Did you know that Supernova winds can push Dark Matter around?

This article reads like a laundry list of the failures of Dark Matter
theory, masquerading as an article about a triumphant breakthrough in
modeling it.

Why doesn't DM gather around a galaxy's centre? Supernovas.

Why does DM seem to coincide with where the stars are? Supernovas push
the smaller stars away, and the DM follows those stars.

Why aren't there more dwarf galaxies as predicted by DM theory? They're
there, but supernovas prevent star formation in some of them, so they
can't be seen.

Dark Matter this, Supernova that. All of this effort in trying to make a
pre-conceived notion look like reality!

Yousuf Khan

***
Supernova Winds Shape Galaxies : Discovery News
"Previous attempts to model galaxy formation based on the highly
successful theory of cold dark matter -- which states that invisible
material must account for 85 percent of the mass of the universe -- have
done "an awesome job" of explaining such global properties as where,
when and how many galaxies should form, notes Governato. But the models
have failed to reproduce some of the key features of individual galaxies.

In particular, those simulations have produced galaxies whose centers
are stuffed with too much dark matter and that are surrounded by a
spherical distribution of stars that actual dwarf galaxies don't
possess. Dwarf galaxies, which are low-mass bodies with relatively
uniform distributions of stars, are the most common type of galaxy in
the neighborhood of the Milky Way."
http://news.discovery.com/space/supe...formation.html

Yousuf Khan wrote:

This article reads like a laundry list of the failures of Dark Matter
theory, masquerading as an article about a triumphant breakthrough in
modeling it.

Why doesn't DM gather around a galaxy's centre? Supernovas.

Hah, what? That doesn't even make any sense.


Why does DM seem to coincide with where the stars are? Supernovas push
the smaller stars away, and the DM follows those stars.

That's even more wrong. Neat.


Why aren't there more dwarf galaxies as predicted by DM theory? They're
there, but supernovas prevent star formation in some of them, so they
can't be seen.

I sometimes wonder if there's a bias in finding dwarf galaxies. Not gonna
notice the ones you can't see...

Though I think it is amusing the biggest failing people tend to find with
dark matter, assuming they aren't railing against the conceptual foundation,
is a fine tuning issue like 'not enough dwarf galaxies'.


Dark Matter this, Supernova that. All of this effort in trying to make a
pre-conceived notion look like reality!

Yousuf Khan

***
Supernova Winds Shape Galaxies : Discovery News
"Previous attempts to model galaxy formation based on the highly
successful theory of cold dark matter -- which states that invisible
material must account for 85 percent of the mass of the universe -- have
done "an awesome job" of explaining such global properties as where,
when and how many galaxies should form, notes Governato. But the models
have failed to reproduce some of the key features of individual galaxies.

Huh. Just read an article in ApJ (or MNRAS?) about a simulation that
reproduces the Tully-Fisher relation for galaxies using dark matter.

What was found, relevantly enough, is that the baryonic matter seems to
'follow' the dark matter around. That jives with my expectations, given
overall abundances. Wouldn't want the gravitational version of 'tail wagging
the dog'.


In particular, those simulations have produced galaxies whose centers
are stuffed with too much dark matter and that are surrounded by a
spherical distribution of stars that actual dwarf galaxies don't
possess. Dwarf galaxies, which are low-mass bodies with relatively
uniform distributions of stars, are the most common type of galaxy in
the neighborhood of the Milky Way."
http://news.discovery.com/space/supe...formation.html

Supernova winds blow galaxies into shape
http://www.sciencenews.org/view/gene...ies_into_shape
A new simulation that combines supernova winds with the mysterious
material known as cold dark matter almost perfectly accounts for the
structure of dwarf galaxies in nearby reaches of the universe.

On Jan 13, 11:56*pm, Sam Wormley wrote:
Supernova winds blow galaxies into shapehttp://www.sciencenews.org/view/generic/id/54015/title/Supernova_wind...
A new simulation that combines supernova winds with the mysterious
material known as cold dark matter almost perfectly accounts for the
structure of dwarf galaxies in nearby reaches of the universe.


Dark matter is absolute and total bull****.
And it always has been.


john

Dear Yousuf Khan:

On Jan 13, 10:16*pm, Yousuf Khan wrote:
This article reads like a laundry list of the failures
of Dark Matter theory, masquerading as an article
about a triumphant breakthrough in modeling it.

Why doesn't DM gather around a galaxy's centre?
Supernovas.

