A new theory of how galactic spiral arms work simulated

On 4/21/11 7:45 AM, john wrote:


The arms break up about as frequently as
electrons break up.


Too bad you have never done any self-education about
density waves and spiral arms, John. You might want
to start he http://casa.colorado.edu/~danforth/science/spiral/

On Apr 24, 7:19*pm, Sam Wormley wrote:
On 4/21/11 7:45 AM, john wrote:



The arms break up about as frequently as
electrons break up.

* *Too bad you have never done any self-education about
* *density waves and spiral arms, John. You might want
* *to start hehttp://casa.colorado.edu/~danforth/science/spiral/

"Density waves" is B.S.
They just showed that. You might want to read what they said.

Density waves, like Dark Matter, is knee-jerk
"fantasy physics" trying to get around the blatant
observation that motion of galactic arms proves our
"suck gravity" to be WRONG. Black Holes were already a
plain-as-the-nose-on-your-face indication of that obvious fact.

Too bad you have never done any actual thinking, Sam.
Analyze what you read- don't just believe it.

Think about suck gravity for a minute (maybe it will
take you longer- probably it will); how does ANY
influence (I won't call it a force so you don't jump on that)
how does ANY influence travel in the OPPOSITE
DIRECTION that it acts?

Does a tsunami move TOWARDS the epicenter?
Which slows you down. a headwind or a tailwind?
If you fall asleep in the sun, is it the side facing
the sun that gets burned or the side away?

How does something self-gravitate? Does it
put out a radiation that
travels in a circle?

How many does it take to Tango, Sam?

Density waves? That's an apt description of
the thinking in Physics, maybe. I can't believe how
dense most of these 'thinkers' seem to be.

Yikes!! Am I in some kind of weird dream where no-one can
use even the most elementary logic? Wake up, guys!!

john

On 24/04/2011 9:19 PM, Sam Wormley wrote:
On 4/21/11 7:45 AM, john wrote:


The arms break up about as frequently as
electrons break up.


Too bad you have never done any self-education about
density waves and spiral arms, John. You might want
to start he http://casa.colorado.edu/~danforth/science/spiral/


Actually, Sam, this study is debunking the density wave theory.

Yousuf Khan

On 4/25/11 10:17 AM, Yousuf Khan wrote:
On 24/04/2011 9:19 PM, Sam Wormley wrote:
On 4/21/11 7:45 AM, john wrote:


The arms break up about as frequently as
electrons break up.


Too bad you have never done any self-education about
density waves and spiral arms, John. You might want
to start he http://casa.colorado.edu/~danforth/science/spiral/


Actually, Sam, this study is debunking the density wave theory.

Yousuf Khan

As always, I encourage readers to read the links and the associated
references for a better understanding!

Summary from: http://casa.colorado.edu/~danforth/science/spiral/

"A great deal of work has been done on spiral structure since the early
work of Lindblad. While it seems density waves are a very efficient way
to form arms, there appear to be more than one way to skin a galactic
cat. While some theories such as MHD have been pretty conclusively
discounted, the strengths of those still in the running are
complimentary and may explain different facets of the problem.
Stochastic star formation and chaotic theory seem to explain
smaller-scale structure well while global modes and driven systems are
more coherent over the larger scale. Observations of our own galaxy
suggest that many or all of these systems are at work to one degree or
another".

On Mon, 25 Apr 2011 11:17:14 -0400, Yousuf Khan
wrote:

Actually, Sam, this study is debunking the density wave theory.

I think "debunk" is the wrong word. The analysis doesn't strongly
argue against the density wave theory (which itself has some direct
observational support), but rather, demonstrates a simulation that is
able to produce arm structure via a different mechansism.

All very interesting and useful. And I think it is far too early to
say with any confidence that either theory is entirely right or wrong,
or that galactic arms aren't the product of multiple causes.

On Apr 25, 8:17*am, Yousuf Khan wrote:
On 24/04/2011 9:19 PM, Sam Wormley wrote:

On 4/21/11 7:45 AM, john wrote:

The arms break up about as frequently as
electrons break up.

Too bad you have never done any self-education about
density waves and spiral arms, John. You might want
to start hehttp://casa.colorado.edu/~danforth/science/spiral/

Actually, Sam, this study is debunking the density wave theory.

