[Bored chemist]

So why do you all insist to ignore the key functionality of the spiral?

Because there is no reason to suppose it has a function.

[Origin]

If the signals from that quasar did indeed travel for 13.03 billion years, and the universe was/is still expanding all that time, the original signals should have red shifted out of what we expect from a quasar

What are you talking about?  The red shift of quasars are how we know their distance and age.

How can light, given off by a quasar, traveling in an expanding universe for 13 billions of years, avoid all the extra 13 billion years of red shift, due to the continuing expanding universe?

What are you talking about?

If space-time is expanding all energy wavelengths stretch out, to lower and lower and lower energy.

Which is exactly what we see in a quasar's red shift.

What someone should do is use the observed energy signal and back calculate 13 billion years

This sounds like a homework question  usually asked in freshman astronomy.

[Dave Lev (OP)]

1.  Galactic rotation.

That includes the rotation of the spiral arms of the galaxy.

No, it isn't
Did you had the chance to read the following message from Halc:

Quote from: Bored chemist on Yesterday at 09:55:04
So, you accept that, without it, Kepler's laws are broken.

FYI, there's a lot of references to Kepler's laws (the third one especially), yet those laws only apply to orbits of insignificant masses about one significant (effectively point) mass. So the laws are not violated either with or without dark matter since the laws are not applicable in the first place.
1) 'Orbits' about the galaxy are not elliptical, or even planar.
2) A line segment joining some star and center of the galaxy does not sweep out equal areas during equal intervals of time, although it's pretty close with any star that has little eccentricity to its path.
3) 'Orbit' periods do not follow the square-cube rule, with or without dark matter.

There is no "arm" in this explanation.
In order to get better understanding, please also see the following:
https://en.wikipedia.org/wiki/Galaxy_rotation_curve
"The rotation curve of a disc galaxy (also called a velocity curve) is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's center."
"The galaxy rotation problem is the discrepancy between observed galaxy rotation curves and the theoretical prediction, assuming a centrally dominated mass associated with the observed luminous material."
Therefore, it is all about star that orbits around "centrally dominated mass" at a "radial distance from that galaxy's center."
There is no arm in this story.
It is all about a star that orbits at a constant radius around the center of the galaxy.
Actually, in this article, they discuss about the arm and they claim:
"When mass profiles of galaxies are calculated from the distribution of stars in spirals and mass-to-light ratios in the stellar disks, they do not match with the masses derived from the observed rotation curves and the law of gravity. A solution to this conundrum is to hypothesize the existence of dark matter and to assume its distribution from the galaxy's center out to its halo."
So, they don't claim that stars are bonded to the arm, but try to calculate the effective mass due to the distribution of stars in spirals and find that those stars "do not match with the masses derived from the observed rotation curves and the law of gravity"
Therefore, they just ignore the observation that all of those stars are bonded in the spiral arms and totally ignore the real meaning of all observations.
Hence, they clearly see that the arms are full with stars, but from their point of view, each star must bond itself to the center of the galaxy and not to the spiral arm.
Therefore, the spiral arm has no real meaning to our scientists.

So why do you all insist to ignore the key functionality of the spiral?

Because there is no reason to suppose it has a function.

Is it?
Please look at the following image:

Please look at the following image of the Milky way:
https://www.researchgate.net/figure/Schematic-view-of-the-spiral-arms-of-the-Milky-Way-Georgelin-Georgelin-1976-with-the_fig1_23795669

Please set each star at a fixed velocity and fixed orbital radius.
What would happen to the spiral structure after just one galactic orbital cycle?
Don't you agree that stars would be moved outside the arms and the spiral shape would be broken?
Actually, there is no need for one full galactic cycle, even after 0.1 of a cycle, stars would already be moved away from the arms (especially at the far end) and the spiral shape would be broken.
The Sun complete one galactic cycle in 240 MY.
So, in just 24MY from now our sun would be out of the Orion spiral arm.
In the same token we can assume that also 24 MY ago it was also outside the spiral arm.
Therefore, we are just lucky that as we open our eyes suddenly the Milky Way got its wonderful spiral structure.
We are also so lucky that every two galaxies out of three in the entire universe are just transformed into spiral galaxies.
Wow how lucky we are that we can observe 280B spiral galaxies at all ages (from only 0.5BY to 13.8BY).
Sorry, those 280 Billion galaxies do no lie to us. There is no luck in those spiral galaxies.
They all work on the same basic law of newton gravity force that bond a star to the spiral arm and is called metastable stage.

