Dark matter is currently in that stage: we have observed that it is, even though we don't yet have a complete theoretical explanation of what it is. — Pfhorrest

Science has no idea what 'it' is, or even if 'it' exists, and it's never observed any such thing. That would be a huge headline! Dark matter is used to explain why the motion of galaxies varies from what is predicted. But it's possible there's something wrong with the prediction - that's what Mordehai Milgrom thinks. Not everyone agrees that there must be dark matter. But radio waves, germs, and wind are not a matter of conjecture

Metaphysics, anyway, is not 'beyond explanation'. Strictly speaking it concerns 'first philosophy', what the nature of reality must be to account for the experiences we have and the observations we make; what is beyond observation but suggested by it. And in this case it concerns a conjecture which currently has no physical basis, but which is suggested by observation, which is completely in keeping with both the meaning of the term and the reality of the situation.

Supernatural things have no physical effects to be observed at all. Paranormal things supposedly do, but the occurrence of the claimed phenomena has not yet been confirmed. — Pfhorrest

You don't know this, it's a supposition. There's a lot of controversy in the field of PSI, but there's also a lot of goalpost shifting and arguments about statistical significance and the like. Our notion of reality has exceedingly porous boundaries.

Science has no idea what 'it' is, or even if 'it' exists, and it's never observed any such thing. That would be a huge headline! — Wayfarer

You're behind the times. MOND is dead. There was a huge headline, about the Bullet Cluster observation. We looked at two galaxies that had collided, both the direct starlight and the gravitational lensing. The luminous matter clumped as expected normally, but the gravitational lensing showed that significant mass of the galaxies had passed right through them exactly as expected by a WIMP model, and in a way unexplainable by MOND.

Prior to that you'd have been right, we weren't sure if there was some stuff there or just if our model of gravity was wrong. Now we know there's definitely some kind of stuff there, we just don't know much about it yet.

Metaphysics, anyway, is not 'beyond explanation'. Strictly speaking it concerns 'first philosophy', — Wayfarer

That's not the way you seemed to be using it. You seemed to be using it to mean "supernatural", outside the domain of physics. Empirical phenomena that just don't yet have an explanation in terms of other better-known phenomena are not "metaphysical", they're just as-yet-unexplained.

You don't know this, it's a supposition. — Wayfarer

It's definitional. If something is supposed to have empirical, physical effects, then it's a supposed natural phenomenon, not supernatural. If the supposed phenomenon were conclusively confirmed to occur, even if it lacked an explanation, it would just be normal science (not in the Kuhnian sense, just) not paranormal.

There's a lot of controversy in the field of PSI, but there's also a lot of goalpost shifting and arguments about statistical significance and the like. — Wayfarer

If there's some evidence for something, but not undeniable evidence, leaving room for doubt about whether the phenomenon actually occurs, then it's not "confirmed" yet. That doesn't mean it's definitely not happening, it just means there is as yet conclusive consensus that it's definitely happening.

What the hell are "direkt observations" anyways? It's not like the photons hitting your retina are a cat, a rock etc. Neither are the vibrations carried to your eardrums a guitar.

Dark matter is used to explain why the motion of galaxies varies from what is predicted. But it's possible there's something wrong with the prediction — Wayfarer

It's possible there's something wrong with any prediction. It's possible cats are entirely an illusion. The only difference is the likelihood of it being the case.

Now we know there's definitely some kind of stuff there, we just don't know much about it yet. — Pfhorrest

I just can't help being reminded of epicycles and crystal spheres.

It's definitional. If something is supposed to have empirical, physical effects, then it's a supposed natural phenomenon, not supernatural. — Pfhorrest

The placebo effect doesn't have a naturalistic explanation, or at least a physical explanation.

Just remember the meaning of 'phenomenon' - it's 'what appears'. And empiricism is always going to seek for explanations on the level of 'what appears', or extrapolations from 'what appears' on the basis of mathematical extrapolation. Empiricism excludes some kinds of explanatory models purely as a matter of principle, but then forgets that it's done so.

What the hell are "direkt observations" anyways? It's not like the photons hitting your retina are a cat, a rock etc. Neither are the vibrations carried to your eardrums a guitar. — Echarmion

You're confusing two kinds of explanation here. Of course one can question the nature of observation itself - that is the task of philosophical analysis. But when it comes to dark matter, it's proposing a natural explanation which consists of some kind of 'matter' the likes of which is completely unknown, to explain observational anomalies in cosmology.

