Why are we so sure that there is a need for dark matter?

[Dandav]

Few more questions with regards to the following message:

3 hours ago, Dandav said:

"In consequence, it means that the bars of the spiral galaxies are losing angular momentum, and therefore slowing down while growing in size and mass."

1. How the Bar increases its size? From where that mass is coming from? Is it from the Bulge or from the spiral arms + ring?

2. Do you agree that if the Bar increases its size in the direction of the spiral arms, then it proves that it gets the matter from the Bulge and Vice versa?

3. If we ONLY observe that the Bar increases its size in the direction of the spiral arm, then why do we think that the matter in the bar is coming from outside the bar?

4. While we clearly observe that the bar is slowing down, do we also observe any sort of slowing down in the spiral arm motion?

5. If the answer is No, then how can we explain the situation that the spiral arm keeps its orbital motion, while the bar is slowing down?

6. If stars in the spiral arms are affected by the dark matter, then why stars in the bar are not affected by that dark matter.

Please be aware that the spiral arms in the Milky way starts at about 3KPC while the bar ends at almost the same distance (3KPC).

If they are all affected by dark matter, then why the bar has a Bar shape instead of spiral shape?

7. Why do we think that stars at the bar (even at the edge of the bar - 3KPC) must be locked to the Bar arm, while stars at the spiral arms (even at almost the same distance - 3KPC) can't be locked to the spiral arm?

Edited December 22, 2022 by Dandav

[Dandav]

Please read the following message from NASA:

 

https://www.dailymail.co.uk/sciencetech/article-9906101/NASA-break-spiral-arm-Milky-Way-stretches-3-000-light-years.html

"NASA finds a break in one of the Milky Way's spiral arms that stretches 3,000 light-years and looks like a SPLINTER coming out of a piece of wood"

They even offer an image:

 

 

We see the SPLINTER (that Nasa claims that it looks as a piece of wood) while it cuts the Sagittarius arm from side to side  and it is there Infront our eyes.

That splinter starts at about 7,000LY away from us and ends at about 4,000LY

However, as it looks like a solid piece of wood, then why our scientists don't even consider the possibility that this structure represents an object where all the stars there are locked/bonded to each other by gravity force which means - gravitational arm?

They call it spiral arm break. Therefore, they do understand that this splinter had been broken from a spiral arm.

Therefore, as this splinter represents a gravitational arm structure that looks as a piece of wood, then why can't we understand that the broken arm from where it had been ejected must also be a gravitational arm structure.

Our scientists informed us that they have found 512 G stars in a spherical radius of 100LY around us. 

As the diameter of Orion arm is 1000 LY, then its radius should be 500LY.

Hence, there are 512 * 5^3 = 64,000 G stars is a 1000LY sphere of the Orion arm.

This doesn't include other kinds of stars, BHs Gas clouds... that should exist in the arm.

Based on this calculation, that splinter with its 3000LY size, should have more than 200,000 G Stars plus other stars BHs and gas clouds.

As it cut the Sagittarius from side to side, then it must come at high momentum.

In the image we see that it didn't break the Sagittarius arm.

The splinter just penetrates into the arm and it seems that it had been locked into the Sagittarius arm.

All of that without even a single collision between stars from both sides.

Based on that image the splinter is coming from the Scutum arm  at the direction of the galaxy center. We actually see that its current location is not too far away from one side of the Bar.

The Bar ends at 3KPC which means - 10,000LY.

The upwards side of the splinter is located 3000LY inwards to the center (let's say - 20,000 Ly from the center) while the downwards side is located at about 23,000LY from the center of the galaxy.

Therefore, a star at the upwards location should face a different gravity force due to dark matter than a one in the downwards side.

Therefore, how could it be that stars in the splinter at different radius from the center are not affected by the different dark matter gravity force and keep themselves all together in that splinter that looks as a piece of wood?

How the density wave theory could explain the existence of this solid structure in the spiral disc while based on that theory stars in the disc aren't locked together and affected by the dark matter gravity?

Could it be that this observation is the missing smoking gun that proves that the spiral arm is gravitational arm?

As our scientists fully confirm that stars in the bar are locked to each other by gravity, then why it is so difficult for them to accept the idea that stars in the spiral arms are also locked together by gravity force?