Hence, As long as our scientists would refuse to understand the real meaning of spiral arms, they won't understand how spiral galaxy really works.

[Bored chemist]

No, it isn't

Yes it is.

Did you had the chance to read the following message from Halc:

Yes.

There is no "arm" in this explanation.

There are also no mentions of penguins eating fish.
But that does not mean that penguins do not eat fish, does it?

You problem isn't just a lack of understanding of science, it's a failure to understand basic logic.

"The rotation curve of a disc galaxy (also called a velocity curve) is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's center."

And the stars in the arms are rotating about the centre of the galaxy.

So, as I said

1.  Galactic rotation.

That includes the rotation of the spiral arms of the galaxy.

Is it?

Is what?
Anyway, you already lost this argument earlier in the thread.
Why are you trying, once again, to pretend that someone assigned a purpose to the spiral?

If you prefer to call this activity as effect instead of function - then this is perfectly OK.

It is perfectly OK for me to use the right word.
It is not OK for you to use the wrong one.

[Dave Lev (OP)]

Quote from: Dave Lev on Yesterday at 05:27:44
"The rotation curve of a disc galaxy (also called a velocity curve) is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's center."

And the stars in the arms are rotating about the centre of the galaxy.

As you claim that the stars in the arms are rotating about the centre of the galaxy, then do you agree that each star keeps its galactic orbital radius and orbital velocity?
If so and as your logic is superior;

You problem isn't just a lack of understanding of science, it's a failure to understand basic logic.

Would you kindly explain how all those billions of stars that are orbiting at the same velocity (about 220Km/s)  but at different galactic radius (from 3KPC to 15KPC) could be kept at the same spiral arm for even one orbital galactic cycle without breaking the spiral shape?
In order to help you please look again at the following image of the Milky way:

Quote from: Dave Lev on 08/07/2022 06:22:55
Please look at the following image of the Milky Way:
https://www.researchgate.net/figure/Schematic-view-of-the-spiral-arms-of-the-Milky-Way-Georgelin-Georgelin-1976-with-the_fig1_23795669
Please set each star at a fixed velocity and fixed orbital radius.

Based on my basic logic, while a star at 15KPC complete only one galactic cycle, a star at the same arm at 3KPC would have to set 5 orbital cycles.
So please, based on your superior logic, how many orbital cycles (for the one at 15KPC) are needed in order to break the spiral arm structure?

[Dave Lev (OP)]

There are also no mentions of penguins eating fish.
But that does not mean that penguins do not eat fish, does it?

Dear BC
I hope that you do understand that spiral arms are quite more complicate than penguins eating fish.
The Milky way is waiting for your superior Logic.
All the other 280 Billions of spiral galaxies are also waiting.
So, please harry up.
They all might lose their spiral arms as the dark matter by itself can't help.

[Bored chemist]

I hope that you do understand that spiral arms are quite more complicate than penguins eating fish.

Yes. That's why I chose a simple example- in the hope that you would understand.
But it seems I overestimated your intelligence.
As far as I can tell, you just are not bright enough to realise why you are wrong.
I feel like might as well try to explain astronomy to a dog.
It won't matter how hard I try to teach, not how carefully the dog listens.
He never will understand.

And it seems to be the same with you.

[Dave Lev (OP)]

As far as I can tell, you just are not bright enough to realise why you are wrong.
I feel like might as well try to explain astronomy to a dog.

Let's make it clear.
In order to avoid the message about your inability to explain how spiral galaxy really works, you attack the messenger.
This is your expected approach which you constantly use any time that you have no clue what should be the real answer.
You are using the Dog, penguins and fish just to show that you don't have a basic clue about my following question:

Would you kindly explain how all those billions of stars that are orbiting at the same velocity (about 220Km/s)  but at different galactic radius (from 3KPC to 15KPC) could be kept at the same spiral arm for even one orbital galactic cycle without breaking the spiral shape?
In order to help you please look again at the following image of the Milky way:
Quote from: Dave Lev on 11/07/2022 05:27:44
Quote from: Dave Lev on 08/07/2022 06:22:55
Please look at the following image of the Milky Way:
https://www.researchgate.net/figure/Schematic-view-of-the-spiral-arms-of-the-Milky-Way-Georgelin-Georgelin-1976-with-the_fig1_23795669
Please set each star at a fixed velocity and fixed orbital radius.
Based on my basic logic, while a star at 15KPC complete only one galactic cycle, a star at the same arm at 3KPC would have to set 5 orbital cycles.
So please, based on your superior logic, how many orbital cycles (for the one at 15KPC) are needed in order to break the spiral arm structure?

