Re: swift grb data rules out beamed theory


Craig Markwardt wrote:
"sean" <jaymoseley@xxxxxxxxxxx> writes:

Craig Markwardt wrote:
"sean" <jaymoseley@xxxxxxxxxxx> writes:
...
Note from my quotes that I have stated that rapid
variations in the optical lightcurve should be
seen if the time scale of the sampling were short
enough. One of my theoretical criticisms of current
procedures and beamed theory was that the power law
fitting of optical data employed by the astrophysics
community was in fact a misguided procedure
that disguises the true variability of magnitude within
the optical lightcurves by incorrectly smoothing out
the observed variability in the the optical lightcurve,
particularly in early time lightcurves where
flucuationsare more easily seen due to the relative
brightness of grb afterglow.
Note that Craig seems to be in denial that power
law fitting takes variable brightness observations
and fits them to a straight line power law.
Especially considering that Craig himself has insisted
many times that the decay rate is best described by
a smooth power law decay with at most 1 break.
Here is Craigs quote from years ago trying desperately
to show how my non `power law` approach is just not
acceptable
"..Also, as has been pointed out, trying to infer that
something is a "peak" when the data are as noisy
and as sparse as they are, is in my view a dubious
practice. Simply "connecting the dots" will lead
to *a possible* solution, but ultimately a very
*low probability* one a priori.
A more appropriate approach would be to start with
a featureless model of the decline (say, a power law),
then add a gaussian or some other simple
parameterization of the putative peak. By computing
the F-statistic, one can then find out how significant
the additional peak is, statistically speaking,.."

And here is Staneks reply that this method as endorsed
by Craig is basically, well unscientific as regards grb`s..

"....but with clear short-timescale variations, as
reported before by Morris et al. (2006b). Trying to
describe these erratic events with smoothpower-law
fits is often a dubious statistical proposition..."

Note how Stanek clearly criticises Craigs approach
and endorses my argument that the small time scale
variations in optical data has to be accepted
without ANY power law smoothing.>
... much snipped ...

"Sean," I am not sure what prompted this strange post. It appears
that in many cases you have completely misinterpretted my words or
taken my posts out of context. Examples: (1) the Feb 2001 post that
you cite several times, was a discussion of a *single burst* afterglow
(GRB 970508), not all afterglows in general. (2) It was a discussion
of ways to *admit* (not reject!) variability interpretations in a case
of a noisy and poorly sampled light curve. (3) You are fixated on a
"power law." However, I gave that as an *example,* "(say, a power
law)," but not an exclusive example. I have always been in favor of
letting the data drive the analysis. Sometimes the "flares" are
obvious and no statistical test is needed. However, the discussion in
2001 (GRB 970508) this was not the case. Certainly in the pre-Swift
era almost all detected afterglows were quite smoothly decaying
(Berger et al 2005 and interpret them as a normal human being would.
This is a ridiculous argument you make here.You are trying
to have it both ways. Stanek shows that power law fitting
cannot be considered acceptable. You clearly did think it
was acceptable previously as the example you cited above
was clearly intended as a sample of how one had to use
it as the norm.
Not as you now pretend as an exception. You are rewriting
history to make it sound like you thought all along that
fitting lightcurve data to power law was wrong now that
you know Staneks research results vindicate my argument
and trash yours.
Anyways look at Martin Hardcastle and Joe Lazio. They
definitely say power law etc is neccesary even if you
pretend you didnt. AND I`ve supplied quotes that
clearly show you support its use in grb studies.
I admit Some quotes you dont use the word `power law`.
Buts its all the same. If you want to take the data,
use error bars and do fittings to within parameters etc .
Thats power law fitting and you know it. Anyways in the
pre Swift era there are lots of examples of decay rates
in afterglows that are spikey. You just think theyre
smooth because you power lawed them all into straight
lines! Just as Stanek says now is unsuitable for grbs.
Just as I predicted a priori in 2001
There are other examples of your bizarre
misreading of my posts (discussion of the "flat part" of GRB
060210??). I encourage you to read the words that I actually wrote,
Your point about my `flat` referernce if I can
explain. First your quote..

Craig "..Or, while the gamma-ray light curve for
GRB 060210 has multiple peaksspanning hundreds of
seconds, the available optical light curve has only
a single peak. Again, not a copy. Your theory is
not really vindicated at all..."