 

 

 

Edited December 24, 2022 by Dandav

[Dandav]

In the following article, there is an explanation how the Bar in the galaxy could be form:

http://burro.astr.cwru.edu/Academics/Astr222/Galaxies/Spiral/bars.html

"What makes a galaxy barred? "

I would like to focus on the starting point of this explanation.

It is stated: 

"Take a disk where all the stars are rotating on perfectly circular orbits - relative to one another, the stars aren't moving."

Is it real?

Is it possible to ask the mother nature to offer us a disc of stars?

Please be aware, that they specifically discuss about stars without any sort of central mass.

Don't you agree that in the nature, if you set several stars next to each other you would get a star cluster or globular star cluster? which means sphere structure (not a disc).

There are millions over billions of spiral galaxies.

If all of them had started from a disc then we should find at least one similar disc of stars in the open space.

So please, did we ever see that kind of star disc where all the stars are rotating on perfectly circular orbits? (Please do not offer an image of spiral galaxy as the mission is to explain how the galaxy disc had been created at the first stage)

Don't you agree that it is a fatal mistake to start the story of the spiral galaxy from that kind of disc?

As the starting point is a fatal mistake, then how can we consider the rest of the story as real science?

They also can't explain many enigmas about the galaxy.

For example, why there are so different features in the same galaxy (Bulge, Bar, Ring and spiral arms), why there is so unique order in those features, why there is a ring (and it is there just between the bar to spiral arms), why we clearly see that the bar is slowing down but it never stops, why the Disc is thick at the base (3000LY) while so narrow at the edge (400LY) and many other questions.

Edited December 26, 2022 by Dandav

[Dandav]

In order to explain the full structure of spiral galaxy and how it had been formed, our scientists should start their explanation with a real spherical shape of stars as globular cluster.

How could it be that they took the freedom to start their explanation with this unrealistic disk where all the stars are rotating on perfectly circular orbits?

Is it realistic?

Sorry, they should start the explanation with a spherical shape as globular cluster as this is realistic shape of stars in the Universe.

We see them by millions and billions.

Therefore, their mission is to start with a spherical shape as globular cluster or Bulge, and show how that cluster/bulge could be transformed into real spiral galaxy.

If they can't accomplish this mission, then why can't they admit that they really don't know how spiral galaxy had been evolved?

Why they refuse to consider the Tidal gravity impact?

How can I convince them to think about that key idea that is vital for the creation and operation of all the billions spiral galaxies in the universe?

I can only promise them that once they would be ready for the tidal impact, they would get answers to all the questions about spiral galaxy and all the other shapes of galaxies in the entire Universe without any need for dark matter, density wave or any other imagination.

Edited December 26, 2022 by Dandav

[Dandav]

 

Please look at the following basic image of the Milky way: 

 

 

Do you confirm that the thickness of the spiral arms at the base ( just at the end of the Bar) is maximal (3000LY) while as we move further away, the arm become narrower?

Can you please specify to which direction the bar rotates?

Is it in the direction of the spiral arms or further away?

Do you agree that if the Bar rotates in the direction of the arm, then we could understand that the bar funnel stars from the spiral arms to the Bulge?

However, as it rotates to the other direction, then why is it so difficult for us to understand that the bar funnels stars from the Bulge into the spiral arms?

This is similar to garden sprinkler.

Please see the following image:

The sprinkler Bar ejects water while it rotates to the other direction of the water flow.

Don't you agree that the water jet stream from the sprinkler looks spiral and it is less massive as we move further away from the bar and therefore, there is high similarity between the bar in the galaxy to the bar in the garden sprinkler?

 

 

Please be aware that the bars in each system ejects matter and rotates at the opposite direction of the jet stream.

However, while the matter flows from the bar sprinkler is water jet stream, the matter flows from the Bar galaxy is stars, Bhs & gas clouds jet stream, while both jets looks spiral.

Edited December 26, 2022 by Dandav

[Dandav]

 

Our scientists at NASA fully confirm that "Half of All Stars Are Rogues Between Galaxies"

https://www.space.com/27682-rogue-stars-between-galaxies.html

"As many as half of all stars in the universe lie in the vast gulfs of space between galaxies, an unexpected discovery made in a new study using NASA rockets. These stars could help solve mysteries regarding missing light and particles that theory had suggested should exist, scientists say."

All of those stars had been ejected from their home galaxy as water from garden sprinkler.