Therefore, please don't take it personally as all the Astronomers together in the entire universe don't have a basic clue how the dark matter can form the unique shape of spiral galaxy.
So, you can go on with your Zoo land as you wish. Unfortunately, it won't help even for one spiral galaxy to keep its spiral structure for just one galactic cycle.
The dark matter by itself can't explain the Bar, Ring and spiral structure.

However, our Astronomers don't really care about it.
They just offer an imagination that is called dark matter to solve the orbital velocity while they totally ignore the full structure of the galaxy.
Hence, they clearly ignore any observation that could contradict their theory.
They don't care that any second galaxy in the Universe is spiral.
They don't care that there are 280 Billions of spiral galaxies just in the visible Universe.
They only care that the current mainstream would be kept on forever.
We OBSERVE that the bar transfer stars to the spiral arms and ring.
It is stated clearly:
https://scitechdaily.com/galactic-bar-paradox-a-mysterious-and-long-standing-cosmic-conundrum-resolved-in-cosmic-dance/
"The bar in the center and the spiral arms are thought to rotate at different speeds. If they are disconnected the bar shows its true and smaller structure (left). Every time they meet, the bar appears longer and its rotation slower (right). Credit: T. Hilmi / University of Surrey"
So it is stated clearly:
" If they are disconnected the bar shows its true and smaller structure (left)."
Hence:
Once the Bar is disconnected from the spiral arm, it becomes SMALLER.
Therefore, stars are transferred from the bar directly into the spiral arms & Ring.
That observation proves that the Bar is used to funnel stars from the Bulge into the spiral arm/Bar and not vice versa.

However, this observation kills the current mainstream:

Our scientists wish to believe that the SMBH eats stars from the Bulge while new stars are delivered/funneled from the bar to the Bulge.
However, how could it be that the Bulge can supply stars outside to the Bar and at the same time supply stars to the SMBH to be eaten while it is still full with so many stars?
So, from where all the matter for those stars in the Bulge are coming from? If it is not from outside (bar) and it is not from inside (SMBH) then from where the matter is coming?
I hope that by now we all fully accept the observation that the Bar funnels stars from the Bulge to the spiral arms and ring.
Hence, could it be that the second imagination of our scientists that the SMBH is eating stars from inside the Bulge is just incorrect?

[Bored chemist]

I chose a simple example- in the hope that you would understand.
But it seems I overestimated your intelligence.
As far as I can tell, you just are not bright enough to realise why you are wrong.
I feel like might as well try to explain astronomy to a dog.
It won't matter how hard I try to teach, not how carefully the dog listens.
He never will understand.

And it seems to be the same with you.

[Dave Lev (OP)]

He never will understand.

As you think that you do understand, then please advice what is the meaning of the following message:

" If they are disconnected the bar shows its true and smaller structure (left)."

https://scitechdaily.com/galactic-bar-paradox-a-mysterious-and-long-standing-cosmic-conundrum-resolved-in-cosmic-dance/
"The bar in the center and the spiral arms are thought to rotate at different speeds. If they are disconnected the bar shows its true and smaller structure (left). Every time they meet, the bar appears longer and its rotation slower (right). Credit: T. Hilmi / University of Surrey"

Actually, you don't need to know science. Basic logic is good enough.
So, please based on your superior logic, what do you understand from the observation that the bar is shorter/smaller at the moment of disconnection from the spiral arm?

What is the real flow of stars?
Is it from the Bar to the spiral arm, or from the spiral arm to the bar.

[Halc]

I have also said that trying to explain something to you is about as productive as explaining it to my cat.
You display negligible reading comprehension skills, and mathematics and logic skills are also lacking.

This topic seems to be devolving into assertions of slander against these 'astonomers' that have so little clue, so I am once again threatening to close the topic that has long since passed any hope of making progress.
But let me put a little reading comprehension test, based on some past responses. Apologies for treating you like an 8 year old in a quiz here, but you're determined to act like one.

What is being violated without dark matter is basic Newtonian law. We have objects (our solar system say) that accelerate far more than can be accounted for by the sum of the forces applied by all the various baryonic masses in the galaxy. Thus there must either be more (a lot more) mass that isn't baryonic, or Newton's laws (the inverse square one concerning gravitational attraction) are wrong.

