[WWW] A possible solution to the dark energy, cosmic acceleration and horizon problems

I've just rewritten an article in which I present a model that
resolves the Horizon Problem and proposes a new explanation for the
origins of the CMBR. Also it shows, by way of its excellent fit to
resent Type 1a Supernovae data, that the universe is not accelerating,
thereby eliminating the need to postulate dark energy.

You can see it at

http://www.softcom.net/users/der555/horizon.pdf

Dave Rutherford

In article , Dave Rutherford
writes:

I've just rewritten an article in which I present a model that
resolves the Horizon Problem and proposes a new explanation for the
origins of the CMBR. Also it shows, by way of its excellent fit to
resent Type 1a Supernovae data, that the universe is not accelerating,
thereby eliminating the need to postulate dark energy.

You can see it at

http://www.softcom.net/users/der555/horizon.pdf

Some comments. The numbers refer to your section numbers.

2.


The light paths imply that the light is travelling through space, but it
looks like r corresponds to P_0 at an earlier time. However, when the
light was there, the observer was not, since he is not moving with the
light. Maybe the diagram is confusing. My other points are independent
of this. In any case, the diagram needs to be clearer.

The assumption that the speed is relative to its location on the circle
is rather vague. It could be interpreted to mean that your theory is a
variant of the variable-speed-of-light theory. In that case, it is
ad-hoc. It is well known that a variable speed of light can solve the
horizon problem, but the motivation is otherwise weak.

It is not clear what you mean by experience showing that light from more
distant sources propagates at the same speed as that from nearby
sources. If it didn't, how would we notice it?



4.


The reason given why no relativistic correction is needed is rather
dubious. Hogg and Bunn have shown that applying a relativistic
correction to the recession velocity leads to the same results as in the
"expanding space" paradigm. See http://arxiv.org/abs/0808.1081 .

You define a distance and define a redshift and they can be compatible,
but it is not obvious why, at least for low redshift, the Doppler
formula should not hold. Hubble's Law (in the sense of the relation
between apparent magnitude and redshift) has been observed to hold to
rather large distances and does not follow your form. In other words,
your ideas might be consistent, but don't match observations.



5.


The power spectrum of the CMB was predicted in conventional cosmology
long before it was observed. The precise shape depends on various
parameters, but it is not possible to create ANY shape. Also, some
parameters are independently constrained. The fact that conventional
cosmology predicts a power spectrum similar to that observed is a huge
point in its favour. Since it has already been observed, you cannot
strictly speaking predict it, but you need to show that the details
follow from your theory in an unambiguous way which could have been
arrived at before the detailed CMB observations were made.



7.


You need to compare the goodness of fit for your model to that of the
conventional cosmology.

The m-z relation is not the only indication of a cosmological constant.
If your model doesn't need it for the m-z relation, you have to explain
how other observations are compatible with your model without a
cosmological constant.

On Mar 23, 4:00 am, Phillip Helbig---undress to reply
wrote:

Some comments. The numbers refer to your section numbers.

2.

The light paths imply that the light is travelling through space, but it
looks like r corresponds to P_0 at an earlier time. However, when the
light was there, the observer was not, since he is not moving with the
light.

The point P_0 is a point comoving with space that represents here and
now (always at \theta = 0, in this case). I don't recall introducing
an observer in this section.

Maybe the diagram is confusing. My other points are independent
of this. In any case, the diagram needs to be clearer.

Figure 1 was patterned on a polar coordinate system. But, instead of
representing spatial coordinates, mine represents spacetime
coordinates. My r represents the time coordinate (analogous to ct in a
conventional spacetime diagram) and the three spatial coordinates
exist on an expanding circle centered at the origin. Time extends
outward radially from the origin in all directions and is increasingly
positive as it extends outward, just as r in conventional polar
coordinates extends outward radially from the origin and becomes more
positive as its distance from the origin increases.

The assumption that the speed is relative to its location on the circle
is rather vague. It could be interpreted to mean that your theory is a
variant of the variable-speed-of-light theory.

As I stated in my article, the speed of light is _constant_ (c)
relative to its location on the circle everywhere along the circle. It
does not vary.

It is not clear what you mean by experience showing that light from more
distant sources propagates at the same speed as that from nearby
sources. If it didn't, how would we notice it?

Hold up a piece of cardboard to the night sky, along your line of
sight, then remove it from your line of sight. If light from distant
sources propagated more slowly than nearby sources, the former would
`blink on' after the latter. That's a pretty simplistic example, but
I'm sure a more sophisticated version of this experiment could be set
up that could actually measure the effect.

4.

The reason given why no relativistic correction is needed is rather
dubious. Hogg and Bunn have shown that applying a relativistic
correction to the recession velocity leads to the same results as in the
"expanding space" paradigm. Seehttp://arxiv.org/abs/0808.1081.

I'm just showing that, using my model, it's possible to explain
observation without having to invent dark energy.

