On 4 Apr, 23:53, HW@....(Henri Wilson) wrote:
On Wed, 4 Apr 2007 22:23:12 +0100, "George Dishman" wrote:
"Henri Wilson" HW@.... wrote in message
news
On Mon, 2 Apr 2007 22:34:19 +0100, "George Dishman"
wrote:
"Henri Wilson" HW@.... wrote in message
...
On Sun, 1 Apr 2007 15:04:46 +0100, "George Dishman"

Given that you now accept the huff-puff nature, you
need to reconsider your justification for saying
that Cepheids that are currently thought of as
isolated might actually be part of a binary.

Every one I read about seems to have a companion star.

Put "solitary cepheid" into Google and you get a number
of hits. At least one was a survey listing both categories
with similar numbers of entries. I looked it up earlier
at work and don't have the reference here and it was in
postscript but I'm sure you can find a readable version
with a little hunting.

I'm sure there are many that have very slow orbit periods.

A thought just ocurred, are you perhaps seeing a bias
by looking mainly at milliseond pulsars? These are fast
because they get "spun up" by matter falling in from a
companion.

They are fast because the stuff that made them had some net angular momentum.

The "stuff that made them" was a star that exploded and
stars don't spin that fast, they would fly apart through
centrifugal force in the process. They have to get down
to their very small size first then be spun up to speed.

They all orbit the galaxy, so what. The orbital period
needs to be a few years or less for any significant
effects to show up.

They orbit all kinds of objects, not just the galaxy...and other objects
orbit
them.
Many orbits will involve more than one other object and will be unstable.

The question remains, so what? other than in fairly tight
binaries and near misses of unbound objects, the speed and
acceleration will be too low to produce any significant
brightening.

That depends entirely on distance. ...although extinction plays a part. Time
compression can occur at large distances.

Not with the levels of speed equalisation distances
that are given by your program. Only tight binaries
are going to show any effects at all.

I'm now of the opinion that not much unification occurs in intergalactic space
(below the WDT). Most occurs within the confines of a galaxy....particularly
near the source.....but this could vary enormously from one situation to
another.

All our discussions have been on objects in our
own galaxy. The ISM is what matters as it is
denser than the IGM.

It isn't difficult to produce variations of 1.5 mag. ..but 3 is about the
limit
with the BaTh before the critical distance is reached and the curves
become
peaked.

Try it now that your program shows the red and blue curves
separately. Take a Cepheid you think you can model with a
varation of 1.5 mag or more, match the red curve to the
velocity profile and tell me how much variation the green
curve predicts. The remainder is intrinsic.

As a result of my dropping the 'incompressible photon' theory the red curve has
now been replaced by the green one.

The question remains, if you match the velocity curve
what fraction of the luminosity variation is due to
c+v and what fraction is intrinsic?

There still appears to be no theory that explains any intrinsic brightness
variation of huff-puff stars.

This is a slightly better introduction than the bulk:

http://www.astro.utoronto.ca/~mhvk/AST221/pulsators.pdf

George, have a look at their velocity and brigtness curves, about half way
down.
Do you notice something?

I notice you are not acknowledging that your claim
that there was no theory (or more accurately model)
was wrong.

In every paper I have read about cepheids, the authors admit the have no
theory to link the surface movement to the brightness curve.

Read some textbooks, not papers. Papers focus on moving
the body of knowledge forward and don't usually cover
existing 'state of the art'.

I won't comment on that without doing some study for myself.

The theories involved would include thermodynamics, radiation
pressure, fluid dynamics and the bit that a lot of simpler
pages leave out is the importance of opacity. The stellar
structure forms a relaxation oscillator.

That's the theory.

Yes Henry, the stuff you claimed didn't exist.

George