Facts against BB Theory

In article , jacob navia
writes:

Le 27/05/2014 09:36, Phillip Helbig---undress to reply a ecrit :
In article , jacob navia
writes:

In any case not in the solar system or is it? Is there "dark" matter
between the screen where my mail client is displayed and my eyes?

Maybe. It depends on what it is. There are 311 million or whatever
neutrinos per cubic metre, and dark matter interacts less than
neutrinos.

Neutrinos are detectable. They interact in huge tanks of chlorine that
can detect them!

Right, but you can't detect them between your computer screen and your
eyes. The point is that there is something definitely there which is
very difficult to detect, and not that long ago was undetectable, like
dark matter today.

This is OF COURSE OK. What I do not see in the "dark" matter theory is
any particle, wave or physical manifestation of that state of matter.

Nor any experiment that would attach that missing mass to SOMETHING!

In other words, like neutrinos after they were postulated by Fermi and
Pauli and before they were detected.

In article ,
jacob navia writes:
I have no alternate theory, I am not a
professional astronomer and most of what I say is not well founded,

That being the case, you might find better responses if you ask
questions rather than assert things that are incorrect.

Some years ago [dark matter] was in the intra-galactic space, now
it is maybe in the intra-cluster space...

I don't know what you mean by the above. The first indication of
dark matter (DM) was in galaxy clusters. Rotation curves came
later. There's probably some DM everywhere, but the distribution is
clumpy. The ratio of dark to visible matter varies because visible
matter, because it sticks together, is even clumpier than DM.

It interacts only gravitationally with matter, and it is completely
invisible otherwise.

DM searches are based on the possibility that DM has a non-zero cross
section for the weak force. That wouldn't have cosmological effects
but would make DM detectable in laboratory experiments.

No particle nor any physical stuff is associated with this "dark" matter

I don't understand what you mean by this. There are numerous
suggestions from particle physics for what DM could be. Any of those
or something completely different would satisfy the cosmological
constraints.

Sudenly I have to believe
in this "matter" as an article of faith.

Hardly. The single hypothesis of DM explains galaxy rotation curves,
cluster velocity dispersions, gravitational lensing (both weak and
strong), several of the peaks in the CMB power spectrum, and probably
galaxy clustering -- all with _the same amount_ of DM. That's pretty
good evidence, though perhaps a different explanation of all these
phenomena will emerge. There's also direct evidence in the Bullet
Cluster.

I actually share your philosophical dislike for DM (at least the
nonbaryonic variety), but I've learned over the years that my
philosophical opinions are irrelevant. What matters is the evidence,
and the evidence at this stage seems overwhelming. If you are not
aware of the evidence, you might want to find out what it is before
forming an opinion.

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

On 5/29/2014 8:49 AM, Steve Willner wrote:
..
I actually share your philosophical dislike for DM (at least the
nonbaryonic variety), but I've learned over the years that my
philosophical opinions are irrelevant.

Still, why do you dislike it? Wouldn't it be nice, for
instance, if axions existed more or less as they were
proposed to solve the strong CP problem, and in the
process also would explain cosmological observations?

To me that seems as satisfying as when the cosmological
constant would nicely match the vacuum energy of quantum
field theory, which of course it doesn't by many orders
of magnitude, so at least there we do have room for
philosophical dislike. (Dislike of QFT, or Lambda CDM,
or both.. Three options, philosophically speaking!)

--
Jos

The voids are not created by evacuating galaxies. Galaxies are born at
the edges of large voids created by cold dark matter. In fact your
argument shows that the universe cannot be too old because otherwise
random motions of the galaxies would disperse them into the voids.

I don't think galaxies can "disperse" into voids , at least not while
the Universe is expanding. Consider that within a void all geodesics
are diverging. Any material object entering this type volume will
"shed" relativistic mass to the vacuum, and thus momentum ,in an
opposite sense to an object within a gravitational well.

I suspect that galaxies presently within voids were trapped there when
3 or more voids converged around them.

If the voids stop expanding then dispersion can occur.

Brad

On Friday, May 16, 2014 10:50:00 PM UTC+2, Phillip Helbig---wrote:

Right. Not only the existence of the CMB itself, but details. I don't
know how many plots of the CMB power spectrum I had seen, in very much
detail, even before the first peak was observed. Planck is now
approaching the details of theoretical predictions. Yes, there are some
free parameters, but a) most of them are known from other sources, so
not really free, and b) fitting all the data in a CMB map with just a
handful of parameters illustrates that people actually understood this
in detail before the observations.

I think some of the information is he
http://adsabs.harvard.edu/full/1992ApJ...396L...1S

The problem I have is with the first peak partly because the lower
l values are of "no importance" to calculate the cosmological parameters.

In order to improve my understanding of the CMD radiation I have performed
a simulation of a CMB sphere. The results are he
http://users.telenet.be/nicvroom/WMA...simulation.htm
The simulation is based on two types of hills and valleys:
large ones and small ones. Only the position is random. The height and the
size are constant.
Picture #1 shows the Planck observed CMB.
Picture #2 shows a simulation with both large and small hills and valleys.
The similarity is remarkable.
Picture #3 shows only the small hills.
The chalange is to calculate the Power Spectrum of the simulated CMB radiation
pictures and to see if they match the observed CMB radiation.
If someone can give me a hint how to do that I will be gratefull.

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

Am 29.05.2014 08:49, schrieb Steve Willner:

... There's also direct evidence in the Bullet Cluster.