Not required. DM's velocity (as stuff) is highest near the center, so
its density is lowest. Simple inviscid fluid flow (you know, your
favorite Dark Fluid...)

Why does DM seem to coincide with where the
stars are? Supernovas push the smaller stars away,
and the DM follows those stars.

Doesn't follow. Simply says that supernovas primarily exist in the
centers of galaxies. We don't have resolution to see much finer than
this.

Why aren't there more dwarf galaxies as predicted
by DM theory? They're there, but supernovas
prevent star formation in some of them, so they
can't be seen.

Dark Matter this, Supernova that. All of this effort
in trying to make a pre-conceived notion look like
reality!

You *have* to wear the garment to know where it itches, and what it
leaves uncovered. Its just Science, not Religion. Make predictions,
test, see how you did. Try again.

David A. Smith

Yousuf Khan wrote:

This article reads like a laundry list of the failures of Dark Matter
theory, masquerading as an article about a triumphant breakthrough in
modeling it.

Why doesn't DM gather around a galaxy's centre? Supernovas.

Why does DM seem to coincide with where the stars are? Supernovas push
the smaller stars away, and the DM follows those stars.

Why aren't there more dwarf galaxies as predicted by DM theory? They're
there, but supernovas prevent star formation in some of them, so they
can't be seen.

Dark Matter this, Supernova that. All of this effort in trying to make a
pre-conceived notion look like reality!

Yousuf Khan

***
Supernova Winds Shape Galaxies : Discovery News
"Previous attempts to model galaxy formation based on the highly
successful theory of cold dark matter -- which states that invisible
material must account for 85 percent of the mass of the universe -- have
done "an awesome job" of explaining such global properties as where,
when and how many galaxies should form, notes Governato. But the models
have failed to reproduce some of the key features of individual galaxies.

In particular, those simulations have produced galaxies whose centers
are stuffed with too much dark matter and that are surrounded by a
spherical distribution of stars that actual dwarf galaxies don't
possess. Dwarf galaxies, which are low-mass bodies with relatively
uniform distributions of stars, are the most common type of galaxy in
the neighborhood of the Milky Way."
http://news.discovery.com/space/supe...formation.html

A false curve fitting is fine for interpolation but fails for
extrapolation. When a curve fit is falsified outside its interval -
fitting one cycle of a sine wave with an odd-power polynomial - it is
beacause the fitting function is incorrect. One can ultimately add
one parameter for every observed point save one. The next observation
then adds yet another parameter.

Economics calls this "heteroskedasticity," covering your erroneous ass
with pleas of "mea culpa!" Now, the pretty part: Heteroskedasticity
is heteroskedastic!

Google
Heteroskedasticity 356,000 hits
Heteroscedasticity 302,000 hits

Contemporary physical theory is lost. Quantized gravitations are
disasters, string theory being the big road kill. SUSY is a
disaster. There is no Higgs boson, there is no proton decay, there is
no zoo of particle partners. There are no alternatives, for young
faculty with alternate approaches are defunded for insubordination and
thoughcrime. Grant funding is intolerent of risk.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm

dlzc wrote:
Dear Yousuf Khan:

On Jan 13, 10:16 pm, Yousuf Khan wrote:
This article reads like a laundry list of the failures
of Dark Matter theory, masquerading as an article
about a triumphant breakthrough in modeling it.

Why doesn't DM gather around a galaxy's centre?
Supernovas.

Not required. DM's velocity (as stuff) is highest near the center, so
its density is lowest. Simple inviscid fluid flow (you know, your
favorite Dark Fluid...)

That was my original idea of why Dark Matter doesn't concentrate around
the center of the galaxy, and that works with major galaxies like the
Milky Way. However with dwarf galaxies that assumption would mean that
there's can be no Dark Matter at all in those galaxies since there
wouldn't be enough mass to hold onto it, which we know "observations"
state that they must contain some.

However, it's possible that dwarf galaxies contain a lower-velocity Dark
Matter halo, that sticks to those galaxies without flying off. So the
question would then become why is Dark Matter so conveniently of the
exact right velocity required to fit a galaxy of a certain size? Then
the follow on question would be, if that dwarf galaxy is swallowed by a
bigger galaxy, then why is the Dark Matter distribution of the newly
formed galaxy exactly right again? Did the slow-speed DM of the dwarf
speed up once it entered the bigger galaxy? If so, then why?

Of course, this new theory says that's all caused by supernova bursts,
pushing the Dark Matter around, indirectly.

Why does DM seem to coincide with where the
stars are? Supernovas push the smaller stars away,
and the DM follows those stars.