The bat light curve available to me shows only 20
seconds of fine bin sampling so I wasnt sure where
you got the `100`s of seconds`. But in the Stanek paper
only the X ray was compared to optical (R) and there X
is 100`s of seconds so I assumed you were mistakenly
refering to that as the gamma lightcurve. Stanek
compares the spikey x curve with the flat part of the
R-optical curve. So I had to try to read your mind
there and assume you were referring to X not BAT and
comparing that to the flat part of the early optical.
Sorry if I got you wrong on that. But the fact is that
your statement says 2 incorrect things. First you say
gamma has 100s of seconds of multiple peaks whereas my
available download has a clear rise and fall in only
about 20 sec (albeit with multiple smaller peak
features within that broad rise decay envelope.)
Even if you include what looks like post burst noise
after 20 sec its not clear its spikey from the graph
and its much lower brightness than the main part of
the 20 second burst.
And secondly you say that optical has only one peak
when it clearly has at least 4. And then even the
sampling is limited. If you care to supply a bit
more detail to explain how you get 100s of seconds
in gamma please do. But optical definitely has more
than 1 peak. And furthermore all 3 X, gamma and
optical have the same overall profile as I say
exists in all grbs. AND each decay starts later
and is longer proportional to where the wavelength
is longer. So gamma is 10s of seconds, X 100`s of
seconds and optical is thousands ,
Exactly as I predicted in 2001. And exactly as
you said was not possible in 2001.
Im right again , youre wrong. And I use Swift
era data as my proof. You only use false imaginary
data.

It would probably be quite convenient to you if you did not have to
provide any quantitative measure of the success or failure of your
"theory," which you claim works for all bursts(!). However, being
objective usually involves being quantitative. Your manner of
"analysis" suggests a large amount of cherry-picking and *sub*jective
interpretation, which is prone to huge biases. I can only encourage
now, as I did in 2001, for you to try to remove your personal biases
and stake in this issue so that you can be objective.

I suspect that you don't really understand the nature of error bars
and uncertainty, much less what data modeling is. These are basic
issues in science and analysis that can't be ignored. Measurement
uncertainties (both statistical and systematic) fundamentally limit
how we can interpret the data. I encourage you to learn about
probability and statistics. A text like Bevington (2002) is great.
This repeated argument you use (that I dont understand
error bars etc) is dishonest, libelous and untrue.
To start with I have made analysis of other data in the
past using chi squared fitting error bars etc and
even posted results here on this group to you!!!. Thats
the first example of how disreputable you are in falsely
suggesting I dont understand traditional data analysis .
I have online proof to show your accusations are false.
How could I calculate and supply fits of data to error
bars etc if I didnt understand data analysis?
The second lie you peddle is that I dont accept its
use generally in the sciences. As usuall your
mudslinging is meant to confuse other readers and
disguise the fact that It is me who supplies
the more scientific methods , not you in grb studies.
Staneks paper shows you to be incompetent and you are
trying to divert attention away from the fact that you,
Martin Hardcastle and Joe Lazio have presented arguments
that are now discredited by Staneks paper.
The fact is that I have never promoted the falsehood
that you peddle that I believe that data fitting using
error margins power law etc is unsuitable for all
scientific research. I have always said that it is only
in the analysis of grb afterglows that power law smoothing
shouldnt be used. I say this because my model predicts
that the lightcurve in optical should exhibit multiple
fluctuations of much greater magnitude than even that
suggested by those suggested in optical lightcurve data
currently.
In turn this implies that although I dont deny that a
observed rebrightening could be due to observational
error margins , in fact its more likely that its a real
rebrightening and most likely more extreme and frequent
than is seen even in the optical data.
The only conclusion I can reach theoretically is that
rather than being too spikey due to observational error,
the lightcurves are too smooth due to too long and not
frequent enough exposures in optical bands. Thats why
I argue that the last thing a scientist must do is to
smooth out the data even more than those limitations
inherent in observing in optical imply.
Hence my objection to power law use in grb analysis.
But never do I say that in other fields the same must
be applied. And thats the filthy lie you peddle to make
my arguments appear less credible.
I demand you apologize for peddling lies that I dont
understand chi squared and power law smoothing and I
demand an apology from you for your lie that I dont
accept that use of power law smoothing chi squared
etc is suitable in any other fields of scientific
research.


It's not possible to have a "discussion" with you, if you insist on
warping words and taking postings out of context. Assertions need to
be substantiated. You are certainly free do to what you wish, but it
won't involve me.
Its not possible to have a honest discussion with
you as long as you peddle lies
like all your above false accusations to cover
your own discredited arguments (see your quotes at beginning
of this thread and Staneks confirmation that you were wrong)
An apology from you is in order.

Sean
www.gammarayburst.com

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