Not the only BB fairy story:

X. Hernandez et al, Gravitational anomalies signaling the breakdown of
classical gravity, http://arxiv.org/abs/1401.7063

Peter Wolff
www.wolff.ch

[Mod. note: you don't have to be a BB-denier to take MOND seriously,
or vice versa -- mjh]

On Friday, May 23, 2014 3:53:59 AM UTC-4, Phillip Helbig---undress to reply wrote:
Of course small stars have a life expectancy much longer than the
current age of the universe. There is no problem here, since this
applies mostly to the future. Suppose I buy some land and build a house
on it, a robust house of stone. A year later someone walks by and
says "This house will probably last a few centuries, at least; I can't
believe it's just a year old." Make sense? No.

Agreed - a witheringly bad analogy!

In a paper entitled "Is the universe simpler than [L]CDM?"
[http://arxiv.org/abs/1401.1146 ] the authors review "apparent
discrepancies with observations on small [galactic] scales, which
[L]CDM must attribute to complexity in baryon physics or galaxy
formation. Yet galaxies exhibit structural scaling relations that
evoke simplicity, ...".

This paper asks pertinent questions and evaluates the strength of
cosmological assumptions. Cosmology profits from this sort of
empirically-based scientific skepticism. We need much more of it.

[Mod. note: reformatted -- mjh]

Op donderdag 29 mei 2014 08:49:14 UTC+2 schreef Steve Willner:
Hardly. The single hypothesis of DM explains galaxy rotation curves,

With due respect,
The problem is that flat galaxy rotation curves cannot be explained
with (visible) baryonic matter. That means more matter is required.
The issue is if this missing matter is either baryonic or non baryonic
matter or both.

cluster velocity dispersions, gravitational lensing (both weak and
strong),

The problem with gravitational lensing IMO is that the mass with causes
the lensing is very much considered as a point source. That means
the area around this object is empty. The larger the source (galaxy
or galaxy cluster) the larger this empty space.
This makes it difficult to explain that only 15% of all matter is
baryonic and most is non-baryonic.

several of the peaks in the CMB power spectrum,

The issue is here the mathematics behind. That means the mathematics
to calculate the PS based on baryonic matter and the PS based on
non-baryonic matter. The problem is how do you demonstrate
that the mathematics is correct. The result that 85% of the matter
is non-baryonic matter in order to simulate the observed CMB radiation
is no prove that the used mathematics is correct.
(I'am not claiming that it is wrong)

and probably galaxy clustering -- all with _the same amount_ of DM.

I expect you mean percentage ?

That's pretty good evidence, though perhaps a different explanation
of all these phenomena will emerge.

I think there is a missing matter problem. The Question is: is this
baryonic or non-baryonic.

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

Am 01.06.2014 07:50, schrieb Homo Lykos:
Am 29.05.2014 08:49, schrieb Steve Willner:

... There's also direct evidence in the Bullet Cluster.

Not the only BB fairy story:

X. Hernandez et al, Gravitational anomalies signaling the breakdown
of classical gravity, http://arxiv.org/abs/1401.7063

Peter Wolff
www.wolff.ch

[Mod. note: you don't have to be a BB-denier to take MOND seriously,
or vice versa -- mjh]


Yes, but a GR/Newton-denier on cosmic scales (below the "MONDian" a0
threshold) and GR/Newton is the base of all well-known
BB-(Friedmann-Lemaitre-)Models. But it's correct that (at least) one
other Model exists: Bekensteins not really well-known and very complex
relativistic MOND approach.

[Mod. note: the physics of the evolution of the universe would
obviously be significantly different in a MONDian world, but, for
example, most MOND papers I've seen sign up implicitly or explicitly
to the cosmological origin of the redshift and the primordial nature
of the CMB. -- mjh]

In article , Nicolaas Vroom
writes:

Op donderdag 29 mei 2014 08:49:14 UTC+2 schreef Steve Willner:
Hardly. The single hypothesis of DM explains galaxy rotation curves,

With due respect,
The problem is that flat galaxy rotation curves cannot be explained
with (visible) baryonic matter. That means more matter is required.
The issue is if this missing matter is either baryonic or non baryonic
matter or both.

In the context of rotation curves alone, yes, but you need some theory
which fits ALL the observations.

cluster velocity dispersions, gravitational lensing (both weak and
strong),

The problem with gravitational lensing IMO is that the mass with causes
the lensing is very much considered as a point source. That means
the area around this object is empty. The larger the source (galaxy
or galaxy cluster) the larger this empty space.
This makes it difficult to explain that only 15% of all matter is
baryonic and most is non-baryonic.

I think there is a misunderstanding here. Either light goes through a
transparent gravitational lens or it passes by the lensing mass. In the
latter case, if it is spherically symmetric, then the effect is the same
as if it were a point mass. This is fine for microlensing and many or
most cases of strong lensing (by definition: multiple images). In the
case of galaxy clusters, then the whole point is essentially to map the
distribution of mass in the cluster; there is certainly no point-mass
approximation here.

several of the peaks in the CMB power spectrum,

The issue is here the mathematics behind. That means the mathematics
to calculate the PS based on baryonic matter and the PS based on
non-baryonic matter. The problem is how do you demonstrate
that the mathematics is correct. The result that 85% of the matter
is non-baryonic matter in order to simulate the observed CMB radiation
is no prove that the used mathematics is correct.
(I'am not claiming that it is wrong)

But the burden of proof is on you to say that it is wrong if you believe
it. If you don't believe that it is wrong, then don't mention it.
There is no bizare physics in this. The details are complicated, but in
essence this is straightforward.

I think there is a missing matter problem. The Question is: is this
baryonic or non-baryonic.

This has long since been answered. Why would anyone even be thinking
about non-baryonic matter (except from a purely theoretical point of
view) if baryonic matter could fit all observations. Read up on the CMB
stuff; the data are so good now that there is absolutely no way that the
power spectrum can be fit with purely baryonic matter.