Critical Test for the Big Bang and Discrete Fractal Paradigms

Joseph Lazio wrote:

While interesting, if you're using intraday variability (IDV) in the
usual sense, it is not mysterious. There have been quite convincing
observations that IDV results from a radio-wave propagation effect in
our Galaxy.


replied:

Would you please explain a bit more about the physics involved? What
would be the cause of the "radio-wave propagation effect in our
Galaxy"?

Go to ADS

http://adsabs.harvard.edu/abstract_service.html

Type "scintillation radio waves interstellar" into the "Abstract words"
box.
Click on "submit". Scan the returned list of titles. Read a few
abstracts,
then a paper or two.

Michael Richmond

Stupendous_Man wrote:

Go to ADS

http://adsabs.harvard.edu/abstract_service.html

Type "scintillation radio waves interstellar" into the "Abstract words"
box.
Click on "submit". Scan the returned list of titles. Read a few
abstracts,
then a paper or two.

Michael Richmond


Thanks for the recommendation. If you could identify a specific review
paper that gives a good, up-to-date summary, I would welcome that. I
had also downloaded astro-ph/0610737 by Mark A. Walker entitled Extreme
Scattering Events: Insights Into The Interstellar Medium On AU-Scales",
and started reading it.

Is it generally accepted that there are previously-largely-unknown
AU-sized, spherically symmetric "objects" composed of plasma, and in
numbers possibly approaching 10^5 times the number of stars? Am I
reading this correctly? Who ordered these objects?

Robert L. Oldershaw

"re" == rloldershaw@amherst edu writes:

re Stupendous_Man wrote:
Go to ADS

http://adsabs.harvard.edu/abstract_service.html
Type "scintillation radio waves interstellar" into the "Abstract
words" box. Click on "submit". Scan the returned list of titles.
Read a few abstracts, then a paper or two.

re Thanks for the recommendation. If you could identify a specific
re review paper that gives a good, up-to-date summary, I would
re welcome that.

Rickett (1990, ARAA, URL:
http://adsabs.harvard.edu/cgi-bin/np...%26A..28..561R
) is a good place to start.

Although a bit obscure, an extremely lucid discussion is in Narayan
(1992, Proc. R. Soc. London A, 341, 1510.

Finally, there are a couple of conference proceedings that are also
useful:

Cordes, James M.; Rickett, Barney J.; Backer, Donald C.
Radio wave scattering in the interstellar medium; Proceedings of the
AIP Conference, University of California, San Diego, CA, Jan. 18, 19,
1988

(I forget the title, but the proceedings are
Astrophysics and Space Science, v. 278, Issue 1/2, p. 5-10, 2001.)



re I had also downloaded astro-ph/0610737 by Mark A. Walker entitled
re Extreme Scattering Events: Insights Into The Interstellar Medium
re On AU-Scales", and started reading it.

re Is it generally accepted that there are previously-largely-unknown
re AU-sized, spherically symmetric "objects" composed of plasma, and
re in numbers possibly approaching 10^5 times the number of stars?
re Am I reading this correctly?

I wouldn't say "previously-largely-unknown." Their effects were first
reported by Fielder et al. (1987). As for their numbers, densities,
and geometries, by-and-large all we measure are one-dimensional cuts
through these objects (though that may be changing with some of Dan
Stinebring's work). *If* one models them as spherically symmetric
objects, then, yes, they do appear to have extreme properties.
However, even a casual perusal of a dust cloud or similar image may
cause one to wonder about the appropriateness of assuming spherical
symmetry.


re Who ordered these objects?

I often wonder if the casual sci.astro reader understands my comment
that I wasn't consulted about the design of the Universe.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

Joseph Lazio wrote:


During the past month there have been no major developments regarding
the critical paradigmatic test discussed above, but there has been at
least one notable, although tentative, addition to the observational
evidence.

M.R.S. Hawkins has submitted a paper to A&A regarding timescale
variations in AGN. Free copies can be obtained at www.arxiv.org , by
searching on Hawkins or looking up astro-ph/0611491. In this paper data
from two largescale AGN monitoring programs have been combined and
analyzed for timescale variations.

At this point one cannot unambiguously say whether the observed
variations are due to microlensing or due to intrinsic variations by
the quasar (or presumably some combination of the two).