The key point, and where you entered the argument, is that nothing corresponding to dark matter has been directly observed, despite large and elaborate experimental apparatus having been set up for that purpose. We might agree or disagree on what it means, but the absence of direct observation is not a matter of opinion.

What the hell are "direkt observations" anyways? It's not like the photons hitting your retina are a cat, a rock etc. Neither are the vibrations carried to your eardrums a guitar. — Echarmion

Yeah, and that's kind of my point. Indirect observations aren't really fundamentally different from direct ones. Everything is to some degree indirect, it's just a question of how much. All we directly see is patterns of light (if we can even take for granted that we actually have eyes attached to actual optical nerves attached to our brains... in an even more skeptical sense all we see is impressions of color in our minds, that we indirectly infer arise due to the impingement of colored light on the eyes we seem to have). The existence of permanent objects in three-dimensional space is indirectly inferred from those patterns of light. The specifics of what objects there are where and what they do is indirectly inferred by the behavior of other objects.

The placebo effect doesn't have a naturalistic explanation, or at least a physical explanation. — Wayfarer

We know that the brain controls many aspects of the body, and that mental states correlate to brain states. It's not at all spooky or paranormal or supernatural that someone's mental states would affect things about their body. We don't know the specific details involved, but that's a far cry from "naturalism and physicalism can't account for this!"

Just remember the meaning of 'phenomenon' - it's 'what appears'. And empiricism is always going to seek for explanations on the level of 'what appears', or extrapolations from 'what appears' on the basis of mathematical extrapolation. Empiricism excludes some kinds of explanatory models purely as a matter of principle, but then forgets that it's done so. — Wayfarer

What would a supernatural explanation even look like? A natural explanation is an account of one kind of phenomenon in terms of another kind of phenomenon: when you see this kind of thing happen you should expect to also see this kind of thing happening. But supernatural things aren't phenomena by definition; they're non-empirical. So "when you see this kind of thing happening you should expect to, er... well you can't see this other kind of thing at all, but it's why that kind of thing is happening, I swear".

Things that have no experiential impact whatsoever to anyone ever are of no consequence to anyone ever, and are rightly disregarded as literal nonsense. Things that do have experiential impact are by definition empirical, natural, physical things.

@StreetlightX This conversation seems to have veered way off the original topic, any chance you can do another thread split for us?

You're confusing two kinds of explanation here. Of course one can question the nature of observation itself - that is the task of philosophical analysis. — Wayfarer

No. If I were questioning the nature of observation itself, I'd be asking whether and how what's in your mind is actually related to anything outside of it.

What I am saying is that, according to physics, everything we observe is indirect, an effect. If I "look" at a rock, all I am perceiving is the effect that photons reflected from the rock have on my retina, nerves and brain. How is that a "direct" observation of the rock?

But when it comes to dark matter, it's proposing a natural explanation which consists of some kind of 'matter' the likes of which is completely unknown, to explain observational anomalies in cosmology. — Wayfarer

That sentence doesn't make any sense to me. What does "the kind of which is completely unknown" mean? You could say the same of "normal matter" or "antimatter".

The key point, and where you entered the argument, is that nothing corresponding to dark matter has been directly observed, despite large and elaborate experimental apparatus having been set up for that purpose. — Wayfarer

What do you mean by "corresponding to"? Why would something have to correspond to something else?

We might agree or disagree on what it means, but the absence of direct observation is not a matter of opinion. — Wayfarer

It's even less than an opinion if you can't explain what "direct observation" even is.

This conversation seems to have veered way off the original topic, any chance you can do another thread split for us? — Pfhorrest

We're only two pages in and the OP this thread was zombiefied from 6 months ago, so I think it's fine to simply let conversation continue as is here.

Everything is to some degree indirect, it's just a question of how much. — Pfhorrest

Yes, there's the question of 'the nature of perception and observation' but that is not what is at issue in the discussion of dark matter.

The existence of permanent objects in three-dimensional space is indirectly inferred from those patterns of light. — Pfhorrest

That sounds more like Kant than scientific realism. Again, I don't think it's mistaken but I also don't think it's relevant to the point at issue.

We know that the brain controls many aspects of the body, and that mental states correlate to brain states — Pfhorrest

The latter is certainly not known at all. That is simply brain-mind identity theory, but as you say, that is totally off topic here. Let's simply observe the physicalist assumptions that underlie this confidence.

