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Scientific testing (split from goal of science)


Reg Prescott

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Harumph

 

How about this then...

 

Assuming that the dinosaurs-succumbing-to-a-meteor-strike theory is, er, accurate, do you believe there a correct answer to the question "There is a certain number of days since that meteor struck the Earth?"

 

Oh, and let's stipulate GMT to keep the pedants happy.

 

And if there's no such thing as truth, why did my science teachers at school keep telling me all my answers were wrong? :mad:

 

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P.S. from dictionary.com's entry for "accurate" :

 

SynonymsExpand
1. true, unerring. See correct.
Edited by Reg Prescott
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If you accept the premise a meteor hit the Earth, how could it be a variable number of days ago, GMT or otherwise?

 

Exactly

 

Well, I was worried some smartass might drop in and tell us about the Earth's slowing rotation, or....

 

 

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Hey, you know what. It just struck me. I think you guys are afraid to use words like true and truth coz you feel it'll put you on a par with the religious wackos.

 

I don't think it will.

Edited by Reg Prescott
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I'm no scientist, but Truth may have two flavors. One is spritual, absolute and universal. The other truth is defined and situational which makes it seem less nebulous and more useful to me.
Is situational a word? been a long week.

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Getting back to swansont's wonderful hole...

 

Lets use a simple example. Is a hole real? i.e. is it a physical entity? Or is it just a convenient description about a lack of solid material. You can't hand me a hole, all by itself.

 

If I have a description involving a hole: "I dug a hole in the ground" (and I indeed moved some dirt as one does while digging), is that a true statement? Does it remain true even if one thinks that holes are an abstraction? It seems to me that this implies two different meanings for "true" and the problem here is that you keep hopping back and forth between them, whenever it's convenient for you.

 

The first reason your question gripped my attention is because it immediately reminded of a similar issue in the philosophy of mind, namely (and this might sound silly but it's not) : Is the mind (entirely) inside the head or not?
Consider the case of your leaving a footprint in the sand on a beach. Then, somewhere and sometime else, freak weather conditions result in a perfect replica of your footprint being created. The question is : Is this a footprint? Or is what makes a footprint a footprint dependent upon its causal history?
But that's a story for another camping adventure...
My second thought takes us to the terrifying precincts of the philosophy of language and the problem of non-referring terms. For example, a statement such as "Pegasus is white" is perfectly intelligible, and apparently quite meaningful, but the term Pegasus (presumably) refers to nothing, or to be more correct before the pedants have a fit, it doesn't refer.
Just like your hole. Or it it? Is the shadow on the wall a referring term? Or the footprint in the sand? Beats me, chaps.
Anyone unfortunate enough to be tied down and subjected to a course in the philosophy of language may have to listen to an initial six lectures on the dreaded statement "The present king of France is bald". All agree, I think, that "the present king of France" does not refer, but not all agree on the truth value that should be assigned to the statement: Russell says false; Strawson says neither true nor false; and the bloodbath continues...
But I don't think anyone has ever suggested that this implies "two different meanings for 'true' ".
These are my only -- not very carefully considered and probably a load of bollocks-- thoughts so far...
Edited by Reg Prescott
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Er, are you truly cool with that, dude?

 

I'm not knocking it; just wondering if you're willing to accept the ...um, potentially unpalatable implications of your own unorthodox definition.

Now you have lost me... what implications other than we can accept that more that one theory can describe some given observed phenomena. We see this quite a lot with phenomenological models. I offer Ginzburg–Landau theory and BCS theory of superconductivity as examples.

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But I don't think anyone has ever suggested that this implies "two different meanings for 'true' ".

 

 

I did. And I can't help but notice that you punted on answering the question about the reality of the hole.

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We can all agree that both theories are empirically adequate to the same degree (i.e. they both work equally well), but how many of you would be willing to bite the bullet and concede that both theories are true? (in the normal sense of true - i.e. corresponds with what is the case in reality)

They would be considered 'true' is the 'empirically adequate' sense you describe, which is what most of us think is really the best you can hope for. I don't think your definition of 'true' as in 'corresponds with reality' is great. What is reality and what is this correspondence?