However, if the timescale variations are due to microlensing, then

1. the lower limit mass for the lenses is ~ 0.4 solar masses, and

2. the number of lenses must be significantly more abundant than the
abundance inferred from the MACHO results (Alcock, et al, ApJ, 486,
697, 1997); moreover

3. the results are consistent with derived lens estimates of ~/ 0.2
solar masses for Q2237+0305 (Kochanek, C.S., ApJ, 605, 58, 2004) and
~/ 0.5 solar masses for Q0957+561 (Refsdal et al, A&A, 360, 10, 2000).

So the new results are still tentative, but it cannot escape notice
that this study joins a large and growing list of observations that
*suggest* a very large number of dark matter objects within the
conservative mass range of 0.1 - 0.6 solar masses.

Excuse me for pointing this out again, but I think it is very
important. The full range of possible masses for dark matter candidates
extends over a range of 10^70. From within this enormous range, the
Discrete Fractal paradigm predicted (see ApJ reference above) that the
dominant galactic dark matter populations would be observed to fall
within the mass range of 0.1 - 0.6 solar masses (two sharp peaks at
0.15 and 0.58 solar masses).

Surely, the wait for a definitive resolution of the test cannot last
too much longer (he says with a wistful sigh).

Robert L. Oldershaw

In article ,
" writes:

M.R.S. Hawkins has submitted a paper to A&A regarding timescale
variations in AGN. Free copies can be obtained at www.arxiv.org , by
searching on Hawkins or looking up astro-ph/0611491. In this paper data
from two largescale AGN monitoring programs have been combined and
analyzed for timescale variations.

At this point one cannot unambiguously say whether the observed
variations are due to microlensing or due to intrinsic variations by
the quasar (or presumably some combination of the two).

However, if the timescale variations are due to microlensing, then

1. the lower limit mass for the lenses is ~ 0.4 solar masses, and

2. the number of lenses must be significantly more abundant than the
abundance inferred from the MACHO results (Alcock, et al, ApJ, 486,
697, 1997); moreover

In other words, there must be a contradiction with the well studied
MACHO result.

Excuse ME for pointing this out again, but I've pointed out a couple of
times here before (with refereed-journal references) that Hawkins's idea
that QSO variability is mainly caused by microlensing is interesting,
but doesn't stand up to a quantitative analysis.

To those who work in the field, citing Hawkins as support of your idea
is not going to lend it credibility; quite the opposite.

To quote: "If the variations are interpreted as due to gravitational
microlensing". Even if everything else is correct, this is an
ASSUMPTION. However, this assumption has been ruled out, since if the
variations were due to microlensing, the statistical properties of QSO
light curves published by Hawkins himself should be different than what
they are.

Actually, one could probably rule out your idea, since if all the dark
matter is in these objects, it WOULD cause significant QSO variability
by microlensing, but that has been ruled out. You're in good company:
your theory makes a testable prediction and was tested. It was ruled
out. End of theory. No amount of selective citing will save it.

Phillip Helbig---remove CLOTHES to reply wrote:

Actually, one could probably rule out your idea, since if all the dark
matter is in these objects, it WOULD cause significant QSO variability
by microlensing, but that has been ruled out. You're in good company:
your theory makes a testable prediction and was tested. It was ruled
out. End of theory. No amount of selective citing will save it.


You are remarkably sure of yourself! Would you go so far as to say that
there is absolutely no chance that you could be wrong?

My post clearly noted the tentative nature of the Hawkins paper.

You say (without citing actual scientific evidence) that the
microlensing interpretation for at least part of the variability has
been ruled out. Apparently the editors and referees at A&A take a more
open-minded view of the situation. Otherwise they would have rejected
the paper or insisted that the microlensing interpretation be removed.

Are we sure that we have considered an adequate range of possibilities
for the spatial distribution and velocity distribution of the dark
matter objects in the AGN setting, before summarily dismissing the
whole idea? I suspect that those who do reject the whole idea are
basing their rejection on an over-simplified models for those
distributions.

I think that it is quite possible that our understanding of QSOs is
still rudimentary and contains significant gaps. Summary dismissals
based on current understanding are probably premature.

Robert L. Oldershaw

I am currently reading "A Survey of 56 Midlatitude EGRET Error Boxes
For Radio Pulsars" (ApJ 652, 1499-1507, Dec 1, 2006).

Basically the story is as follows. The EGRET observations detected 50
to 100 gamma-ray sources at mid-Galactic latitudes. These sources are
quite faint and have steeper spectra than their counterparts at lower
latitudes; their energies are 100 Mev. The questions a What are
these very faint but very energetic sources, and are we seeing the
"tip-of-the-iceberg" type of situation where a very large population of
high-energy sources is out there but are mostly just below current
detection and resolution capabilities?

