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Galaxy Without Any Dark Matter Baffles Astronomers (arstechnica.com)
A distant galaxy that appears completely devoid of dark matter has baffled astronomers and deepened the mystery of the universe's most elusive substance. The Guardian reports: The absence of dark matter from a small patch of sky might appear to be a non-problem, given that astronomers have never directly observed dark matter anywhere. However, most current theories of the universe suggest that everywhere that ordinary matter is found, dark matter ought to be lurking too, making the newly observed galaxy an odd exception. Dark matter's existence is inferred from its gravitational influence on visible objects, which suggests it dominates over ordinary matter by a ratio of 5:1. Some of the clearest evidence comes from tracking stars in the outer regions of galaxies, which consistently appear to be orbiting faster than their escape velocity, the threshold speed at which they ought to break free of the gravitational binds holding them in place and slingshot into space. This suggests there is unseen, but substantial, mass holding stars in orbit. In the Milky Way there is about 30 times more dark matter than normal matter. The latest observations focused on an ultra-diffuse galaxy -- ghostly galaxies that are large but have hardly any stars -- called NGC 1052-DF2. The team tracked the motions of 10 bright star clusters and found that they were traveling way below the velocities expected. The velocities gave an upper estimate for the galactic mass of 400 times lower than expected. The researchers described their discovery in the journal Nature.
The thing is, our theory of gravity (general relativity) makes a lot of other predictions on scales of the same order, and they seem to work fine. There are also cases like the Bullet Cluster where the dark matter and ordinary matter components of two galaxies get separated from eachother, and the dark matter component can be seen by its gravitational lensing effect.
There's also the issues with particle physics. The Standard Model is incomplete (there are observations it can't account for), and when extending the standard model in ways to account for those observations, many models wind up including particles that would behave consistently with dark matter.
There is a very promising theory by a Dutch theoretician (paper here), which can explain the observations without the need for dark energy / matter. I have seen the presentation of his work, and, as far as my understanding, it is based on idea that gravity is an emergent force, so-called entropic gravity Drupal.
Newtonian mechanics makes pretty good estimations of lots of phenomena on the human scale, but we know that that was not the end of the story.
The name "dark matter" itself is indicative of it being known unknown. It's not named something vaguely Greek or Latin like the lots of the pedestrian forms of matter because we don't know with confidence what it is yet, and haven't had direct evidence as it's particular nature as "matter", and the phenomena might possibly not even be due to matter at all. The evidence is galactic motions and larger don't work mathematically with the conventional cosmological models if you only include the more familiar forms of baryonic matter we observe, but the math works much better if you have a whole lot of matter that we can't "see" outside of those gravitational effects. So you have a placeholder or best guess that seems to make the most sense when paired with what else we think we know, and you can plug it into the models and try to predict where it would be.
"Dark matter" may turn out to be "correct" in the sense that there may be a bunch of non-ordinary matter in the places we are guessing it is that is causing the expected gravitational effects, but the current state of the theory is inherently incomplete because dark matter can only defined now by saying it is not ordinary matter, but there is not an affirmative evidence backed argument for what it actually is. It could be something like WIMPs or whatever, but we need more evidence beyond relying on ad hoc fixes to earlier theories that failed in the face of anomalous galactic motions.
You may be correct that dark matter and dark energy may not be the only possible explaination, but the point Megol made still stands. OP claims that that science lays them out as fact and says our observations are wrong, which is complete nonsense. Dark matter/energy are modern equivalents of "here be dragons", we know something is going on but we are unsure of the exact nature of that something. Continuing observation is used to narrow down the possibilities. The article was about finding a galaxy that is extraordinary in that we can understand everything that is happening, the first time we can say that out of the approx. 400000000000 galaxies in the observable universe.
Please, note that there is are some very powerful distinctions between practical engineering and the predictive power of science.
There are but literally every bit of engineering is based on scientific evidence. Whether or not the person doing the engineering fully and properly understands that science does not make it less true. Engineering doesn't work unless it is based on the ability of science to make predictions. There is science independent of engineering but not the other way around.
People sometimes call engineering "applied science". I think that definition is incomplete. I think it is "applied science with economic and temporal constraints". Engineering is science applied to practical tasks within the constraints of a budget and with a deadline.
Within it's tested limits the standard model is highly accurate. However given that this has been achieved by doing lots of experiments and using them to find some 20 odd constants, so that the model fits the experimental data then that's hardly surprising.
However step outside the tested limits and it's anyone's guess as to whether it's correct or not. Then add in that gravity is absent from the model and clearly at best it is incomplete and incomplete is also "flawed".