Ok, that makes sense, but I still think his statements highlighted by Jim are consistent.

Jim's point seems to be that Soupdragon2 says that he works within the Popperian context in this thread, but clearly he does not, at least as far as the definition of "scientific theory" is concerned. It's only in the definition of falsifiable that we are limited to the Popperian context.

I've accepted that, and said so before, though.

This is part and parcel of "doing" philsophy.

No, Jim wants me to define what I mean by scientific theory.

However, I have pointed out that I am working within Popper's definition, where the terms falsifiable, testable, and scientific are synonymous. Outside this context, suffice to say that the definition can be much broader, but that is of little relevance to this thread.

Well, science is a philosophical activity, but for the purpose of this thread we are working within Popper's philosophy.

You seem to have accepted that DM is not falsifiable, but now claim that this fact is of trivial significance. I still maintain that Falsifiability is important because it raises red flags, and thus exposes much of the folly behind DM.

In other words I think that Fal is a useful tool, and you claim that it isn't. These are value judgements.

No one has directly countered my arguments that DM is not falsifiable. Trying to undermine the roll of philosophy in science is, again, a side issue. As I stated in my original LP, science and philosophy are inextricably entwined in respect of Fal, however hard you might try to take the philosophy out of science.

Hence the part covered by that ellipsis: "but clearly he does not, at least as far as the definition of "scientific theory" is concerned."
You've used much broader definitions within this thread. That's his point, those are the contradictions.
I know what the purpose of the thread is--it's to allow you to explain your statement. That ain't happening.
Not in the fashion that you have managed it. You've avoided the definition of "scientific theory" and expanded your version of "Dark Matter" to something that does not even require falsifiability--you even say that it is not so much a theory, as an infinite supply of theories--so it exposes nothing. At least, it exposes nothing about Dark Matter, or its implications.
I claim that it isn't? Where have I claimed that??
O yes we have.
I would never try to take philosophy out of science. It is too important to me. Just as I would like to eradicate weak science, I'd like to do the same to weak philosophy.

Are you sure about this? Look here.

You're still playing word games, rather than facing the facts.

I have raised strong arguments supporting my contention that DM is not falsifiable. Everytime we focus on these, you allege contradictions somewhere earlier in the thread.

Well, how about this.

I have never inferred that DM does not require falsifiability. This is illogical. I have claimed that it is not falsifiable.

dgruss23 elucidated my argument by pointing out that individual candidates might be falsified, but that there seems to be an infinite number of candidates waiting in the wings. In other words we have a mindset in operation. Candidates can be conceived ad infinitum in order to justify the concept.

On this basis DM is too general to be considered falsifiable.

It exposes the fact that DM is not falsifiable. The purpose of this thread, no less!

I'm sure. (What was it I was to look for?)
You mean, trying to pin down the definitions? That's not a word game. It's an attempt to avoid the word games--when you use a term in one fashion, and then draw conclusions by using it in another.

So, in that context, if Dark Matter is not falsifiable, it is not even a scientific theory. Your answer to that has been that you're willing to consider an expanded definition of scientific theory--hence, the contradictions. You can't have it both ways.

It is tempting to "do science" just by philosophizing. Very tempting. The successful attempts have been spectacular--but ultimately, they did not stand on their philosophy alone. The science part had to be done. Similarly, you're not going to be able to dismiss Dark Matter based only on a philosophical gedanken.

Just because your view of Dark Matter presents with an apparently infinite supply of possibilities (I'm not convinced), that is not a "serious blow" to any theory--science, at least in the Popperian sense, always has to present an infinite supply of possibilities. If it stops, then it's no longer a "scientific theory."

I don't want it both ways. I accept that DM might be considered scientific outside the Popperian context, but for the purpose of this thread I have worked within it. For Popper, of course, a theory is only scientific if it is falsifiable, and in this context -- and only in this context -- the terms testable, falsifiable, and scientific are synonymous.

We get to page 25 and you now describe Falsifiability as a 'philsophical gedanken'. Let's face it, you are on the back foot, and flailing desperately.