What would a supernatural explanation even look like? — Pfhorrest

There are many subject areas that are out of the scope of naturalism. Of course, 'supernatural' is a loaded word, but then I didn't introduce it. I said that questions like the existence of dark matter/energy are in a sense metaphysical questions - something that is suggested by observation, but is now and possibly forever beyond the scope of observation.

What I am saying is that, according to physics, everything we observe is indirect, an effect. — Echarmion

I don't know a lot of physics, I studied it formally up to high school level, and I've read quite a few books on physics, but that was never stated as part of physics. It might have been stated because of 'philosophical reflections on the nature of physics' but it's not something taught in physics per se.

It's even less than an opinion if you can't explain what "direct observation" even is. — Echarmion

Direct observation = observing directly. Observing that movement of masses of air causes trees to bend, that germs cause disease, that radio waves can be detected with the appropriate instruments. Abductive inference = reasoning from effect to cause i.e. 'because this happened, then the cause must be X'. But in this case, 'X' stands for something that not only hasn't been observed, but may possibly never be observable in principle.

I don't know a lot of physics, I studied it formally up to high school level, and I've read quite a few books on physics, but that was never stated as part of physics. It might have been stated because of 'philosophical reflections on the nature of physics' but it's not something taught in physics per se. — Wayfarer

Obviously anything referencing the terms "direct" or "indirect observation" is philosophy and not physics. My point is that your distinction between direct and indirect has no basis in physics as we currently understand it.

Direct observation = observing directly. — Wayfarer

is this supposed to be a joke?

Observing that movement of masses of air causes trees to bend, that germs cause disease, that radio waves can be detected with the appropriate instruments. Abductive inference = reasoning from effect to cause i.e. 'because this happened, then the cause must be X'. But in this case, 'X' stands for something that not only hasn't been observed, but may possibly never be observable in principle. — Wayfarer

How is "germs cause disease" not an abductive inference? You even reference instruments. "The instrument beeps, therefore it has detected a radiowave" is very clearly reasoning from effect to cause.

is this supposed to be a joke? — Echarmion

Ask a stupid question.....

How is "germs cause disease" not an abductive inference? You even reference instruments. "The instrument beeps, therefore it has detected a radiowave" is very clearly reasoning from effect to cause. — Echarmion

:clap: :up:

I'll let you take things from here, you've clearly got this and I'm tired of this shit.

Yeah Wayfarer has, uh, issues understanding what 'observation' entails in scientific contexts. As long as it relates to science you can be sure he will lie and obscuate in order to peddle whatever supernatural trash he's into.

In the paradigm cases that have been brought up - radio waves, wind, and germs - there is a clear correlation in theory and observation between cause and effect. The cause of the associated phenomena is understood clearly and can be explained directly. I don't think the statements that germs cause disease, that masses of moving air constitute wind, and that radio waves are an invisible form of radiation that exists on the electromagnetic spectrum, are metaphysical statements. But the statement that 'some unknown form of matter causes the discrepancy that is observed in the motion of galaxies' clearly is a metaphysical statement, because it posits the existence of some form of matter that can't even be detected by current physics, hence is beyond or above, 'meta', current physics.

Happy to be corrected, but other than stupid questions and hostile invective, nothing has been close.

Except it can be observed. See the Bullet Cluster again.

All working physicists informally appeal to "directness" whenever they make an inference, even though Physics possess no theory of directness. For otherwise a physicist could not claim to learn anything from an experiment, nor for that matter could he find the sentences of physics intelligible. So although directness/indirectness aren't themselves defined in terms of physical criteria, the converse is true.

Exactly the same issue applies to language in general, for we are taught the meaning of words either through ostensive definition, or by verbal definitions that implicitly appeal to earlier ostensive definitions for their intelligibility. And yet we have no linguistic criteria for translating verbal definitions into ostensive definitions and vice-versa, for languages are only publicly defined up until verbal criteria.
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In line with language in general, the semantics of Physics is both under-determined and redundant; one Physicist's "natural" object is another Physicist's "metaphysical garbage", because they might each understand physics using different semantic foundations that are rooted in different ostensive definitions.

Except it can be observed. — Pfhorrest

The purported EFFECTS can be observed. But dark matter itself cannot be and hasn’t been observed. This is fact.

In line with language in general, the semantics of Physics is both under-determined and redundant; one Physicist's "natural" object is another Physicist's "metaphysical garbage", because they might each understand physics using different semantic foundations that are rooted in different ostensive definitions. — sime

:up: And the reason for that is not a matter for physics.