You define a distance and define a redshift and they can be compatible,
but it is not obvious why, at least for low redshift, the Doppler
formula should not hold.

I'm defining cosmological redshift, not Doppler redshift.

Hubble's Law (in the sense of the relation
between apparent magnitude and redshift) has been observed to hold to
rather large distances and does not follow your form.

If you're referring to

\mu = 5*log(d_L)+25

where d_L = d_0*(1 + z), then Hubble's Law (d_0 = c*z/H_0) doesn't
even come close to holding for large z.

In other words,
your ideas might be consistent, but don't match observations.

I showed in Figure 3 that my ideas match observation (Riess et al.
2007) very well.

5.

The power spectrum of the CMB was predicted in conventional cosmology
long before it was observed. The precise shape depends on various
parameters, but it is not possible to create ANY shape. Also, some
parameters are independently constrained. The fact that conventional
cosmology predicts a power spectrum similar to that observed is a huge
point in its favour. Since it has already been observed, you cannot
strictly speaking predict it, but you need to show that the details
follow from your theory in an unambiguous way which could have been
arrived at before the detailed CMB observations were made.

I don't know what all the properties of light emerging from a
convergence point would be. But I do know that one of the properties
it shares with the CMB observations is omnidirectionality. I'll have
to think about the others. Do you have any ideas?

7.

You need to compare the goodness of fit for your model to that of the
conventional cosmology.

I only need one arbitrary parameter (the Hubble constant) for my model
to fit observation. How many does conventional cosmology need?

The m-z relation is not the only indication of a cosmological constant.
If your model doesn't need it for the m-z relation, you have to explain
how other observations are compatible with your model without a
cosmological constant.

Which observations are those?

On Wed, 23 Mar 11 12:00:24 GMT, Phillip Helbig wrote:
The fact that conventional cosmology predicts a power spectrum
similar to that observed is a huge point in its favour.

The power spectrum is simply a normal curve when plotted on a
logarithmic axis, isn't that right? What's so special about that?

Eric Flesch

[Mod. note: no, it's not: see e.g.
http://en.wikipedia.org/wiki/Cosmic_...y_anis otropy
-- mjh]

On Mar 24, 5:13 am, Dave Rutherford wrote:

The point P_0 is a point comoving with space that represents here and
now (always at \theta = 0, in this case).

P_0 is actually an event (here and now), not a point. I'll have to
change that in my article.

In article , Dave Rutherford
writes:

The point P_0 is a point comoving with space that represents here and
now (always at \theta = 0, in this case). I don't recall introducing
an observer in this section.

I was assuming the observer is at P_0.

You define a distance and define a redshift and they can be compatible,
but it is not obvious why, at least for low redshift, the Doppler
formula should not hold.

I'm defining cosmological redshift, not Doppler redshift.

But, in the limit of small distances, do you recover the Doppler shift?

Hubble's Law (in the sense of the relation
between apparent magnitude and redshift) has been observed to hold to
rather large distances and does not follow your form.

If you're referring to

\mu = 5*log(d_L)+25

where d_L = d_0*(1 + z), then Hubble's Law (d_0 = c*z/H_0) doesn't
even come close to holding for large z.

Hubble's law, in terms of the PROPER DISTANCE, holds exactly. But this
is not observable. The relation between apparent magnitude and redshift
is linear only at low redshift.

In other words,
your ideas might be consistent, but don't match observations.

I showed in Figure 3 that my ideas match observation (Riess et al.
2007) very well.

Quantitatively? Better than conventional cosmology?

I don't know what all the properties of light emerging from a
convergence point would be. But I do know that one of the properties
it shares with the CMB observations is omnidirectionality. I'll have
to think about the others. Do you have any ideas?

Omnidirectionality is a rather low common denominator. Look at the
shape of the power spectrum.

The m-z relation is not the only indication of a cosmological constant.
If your model doesn't need it for the m-z relation, you have to explain
how other observations are compatible with your model without a
cosmological constant.

Which observations are those?

Structure formation, gravitational lensing etc. Search for "cosmic data
fusion" and see what you find. (Not my choice of term, but probably
most hits will be relevant for this phrase.)

Cosmology is now a data-driven science; any alternative theory has to
at least fit observations as well as conventional theory.

On Mar 24, 3:40 pm, Phillip Helbig---undress to reply
wrote:
In article , Dave Rutherford

I'm defining cosmological redshift, not Doppler redshift.

But, in the limit of small distances, do you recover the Doppler shift?

In the limit of small z, my velocity-redshift relation approaches the
Hubble relation. See Figure 2 in my article. So I guess that if the
Hubble relation recovers the Doppler shift in the limit of small
distances, then mine must also.

Hubble's Law (in the sense of the relation
between apparent magnitude and redshift) has been observed to hold to
rather large distances and does not follow your form.

If you're referring to

\mu = 5*log(d_L)+25

where d_L = d_0*(1 + z), then Hubble's Law (d_0 = c*z/H_0) doesn't
even come close to holding for large z.