 

 

And who among you would prefer to say "We have two theories that are empirically indistinguishable but logically incompatible. One may be true and the other false. Or both may be false. But as a matter of pure logic, both cannot possibly be true."

Which suggests we have to be more careful with the word 'true' in this context.

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Now you have lost me... what implications other than we can accept that more that one theory can describe some given observed phenomena. We see this quite a lot with phenomenological models. I offer Ginzburg–Landau theory and BCS theory of superconductivity as examples.

 

Well, let's make an analogy (and the historical accuracy isn't important). How many of you hoodlums are old enough to remember Uri Geller of spoon-bending fame - loved my many and despised by the skeptics. James Randi, for one, decided that even if he could not catch that scoundrel red-handed, he would at least show the world that any magician worth his sodium-chloride could replicate what Geller was doing. And he did.

 

Now, let's say we invite 100 talented magicians to replicate the Geller magic. And they do, each in a different way.

 

But surely only one or none of them can be doing it in the same way Geller did.

 

Capiche, paisan?

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But what we can all agree on, I presume, is that whatever we take our theories to be, we hope that they will generate true observational consequences or predictions. A perfect theory would generate only true predictions, given the proper background assumptions.[/size]

The theories should allow us to make predictions that can then be tested against nature. Taking into account experimental errors, the statistical nature of analysing the data, the domain of validity of the theory, any approximations needed to make the calculations and so on, the numerical predictions should be consistent with nature. Most of us think that this is really the best one can hope for.

 

Maybe we are wrong, but right now it hardly matters and differing philosophies have little impact on science day to day. Only the core idea of the scientific method matters.

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They would be considered 'true' is the 'empirically adequate' sense you describe, which is what most of us think is really the best you can hope for. I don't think your definition of 'true' as in 'corresponds with reality' is great. What is reality and what is this correspondence?

 

Everyone seems to be harboring Californian transcendental yoghurt-and-sesame-seed concepts of reality.

 

Reality is just what's out there. It needn't be anything very sublime or Kantian.

 

The statement "Paris is the capital of France" is true if and only if, in reality, Paris is the capital of France. Hands up who's been there? Welcome to reality.

 

The hypothesis "Pigs like to wallow in mud" is assigned a truth value of T if and only if... well, you get it :)

Maybe we are wrong, but right now it hardly matters and differing philosophies have little impact on science day to day. Only the core idea of the scientific method matters.

 

I believe it was Richard Feynman who observed "Philosophy of science is about as useful to scientists as ornithology is to birds"

 

You guys can be so cruel :mad:

Edited by Reg Prescott
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But surely only one or none of them can be doing it in the same way Geller did.

It is a nice analogy, but only an analogy. You have assumed that we can really know how Geller did it. This would equate to some deeper knowledge of nature beyond science in your analogy. All these other magicians model what Geller did equally as well, they all matched the observed effects of Geller. They are all 'equally as good theories'.

 

Now of course, some of the methods used by the magicians maybe easier than others. These 'theories' maybe conceptionally easier or not, but for sure easier to work with. The magic community needs to think hard about this. Maybe a 'theory' that is easier to implement, but conceptionally difficult is 'better' than a conceptionally easy one that is hard to implement. And of course, if you just want to bend spoons then the 'phenomenological model' of using a vice works quite well!

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It is a nice analogy, but only an analogy. You have assumed that we can really know how Geller did it. This would equate to some deeper knowledge of nature beyond science in your analogy. All these other magicians model what Geller did equally as well, they all matched the observed effects of Geller. They are all 'equally as good theories'.

 

We don't need to know how he did it to know that he did it in only one way (at least on each occasion), right?

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Reality is just what's out there. It needn't be anything very sublime or Kantian.

You mean what we can observe and measure?

 

If so, then to understand any of this we need models.

 

The statement "Paris is the capital of France" is true if and only if, in reality, Paris is the capital of France. Hands up who's been there? Welcome to reality.

