Dark matter so far not detected but researchers find cause for hope in that fact…

And that's my issue with science education. - Science classes have "evolved" into memorizing vocabulary, memorizing chemical names and cycles, and rote computation. Memory rather than critical thinking is paramount. - Science has explained everything. There is nothing exciting or challenging left. - Science is complicated, so just trust the geeks in white lab coats. However, the words "We don't know," and "This is a mystery" is incredibly inspiring to young people! Considering that the "facts" in science change over time, the focus in science education should be on observing, thinking, experimenting, and discovering. Here's my challenge:

What is the earliest recorded scientific experiment in history that involved changing only one variable, observation, and a control group?

Querius

Graham2:

OK, so how would you people approach the problem ?

I think the main issue here is that Scientism seems to have great difficulty saying, "We really don't have a clue and are just pulling stuff from our nether regions." But if this is the actual case, then a scientist who is not trying to present science as the eminent arbiter of all truth should have little difficulty saying so. Phinehas

Some of us would be interested to know what alternative cosmologies are available if no dark matter does turn up. If it is really a quarter of the universe, how strange that we never detect it.

But we *have* "detected" something that's causing the outer stars in galaxies to rotate faster than they're supposed to based on the estimated mass of the galaxy based on the brightness of the galaxy inferring the accumulated mass of the stars. Yeah, there's potential for error here! It's assumed that the extra, undetected mass is causing this difference along with increased gravitational lensing effects. The extra mass might be due to neutrinos, brown dwarf stars, "dark" matter, or possible the result of accumulated error in the radius squared term of Kepler's third law over galactic distances. Querius

Yeah, but I don't remember suggesting that we should never use Newtonian mechanics ever again. Where did that come from? I do think, however, that we will not solve some of the toughest physics problems until we get a fundamental understanding of phenomena like motion and gravity. We don't. Right now, all we have are equations. We need causal principles. Mapou

I was responding to this : So I would suggest that we first try to get a true and thorough understanding of the small problems before attacking the big ones Graham2

Wow. I was just trying to say that we should get a better understanding of the phenomena that we think we understand but really don't. That is all. You'd be surprised what a little fundamental understanding can do. If you got a problem with that, let me know. Mapou

Mapou: So we should forget everything we know and retire to an empty room to start again ? Should we never apply Newtonian mechanics, ever again, until we have the fundamentals sorted ? YES or NO, could you pick one ? Graham2

OK, so how would you people approach the problem ?

The problem I see is one of not having a true cause/effect understanding of most of the phenomena they study. Neither Newtonian nor Einsteinian gravity theories explain what causes gravity, a billion physicists claiming otherwise notwithstanding. Those theories are just descriptive equations with no causal mechanisms to speak of (no, it's not the curvature of spacetime). At least Newton had the humility to admit as much. Consider that physicists don't even understand ordinary motion. Ask any physicist what causes two particles in relative inertial motion to remain in motion and you come face to face with total ignorance if not outright superstition. Is it any wonder they have no clue as to what's keeping galaxies from flying apart? So I would suggest that we first try to get a true and thorough understanding of the small problems before attacking the big ones. Physics: The Problem with Motion. You don't understand motion even if you think you do. Mapou

Alright then, start proposing some alternate cosmologies. We are all waiting. Graham2

Some of us would be interested to know what alternative cosmologies are available if no dark matter does turn up. If it is really a quarter of the universe, how strange that we never detect it. News

OK, so how would you people approach the problem ? Graham2

Why does this sound like the extended complications of explaining a helio-centric solar system as the observations of planets became more accurate? I can, however, understand the advantage of having a topic that can neither be proven nor disproven to fuel your career. An endless series of papers and seminars. mahuna

They have Einstein's gravity theory (general relativity), but whenever the actual attractive forces are stronger than the theory predicts, then they add invisible "dark matter" suitably distributed to increase the attraction so it fits the data. If actual forces observed are weaker than the theory says they should be, then you have "dark energy", also undetectable, to help weaken the attraction in just the right way to fit the data again. Of course, any mix of the two also comes in as needed. In other words, no matter what is observed, the theory remains right, while undetectable "dark" spirits are invoked, assumed to be distributed just right to explain any conceivable discrepancy away. Kind of similar tautological scheme to neo-Darwinian evolution theory, which is always right, regardless of what the data shows. nightlight