200 Billion Planets + 160 Billion Planets = Whole Lot of Planets!

On Jan 21, 9:17*am, Phillip Helbig---undress to reply
wrote:
In article , "Robert L.

Do they claim that stellar-mass primordial black holes make up an
appreciable fraction of the dark matter?

PS: I really have no desire to continue discussions with anyone who
claims or implies that they know the answers to scientific questions
before they are answered empirically.

Let's see---DSR was published long before there were large-scale
microlensing detections of compact objects. *You have claimed to know
the answer to the question of what the dark matter is before there was
any empirical answer.
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(1) I did a search on "Primordial Black Holes" at arxiv.org papers
posted from 2005 to 2012 and found 124 entries. These are just the
papers with "PBHs" in the paper title. Many more papers discuss the
issue without having "PBH" in the title.

In scientific publications I have not claimed that I "knew" what the
dark matter was. I argued that there were theoretical and empirical
motivations for treating PBHs as a leading dark matter candidate.

As a scientist, I eschew absolutes - especially when it come to the
issues of what we know and what we do not know.

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

In article , "Robert L.
Oldershaw" writes:

Do they claim that stellar-mass primordial black holes make up an
appreciable fraction of the dark matter?

(1) I did a search on "Primordial Black Holes" at arxiv.org papers
posted from 2005 to 2012 and found 124 entries. These are just the
papers with "PBHs" in the paper title. Many more papers discuss the
issue without having "PBH" in the title.

Right. The crucial question is whether it is possible that they make up
an appreciable fraction of the dark matter. I am not aware of any
serious theoretical problems with this, but as you know my conclusion is
that it is observationally ruled out. At one time, dark baryons (before
tight BBN constraints) and neutrinos (before their masses were tightly
constrained) were considered as candidates for making up a significant
fraction of the dark matter. Both are now ruled out, but of course
there are still papers being written on dark baryons (e.g. cold gas) and
neutrinos.

In scientific publications I have not claimed that I "knew" what the
dark matter was. I argued that there were theoretical and empirical
motivations for treating PBHs as a leading dark matter candidate.

Yes, there were. But if the observations rule them out, then too bad.

Do you know of anyone other than Mike Hawkins who claims that PBHs make
up a significant fraction of the dark matter?

(Of course, even if they did, it still doesn't mean that DSR is right.
If this mass quantization is really observed, then that would be really
interesting, but as has been pointed out many times, one has to handle
both the theoretical and observational errors correctly and have a
well defined sample which was defined without any reference to possible
mass quantization. In other words, citing a few systems where the fit
looks good isn't convincing.)

I've known Mike Hawkins personally since 1994. I think his first couple
of papers on this topic were brilliant, and for a while I entertained
the idea that PBHs might make up a significant fraction of the dark
matter. I spent a lot of time on this (some of the stuff is published,
some is not) but came to the conclusion that the idea is observationally
ruled out. Unfortunately, Mike Hawkins seems to paint himself into a
corner here; it would be nice if he would at least address published
criticism in his papers.

"Robert L. Oldershaw" wrote in
:

On Jan 21, 9:17*am, Phillip Helbig---undress to reply
wrote:
In article , "Robert L.

Do they claim that stellar-mass primordial black holes make up an
appreciable fraction of the dark matter?

PS: I really have no desire to continue discussions with anyone who
claims or implies that they know the answers to scientific
questions before they are answered empirically.

Let's see---DSR was published long before there were large-scale
microlensing detections of compact objects. *You have claimed to know
the answer to the question of what the dark matter is before there
was any empirical answer.
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(1) I did a search on "Primordial Black Holes" at arxiv.org papers
posted from 2005 to 2012 and found 124 entries. These are just the
papers with "PBHs" in the paper title. Many more papers discuss the
issue without having "PBH" in the title.

Is that the extent of your research on the subject?

Have you, say, done any research on the microlensing surveys designed to
look for these things? You know, the important bit in the scientific
method you claim to adhere to, where you actually test your predictions?

If you had, you would have seen that pretty much the entire mass range of
primordial black holes have been excluded as dark matter, with that last
bit being worked on at this time with no real expectation that there is
anything there.

Note that the mass range that your predictions lie in has been rather
resoundingly excluded by observation.


In scientific publications I have not claimed that I "knew" what the
dark matter was. I argued that there were theoretical and empirical
motivations for treating PBHs as a leading dark matter candidate.

What about now, given the fact that microlensing searches have shown that
the theory is wrong?


As a scientist, I eschew absolutes - especially when it come to the
issues of what we know and what we do not know.

As a scientist you should probably listen to the literature that
disagrees with you, rather than ignoring it. Just a thought.


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

I want to share with you which i little know about planets which is that Even with 500 million planets with intelligence, the typical distance between them is going to be huge, about 40 light years. And I think that we would be very lucky to find one within 200 light years. There is not way that we can detect cities at that distance. It would take 20,000 years for a space probe to cross that distance.