The cited paper explores the possibility that these mystery sources are
pulsars. Of the 56 source error boxes tested, 13 contained pulsars and
43 mystery sources remain a mystery.

The authors conclude: "Non-pulsar source classes should therefore be
investigated further" and noted that microquasars (black holes in
binary systems) might be a possibility.

It seems to me that a second front is opening up in the critical test
of paradigms that is the topic of this thread. Previously I believed
that microlensing were the best way to resolve the issue of whether or
not there is a huge Galactic population of stellar-mass black holes, as
predicted by the Discrete Fractal Paradigm. Now I am beginning to think
that gamma-ray experiments may provide an equally important, and
possibly more definitive, source of data for this test.

Does anyone have updated information on the status of the advanced
AGILE and GLAST satellites which were scheduled for launch somewhere in
the 2006-2008 time frame? These missions offer order-of-magnitude
increases in sensitivity in the important energy range of 1 Gev to 200
Gev. The combination of microlensing results and gamma-ray results
should be extremely useful in answering the key question of this
thread.

Robert L. Oldershaw

wrote:


Regarding the critical test between the Discrete Fractal Paradigm and
the Standard (Big Bang+Inflation) Cosmological Paradigm, which is the
subject of this thread, some interesting observational results were
made available last week.

In astro-ph/0701325 at www.arxiv.org, Raiteri et al report on optical
spectroscopic monitoring of the BL Lac object AO 235+164. Results for
the broad line region do not fit well with a microlensing
interpretation. Variations in the continuum flux coming from a smaller
and more central region, on the other hand, are consistent with a
microlensing interpretation.

Most relevant to this discussion is the fact that the typical timescale
of the variations (2-3 months) implies lens masses of ~10^-4 solar
masses, as reported by the authors of this preprint. This is quite
consistent with the predicted 8 x 10^-5 solar mass ultracompacts
specified by the Discrete Fractal Paradigm. This class of
planetary-mass dark matter objects is highly diagnostic since no other
theory predicts anything remotely similar.

These results are limited and tentative, but once again one of the two
specific masses uniquely predicted by the DFP has found *empirical*
support.

Microlensing in a quasar (QSO 2237+0305) has recently been
unambiguously identified and reported (astro-ph/0701300), but no mass
estimates are given in their preprint.

RLO

On Jan 15, 3:40 am, "
wrote:
wrote:


In an effort to keep this thread alive, since I hope that in the not-
too-distant future some highly significant test results will become
available, I offer a brief report on some new data on BL Lac
variability and its possible interpretation in terms of microlensing.

In astro-ph/0701420 at www.arxiv.org the authors Ciprini et al discuss
the variability of the BL Lac object PKS 0735+178.

This system had been monitored for decades and characteristic
timescales in the variations are reported. The "rather achromatic
behavior" has two general times scales: short-term events with
timescales of roughly 27-79 days, and long-term events with timescales
of 4.5-13 years.

If my memory serves me well, numerous authors who have studied QSO
microlensing, such as Refsdal, Gunn, Schild, Hawkins, Schneider, and
many others, have demonstrated that the approximate timescales for
stellar-mass lenses should be on the order of 10 years, and the
approximate time scales for planetary-mass lenses should be on the
order of 90 days.

These two timescales are rough estimates that have to be refined to
take into account the actual parameters of the system being studied.
It is interesting that the newly reported data for PKS 0735+178 once
again suggests the *possibility* of microlensing by two distinct
populations of lenses: a planetary-mass population and a stellar-mass
population.

Clearly, one cannot claim that this new data changes the status of the
"Critical Test" of this thread. It is one more piece of evidence that
could be interpreted in a number of different ways. However, the new
results reaffirm previous observations of two distinct timescales in
the variability of distant QSOs and AGN. In the long run, this may be
an important and diagnostic feature of QSO variability, and its
possible microlensing interpretation.

Robert L. Oldershaw

" wrote:

In an effort to keep this thread alive,
since I hope that in the not-too-distant
future some highly significant test results
will become available,

Thanks for reminding me of a question I've been
wanting to ask here. I read that the Hubble
suffered some major breakdown just short of
its expected lifespan. I'm not claiming I have
any idea what was lost in terms of hardware.
I'm not claiming I know what the planned 2008
mission can return to service, either.

What I want to know is, what was lost in terms
of expected data that would have been settling
or lending support/dismissal to some proposed
solutions of some of the "big questions" here?

What was "upcoming" that is now "indefinitely
delayed"? Are other, planned tools going to
provide this data later, or are we "back to
square one" in some cases?

IMWTK

xanthian.