The purported EFFECTS can be observed. — Wayfarer

This is an oxymoron. All scientific observation is observation of effect.

We discovered that atoms have nuclei because of the effects of particle scattering. But of course only a scientifically illiterate moron would argue that we 'didn't really observe' atomic nuceli in the Geiger-Marsden experiments, for instance. Only the same moron would say that the experiment only proved the 'metaphysical' notion of a nuceli. This same moron would have a surprise in store for him when he realizes how particle accelerators work to observe things too.

How is "germs cause disease" not an abductive inference? — Echarmion

‘Abductive reasoning (also called abduction,[1] abductive inference,[1] or retroduction[2]) is a form of logical inference which starts with an observation or set of observations and then seeks to find the simplest and most likely explanation for the observations. This process, unlike deductive reasoning, yields a plausible conclusion but does not positively verify it.’

I believe the germ theory of disease has been verified. You don’t?

The ontology of the probability wave and so also the atom is still one of the outstanding problems of physics, and the particle accelerator has still not resolved that issue, philosophically, Although I realise philosophy may not be of particular interest to you.

Except the experiments I mentioned have nothing to do with any of that so maybe come back when you're done parading your utter, shameless ignorance of science about.

This is a ‘philosophy forum’. I think it’s interesting that all of this grew out of my suggestion that the nature and existence of dark matter might be a metaphysical question. Look at the reaction. It’s a sane and sober point. If ‘dark matter’ is real, it means that either our notion of what constitutes ‘matter’ is radically insufficient’, or alternatively, that our understanding of current physics is. How is this *not* a metaphysical issue?

Nope, not getting distracted by your usual attempts to change the subject. You have a terrible, horrible, no good, very bad understanding of scientific observation. That's all I came to say. It doesn't help that you regularly peddle pseduo-scientifc sake oil.

In the paradigm cases that have been brought up - radio waves, wind, and germs - there is a clear correlation in theory and observation between cause and effect. — Wayfarer

Cause and effect is itself a theory based on correlation, so I'm not sure what this sentence means.

The cause of the associated phenomena is understood clearly and can be explained directly. — Wayfarer

Really? Can we understand clearly the nature of wave function that ultimately "causes" all the examples you named? Can we directly explain gravity? The clear and direct explanations you posit are based on popular simplifications. In fact, the nature of "normal" matter is hardly less mysterious than that of dark matter.

But the statement that 'some unknown form of matter causes the discrepancy that is observed in the motion of galaxies' clearly is a metaphysical statement, because it posits the existence of some form of matter that can't even be detected by current physics, hence is beyond or above, 'meta', current physics. — Wayfarer

But it isn't unknown. We know a whole lot of it's properties.

‘Abductive reasoning (also called abduction,[1] abductive inference,[1] or retroduction[2]) is a form of logical inference which starts with an observation or set of observations and then seeks to find the simplest and most likely explanation for the observations. This process, unlike deductive reasoning, yields a plausible conclusion but does not positively verify it.’

I believe the germ theory of disease has been verified. You don’t? — Wayfarer

This reads like you're saying that, once a theory arrived at via abductive reasoning is verified, the abduction part it's based on vanishes. That seems nonsensical.

If ‘dark matter’ is real, it means that either our notion of what constitutes ‘matter’ is radically insufficient’, or alternatively, that our understanding of current physics is. How is this *not* a metaphysical issue? — Wayfarer

Both of these options seem evidently within physics. There's nothing "meta" about them.

All working physicists informally appeal to "directness" whenever they make an inference, even though Physics possess no theory of directness. For otherwise a physicist could not claim to learn anything from an experiment, nor for that matter could he find the sentences of physics intelligible. — sime

How does any of this follow?

Your concern is touching, but I get by.

In fact, the nature of "normal" matter is hardly less mysterious than that of dark matter. — Echarmion

I rest my case.

I just like helping the disabled, physically or otherwise.

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The purported EFFECTS can be observed. But dark matter itself cannot be and hasn’t been observed. This is fact. — Wayfarer

Do you think black holes have never been observed too? Because we've observed them with the exact same methods as we've observed dark matter.



Anyway, how did we get stuck on this topic of dark matter, when the only thing even vaguely relevant to the OP is dark energy (as a possible source of continuous energy to combat the heat death of the universe, and an explanation for how that heat death hasn't already happened). And dark matter and dark energy, besides having "dark" in the name, have nothing to do with each other.