Geometry of Look-Back

On Thu, 03 Jan 13 07:35:24 GMT, Steve Willner wrote:
Phillip Helbig---undress to reply writes:
you have to explain the stability of the universe if it is not flying apart.

The point is that a static universe might be in equilibrium, but it is
unstable unless one puts in new physics.

It's not hardly new physics anymore to model the universe as a 4-space
embedded into an n-space, or specifically as an onion peel onto a
spherical 5-or-6-space. This confers stability via the surface
tension and orthonormal gravitational scalar of the bulk, ie,
Einstein's constant..

Nevertheless, if a new model fits the data (and isn't grossly
contrived with a huge number of free parameters), I'd expect people
to consider it.

The only part of FRW I have no answer to is the observed increase of
CMB temperature with look-back time -- that kills any static model
stone-cold dead -- except that a case for publication bias can be
made here, which I've discussed in the other thread. This includes
the question of how much our expectations bias our results, a- la
Millikan oil drop experiments. This is a broad unquantified topic
that normally one would want to avoid.

In article , Eric Flesch
writes:

The only part of FRW I have no answer to is the observed increase of
CMB temperature with look-back time -- that kills any static model
stone-cold dead -- except that a case for publication bias can be
made here, which I've discussed in the other thread. This includes
the question of how much our expectations bias our results, a- la
Millikan oil drop experiments. This is a broad unquantified topic
that normally one would want to avoid.

I don't think you've made a very convincing case here. As I pointed
out, publication bias can cut the other way too. Also, consider that
you know about the late publication of one paper. If you believe
publication bias is so rampant, then think of all the stuff you don't
know about. :-) Also, make sure that YOU don't have a bias here, i.e.
that you aren't giving too much weight to one paper and too little to
several others.

In article ,
Eric Flesch writes:
It's not hardly new physics anymore to model the universe as a 4-space
embedded into an n-space, or specifically as an onion peel onto a
spherical 5-or-6-space. This confers stability via the surface
tension and orthonormal gravitational scalar of the bulk, ie,
Einstein's constant..

I have no problem with the basic idea, of course. What I don't
understand is how this leads to stability and not merely an unstable
equilibrium.

The only part of FRW I have no answer to is the observed increase of
CMB temperature with look-back time

If the model is static, where does evolution come from? Or
equivalently, why does the Universe have a finite age? Also, what
about SN light curves slowing with redshift?

No hurry to answer before you have worked out more details and are
ready to explain, but these will be obvious questions.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

On Thu, 03 Jan 13, Phillip Helbig wrote:
I don't think you've made a very convincing case here.

Absolutely right. I haven't laid out anything comprehensive because
it's not ready and I did say a couple times that my goal was to
present it in the early 2013 if I could sort out the issues. These
discussion have helped to sort out individual issues.

If you believe publication bias is so rampant, then think of all
the stuff you don't know about. :-)

Right again, and that applies to us all.

Also, make sure that YOU don't have a bias here, i.e.
that you aren't giving too much weight to one paper and too little to
several others.

Exactly, for me to state that the dependency of CMB temperature with
redshift is ill-founded, I need to read the whole literature on that
topic. A big ask for an amateur like me, with limited time available.
Which is why I can't be more definitive or convincing at this time, or
maybe any time soon. But thanks for the helpful discussions.

Eric

On Thu, 03 Jan 13, Steve Willner wrote:
Eric Flesch writes:
... the universe as a 4-space embedded into an n-space, or
specifically as an onion peel onto a spherical 5-or-6-space. This
confers stability via ... gravitational scalar of the bulk

I have no problem with the basic idea, of course. What I don't
understand is how this leads to stability and not merely an unstable
equilibrium.

Pretty much all such gr-qc work is done assuming a void bulk. Talk
about an elephant in the room! If we fill the bulk with n-space
matter & energy, so we are just a sub-universe of the larger universe,
then stability follows as naturally as the stability of standing on
the Earth. Also this allows for galaxies to be spigotted from the
bulk, so no more mystery about matter erupting from galaxy centres,
the "bar" of bar spirals, etc.

