I agree (although it might be better to say "scientific" rather than "valid", since "valid" might tend to mean that the statement is very well supported as opposed to "of the right form as to be scientific and potentially valid").

Dark matter is called upon to explain an observation. If some alternative explanation arises that is well supported by additional observations, it may replace the dark matter idea, which would then not be needed and could be considered "falsified." That's why I would say that dark matter is certainly falsifiable. But currently it is our best explanation, and it has numerous lines of support.
There is extremely strong evidence for quarks and black holes. If their predictions had not panned out as they have, they might have been falsified. But they weren't. They were supported. There are extensive experiments seeking dark matter and gravity waves. If all such searches fail, this will not exactly "falsify" these concepts, but it may call for alternatives to be followed and other experiments to be employed.

Popper was a thoughtful philosopher of science, and his insights are generally helpful to scientists. But he is not God of Science. Popper may have contributed a useful framework, but science is a large and complex structure, not just a framework.

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Everyone is entitled to his own opinion, but not his own facts.

How about "scientifically valid?" You're right - just plain "valid" isn't good enough wording.

Cosmology is allowed a little latitude, but should still be based upon local observable, Not noobservables.

Dark Matter is based upon non-observation, and since none of the tests, and there has been a mirid of them, have yielded a single positive result, I do not understand why "the best explanation" is a good description of this conundrum.

I think "the first explanation the mainstream latched onto and they stubbornly refuse to seriously consider other alternatives" is a better discription of the current situation.

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jwj

It's ok not to know.

At the end of page 9 and beginning of page 10 it seemed this thread was beginning to achieve some focus.

Worm hunter: OK, Soup, what exactly about DM/DE do you find unfalsifiable?
http://www.badastronomy.com/phpBB/vi...=299767#299767
Xbalanque: And that's really the whole point of this, isn't it? Thanks for getting it back on track.
http://www.badastronomy.com/phpBB/vi...=299821#299821
jaydeehess: Pains me to say it since I was so snarky before but I agree with soupdragon. DM/DE is not a theory, it is a patch.
http://www.badastronomy.com/phpBB/vi...=299824#299824

And I tried to pin down the DM and DE proponents by getting them to clarify their positions.
http://www.badastronomy.com/phpBB/vi...=299969#299969

Sure, but while they maybe 'scientifically valid' in some vague sense, they are not falsifiable in any strict sense, and this is THE darned issue!

My bold above. Yes, this maybe a better description, at least given that some people clearly do not understand the concept of Falsifiability as outlined by Popper, and this is/was THE issue!

Edits: Typos

The original issue of this thread -- which still has not been settled -- was your claim that "a lot of scientific theories are not falsifiable".
Let's not lose sight of that.

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"All your bias are belong to us." Ara Pacis
"A witty saying proves nothing." Voltaire

And I stand by that. But let's take it one step at a time for the sake of simplicity. Too many posts are veering off on tangental orbits as it is!

OK, Soupdragon2, you say that DM/DE add subjectivity. But you dont give examples of what you find subjective about them. I understand that at one point they were patches if you will, but i think we have moved past that stage through thte use of predictions and testing of atleast the observable effects on the universe. Unless you have a reason to think that the tests were improperly done or unfalsifiable to begin with, why do you still think that they are unfalsifiable. Sorry if I am just missing it here but i have yet to see you actually apply Poppers definition to either DM/DE, but only state it.

What i have learned from this thread so far: A theory/auxilary hypothesis must make testable predictions in which it is possible for the said theory/auxiliary hypothesis to fail. Seems pretty logical to me. But DM/DE has been showin to make testable predictions which they could of failed.

At this point I am going to rephrase my question a bit: If you dissagree with the tests of DM/DE then can you point out why?


Couldnt it be said that the whole DM/DE discusion is a tangental orbit? Considering that they are two scientific theories and your statement was "a lot." And lets not forget that you have since argued that they arent even theories but, Auxilary Hypothesis. Unless if im not mistaken DM/DE are ah's of Gravity. Are you trying to say that Gravity is unfalsifiable?

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They call 'em fingers, but i've never seen em fing..... oh there they go!! otto

The AH should improve the theory, by adding information to it. The more informative, the most testable/falsifiable.

However, I think that some people are trying to claim DM and DE as theories in their own right?

To you, maybe. But some people have used terms like 'provable'. Remember, if we follow Poppers methodolgy, a theory can never be conclusively verified, only conclusively falsified.