* * * * Yousuf Khan

The funny thing is I cannot ever remember hearing the density wave
theory as a credible theory.

On 25/04/2011 1:42 PM, Chris L Peterson wrote:
On Mon, 25 Apr 2011 11:17:14 -0400, Yousuf Khan
wrote:

Actually, Sam, this study is debunking the density wave theory.

I think "debunk" is the wrong word. The analysis doesn't strongly
argue against the density wave theory (which itself has some direct
observational support), but rather, demonstrates a simulation that is
able to produce arm structure via a different mechansism.

All very interesting and useful. And I think it is far too early to
say with any confidence that either theory is entirely right or wrong,
or that galactic arms aren't the product of multiple causes.

Well, actually, the density wave theory wasn't conclusively proved yet
to call it debunkable, true. But somehow the density wave theory had
become the favoured theory. We won't know for sure until we set up a 1
million year observational survey to see how stars move with the arms.
Perhaps we might get sensitive enough observations in 100,000 years to
make the call, but I don't know.

Yousuf Khan

On Apr 25, 7:04*pm, Sam Wormley wrote:
On 4/25/11 10:17 AM, Yousuf Khan wrote:









On 24/04/2011 9:19 PM, Sam Wormley wrote:
On 4/21/11 7:45 AM, john wrote:

The arms break up about as frequently as
electrons break up.

Too bad you have never done any self-education about
density waves and spiral arms, John. You might want
to start hehttp://casa.colorado.edu/~danforth/science/spiral/

Actually, Sam, this study is debunking the density wave theory.

Yousuf Khan

As always, I encourage readers to read the links and the associated
references for a better understanding!


This is how I know that you are not even genuine empiricists for even
though they once were advancing along a productive path which I found
interesting,they are now locked in their homocentric imaginations and
can't even apply analogies to observations anymore so let me help you
out Sam with imaging.

http://images.astronet.ru/pubd/2003/...el_lula_c2.jpg

What an empiricist,if there were genuine ones,would do is determine
that hurricanes and galactic structure have similar features due to
comparable dynamics in such a way that a hurricane exists in certain
conditions yet moves while retaining its structure,a galaxy too may
move and be influenced by even greater rotations or influences acting
to give it both its structure,internal motion and an unknown external
motion.Even assuming observers can untangle themselves from the right
ascension mess which will eventually free the Earth's orbital
characteristics but also the solar system's galactic orbital motion
from homocentricity,it may be decades before the next clue
surfaces.Like the Earth's 26 mile spherical deviation or the jig-saw
of plate tectonics as it applies to crustal evolution and
motion,readers can probably grasp that some correlation exists between
the meteorological structures and their astronomical counterparts
without having to draw unnecessary conclusions in the absence of more
precise reasoning.

I certain understand that you destroyed your imaginations as a tool to
fill in speculative gaps by putting all your conclusions in the
imagination,I wouldn't expect you to understand this but as an
astronomer who has a keen interpretative sense you can take it from me
that the study of galactic structure in your hands is an uneventful as
the replies you have received so far.

On Mon, 25 Apr 2011 16:11:51 -0400, Yousuf Khan
wrote:

Well, actually, the density wave theory wasn't conclusively proved yet
to call it debunkable, true. But somehow the density wave theory had
become the favoured theory.

No theory is ever proven, conclusively or otherwise. The density wave
theory is favored because it has both theoretical and observational
support. This new theory forms a theoretical basis, but is thus far
missing any observational support. And of course, as I noted, both
theories can be correct- they are not necessarily mutually exclusive.

Chris L Peterson:
No theory is ever proven, conclusively or otherwise. The density wave
theory is favored because it has both theoretical and observational
support. This new theory forms a theoretical basis, but is thus far
missing any observational support. And of course, as I noted, both
theories can be correct- they are not necessarily mutually exclusive.

If I read you correctly you are effectively saying that the answer to a
certain question may not be at either extreme, but somewhere in the
middle. Furthermore, you are conceding that we don't yet know the
answer to the question with any certainty.

Do you have any idea how anti-American-and-friend-of-Bin Laden that
kind of talk is? Learn to jerk your knee.

Davoud

--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.

usenet *at* davidillig dawt cawm