Your explanation is valid as long as we ignore the arms.

What exactly do you think I was saying in that quote?
Please don't just copy my words. Tell me in your own words what the post was about.
You don't have to agree with the words, just give an indication the comprehension isn't totally absent.
Why do you think mention of arms was necessary?
Who was the comment addressed to?
What was the purpose of my posting that when I've been mostly keeping out of this?
Was the purpose served?

You go on to reference the same comment again, like it somehow backs some assertion of yours.

There is no "arm" in [Halc's same] explanation.
In order to get better understanding, please also see the following:
https://en.wikipedia.org/wiki/Galaxy_rotation_curve
"The rotation curve of a disc galaxy (also called a velocity curve) is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's center."

The rotation curve comment you quote also does not mention 'arms'. What do you think the wiki comment says? Why was a reference to my comment (especially my lack of mention of 'arms') relevant to this comment?

Quote from: Dave Lev on 08/07/2022 06:22:55
Please set each star at a fixed velocity and fixed orbital radius.
Based on my basic logic, while a star at 15KPC complete only one galactic cycle, a star at the same arm at 3KPC would have to set 5 orbital cycles.
So please, based on your superior logic, how many orbital cycles (for the one at 15KPC) are needed in order to break the spiral arm structure?

Here you actually make a point. Stars closer to the center go around much more often than the ones further out. The ratio of 5 is poor mathematics, but the ratio is not far from that. You're giving evidence that your assertions are wrong. Not sure why you're doing this.
As for superior logic, you commit a straw man fallacy here, asserting facts that are not held by these 'clueless' astronomers, only by you. So that's the demonstration of 'superior logic' you've been requesting.

As you think that you do understand, then please advice what is the meaning of the following message:
https://scitechdaily.com/galactic-bar-paradox-a-mysterious-and-long-standing-cosmic-conundrum-resolved-in-cosmic-dance/
"The bar in the center and the spiral arms are thought to rotate at different speeds. If they are disconnected the bar shows its true and smaller structure (left). Every time they meet, the bar appears longer and its rotation slower (right). Credit: T. Hilmi / University of Surrey"

OK, since you quoted that, what do you think it says? This is a reading comprehension test remember.
Why do you think this comment is relevant here?
The comment is a caption, and is obviously commenting on the images above it. What is it saying that you think is worthy of being introduced in this topic?


If this is too difficult, you've really no business wasting all our time on this site.

[Dave Lev (OP)]

Quote from: Dave Lev on 08/07/2022 06:22:55
Please set each star at a fixed velocity and fixed orbital radius.
Based on my basic logic, while a star at 15KPC complete only one galactic cycle, a star at the same arm at 3KPC would have to set 5 orbital cycles.
So please, based on your superior logic, how many orbital cycles (for the one at 15KPC) are needed in order to break the spiral arm structure?

Here you actually make a point. Stars closer to the center go around much more often than the ones further out

Thanks

The ratio of 5 is poor mathematics, but the ratio is not far from that.

The distance that a star should cover in one orbital cycle is:
S=2πR
Hence,
S3 (for the one at 3KPC) = 2π3KPC
S15 (for the one at 15KPC) = 2π15KPC
Hence
S15 / S3 = 5.
As both stars orbit at the same velocity, then by the time that S15 sets only one orbital cycle, S3 would have to set exactly 5 orbital cycles.
So why do you claim that "The ratio of 5 is poor mathematics"?
Can you please offer better mathematics?

Our Sun is located at about 7.5KPC from the center of the galaxy.
Therefore we can claim that
S7.5 / S3 = 2.5

You're giving evidence that your assertions are wrong. Not sure why you're doing this.

Sorry, why do you claim that my assertions are wrong.
What is wrong?
Please look again on the following image of the milky way:

Please look at the following image of the Milky Way:
https://www.researchgate.net/figure/Schematic-view-of-the-spiral-arms-of-the-Milky-Way-Georgelin-Georgelin-1976-with-the_fig1_23795669
Please set each star at a fixed velocity and fixed orbital radius.
Based on my basic logic, while a star at 15KPC complete only one galactic cycle, a star at the same arm at 3KPC would have to set 5 orbital cycles.

What is wrong with my logic?
Don't you agree by now that by the time that S15 would set only one orbital cycle, S7.5 would have to set 2.5 cycles and S3 would have would set 5 cycles?
If you agree with that, then why don't you agree that after one orbital cycle of S15, that spiral arm shape must be broken.
So how can we explain that 280B galaxies at the entire visible universe at different ages keep their spiral shape for very long time?
If you still think that dark matter by itself can keep the spiral shape after one orbital cycle of S15, then please explain how it works.

