Thread: Dark matter is:
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Old November 2nd 17, 02:40 AM posted to sci.astro.research
Phillip Helbig (undress to reply)[_2_]
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Default There is nothing there (Xenon Collaboration)

In article , jacobnavia
writes:

First Dark Matter Search Results from the XENON1T Experiment:

quote from the abstract
A profile likelihood analysis shows that the data are consistent with
the background-only hypothesis.
end quote

There is it. One Ton of Xenon liquid/gas and years of effort show us
that there is nothing there. The detector doesn't detect anything but
background noise.

This means that since there is nothing exotic, matter has behaviours
that we do not understand at all.


No. It means that this detector didn't detect what it could have
detected. It doesn't mean that dark matter is ruled out. It doesn't
even mean that WIMPs are ruled out.

WIMPS were tied to CDM cosmology and their absence means that many
theories are just wrong.


Where are WIMPs tied to CDM cosmology? Dark matter, yes, but dark
matter doesn't have to be WIMPs. In particular, it could be
self-interacting and form objects the size of a baseball, or a house, or
a mountain. Or it could be in primordial black holes of 100 solar
masses or so (smaller ones are ruled out by microlensing).

At each scale then, we can discover new forces that attract matter to
itself. At galactic scales this attractive force holds the disk spinning
like a rigid whole.


No. You are referring to flat rotation curves of galaxies. This
doesn't mean that the angular speed is constant with radius
(approximately, and above some minimum radius), but rather the actual
physical speed. Rigid rotation would imply that the speed of rotation
increases with distance.

And no, I can't calculate that. Astronomers can, doesn't look (to me) a
very difficult undertaking. They have the mass distribution of the
galaxy, what can be accounted by gravity, and the rest. This rest is the
effects of that force.


Yes, this is MOND, essentially.