 

[Dandav]

There is only one basic force that is responsible for the spiral galaxy activity. That force is called - Gravity force.

Its impact is as follow:

1. Gravitational arm impact - The Bar, the ring and the spiral arms are all gravitational arms. That means that stars are locked by gravity to each arm and they go with it wherever it goes.

2. Tidal gravity impact - Our scientists have found full correlation between the bar to the spiral arms. This correlation is due to the Tidal impact.

That's all. (No need for dark matter - Just pure gravity force between ordinary matter)

Once we agree on that, we can easily explain how spiral galaxy works and answer all the questions about its features.

[Dandav]

Orbital velocity of star in the gravitational arms (Bar, Ring & spiral arms):

The total orbital motion of a star in any kind of gravitational arm is based on three basic motions:

1. Local motion - This is the local motion that is needed to lock the star to the gravitational arm. It is similar to the motion of star in a multiple stars system as star cluster.

2. Arm Motion - The motion of the gravitational arm in the galaxy

3. Motion in the arm - The motion of the star in the gravitational arm

Hence

Star total motion in any gravitational arm = Local Motion + Arm Motion + Motion in the arm

Edited December 26, 2022 by Dandav

[Dandav]

Bulge & Bar shape

Please remember the following forces on the Bulge due to tidal gravity impact.

Bulge shape In a ring galaxy:

 

Due to the symmetrical shape of the ring, the tidal gravity due to that ring would squeeze the bulge from upwards and downwards, and force it to get the pita bread shape.

In spiral galaxy:

 

The base point of each spiral galaxy would set the maximal gravity force on the Bulge.

Therefore, the tidal force on the Bulge due to those two base points would squeeze the bulge into that bar shape.

Therefore, that bulge with its bar arms is one object. It should be called Bar shape bulge. The whole bulge would rotate with the rotation of the bars.

Due to that squeezing tidal force, the bulge would have to funnel matter/stars outwards through those two bars in the direction of the spiral arms.

By doing so, any star that funnels outwards from the bulge would be locked by gravity to the other nearby stars in the bar and they all would be forced to drift outwards. 

Therefore, the bar is the first element that force a free orbital motion star in the Bulge to be locked into the gravitational arm that is called "Bar".

However, the key question is as follow:

Why the bar rotates?

Please focus on the orbital motion of the stars in the bar based on the following image: 

 

We clearly see that the star velocity is increasing dramatically as it drifts outwards in the Bar.

Hence, from where the Bar gets the requested energy to keep that motion?

How could it be that its rotation never stops?

Any Idea?

Edited December 27, 2022 by Dandav

[Dandav]

in order to understand how Tidal works, let's look at the following image:

 

https://www.astronomynotes.com/gravappl/s10.htm

It is stated:

1. Moon pulls on Earth's tidal bulge to slow down Earth rotation

2. Earth tidal bulge pulls Moon ahead in its orbit - Moon spirals outwards in its orbit.

Now, let's translate that tidal understanding to spiral galaxy.

Instead of the Earth we would set there a Bulge.

Instead of the Moon we would set there a globular star cluster.

It is very clear that the Bulge would be squeezed and set its bar shape.

Now let's translate the following:

1. Moon pulls on Earth's tidal bulge to slow down Earth rotation

After translation:

1a. Globular star cluster pulls on bulge's tidal bar to slow down Bulge (with its bar) rotation

Hence, It is expected that due to tidal, the globular cluster would force the Bulge to form its Bar shape however, the same tidal force would slow down the rotation of the bulge with its bar arms.

Therefore, based on tidal force, the bar should slow down!

Our scientists clearly observe that the bar is slowing down.

However, somehow it never stops!

Let's translate the following:

2. Earth tidal bulge pulls Moon ahead in its orbit - Moon spirals outwards in its orbit.

2a. Bulge tidal Bar pulls Globular cluster ahead in its orbit - Globular cluster spirals outwards in its orbit.

Hence, It is expected that due to tidal, the Bars would force the globular cluster to move ahead in its orbit and it would spirals outwards in its orbit.

Please remember - Spiral outwards!!!

Therefore, if there was just one globular cluster, that cluster must spiral outwards over time due to tidal force.

However, we already know that stars in the bar are locked together and creates globular clusters.

As the tidal force push more and more stars into the Bar, it would extend its length and set more and more globular clusters in the bar. At some point the globular cluster at the edge of the bar would be disconnected from the Bar and reconnected to that globular cluster that was there instead of the moon.

