Evidence for a static universe

On Tuesday, December 6, 2016 at 5:41:40 PM UTC-5, Phillip Helbig (undress
to reply) wrote:

This was in the context of someone confusing an accelerating universe
with an expanding universe; the supernova data (by which I mean the
stuff the Nobel Prize was awarded for in 2011, not supernova data in
general) were taken decades after the expansion of the universe was
consensus. Even that consensus didn't rely on supernova data, though.

I thought the SNe make up a key part of the
distance ladder for measuring the Hubble parameter.

Yes, they do today, and one can get a good estimate of the Hubble
constant from just them. My point was that the expansion (as opposed to=

the acceleration) of the universe was consensus long before the recent
supernova projects came along.

I think the most thrilling scientific talk I ever attended was by a
member of the supernovae team in 1997. The title was something like
"Observations of distant supernovae and the Hubble constant". I walked
into the talk highly skeptical. Yes, distant supernovae should help us
refine the Hubble constant and help us decide whether the value is
closer to 67 or to 75.

But we would first have to work out any systematics which would
undoubtedly take a few years, and I wasn't going to hold my breath. But
in the middle of the talk the speaker said, "I'd like to stop speaking
about the Hubble constant, and talk about some exciting new results in
the data." He then gave the evidence for an accelerating universe, and
showed how the estimated dark energy is roughly the amount required for
a flat universe, validating models of inflation.

I walked into the seminar highly skeptical, and left with my *mind
blown*.

New to this thread, so please be patient.

David, in your paper you write "It is assumed that the central part of
the light curve could be modelled by a Gaussian distribution of the flux
densities as a function of the epoch differences." You then define (?)
your terms quantitatively, sorta, and your core method.

Why do you make this assumption? And what weights do you use ("A
weighted least squares fit ...")?

In article ,
wlandsman writes:

I think the most thrilling scientific talk I ever attended was by a
member of the supernovae team in 1997. The title was something like
"Observations of distant supernovae and the Hubble constant". I walked
into the talk highly skeptical. Yes, distant supernovae should help us
refine the Hubble constant and help us decide whether the value is
closer to 67 or to 75.

But we would first have to work out any systematics which would
undoubtedly take a few years, and I wasn't going to hold my breath. But
in the middle of the talk the speaker said, "I'd like to stop speaking
about the Hubble constant, and talk about some exciting new results in
the data." He then gave the evidence for an accelerating universe, and
showed how the estimated dark energy is roughly the amount required for
a flat universe, validating models of inflation.

I very probably wasn't at that talk, so probably don't know what exactly
was said, but for the record:

Yes, the supernova data do indicate an accelerating universe. They are
not the only line of evidence. At the time, they were the only test
which, by itself, indicated acceleration, although combinations of other
tests did. (These days, the CMB alone gives very good constraints on
almost all parameters.) The supernova data, however, don't indicate
flatness. In fact, the contours are almost perpendicular to the lines
of constant curvature radius. (This is good, since the CMB is sensitive
mainly to curvature and the contours are degenerate along lines of
constant curvature, so combining the almost orthogonal contours
drastically reduces the allowed region. As luck would have it, BAO
contours are somewhere in between. Just the fact that all three meet at
the same point (lambda=0.7, Omega=0.3, which has been around since the
early 1990s as the concordance model, though with larger uncertainties)
is a really good consistency check.) Yes, they are consistent with a
flat universe, but also with many other, non-flat universes. The CMB
data alone, even today, don't usefully constrain the curvature.

As for inflation, the supernova data can't validate models of inflation.
At best, if one believes (which seems to be a robust prediction) that
inflation implies a flat universe, then the supernova data are
consistent with this prediction.

David, I'm trying to independently reproduce your Figure 2, using
the sources and methods you describe in your paper. And I'm stuck,
pretty much at the beginning; I can't derive an estimate of the
"width", nor "the epoch of maximum flux density". Would you please
provide data - or an explicit pointer to such data - on two SNe
(band, observed magnitudes, dates), one with ~zero z, one ~0.5,
together with the "width" and "epoch of maximum flux density"
estimates you derived from that data (uncertainties would be nice
too)? Thanks.

On Saturday, December 10, 2016 at 12:08:49 AM UTC+11, w=
rote:
New to this thread, so please be patient.

David, in your paper you write "It is assumed that the central part of
the light curve could be modelled by a Gaussian distribution of the flux
densities as a function of the epoch differences." You then define (?)
your terms quantitatively, sorta, and your core method.

Why do you make this assumption? And what weights do you use ("A
weighted least squares fit ...")?

I wanted the simplest description of the curve that was reasonable. A
Gaussian in flux density is a parabola in magnitudes. The point is that
I am looking for redshift dependence and I am willing to sacrifice
accuracy for simplicity. All data is weighed by the given flux density
uncertainties converted to magnitudes.

