Nature 3/5/14: Bold New Strategy In Dark Matter Search?

I note that Livio's and Silk's Nature Comment on dark matter
candidates is exclusively devoted to dark matter composed of ad hoc
and purely speculative particle dark matter.

There is no discussion of astrophysical candidates for the galactic
dark matter, such as primordial black holes, unbound planetary-mass
"nomads", new classes of isolated neutron stars, and ultracompact
objects we probably not even imagined yet.

Livio and Silk call for new thinking in the search for the enigmatic
dark matter that dominates the matter of the cosmos, but then they
just take us around the same old race track of purely hypothetical and
poorly-motivated "sparticles", "WIMPs", "axions", etc.

Where is the bold new approach? Why are the arguments by MRS Hawkins
for stellar-mass black holes routinely ignored?

Let's have some really new thinking on these issues.

Robert L. Oldershaw
http://www3.amherst.edu/~rloldershaw
Discrete Scale Relativity/Fractal Cosmology

In article , "Robert L.
Oldershaw" writes:

I note that Livio's and Silk's Nature Comment on dark matter
candidates is exclusively devoted to dark matter composed of ad hoc
and purely speculative particle dark matter.

Obviously, candidates for dark matter must be speculative; if they
weren't, there would be no puzzle. They are not, however, ad hoc.

There is no discussion of astrophysical candidates for the galactic
dark matter, such as primordial black holes, unbound planetary-mass
"nomads", new classes of isolated neutron stars, and ultracompact
objects we probably not even imagined yet.

Because these have been ruled out by other arguments and this is well
documented in the literature. Also, let me point out that "objects we
probably not even imagined yet" are definitely speculative and ad hoc.

Livio and Silk call for new thinking in the search for the enigmatic
dark matter that dominates the matter of the cosmos, but then they
just take us around the same old race track of purely hypothetical and
poorly-motivated "sparticles", "WIMPs", "axions", etc.

I think the "same old race track" could apply just as well, if not
better, to your claims.

Where is the bold new approach? Why are the arguments by MRS Hawkins
for stellar-mass black holes routinely ignored?

They are not ignored. They have been published in the refereed
literature. They have been found wanting in the refereed literature.
Hawkins is the one who has been ignoring criticism. The very least is
that he could acknowledge arguments against his claims even if he
doesn't agree with them. He has not done this. He has thus
unfortunately placed himself outside the scientific community. No-one
else has shown that the criticisms are invalid.

Op woensdag 12 maart 2014 23:02:52 UTC+1 schreef Phillip Helbig:
In article , "Robert L.

Oldershaw" writes:

Where is the bold new approach? Why are the arguments by MRS Hawkins
for stellar-mass black holes routinely ignored?

They are not ignored. They have been published in the refereed
literature.

The problem is that even if stellar-mass black holes exist than that
is not the solution for the dark matter (dark energy) problem.

The dark matter problem comes in two flavours.
First what is dark matter (non-baryonic) in the first place?
This issue is mainly discussed in the Nature article.
The sad thing is that even if (new) dark matter particles are
discovered the dark matter problem is not solved.
Secondly how much dark matter is missing.
This issue is not discussed in the Nature article.
Of this issue there are four flavours.
1. How much missing matter is there in the solar system?
Almost zero. See page 153 of the book "The Big Bang" by Joseph
Silk 1989. Here we read that the Sun contains a tiny fraction.
2. How much missing matter is there in our Galaxy.
The galaxy rotation curve is used to tackle/solve this problem.
3. How much missing matter is there in the local cluster
and in the clusters surrounding us.
(This issue is discussed in a different thread)
4. What about the CMB radiation.
In order to "explain" the CMB radiation of all matter in the universe
20% is baryonic and 80% non-baryonic (cold dark matter)
The problem is that this result is not in agreement (or not mentioned)
in arxiv.org documents related to item 3 and 4.

In the book TBB at page 237 we read "that the nonbaryonic alternative
for darkmatter is in an equally unsatisfactory state".
In that book to solve the problem blackholes white-dwarfs reddish-
dwarfs and neutron stars are considered

In the Nature article we read:
"If dark matter remains undiscovered then physicists will have to
seriously reconsider alternative theories of gravity."
IMO this is not necessary. The most important issue is #4.
How sure are we that solely by observing the CMB radiation
(which mainly is an imprint what happened 300000 years after the BB)
we can calculate that in our immediate neighbourhood (at present)
80% of all matter is non-baryonic?
One assumption can be that this relation already existed 300000 years
after the BB, but I do not know if that is true.

Chapter 8 in the book TBB "The Primeval FireBall Emerges" gives
the impression that almost all matter during this period after the
BB is baryonic (protons, electrons). The next most important (energy
related) factor to consider are photons (radiation).
At the end of this period 300000 years after the BB Hydrogen atom
formation started (page 164) which was ended at 1 million years.
Nowhere is mentioned that at that moment 80% of all matter is non-baryonic.

IMO the reasoning behind this 80% figure should be reconsidered.

Nicolaas Vroom