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Mysterious Dark Matter Blob Confounds Experts
mayberry42 writes "Astronomers using the Hubble Space Telescope are mystified by a merging galaxy cluster known as Abell 520 in which concentrations of visible matter and dark matter have apparently come unglued. A report on the Hubble observations, published in the Astrophysical Journal, raises more questions than answers about a cosmic pile-up that's occurring 2.4 billion light-years away. 'According to our current theory,' says Arif Babul, the study team's senior theorist, 'galaxies and dark matter are expected to stay together, even through a collision. But that's not what's happening in Abell 520. Here, the dark matter appears to have pooled to form the dark core, but most of the associated galaxies seem to have moved on.'"
We can't directly observe air either (in most cases), but can still measure its effects.
Table-ized A.I.
It's pretty conventional, when discussing astronomical observations, to use the present tense for "when we see it." Since it can't possibly have any effect on us before the light from the event gets here (assuming relativity is correct, yadda yadda) this makes sense. Also, having to say "2.4 billion years ago 2.4 billion light-years away" would just get annoyingly redundant after a while.
There's pedantry which serves the useful purpose of correcting other people's mistakes, and then there's pedantry of the "look how clever I am" variety; posts like yours, which seem to get posted to every single story on any kind of astronomical event that takes place outside the solar system, are examples of the latter.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
"Dark matter" isn't simply regular matter/particles that we just can't see due to not emitting light. We may not know quite what it is, but we have a pretty good idea about what it is not, and that's regular matter as we know it.