The problem is that the notion of France and a capital city are human constructions.

 

But this is okay. All our physical models are based on human constructions. The point of science, over say philosophy, is to match these ideas with what we observe. You cannot really separate theory from experiment cleanly as an experiment needs theory to be designed and uses theory in the analysis of the data. Again, models seem to be really tied with how we view the Universe.

 

 

I believe it was Richard Feynman who observed "Philosophy of science is about as useful to scientists as ornithology is to birds"

Maybe a little harsh, but I am not sure how far off the mark he was. Day to day the basic philosophy of science and indeed mathematics does not direct people working in science and mathematics. Unless you really are interested in 'foundational and philosophical' issues, we keep hold of the scientific method in one form or another and just do our jobs. That is not to say that modern philosophy cannot help guide some of the overall ethos of science and mathematics, but it seems inessential day to day.

We don't need to know how he did it to know that he did it in only one way (at least on each occasion), right?

Still, you are assuming some knowledge beyond 'science'. Maybe Geller's method is not replicated by your group. Maybe it is, but how could you decide? Remember, this is just an analogy and drawing too much from it is dangerous.

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Well, let's make an analogy (and the historical accuracy isn't important). How many of you hoodlums are old enough to remember Uri Geller of spoon-bending fame - loved my many and despised by the skeptics. James Randi, for one, decided that even if he could not catch that scoundrel red-handed, he would at least show the world that any magician worth his sodium-chloride could replicate what Geller was doing. And he did.

 

Now, let's say we invite 100 talented magicians to replicate the Geller magic. And they do, each in a different way.

 

But surely only one or none of them can be doing it in the same way Geller did.

 

Capiche, paisan?

 

That sounds like the point several of us have been making. You can only check the end result — you can't test to see if the mechanism reflects reality.

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That sounds like the point several of us have been making. You can only check the end result — you can't test to see if the mechanism reflects reality.

 

But with all due respect, that wasn't the point. The point was: surely there can only BE one mechanism used by Mother Geller Nature?

 

Not whether we can know what it is.

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But with all due respect, that wasn't the point. The point was: surely there can only BE one mechanism used by Mother Geller Nature?

 

Not whether we can know what it is.

To us, the word mechanism is tied to theory. So, I would say that nature using mechanisms is a subtle point and assumes that nature is inherently mathematical.

 

Loosley, people may say '...nature uses this mechanism' or something like that. What they really mean is that the theory matches the observations well and that this mechanism has given us some further knowledge on how to describe nature.

 

So if someone says 'nature exploits the mechanism of natural selection' (etc) then really they mean something like the above. If they say 'evolution is true', then they mean that the theory of evolution is quite consistent with what we observe.

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To us, the word mechanism is tied to theory. So, I would say that nature using mechanisms is a subtle point and assumes that nature is inherently mathematical.

 

Loosley, people may say '...nature uses this mechanism' or something like that. What they really mean is that the theory matches the observations well and that this mechanism has given us some further knowledge on how to describe nature.

 

So if someone says 'nature exploits the mechanism of natural selection' (etc) then really they mean something like the above. If they say 'evolution is true', then they mean that the theory of evolution is quite consistent with what we observe.

 

 

Erm, what about like effects having like causes? Isn't that a principle you guys endorse?

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Ooh, I almost let this one slip through... :unsure:

 

Maybe we are wrong, but right now it hardly matters and differing philosophies have little impact on science day to day. Only the core idea of the scientific method matters.

 

And "The Scientific Method" is not a philosophy?

 

Do you know how many people have written on The Scientific Method? Do you know how much they share in common? Ans : very little

Edited by Reg Prescott
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Ooh, I almost let this one slip through... :unsure:

 

 

And "The Scientific Method" is not a philosophy?

 

Do you know how many people have written on The Scientific Method? Do you know how much they share in common? Ans : very little

Of course it is a philosophy and I said that the overall philosophy of the scientific method is what matters. Other differing ideas about realism etc hardly matter in science.

