Strange, post # 5)
(ii) "Science has (almost) nothing to do with "truth", whatever that is. For that you want religion." (Strange, post # 10)
Now, let me pose my question to you again:

Now, would you mind answering for me what you make of a claim such as "science has nothing (or almost nothing) to do with truth", please?

 

It seems certain other members -- invested with an authority known only to themselves -- are quite content to blithely stipulate, in no uncertain terms, that all scientists, in all disciplines, in all times, and in all places are quite unconcerned with getting the world right; i.e., in producing theories that are true or approximately so.

 

It's a claim I took to be preposterous in the extreme when I first heard it, and I still do so (and I get accused of insensibility. Sigh!).

 

What's your position on this?

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Thank you for completing the references, I can now re read them fully.

 

Now, let me pose my question to you again:

 

So did you miss the rest of my post or have you set yourself to silent mode again?
If you can't be bothered to answer my comments, how do you expect me to reciprocate?
Edited by studiot
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To the entire site:

 

Don't you see what's happening here? One of "your own" advanced a preposterous claim (about science having nothing to do with truth); a claim that is manifestly false. I suspect he made the claim in the first place due to some trepidation over the implications of what I take to be to the perfectly innocuous word truth and its cognates.

 

The claim has been thoroughly refuted. Quite obviously, at the very least, some scientists, in some disciplines, in some times and places, feel otherwise. They feel science has a great deal to do with truth. Even if they can't always attain it, or even if they can't know they've attained it, they aim for it; they attempt to afford us with good reasons for believing that our best theories are true, or approximately so.

 

I suspect the poster in question (Strange) and his sidekick (Swansont) already see their position is hopeless; alas too much condescension and too many insults have passed under the bridge for them to ever back down, thus the best they can do is squawk "strawman!" "strawman!" ad nauseum. Their calling it one doesn't make it one, though.

 

Anyway, no big surprise so far. What does concern me is this kind of misguided insular loyalty that has prevented any other member from stepping forward and calling bs bs -- the same kind of insular loyalty that induces the Catholic bureaucracy to shield "their own" against wrongdoing.

 

And you wonder why some among us worry about the not-entirely benevolent force of scientism?

Edited by Reg Prescott
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thus the best they can do is squawk "strawman!" "strawman!" ad nauseum. Their calling it one doesn't make it one, though.

 

No, what makes it a strawman is that it misrepresents the position that people were making, in favor of a position that is easily refuted. You were asked to back up your claim, and you have not done so. That's the only way to show that it's not a strawman and refute the claim. Why are you unwilling to do this?

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The only thing I can define is true are my own actions. To lift a finger I must lift a finger. That is a true statement. However I cannot say whether the finger was actually lifted in a 3 or 4 or however many dimensional reality because I can only say what I am observing. Who knows, the reality we perceive could be a projection of a 2 dimensional reality!

 

Physics is indeed describing how things behave and not what they are; as Swanson stated in post 40! Its just like with my own actions, I can judge the truth of an idea, of a statement or equation, but to judge the truth of reality is something that is simply not within the human realm of perception and perhaps not within anythings realm of perception. That's why when we attribute something to reality it is called a theory. Because we simply cannot prove without a doubt that it is true. Besides the fact that in a practical sense it does not really make a difference.

 

You ask the same question over and over SB, what is science after? It is after a better understanding of how things in nature behave. You are stubbornly sticking to a belief that science should, or is, proving reality (your form of truth). Its like a weird scientific religion.

 

I am not a physicist, just a philosopher that enjoys reading far too much, and I have found this discussion to be interesting. However, this argument seems to be in a circulatory pattern. Claim A - Explanation x - Accusation - Explanation y - Claim A....rinse and repeat.

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To the entire site:

 

Don't you see what's happening here? One of "your own" advanced a preposterous claim (about science having nothing to do with truth); a claim that is manifestly false. I suspect he made the claim in the first place due to some trepidation over the implications of what I take to be to the perfectly innocuous word truth and its cognates.