Hubble's law, in terms of the PROPER DISTANCE, holds exactly. But this
is not observable.

How can you claim that it holds exactly if it's not observable?

The relation between apparent magnitude and redshift
is linear only at low redshift.

The relation between the distance modulus (apparent magnitude minus
absolute magnitude) and redshift, in my model, is linear only at low
redshift. I don't see your point.

I showed in Figure 3 that my ideas match observation (Riess et al.
2007) very well.

Quantitatively? Better than conventional cosmology?

If you mean does my curve pass through every data point in the data
set, no. But the concordance model doesn't do that either. If you plot
my model's m-z curve and the concordance model's m-z curve (\Omega_m =
0.31, \Omega_\Lambda = 0.69) against the data, you'll see that they
almost exactly coincide.

I don't know what all the properties of light emerging from a
convergence point would be. But I do know that one of the properties
it shares with the CMB observations is omnidirectionality. I'll have
to think about the others. Do you have any ideas?

Omnidirectionality is a rather low common denominator. Look at the
shape of the power spectrum.

I'll do that.

The m-z relation is not the only indication of a cosmological constant.
If your model doesn't need it for the m-z relation, you have to explain
how other observations are compatible with your model without a
cosmological constant.

Which observations are those?

Structure formation, gravitational lensing etc. Search for "cosmic data
fusion" and see what you find. (Not my choice of term, but probably
most hits will be relevant for this phrase.)

Cosmology is now a data-driven science; any alternative theory has to
at least fit observations as well as conventional theory.

I'll look at how my model fits these other observations, thanks.

"Phillip Helbig---undress to reply"
schreef in bericht ...
In article , Dave Rutherford
writes:

Which observations are those?

Structure formation, gravitational lensing etc. Search for "cosmic data
fusion" and see what you find. (Not my choice of term, but probably
most hits will be relevant for this phrase.)

Cosmology is now a data-driven science;
I do not completely understand this sentence.
IMO Cosmology (Astronomy) was always a data-driven
science. IMO any science is data-driven i.e. is based
on observations.
any alternative theory has to at least fit observations
IMO any theory has to fit all observations.
IMO any theory that fits all observations the most
accurate is the best.
If there are two than the simplests one, wins.
as well as conventional theory.
IMO that is not strictly necessary.
(IMO = My understanding is)

Nicolaas Vroom
http://users.pandora.be/nicvroom/

"Phillip Helbig---undress to reply"
wrote
Cosmology is now a data-driven science;

Nicolaas Vroom wrote:
I do not completely understand this sentence.
IMO Cosmology (Astronomy) was always a data-driven
science. IMO any science is data-driven i.e. is based
on observations.

Phillip's phrase is a commonly-used one today. The basic meaning is
this: 30 years ago (say) there was only a small amount of cosmological
data, and that data often had relatively large error bars. Thus, that
data provided only relatively weak constraints on theory, i.e., a
great many theories could be consistent with the cosmological data
of (say) 1981.

In contrast, today there's a HUGE amount of cosmological data, with
big parts having quite small error bars. And more cosmological data
is arriving each year.

So, doing state-of-the-art cosmology today involves a lot of
sophisticated modelling of many disparate data sets. This is what's
being referred to in the phrase "data-driven science".


For example, in 1981 our knowlege about the cosmic microwave
background radiation (CMBR) could be described in a few lines of
text containing only 5 numbers, only 2 of which are "significant"
for cosmology.
"The CMBR has a black-body spectrum, which in a suitable
reference frame is isotropic on the sky to within a part
in 10^4 or so, with a temperature of such-and-such (around 2.7)
Kelvin. Our solar system has a vector velocity of such-and-such
with respect to that "suitable reference frame."
So, in 1981 the constraints the CMBR put on a cosmological theory
were basically that the theory had to provide a natural explanation
of the CMBR's existence, and could reproduce the temperature and
lack of anisotropy down to the observed limits at that time.

In contrast, today it takes (at the very least) several thousand
numbers to describe our knowledge about the CMBR's statistical
properties. So, today the constraints the CMBR puts on a cosmological
theory also include having to simultaneously reproduce a couple thousand
measured power-spectrum multipole moments and polarizations. (And
still getting the Sunyaev-Zeldovich effect right.)


--
-- "Jonathan Thornburg [remove -animal to reply]"
Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
"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

In article , Dave Rutherford
writes:

Hubble's law, in terms of the PROPER DISTANCE, holds exactly. But this
is not observable.

How can you claim that it holds exactly if it's not observable?

Theory. Within the context of classical cosmology, proper distance is
not directly observable, but nevertheless one can say something about
it.

If you mean does my curve pass through every data point in the data
set, no. But the concordance model doesn't do that either. If you plot
my model's m-z curve and the concordance model's m-z curve (\Omega_m =
0.31, \Omega_\Lambda = 0.69) against the data, you'll see that they
almost exactly coincide.

One needs a quantitative comparison of goodness-of-fit.