Hmmm. Well, this is the central issue...

I plan to do just this! Providing we can all agree that this IS the central issue?

Some kind of focus for the sake of elucidation cannot be a bad thing, can it?

I am happy to work with this. (DM and DE are essentially AHs in respect of gravity.) Does anyone have any problems with this? They may consider this view too simplistic?

No. Certainly not. OK, we are not sure what gravity is exactly, but it is a credible theory given that this force is well tested, and makes predictions that are testable now. Of course, it seems there maybe problems with it, hence DM/DE speculations.

Dark matter halos

I have been trying to remember where i read this article for awhile now and i finally found it. to me it is another example of DM making falsifiable predictions, hence being falsifiable.

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They call 'em fingers, but i've never seen em fing..... oh there they go!! otto

Well do it then!

Tell us exactly why you consider DM/DE, black holes, BBT(?), gravitons, and quarks (anything else?) to not be falsifiable. Well, do it already! Saying over and over what you plan to do looks like a cheap dodge. I don't think after 13 pages that its too much to ask that you answer (and substantiate) the question asked in the opening post.

To answer your question, yes, I will stipulate to all 3 of those points. Like I said, I have small issues with them, but those issues aren't really relevant here. I'll stipulate for the purpose of moving on to the meat of the discussion. Ok - now explain why.

The gravitational dynamics of galaxies and galaxy clusters directly imply that either (1) there is a lot of matter present within these structures that we have yet to be able to detect or (2) that the effect of gravity increases dramatically over very large distances or (3) there is some other unknown explanation for the observed dynamics.

Since precise measurements of the effect of gravity over large but local scales shows no signs of any increase whatsoever (beyond what newtonian and einsteinian gravitational theories predict), then explanation (2) would appear to be highly unlikely, which fits well with the general feeling that such an explanation is ludicrous. The gravitational constant g has always been thought to be constant, and local observations consistently verify this. Numerous variable-g theories have been falsified, and the popular MOND theory has recently had a stake driven through its heart.

So explanation (1) appears the likely candidate, and searches are on to verify it.

The fact remains: there must be some explanation for these observed galactic dynamics. Nobody's absolutely sure about what that explanation is. Explanation (1) is pretty simple and straightforward. Do you have another explanation that is coherent, consistent, and complete? (and why hasn't it been published?)

In view of my summation above, your "refusal to consider other alternatives" position appears highly subjective, paranoid, and conspiratorial. The "mainstream" is comprised of a myriad of independent, scientific minds, not some closed, secret society making selfish decisions as a bloc. If you subjectively think your pet alternatives are not given the attention you think they deserve, it is most likely that such alternatives are simply flawed, and hence further development would be fruitless.

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Everyone is entitled to his own opinion, but not his own facts.

Offhand, I would say that if you weren't prepared to support your statement when you originally made it, you probably should not have made it. Care to recant?

Whew! That was a long read!

I'll chime in on the "are DM/DE theories?" question. I would argue that DM/DE are not falsifiable, because they are themselves falsifications. You don't falsify falsifications, you have to prove that the test that led to the falsification was an invalid test. The standing theory before DM was "All matter in the universe that interacts with gravity, interacts with light also." DM derives from a test that falsified this theory, so you have, "There is matter which interacts with gravity, but not with light. There may be individual theories about the nature of dark matter, which are themselves falsifiable, but to get rid of DM, you have to attack the test(s) of the "bright matter only" theory, and show they weren't valid.

I second everyone else who doesn't understand this part. The only subjectivity that has been talked about has been WRT Freudian psycoanalysis. I think we all agree that psycoanalysis in entirely unfalsifiable, and therefore entirely subjective. I can't imagine what "partial" falsifiability and "partial" subjectivity would look like.

Is psycoanalysis subjective because different researchers can look at the same results and interpret them differently within the framework of the same theory. If a theory becomes partially subjective, are there some observations that must be explained the same way, and others that may be interpreted in different ways? How has DM/DE done this to gravity, or whatever theory they are AHs of?

Good summation, but I think Dark Matter has to be split into two catagories: The "missing matter" on the edges of galaxies and the stuff used to fill the gravametric sink holes in galactic clusters.

Mathematically, MOND provides the best model for the edgy stuff but fails in the second case. On the other hand, textbook newtownian stuff fills the galactic cluster voids, but the 'cusping' features necessary to model the MOND effects require unrealistic parameters and selective interactions.