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P.P.S. @ - "Oh , I forgot, You don't reply to my questions since they are too difficult." -Studiot

 

Yeah, ask some easier questions, dammit :angry:

 

 

You claim you want to discuss the subject of scientific testing, but respond in a completely flippant manner when asked for specifics.

 

We still don't have a working definition of the phrase to discuss. yet you claim to be philosopher of sorts.

 

The phrase (yours not mine) contains two words.

 

'Testing' which is the gerund and is therefore the defining noun.

And 'scientific' which is a qualifying adjective, distinguishing the testing from non-scientific types of testing.

 

I asked several questions in an attempt to clarify this and you have avoided them all, either but just not answering or by saying "I don't know".

Yet despite the list of things you "don't know" about scientific test you are prepared to pontificate at length on the subject.

So is this a case of 'Don't confuse me with the facts I have already made my mind up' ?

 

You have also diverted the discussion away from the topic into a pointless discussion about what is truth and accuracy. completely missing the very good points that moth ( +1 ) has put to you.

 

One of the questions I asked, and you avoided, was about truth. I asked about the use of statistics in scientifc testing.

 

This is because in many if not most instances of testing in a scientific manner we do not know the truth and indeed can never know it.

 

This was what lead Laplace to rediscover the Bayesian theorems in 1770 and develop them further to improve the 'truth' of our knowledge of the actual motions of the bodies in the solar system.

Today we have improved that 'truth' still further using through the continuous application of scientific testing.

 

Since you don't like my difficult questions, Let me ask you an easy question.

 

You have a high fever and obvious infection.

 

Would you prefer the medics to medics to conduct a scientifc test or a non-scientific test on your samples to determine suitable treatment?

Edited by studiot
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Now, here's the problem: if, as you claim (incorrectly, if I may be so impertinent), that you regard your theories as nothing more than models, or calculating devices, or instruments, then the term "truth" is misapplied.

 

That is why I have always put the word "truth" in quotes when using it with regard to science. To highlight that if people (usually outside of science) use the word they do not mean truth in your sense. Remember I started out by saying that science does not deal with truth (in your sense of the word)? Perhaps you can now understand what that means>

 

It struck me later that the concept you've been calling "scientific truth" is that which certain philosophers of science refer to as "empirical adequacy". (note: adequacy is quite a different beast from truth; "adequate" is more akin to good enough).

 

I am not familiar with the terms, but it sounds like a plausible description. (Note that I only called it "scientific truth" because you kept banging on about truth even when told it was irrelevant.)

Now, your question for today, boys and girls, is : imagine a case where you have two theories which postulate completely different entities and mechanisms, yet both are perfectly consistent with all available evidence; nay, let's go further and suppose they're consistent with all possible evidence. No observation or experiment can ever tell between them.

 

We can all agree that both theories are empirically adequate to the same degree (i.e. they both work equally well), but how many of you would be willing to bite the bullet and concede that both theories are true? (in the normal sense of true - i.e. corresponds with what is the case in reality)

 

You were given examples of this before you asked the question the first time. You have been given examples after asking the question previously. Now you have asked the same question again. Are you hoping that if you ask it often enough you will get the answer you want? Or are you just trolling?

 

I imagine most scientists (if they think about it all) would conclude that neither theory is true. As we have many examples where this situation holds, most people have come to the conclusion that science doesn't, in general, deal in truth but only in descriptive models. But as you cannot accept this, I assume this thread will just keep going round in circles.

"More accurate" as in...um, closer to the target?

 

What target?

 

Dare I say.... the right answer? ... the true value?

 

No. The observed value. Which is, of course, only an approximation to the "true value" (if such an ideal thing exists).

Edited by Strange
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SillyBilly, on 03 Oct 2015 - 02:43 AM, said:snapback.png

 

"More accurate" as in...um, closer to the target?

 

What target?

 

Dare I say.... the right answer? ... the true value?

 

 

Strange

 

No. The observed value. Which is, of course, only an approximation to the "true value" (if such an ideal thing exists).

 

 

+1

 

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

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