[The Spoon]

If this is too difficult, you've really no business wasting all our time on this site.

See Halc post above

If this is too difficult, you've really no business wasting all our time on this site.

Quote from: Dave Lev on 08/07/2022 06:22:55
Please set each star at a fixed velocity and fixed orbital radius.
Based on my basic logic, while a star at 15KPC complete only one galactic cycle, a star at the same arm at 3KPC would have to set 5 orbital cycles.
So please, based on your superior logic, how many orbital cycles (for the one at 15KPC) are needed in order to break the spiral arm structure?

Here you actually make a point. Stars closer to the center go around much more often than the ones further out

Thanks

The ratio of 5 is poor mathematics, but the ratio is not far from that.

The distance that a star should cover in one orbital cycle is:
S=2πR
Hence,
S3 (for the one at 3KPC) = 2π3KPC
S15 (for the one at 15KPC) = 2π15KPC
Hence
S15 / S3 = 5.
As both stars orbit at the same velocity, then by the time that S15 sets only one orbital cycle, S3 would have to set exactly 5 orbital cycles.
So why do you claim that "The ratio of 5 is poor mathematics"?
Can you please offer better mathematics?

Our Sun is located at about 7.5KPC from the center of the galaxy.
Therefore we can claim that
S7.5 / S3 = 2.5

You're giving evidence that your assertions are wrong. Not sure why you're doing this.

Sorry, why do you claim that my assertions are wrong.
What is wrong?
Please look again on the following image of the milky way:

Please look at the following image of the Milky Way:
https://www.researchgate.net/figure/Schematic-view-of-the-spiral-arms-of-the-Milky-Way-Georgelin-Georgelin-1976-with-the_fig1_23795669
Please set each star at a fixed velocity and fixed orbital radius.
Based on my basic logic, while a star at 15KPC complete only one galactic cycle, a star at the same arm at 3KPC would have to set 5 orbital cycles.

What is wrong with my logic?
Don't you agree by now that by the time that S15 would set only one orbital cycle, S7.5 would have to set 2.5 cycles and S3 would have would set 5 cycles?
If you agree with that, then why don't you agree that after one orbital cycle of S15, that spiral arm shape must be broken.
So how can we explain that 280B galaxies at the entire visible universe at different ages keep their spiral shape for very long time?
If you still think that dark matter by itself can keep the spiral shape after one orbital cycle of S15, then please explain how it works.

See Halc post above. Anser his points instead of posting anti-science nonsense.

[Origin]

The distance that a star should cover in one orbital cycle is:
S=2πR
Hence,
S3 (for the one at 3KPC) = 2π3KPC
S15 (for the one at 15KPC) = 2π15KPC
Hence
S15 / S3 = 5.
As both stars orbit at the same velocity, then by the time that S15 sets only one orbital cycle, S3 would have to set exactly 5 orbital cycles.
So why do you claim that "The ratio of 5 is poor mathematics"?
Can you please offer better mathematics?

Your attempts at math to support your position are even worse than your arm waving gibberish.

[Dave Lev (OP)]

Quote from: Dave Lev on Yesterday at 05:09:54
As both stars orbit at the same velocity

Oops

Why "Oops"?
Please look at the following rotation velocity of stars:
https://www.astronomy.ohio-state.edu/thompson.1847/1101/RotCurve2.gif
Don't you agree that stars at the spiral disc orbit at almost the same velocity?

As the velocity of stars in the spiral disc is almost the same, don't you agree that those stars at any radius sould cover almost the same distance at any given fixed time fram?
Therefore, while a star at 15 KPC sets only one galactic orbital cycle, how many cycles stars at 7.5KPC and 3KPC would have to do - based on your math?

Quote
Sorry, why do you claim that my assertions are wrong.