 

The claim has been thoroughly refuted. Quite obviously, at the very least, some scientists, in some disciplines, in some times and places, feel otherwise. They feel science has a great deal to do with truth. Even if they can't always attain it, or even if they can't know they've attained it, they aim for it; they attempt to afford us with good reasons for believing that our best theories are true, or approximately so.

 

I suspect the poster in question (Strange) and his sidekick (Swansont) already see their position is hopeless; alas too much condescension and too many insults have passed under the bridge for them to ever back down, thus the best they can do is squawk "strawman!" "strawman!" ad nauseum. Their calling it one doesn't make it one, though.

 

Anyway, no big surprise so far. What does concern me is this kind of misguided insular loyalty that has prevented any other member from stepping forward and calling bs bs -- the same kind of insular loyalty that induces the Catholic bureaucracy to shield "their own" against wrongdoing.

 

And you wonder why some among us worry about the not-entirely benevolent force of scientism?

I'm only quoting your last post here as I'm late coming in and only intend to let you know I'm with you on most of this. You asked for supports. I'm here. But I need time to catch up on all that's been discussed so far. 10 pages!

 

I agree that there is a lot of problems with how many scientists today take conflicting value on what "truth" is. Today's professionals through institutions lack the traditional bottom-up approach that required philosophical dialectic to come first. A PhD is the only sincere degree today that allows them to speak [think] freely. For the undergraduates spend more emphasis on rote learning and clerical training in order to pump out productive people for the work force. So they reverse the traditional order of learning and often lack a good logical background. Instead, everything is about practice. Ironically, although clothed in education, i compare this to how an experienced mechanic of the past might disparage university degrees 'wit all dem theris an stuff' as stupid thinking because they lack the significance of experience. Nowadays, most (not all) scientists are technical laborers who actually work for the deeper thinkers and have developed a similar attitude to the mechanic dismissing the traditional theoreticians who DID originally have to focus on self-reflective thinking up front.

 

I'll be back when I'm caught up. Good effort so far that I read of you though.

 

Scott.

Edited by Scott Mayers
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It's nice to hear some input from outwith the cabal of usual suspects, so thanks to both Cuba and Scott.

 

Physics is indeed describing how things behave and not what they are; as Swanson stated in post 40!

 

Well, the first problem here, as I see it, Cuba, is that it seems you have undertaken -- as certain other members have done -- to speak on behalf of the entire physics community. What gives you that right? Who's to say there are not physicists out there who do feel physics, perhaps even if only in certain areas, is attempting to describe reality? (i.e. is attempting to produce theories that are true or approximately so.)

 

For anyone interested, I've just started what looks like a marvelous book entitled "Quantum Theory and the Flight From Realism" by Christopher Norris. The introduction sketches how Einstein and his acolytes did precisely that -- defended a realist interpretation -- only to succumb to the growing tide of antirealist sentiment (led by Bohr et al) which now constitutes the current orthodoxy, I believe. Perhaps I'll quote some later. Let us bear in mind, though, that this controversy pertains to the domain of QM. Do physicists working in other areas believe their research has no bearing on the way things really are? For example, does Hawking think black holes are merely a useful fiction devoid of any bona fide ontological standing? Ans : I dunno. Do you?

 

The second problem, Cuba, is that physics does not equate with science. Let's all stop being so physics-centric, please. The claims I've been refuting amount to (more or less) :

 

"Science has nothing to do with truth" (note: science, not physics)

 

Even if we grant (which I don't) that antirealism prevails almost without exception in physics, this still leaves... well, everything else! I refuse to believe that all chemists regard theories of atoms and molecules as nothing more than instruments to aid with calculations; I refuse to believe that biologists regard the germ theory of disease as merely a useful fiction; likewise for geologists and tectonic plates, paleontologists and fossils, evolutionists and natural selection; cosmologists and white dwarves, psychologists and thoughts, etc., etc., ad infinitum.

 

The claim that science has (almost) nothing to do with truth was, and remains, preposterous in the extreme.

Edited by Reg Prescott
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