Because of these observations, in my opinion, they are caused by competely different phenomenon.

I think explaination (1) is correct for the missing matter in galaxy clusters, and there was a paper posted last week that speculated the stuff might be small black holes, and they managed to tie this explanation to the current cosmology. This actually makes sense, and so yes, my critic is a little strong - people are still looking for answers.

But to even be published, alternatives must be very close fits to the current cosmology. In THIS environment, it is impossible to weigh alternative answers fairly. The Eriksen paper I started a thread around is a good example: The results of the study are certainly at odds to some degree with the current interpretation of the CMB, but in their conclusion, they state just the opposite. Would it have been accepted for publication if they had stated otherwise? Probably. Would they lose credibility for doing so? Maybe - many have.

Another example is a paper pointing out Two-point compressions are completely at odds with supernova Ia interpretations. The authors conclude the two-point compressions are flawed without even weighing into the discussion to possiblity the supernova interpretations may be biased. Since the two point statistical studies are based on thousands of galaxies, and supernova models on a handful of data points, this is disconcerting.

There was also a very technical paper last week that pointed out as soon as you assume the universe is 70 dark energy, all subsequent calculations are biased by this assumption, and the error margins are diminshed or become convergent, creating more confidence than is justified in the current model.

I think I have demonstrated in my preprint similar biases caused by assumptive use of the current relativistic distance modulus, and compete dismissal of the tensors of polarization as a necessary factor in the calculation cosmic redshift distances - could cause the same false security in the current interpretation of supernova light curves.

I do. I think fundamental errors in understanding the nature of light-in-space have created an unrealistic, unworkable model. I don't think (most of) the astrophysical world is capable of properly weighing the arguments of Arp and Moret-Bailey because of their deep-rooted misconceptions.

Even more fundamentally, there should not be just one acceptable model: Heisenberg should trump Einstein and Newton, there may be more than one scientifically valid explanation for everything we see in the past, and so individual studies should be evaluated on the bases of the physical realities incorporated in the solution, and not, at least initially upon whether or not they fit into the current big picture.

The plasma dudes have put together an alternative cosmology that, in my opinion, is just as flawed as the consensus cosmology. Somewhere in-between or just outside the established parameter window there may be a better solution.

__________________
jwj

It's ok not to know.

A brief recap

Falsifiability

Much of this thread has dealt with confusion over the meaning of the term Falsifiable. Many people seemed to think that a theory is falsifiable if it might be proved wrong at some point in the future. This is not the case. For a theory to be falsifiable it must be testable now*, and the test must be vulnerable to be being proved false, that is, falsified.

In other words, there must be some conceivable way in which the theory can be refuted, otherwise the results of any experiment can be interpreted in such a way as to support the theory.

It is important to recognise that this methodology was formulated by Karl Popper, and that he proposed Falsificationism as a tool for demarcating between science and non-science.

In this context the terms testable and falsifiable are hereafter synonymous.

* It might be argued that a test might be developed at some point in the future, but caution is recommended here, as NO guarantees can be made that these tests -- if and when they come about -- will be workable.

Auxiliary Hypotheses

If we discover a problem with a theory, it is not automatically abandoned. It can be rescued by an Auxiliary Hypothesis, but these are subject to strict rules. For an AH to be valid it must make a theory more testable/falsifiable. In other words it should improve its informative content, and not just patch a leak with hypotheses that are not testable. These would be kludges!

Progress so far

DM/DE

For the sake of simplicity this thread has concentrated on Dark Matter and Dark Energy. I will be happy to look at other theories later, but for the time being we seem to have agreed that this thread needs some focus.

Do DM and DE qualify as Auxiliary Hypotheses?

We also agree that DM and DE are not theories in their own right, but were intended to address problems relating to existing theories, principally gravitational in nature.

On this basis I will examine claims made by DM and DE proponents in respect of their validity. Do they fit the strict criteria necessary to be considered auxiliary hypotheses, or are they, in effect, kludges?

Background

Dark Matter, of course, was hypothesised to account for the 'missing mass' problem, while Dark Energy is hypothesised to be driving the expansion of the universe, alleged to be accelerating. Differing viewpoints ascribe varying importance to DM and/or DE.

Either way, they are not directly observable. Observations did not match expectations, and their existence was inferred to account for this discrepancy. In other words their existence rests on an interpretation of contradictory data.

While this does not in itself invalidate them, it provides a valuable insight into the reasons for their conception.