On Saturday, December 10, 2016 at 6:17:30 AM UTC+11, wr=
ote:
David, I'm trying to independently reproduce your Figure 2, using
the sources and methods you describe in your paper. And I'm stuck,
pretty much at the beginning; I can't derive an estimate of the
"width", nor "the epoch of maximum flux density". Would you please
provide data - or an explicit pointer to such data - on two SNe
(band, observed magnitudes, dates), one with ~zero z, one ~0.5,
together with the "width" and "epoch of maximum flux density"
estimates you derived from that data (uncertainties would be nice
too)? Thanks.

See the reply above. The fitting as stated is a weighted least squares
to the parabola with three parameters. The peak magnitude, the epoch of
the peak magnitude and the width. Note that each filter is treated
independently. They are not combined to get a common width.

On Fri, 09 Dec 2016, "Phillip Helbig" wrote:
wlandsman writes:
showed how the estimated dark energy is roughly the amount required for
a flat universe, validating models of inflation.

As for inflation, the supernova data can't validate models of inflation.
At best, if one believes (which seems to be a robust prediction) that
inflation implies a flat universe, then the supernova data are
consistent with this prediction.

I was going to reply to wlandsman's point, but you've already done it
so well, Phil. Still, the notion that inflation can be "validated" by
estimating just the right amount of invisible material is provocative
at the least. I would call that "not science".

As for inflation "implying" a flat universe, well it's the other way
around in the practical sense that all the inflation calculations have
been done *assuming* a flat universe. Real feet of clay stuff.

Eric

In article , (Eric
Flesch) writes:

On Fri, 09 Dec 2016, "Phillip Helbig" wrote:
wlandsman writes:
showed how the estimated dark energy is roughly the amount required fo=
r
a flat universe, validating models of inflation.

As for inflation, the supernova data can't validate models of inflation.
At best, if one believes (which seems to be a robust prediction) that
inflation implies a flat universe, then the supernova data are
consistent with this prediction.

I was going to reply to wlandsman's point, but you've already done it
so well, Phil. Still, the notion that inflation can be "validated" by
estimating just the right amount of invisible material is provocative
at the least. I would call that "not science".

That's going too far. If---as seems to be the case---it does look like
the universe is close to flat, then this is at least compatible with
inflation. Of course, no observation can validate a theories; theories
can only be falsified, never proven. However, it can increase our
confidence in it.

As for inflation "implying" a flat universe, well it's the other way
around in the practical sense that all the inflation calculations have
been done *assuming* a flat universe. Real feet of clay stuff.

That's not true. Flatness is a robust prediction of inflation (despite
the fact that there were some rather contrived models in the 1990s which
tried to get Omega=0.3 (which is correct) with lambda=0 (which is not)).
The whole idea of inflation is that the observable universe is a tiny
fraction of the universe, so while it is probably not exactly flat, it
is so large that at all scales we can access it appears flat, just as an
architect can assume that the Earth is flat when drawing the plans for
your house.

The strongest argument for inflation is probably the isotropy problem
(horizon problem), since all other explanations tend to be ad-hoc.

On Saturday, December 10, 2016 at 12:52:57 PM UTC-5, David Crawford wrote:
On Saturday, December 10, 2016 at 6:17:30 AM UTC+11, =
wr=3D
ote:
David, I'm trying to independently reproduce your Figure 2, using
the sources and methods you describe in your paper. And I'm stuck,
pretty much at the beginning; I can't derive an estimate of the
"width", nor "the epoch of maximum flux density". Would you please
provide data - or an explicit pointer to such data - on two SNe
(band, observed magnitudes, dates), one with ~zero z, one ~0.5,
together with the "width" and "epoch of maximum flux density"
estimates you derived from that data (uncertainties would be nice
too)? Thanks.

See the reply above. The fitting as stated is a weighted least squares
to the parabola with three parameters. The peak magnitude, the epoch of
the peak magnitude and the width. Note that each filter is treated
independently. They are not combined to get a common width.
Thanks.

I would like to ask you again to please provide data - or an explicit point=
er to such data - on two SNe (band, observed magnitudes, dates), one with ~=
zero z, one ~0.5, together with the "peak magnitude", "width", and "epoch =
of maximum flux density" (or "epoch of peak magnitude") estimates you deriv=
ed from that data (uncertainties would be nice too).

[[Mod. note -- Please limit your text to fit within 80 columns,
preferably around 70, so that readers don't have to scroll horizontally
to read each line. I have manually reformatted this article. -- jt]]

On Sunday, December 11, 2016 at 11:43:42 AM UTC+11,
wrote:
On Saturday, December 10, 2016 at 12:52:57 PM UTC-5, David Crawford
wrote:
On Saturday, December 10, 2016 at 6:17:30 AM UTC+11,
I would like to ask you again to please provide data - or an explicit
pointer to such data - on two SNe (band, observed magnitudes, dates),
one with ~ zero z, one ~0.5, together with the "peak magnitude",
"width", and "epoch of maximum flux density" (or "epoch of peak
magnitude") estimates you derived from that data (uncertainties
would be nice too).

If you contact me on (remove the bird)
I could do this fo all the supernovae. However it may take several
days. David