This ridiculous story (linked below) is a clear example why cosmology needs a Cosmology Uncertainty Principle. I posted about that principle on June 12.
The first line in the attached story:
A massive clump of dark matter may have plowed through a conga line of stars streaming around the Milky Way,
Because the line of stars is not exactly as astronomers expect, the culprit must be dark matter. The possibility that maybe the stars do not always move as predicted is rejected.
This certainty in a prediction from a model cannot be justified.
To prevent this silliness based on certainty cosmologists need the Cosmology Uncertainty Principle.
It is simple: Certainty is not possible at the galactic scale.
These invocations of dark stuff to explain shortcomings in models should not be tolerated. Cosmologists cannot justify their certainty. Any conclusions drawn from that should be discarded.
It is simply impossible to be certain about predictions in cosmology when based on probabilities.
It is impossible to precisely model the motions of a trillion stars in a galaxy, each affected by the motions of all the others. This model must use probabilities to approximate these motions. This model is always an approximation. This approach can get close but never precise. The outcome of a combination of probabilities cannot be predicted with certainty, in games with cards or dice, or in cosmology. However cosmologists reveal that misplaced confidence in their models in their conclusions. This leads to nonsense.
In this story the model must be right but the infamous dark matter ruined the prediction for the star locations, not the model based on probabilities.
This is the laughable explanation in the story, having absolutely no basis, with a random mass, velocity, and time:
the researchers believe the intervening object could be a 5 million-solar-mass blob of dark matter that ripped through the stream at over 500,000 miles (800,000 kilometers) per hour roughly half a billion years ago.
It starts with 'believe' and 'could be' and despite big numbers never includes something believable.
This is not science; this is fodder for tabloids.
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