🚀 go-pugleaf

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.

> 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.

David A. Smith