Doesn't follow. Simply says that supernovas primarily exist in the
centers of galaxies. We don't have resolution to see much finer than
this.


Actually what the article was saying is that in the early days of a
galaxy, supernova explosions arising from the centers of those galaxies
create the momentum to push smaller stars out to farther regions of the
galaxies. Once the small stars are there, these small stars then pull
the Dark Matter out with them due to their gravity. It sounds like a
tail wagging the dog scenario. One would think that since Dark Matter is
much more massive than those stars, the Dark Matter would tend to pull
those stars back towards the centers again, rather than the DM getting
pulled outward.

It's just more of this magical mystery substance called Dark Matter
which is magical not because it's dark, but because it takes on whatever
characteristics you need it to take on to make your theory work. :-)


Why aren't there more dwarf galaxies as predicted
by DM theory? They're there, but supernovas
prevent star formation in some of them, so they
can't be seen.

Dark Matter this, Supernova that. All of this effort
in trying to make a pre-conceived notion look like
reality!

You *have* to wear the garment to know where it itches, and what it
leaves uncovered. Its just Science, not Religion. Make predictions,
test, see how you did. Try again.


Yes, I realize they're just trying to improve the theory here. But I'm
just amused by how they will admit to all of these shortcomings when
they come up with a modification to the theory, but before that they
would rather not admit to any of these shortcomings at all.

Yousuf Khan

General Omar Windbottom wrote:
[...]

An alternative [and more scientific] strategy is to let nature guide
us empirically, and to have the humility and integrity to say: "Gee,
maybe we our assumptions are wrong; let's try different ideas!"

Bullet cluster.


Am I alone on this issue, or do others worry about these issues too?

Yours in science [the kind that was practiced in 1905-1925, not
untestable postmodern pseudoscience],
KNECHT

Yeah because science stopped in 1925.

On Jan 15, 6:28 am, (Phillip Helbig---
undress to reply) wrote [sci.astro.research, 1/15/10, "Exoplanets...":

How can an observation show that something is NOT there, especially
something which is dark? Presumably, you mean that, based on other
observations and some accepted (by whom?) theory of physics, it was
INFERRED that it is not there. A long chain of reason, and hardly
"empirical". Please apply the same standards to all sides.

I believe that astrophysicists generally accept that the CDM model's
initial prediction of centrally-peaked dark matter distributions in
galaxies has been empirically ruled out. This is especially true and
well-documented in the case of dwarf galaxies. You might look up the
literature on this topic and study it. Of course you are free to "go
rogue" on your colleagues and discount their hard-earned observational
work. Your choice.


Also note that, historically, the motivation for dark matter was
observational.

One of modern astrophysics' success stories. Thank you Fritz Zwicky,
Vera Rubin et al., etc., etc.


Why the capitalisation [of SIMULATIONS]? What else would they run on computers?
Reality?

As one who thinks that fractals have played a major role in physics/
biology/geology/economics/etc., and that the fractal approach has an
even more fundamental role to play in cosmology, I obviously think
computers can be very important research tools.
However. computer simulations are a two-edged sword. The danger is
that one can literally get whatever one wants in terms of model-
building. As they say in the field: GIGO [garbage in - garbage out].
Moreover you can make that "garbage" look like the Hope diamond, and
one can back-rationalize the reasoning so that it appears highly
"compelling" and "robust" and "natural". Just so, just so.


You caricature your opponents and/or fail to appreciate the interaction
between theory and observation. Please apply the same standards to all
sides. Case in point: your Discrete Fractal Paradigm, as you often
point out, makes specific predictions about the mass spectrum of dark
matter. This is testable, because objects in such a range would produce
a microlensing signal in QSOs.

(1) My motivation is purely scientific. I am worried about the
untestable post-modern pseudoscience that is like a cancer in the
science that I value so highly. I may emphasize the problem areas in
order to make my case, but I can assure you that I fully appreciate
all of the good science that has been done since 1925 too.

(2) Regarding the Discrete Self-Similar Cosmological Paradigm [aka
Discrete Scale Relativity] and its set of Definitive Predictions
regarding the galactic dark matter, we have gone through this several
times and find that we are in almost complete disagreement on every
aspect of the paradigm and its various definitive tests. Why bring up
this hackneyed argument? I await new and more definitive empirical
guidance on the dark matter issue and I recommend that you do too.
Moreover, this distracts from the more general questions of this
thread, which go beyond any individual's specific theory to
concentrate on general community issues and trends.

RLO
www.amherst.edu/~rloldershaw