🚀 go-pugleaf

On Thu, 16 Aug 2007 12:40:41 -0700, dlzc <dlzc1@cox.net> wrote:

>DEar John C. Polasek:
>
>On Aug 16, 9:20 am, John C. Polasek <jpola...@cfl.rr.com> wrote:
>> On Thu, 16 Aug 2007 07:44:41 -0700,dlzc<dl...@cox.net> wrote:
>...
>> >> The disparity between redshift and intensity
>>
>> >Do you have a citation?  Is intensity higher or
>> >lower than redshift would indicate?
>...
>> >http://www.astro.ucla.edu/~wright/cosmo_01.htm
>> >.. so you get from 1+z to distance via a linear
>> > transformation ("scale factor").
>>
>> > Doppler really doesn't give you distance, just
>> > change in distance.
>>
>> It should give recession velocity, from which a
>> proper H0 would give distance.
>
>As you are aware, the value of H0 is applied directly to (1+z).
>
>...
>> >> The discrepancy might be corrected with proper
>> >> algebra, instead of dark energy.
>>
>> >Get rid of Dark Matter, and there is almost no
>> >need for Dark Energy.  MOND almost works, and
>>>TeVaS does work (as far as I know) at getting
>> >rid of Dark Matter.
>>
>> Excuse my error: what I meant was acceleration,
>> not expansion.  Acceleration of expansion rate is
>> the current big phenomenon being investigated, in
>> which it is universally presented that the observed
>> intensity of SN1A's is lower than might be
>> expected by square law 1/D^2.
>
>Still, do you have a citation?
>
>> No question, you can measure redshift. From it
>> there are several ways of deducing distance. But
>> nowhere do I see it displayed, what equation
>> is being used.
>
>I believe it is straightforward, comparing intensity at characteristic
>times in the "decay curve", to more local "members of the SNIa
>community".  I will have to review the pdf I have at home tonight, and
>I will reply to your message with a link on arxiv.org.
>
>> From astro.ucla (above) you imply a/a0 = 1+z
>> from which 1/D^2 would be proportional to
>> 1/(1+z)^2 but the observed intensity is markedly
>> lower.
>
>I don't find that in the paper, which is why I keep asking for a
>citation.

One paper is http://www.pnas.org/cgi/reprint/101/1/8.pdf which is easy
to read, whose title is Hubble's diagram and cosmic expansion. There
are others. Fig. 6 shows the magnitude deviation d(m - M) for z's to 1
for several percentages of dark energy. 
Even better is http://www.astro.ucla.edu - Supernova Cosmology (which
has Ned Wright's imprimatur it turns out).
>> Time dilation applied to the decay curve is some
>> part of the analysis, but that calculation implies
>> recession velocity, not a/a0.  The papers I have
>> read are quite abstruse, trying to get a handle on
>> the impact of "quintessence", I believe.  It seems
>> there's plenty of places to scrutinize the
>> transformation from redshift to distance or time
>> dilation to distance, enough room for simple
>> error to explain away acceleration.
>
>Much easier for me to believe that the Universe had more "free dust"
>in earlier ages, which would give lower intensities now.  After all,
>we discuss how all these stars are forming, and planets are forming,
>and supernovae are more prevalent in earlier times...
>
>And even easier for me to believe that expansion (even without
>acceleration) is creating places that light could not possibly have
>been directed towards at the time of emission.  Granted, this is an
>"infinitessimal, interstitial" creation... but we are not located
>entirely at the "spherical D surface" that the light was originally
>aimed at, but would have been apparently diced into little bits, and a
>good percentage of us was left out when reassembled to form the
>original target.
>
>To me it makes *sense* that intensity would be lower.
We could make better progress if relativity had viable model, but it
proposes a universe that is homogeneous, isotropic and without a
center, (leaving us essentially without a handle) so even the cause of
expansion is left to hypothesis, not excepting the unblushing use of
dark energy and quintessence and matter/radiation percentages. 
Still can't find the z/distance transform. (It may come as a surprise
that I have my own theory on the structure of the universe).
>David A. Smith
John Polasek