Where has Popper made any such claim? Please provide a reference. As far as I am aware, Popper claimed that science proceeds by conjecture and refutation. This chain maybe infinite, but that is quite a different thing from providing infinite theories to justify one particular concept. This would preclude refutation!

DM is not falsifiable because it is too general, as outlined in previous posts. Side stepping the real issues won't make them go away.

Read it again. I didn't describe Falsifiability that way--I described your arguments so far that way. That's why we're on page 25. We should have been able to wrap this up on page two.
That's all I'm saying
That's your version of Dark Matter--the version that doesn't present testable hypotheses. The one that is not even a scientific theory (which by the way, does not have to be falsifiable, even under Popper, since it is not a scientific theory).

The real issues are not philosophical.

You are blowing more hot air, Milli360. Try constructing some logical and consistent arguments for a change.

You have said no such thing. What you actually said contradicted this, as I pointed out in my previous post.

Here was my post in full for context (Blue added back in).
Stop playing games. This is sophistry. It has been acknowledged that individual candidates might be falsified, but pointed out that an indefinite supply of candidates precludes refutation. DM is therefore not falsifiable.

Do you intend to argue against this, or continually resort to sophistry?

I try.
No, it doesn't. It's what I said. You are the one focussing on "one particular concept."
As I said, and you quote there, "that is not even a scientific theory" so it is not falsifiable. Nor does it need to be. Other people use much narrower versions of the idea than you do--ones that are testable.
Sophistry -- "A plausible but misleading or fallacious argument." All you have to do it refute the fallacious argument. It's not enough to keep repeating the charge.

Thank you. You concede that DM is not falsifiable. At last we agree. A number of people have claimed that DM is falsifiable, but I have argued against this throughout the thread.

Regarding my red highlight, above, it is too late (on page 25) to claim that DM does not need to be falsifiable. This is ludicrous. I rest my case.

It seems we finally have closure. 8)

I am happy to look at other theories now if anyone is still interested...

Ok, now I've been trying to put my "fingers" on a way to explain the following for a while now and an idea just hit me, so here goes.

One of the problems with any scientific theory or model is that it is a simplified abstraction of the more complex real world. I think Popper's falsification ideas suffer the same difficulty. Here I touched upon part of the reason - personal subjectivity in what is compelling evidence.

But there is more to it. Take the Big Bang. Is it falsifiable? If it is, then what observations would falsify it? Its when you start to ponder that question the problem with Popper becomes apparent.

We can think of any complex scientific theory like the set-up for a Jenga game . Each of the blocks is like a part of a theory's substructure. If you've ever played Jenga you know you can remove a lot of pieces and that tower still stands.

So if you're testing a theory and one block fails a test, you still have the other blocks holding up the tower. But unlike a game of Jenga, when one block of a theory is removed, you can modify the block and stick it back in, you can insert another block in its place, you can link together several blocks that are remaining ...

So how do you falsify a theory as complex as the Big Bang, Plate Tectonics .... ? The answer is you have to be able to remove numerous blocks all at once. When that happens not only is the theory falsified, but you have a paradigm shift.

Hopefully this analogy works for most of you, but does any of this sound like Poppers falsificationism as he described it? His concept is really too simple to describe reality isn't it. If so where does that leave us in this discussion?

I've said it before, your version of what you mean by the term "Dark Matter" is not falsifiable--it is not even a scientific theory, as you've said.
"Other theories?" Do you mean, other "scientific theories"? In that sense, we haven't treated one yet. You've a long way to go before we get to "a lot".

It is not my version of DM, nor is it my version of a scientific theory.

Within the Popperian context, a theory or hypothesis has to be falsifaible in order to be considered scientific. The terms falsifiable, testable, and scientific are synonymous within this context, as I have said at least ten times now.

Outside this context the criteria might be less rigorous, but that is irrelevant to this thread.

DM fails to qualify as falsifiable for a number of reasons outlined in ths thread. I say again, it is futile to wait until page 25 and then say that DM does not need to be falsifiable:

No. I mean other theories that might not be considered falsifiable, and therefore not scientific in the Popperian context. See above.

Well, DM is a start.