If the model is static, where does evolution come from? Or
equivalently, why does the Universe have a finite age? Also, what
about SN light curves slowing with redshift?

No hurry to answer before you have worked out more details and are
ready to explain, but these will be obvious questions.

The idea is that these are artefacts of the queerness of look-back
plus our models built on clay feet. And you're absolutely right, I
can be in no hurry to give a proper answer until I have worked it all
out into a well-fitting whole. How long will that take an amateur
like me. Months? Years? So thanks for your help in clarifying this
task, cheers. Eric

In article , Eric Flesch
writes:

... the universe as a 4-space embedded into an n-space, or
specifically as an onion peel onto a spherical 5-or-6-space. This
confers stability via ... gravitational scalar of the bulk

Pretty much all such gr-qc work is done assuming a void bulk. Talk
about an elephant in the room! If we fill the bulk with n-space
matter & energy, so we are just a sub-universe of the larger universe,
then stability follows as naturally as the stability of standing on
the Earth. Also this allows for galaxies to be spigotted from the
bulk, so no more mystery about matter erupting from galaxy centres,
the "bar" of bar spirals, etc.

The idea is that these are artefacts of the queerness of look-back
plus our models built on clay feet. And you're absolutely right, I
can be in no hurry to give a proper answer until I have worked it all
out into a well-fitting whole. How long will that take an amateur
like me. Months? Years? So thanks for your help in clarifying this
task, cheers. Eric

What is the motivation? There is nothing wrong with a non-static
universe, and you seem to be introducing additional complexity to
explain something which doesn't need explaining. Not necessarily wrong,
of course, but Occam would not approve. If, of course, there were
things the standard model couldn't explain, then that would be
motivation, but I don't see any. WMAP could have shown some surprises,
but didn't. We'll see what Planck has in store.

In article ,
Eric Flesch writes:
If we fill the bulk with n-space
matter & energy, so we are just a sub-universe of the larger universe,
then stability follows as naturally as the stability of standing on
the Earth.

Sorry, but I'm afraid I don't follow that. Objects in our universe
are strongly affected by gravity, and that's unstable. (Density
fluctuations grow with time, not damp out.) How does having a
"larger universe" change that?

Again no hurry to answer, but this is the sort of question you'll
eventually need to face.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

In article ,
Eric Flesch writes:
If we fill the bulk with n-space
matter & energy, so we are just a sub-universe of the larger universe,
then stability follows as naturally as the stability of standing on
the Earth.

Sorry to be pedantic, but.....

Standing on the Earth isn't stable, as evidenced by the fact that both
bipedal and quadrupedal living creatures don't remain standing after
they die (and their proprioception -- brain -- muscles feedback loops
shut down): they fall to the ground.

[I think further discussion of how living creatures stand is probably
better off in some other newsgroup. I've set followups accordingly.]

--
-- "Jonathan Thornburg [remove -animal to reply]"
Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
on sabbatical in Canada starting August 2012
"Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral."
-- quote by Freire / poster by Oxfam

On 1/9/2013 9:32 PM, Jonathan Thornburg wrote:
In article ,
Eric Flesch writes:
If we fill the bulk with n-space
matter & energy, so we are just a sub-universe of the larger universe,
then stability follows as naturally as the stability of standing on
the Earth.

Sorry to be pedantic, but.....

Standing on the Earth isn't stable, as evidenced by the fact that both
bipedal and quadrupedal living creatures don't remain standing after
they die (and their proprioception -- brain -- muscles feedback loops
shut down): they fall to the ground.

[I think further discussion of how living creatures stand is probably
better off in some other newsgroup. I've set followups accordingly.]

At the risk of being even more pedantic: as it
appears in the newsgroup your post is lacking
this followup setting! (To be really pedantic:
the moderator should have added: "followups set
back to s.a.r.")

[Mod. note: Followup-To headers sometimes get lost in transit.
However, neither Jonathan's original digression nor this discussion
are really on-topic here --- mjh]

--
Jos