Because they predict the rapid breakup of arms

Wow!!!
You fully that our scientists "predict the rapid breakup of arms"
That exactly meet my assertion that based on the dark matter imagination, spiral arms should be broken very quickly..
You call it: "the rapid breakup of arms".
What is the meaning of "rapid"
Do you agree that the arms are broken very quickly?
If so, how quickly?
Is it after one galactic orbital cycle of our sun (S7.5 - in 240MY) or 0.1 cycle (in 24MY)?
Can we agree on 100MY?
However, how the spiral arm could be recovered?
Can you please explain the process how the dark matter by itself can help the spiral arms to be recovered to their nice symmetrical spiral shape after they have been broken?
Is it just an issue of a good luck like a lottery?
So, what is the chance for the galaxy to win the lottery and gain back its spiral arms
How long time is needed? Is it also about 100MY or 10^10..00 Billion years?

yet most galaxies have arms

That is fully correct. Every two galaxies out of three are spiral.
Therefore, your imagination about "the rapid breakup of arms" is just incorrect.
How can you claim that based on your wrong theory it is predicted that the arms would be broken quickly, while the observation proves that the spiral arms are fully stable in all those 280 Billions galaxies?

Your claims contradict evidence, but that's nothing new.

I claim that the arms are stable (or actually "metastable").
The imagination of "therapid breakup of arms" is just incorrect.
The 280 Billion spiral galaxies PROVE it!
Sorry, as you fully understand that based on the dark matter the arms should be broken quickly, while "most galaxies have arms" then you have to know that your theory about the dark matter imagination is just incorrect!!!!
Therefore, my claim meets the evidence/observation by 100%.

Answer the reading comprehension questions Dave,

I will. Promise.
Please, let me answer your questions one by one.
Let's focus now on your sever mistake about "the rapid breakup of arms".

Your attempts at math to support your position are even worse than your arm waving gibberish.

So please show your math that is based on real data/observation (as I did) and not just "arm waving".

[Bored chemist]

Wow!!!
You fully that our scientists "predict the rapid breakup of arms"

Did you mean "You fully refute..." or "You fully agree..."
You certainly failed writing.
I think you also failed the comprehension.

You need to get to grips with understanding what people write.

Let's focus now on your sever mistake about "the rapid breakup of arms".

No.
We need you to focus on actually understanding what we say.
Otherwise we are back in this territory.

I feel like might as well try to explain astronomy to a dog.
It won't matter how hard I try to teach, not how carefully the dog listens.
He never will understand.

And it seems to be the same with you.

[Dave Lev (OP)]

Quote from: Dave Lev on Today at 05:32:04
Let's focus now on your sever mistake about "the rapid breakup of arms".

No.
We need you to focus on actually understanding what we say.

Halc (& Kryptid) are the only persons in this site that are brave enough to offer real technical data even if it proves my understanding
While you  just say No , No No, without offering any real data or mathematics.
Therefore I really admire Halc for his honesty in this reply.
Halc clearly had stated that our scientists "predict the rapid breakup of arm":

predict the rapid breakup of arms

That prediction is a direct outcome from the Dark matter.
Halc actually confirmed that the arms are broken quickly.
I don't need more than that.

Now, as you claim that I don't know, then would you kindly answer the following questions?

1. Broken arms in spiral galaxy
How quickly the the arms are broken?
Is it after one galactic orbital cycle of our sun (S7.5 - in 240MY) or 0.1 cycle (in 24MY)?
Can we agree on 100MY?

2. Recovery from broken arms
A. Can you please explain the process how the dark matter by itself can help the spiral arms to be recovered to their nice symmetrical spiral shape after they have been broken?
B. Is it just an issue of a good luck like a lottery? What is the chance for the galaxy to win the lottery and gain back its spiral arms
C. How long time is needed? Is it also about 100MY or 10^10..00 Billion years?

Please, this time real technical data and not just arm waving!

 

[Halc]

Quote
Sorry, why do you claim that my assertions are wrong.

Because they predict the rapid breakup of arms

Wow!!!
You fully that our scientists "predict the rapid breakup of arms"

Halc clearly had stated that our scientists "predict the rapid breakup of arm":

predict the rapid breakup of arms

That prediction is a direct outcome from the Dark matter.

You did not answer the questions I required. You thus fail the test of being someone who displays any reading comprehension skills. For instance, this little quote above suddenly suggests that I said that scientists predict the rapid breakup of arms, when I of course made no mention of scientists (or dark matter) in what you quoted. It was your assertions that do, and thus your assertions that contradict the evidence.

Can you please explain the process how the dark matter by itself can help the spiral arms to be recovered to their nice symmetrical spiral shape after they have been broken?

Another example. Nobody every suggested this. You cannot read.

Based on the replies here, and since you would not answer the questions testing if it is worth leaving the topic open, it is (and has been for some time) very apparent that communication with you is not possible. This is a waste of everybody's time. Topic closed.