I agree entirely, and I have maintained that Popper's methodology is far from perfect. I think it is is a useful tool, nonetheless.
If we follow the method closely, I think we can see pretty quickly whether or not a 'theory' is falsifiable. If it fails to qualify, like DM, then red flags are raised, but this, of course, doesn't mean that it might not be considered scientific in a broader sense.

I think subjectivity creeps in when we make judgements as to the reasons why a theory might fail to qualify. There are good reason and bad reasons. This is where I think the value judgements (Personal subjectivity, as you say) enters the equation. Different people seem to have different ideas about what is compelling.

The BBT is a complex and multi-layered theory, sure, and therefore not easily falsified. But if we could verify that red-shift was non-doppler, that would blow a big hole in it, would it not?

A fundamental difference between the BBT and DM, I think, is the fact that DM was conceived to patch a leak (discrepancies in observations), and the BBT was based on observations and supporting evidence, although some might say interpretations there of.

I consider the BBT a theory, therefore, and DM a vague concept where theories can be conceived indefinitley in order to justify it. To some extent I concede that I am making value judgements, but I think they are rational.

When I say "your version" I mean the version that you are using, the concept to which you refer when you say "Dark Matter." I'm not trying to imply that you invented it.
Isn't it relevant to "a lot of scientific theories are not falsifiable"?

In 25 pages no one has raised a case for DM being considered a theory in its own right. It is better described as a mindset or concept, as candidates can be conceived indefinitely in order to justify it.

It is the sticky-tape holding existing models together. Lets face it, what happens if it turns out that there is no DM or DE? Deal with that!

Some people will claim that DM has to exist (mindset), and will continue to conceive candidates to justify the concept. If one candidate fails, another can be brought forward, and therefore DM sidesteps refutation. In short, DM is not falsifiable.

What do you think? We have been over this many times, so you really should have grasped it by now.

I can think of one prominent example, The Bad Astronomer, on page one: "Of course these are falsifiable theories."

But I wasn't sure what definition of "scientific theory" you were using when you said "a lot of scientific theories are not falsifiable" so we waited for your explanation. All you presented was Popper's--which is not applicable in that context, since Popperian scientific theories have to be falsifiable.

Mindsets or concepts aren't really falsifiable, though, are they? But that's the issue--do mainstream scientists have a mindset, and they are unyielding to other possibilities? No, they do not, no matter how much you claim that that is so. That's a form of conspiracy theory.
They are. The data is fairly clear. Now, we have to explain it. I don't see the problem, other than a group of researchers are convinced that their pet theory is getting slighted.

But I don't think I've ever talked to any scientist who didn't think that their research should have more attention!
I grasped it long ago--it is relevant.

Opinions are not facts. Care to construct some arguments, or have you given up?

Given up what? This thread was created so you could explain your statement. Have I given up on that? Almost.

Yeah, right.

Agreed. Only theories are. I'm glad you've now come to accept this. DM is so general that it precludes refutation. In short, DM is not falsifiable.

Well, there seems to be an unquestioning certainty that DM will be found. This diminishes the chances of other possibilities being investigated, but it doesn't rule them out, although I think it makes life more difficult for those who are prepared to explore alternatives.

And now you resort to accusing me of conspiracy theory. Whatever next?

I'm still waiting Mr Milli. Do you plan to respond to my arguments, or continue to misrepresent them?

A distant galaxy with a large blueshift. Well, you made the claim - we're still waiting. Feel free to list (and substantiate) the specific theories (I already listed a few if you just want to work on those).

Could that not be explained away as anomalous, unless we were to find lots of them?

I said this (bold), not dgruss23. Do you accept that DM is not falsifiable in the true sense, although it might be considered scientific in a broader sense, that is, outside the Popperian context? Then perhaps we can move on.

How distant? The most distant galaxies with blueshifts I'm aware of are in the Virgo cluster. NGC 4569 has a redshift of -137 km s-1 and NGC 4192 has a redshift of -46 km s-1 (redshifts corrected for Local group infall to the Virgo cluster). The standard interpretation to explain the large redshift deficit is that these galaxies have large peculiar motions towards the Milky Way (> 1000 km s-1).

What if a galaxy had a redshift of 7000 km s-1 but a measured distance of 160 Mpc? At its measured distance it would be expected to have a redshift of 11,500 km s-1 which is 4500 km s-1 greater than what it actually has? Would the 4500 km s-1 difference be of interest?

I've always accepted it. That's fairly obvious, isn't it?
Your version of what constitutes Dark Matter--others have different opinions. That's why we should be careful of what are our terms.
Nonsense.
Nobody ever said it was easy. Alternatives to the mainstream are always hard. Even Einstein had tough going at times. Do you want know what is a pretty good measure of the ones that are not going to make it? The whining.
Well, you made an offer of a million dollars, and said that we'd just have to trust in your integrity that you actually have it to give out, right? You make it too easy.

What sense is that? I left off the "outside the Popperian context"--that doesn't tell me which sense at all.

Yes, we should be careful with our terms. But no one has challenged my version of what DM is.

The problem that I and a number of others have highlighted is the fact that DM can take so many forms (there seems to be numerous candidates waiting in the wings), and it is therefore too genral to be considered refutable. DM is not falsifiable.

No one should challenge it--after all, it's your version, and you are entitled to it.

Just as in the thread about belief systems. At one point in that thread, your version of "belief system" was so all inclusive that almost anything was included as a belief system--but that made the notion of a belief system trivial, and mostly meaningless. Same thing here--your idea of Dark Matter is so all encompassing, that of course it won't be falsifiable. That's not going to get us anywhere.
I finally got ahold of a copy of this book, The Logic of Scientific Discovery. It was originally published in Vienna in 1934/1935 as Logik dre Forshung, and the copy I found (I'm checking it out of the library in a couple days) is an English translation from 1959. I'm not sure if it is the same edition as soupdragon2's, but I did find some comments of Popper that were even stronger: "Probability estimates are not falsifiable." (p.191)

However, after reading the English footnotes and postscripts (of which I am not finished), it is clear that Popper backpedaled severely on this issue, and soupdragon2's comment is a mischaracterization of Popper's more recent thought. Even on that page 191, in the footnote, Popper says "Yet my reform, proposed in note *I to section 57 (see also note *2 to section 64), changes the situation entirely. For this reform, apart from achieving other things, amounts ot the adoption of a methodological rule, like the one proposed below in section 68, which makes probability hypotheses falsifiable." The emphasis, in red, is mine.

Yet again Milli360, just as I try and pin you down you go off on another tangent.

Do you finally intend to raise a case for DM being falsifiable, based on probability? Or are you questioning my understanding of Popper, again, in order to try and undermine my arguments?

Yes, Popper did a lot of work to clarify his position on probability, but as I pointed out in earlier posts, this relates to more complex areas of Fal that are not, as far as I can see, relevant to this thread. Feel free to construct some arguments if you disagree, as I am sure you will.

http://www.eeng.dcu.ie/~tkpw/
"Most people who think they have a ready rebuff to Popper's position have never read his work. If they only read the original works, in most cases they would see that their supposed "Point that Popper neglected" had already been considered and exploded. A good example of this is Lewis Wolpert's remarks on Popper's works in his otherwise excellent book The Unnatural Nature of Science. He seems to think that Popper's falsifiability criterion ignores hypotheses about probabilities - overlooking the blatant fact that The Logic of Scientific Discovery devotes more than a third of its pages to the two fundamental problems of probability in an effort to find a solution that will also allow hypotheses about the probability of events to be capable of clashing with the evidence! Popper was in fact fascinated by probability and even produced his own axiomatisation of the probability calculus."

It was pointed out earlier that probability estimates are not fasifiable, and that probability statements and hypotheses are different things.

http://www.badastronomy.com/phpBB/po...e&p=299340
Here is a paper about Poppers Propensity interpretation, in .pdf
http://www.univie.ac.at/karlpopper20.../Rosenthal.pdf

If you want to attack Popper, feel free to do so, but again I do not see how this is relevant, as this thread is about falsifiability which I conceded is not perfect in my initial long post, as you know.

A skeptical look at Popper
http://www.stephenjaygould.org/ctrl/gardner_popper.html

Here is a Popper probability blog
http://www.samizdata.net/blog/archives/001144.html

Pin me down on what?