Hence, now there are two globular clusters in a row instead of the Moon.

As more and more globular clusters would be ejected outwards from the Bar, they would be locked together in a row and all of them would spiral outwards over time.

By doing so, they would create the spiral arm in the spiral galaxy.

Therefore, we can claim that the spiral arm is a gravitational arm made out of many globular clusters that are locked together in a row.

Hence, while those locked globular clusters in a row, spiral outwards they form the spiral arm structure. New globular clusters are coming from the Bar and increasing the length of the spiral arms from inside. However, at some point the globular cluster that is located at the far edge of the spiral arm would be ejected from the spiral arm to the open space.

I hope that you do understand my explanation.

However, we still need to answer the following key question:

As the tidal force slow down the bar rotation, how could it be that it never stops???

Edited December 27, 2022 by Dandav

[Dandav]

Bulge rotation:

Due to tidal force, it is clear that the Bulge with its bar arms is one object.

The Bulge rotates with the rotation of its bar.

It is similar to the tidal activity on earth.

The Earth rotates with its bulge rotation:

 

 

Due to that tidal force any atom on earth must rotates with the rotation of the Earth' 'tidal bulge.

In the same token, every atom, star, BH' Gas cloud and even the SMBH in the Bulge must perfectly rotates with the rotation of the bars (without any negative impact on its local motion).

They don't feel this rotation, as we do not feel the Earth rotation.

However, from outside, we can see this rotation.

Please look at the following orbital motion of S2:

It is stated:

https://www.mpg.de/14692117/detection-of-schwarzschild-precession-in-the-orbit-of-star-s2

"Astronomers deduce its existence from the motion of the star S2, which orbits this behemoth at high speed. However, the star's orbit does not remain stationary in space, but moves forward, creating the shape of a rosette."

 

 

 

They also add:

“Einstein’s General Relativity predicts that bound orbits of one object around another are not closed, as in Newtonian Gravity, but process forwards in the plane of motion."

However, could it be that our scientists have got this S2 orbital rosette shape as they assume that the Bulge does not rotate?

I wonder what would be the outcome if they would deduct the bulge rotation from S2 motion.

Could it eliminate the rosette orbital shape and prove that after all S2 Must obey to Newtonian Gravity law?

 

Edited December 28, 2022 by Dandav

[Dandav]

 

Please look at the following image:

https://www.sci.news/astronomy/milky-way-map-09098.html

 

 

"Position and velocity map of the Milky Way Galaxy; arrows show position and velocity data for 224 objects used to model the Galaxy; the solid black lines show the positions of the Galaxy’s spiral arms; the colors indicate groups of objects belonging the same arm. Image credit: NAOJ"

Please focus on the red arrows.

They clearly indicate that stars in the Bar shape bulge are directed outwards and not inwards.

Hence, it was a severe mistake from our scientists to believe that the bar funnels stars from the spiral into the Bulge.

Therefore, I hope that by now we all agree that this observation proves that the bar funnels stars outwards from the bulge directly to the base of the spiral arms.

This is fully correlated with tidal gravity impact!

Edited December 28, 2022 by Dandav

[Dandav]

 

In the following article it is stated:

https://www.wired.com/2011/05/milky-way-symmetry/

"Milky Way Galaxy Has Mirrorlike Symmetry"

 

 

"The finding suggests that the galaxy is a rare beauty with an uncommon symmetry -- one half of the Milky Way is essentially the mirror image of the other half."

There is only one force in the nature that could set this kind of symmetry in the galaxy shape and it is called Tidal.

This is one more indication that the formation of the spiral galaxy is based on tidal impact.

Take out the tidal and you have no spiral galaxy!

Edited December 28, 2022 by Dandav

[Dandav]

Based on observation:

1. Bar activity - Based on the observation we clearly see that stars in the Bar are drifting outwards. Therefore, we have solid observation/evidence that the bar funnels stars outwards from the Bulge - directly to the base of the spiral arms.

2. Bulge - in all the observation we clearly see that the Bulge with its bar arms is one object.

3. Gravitational arms - "NASA finds a break in one of the Milky Way's spiral arms that stretches 3,000 light-years and looks like a SPLINTER coming out of a piece of wood"

https://www.dailymail.co.uk/sciencetech/article-9906101/NASA-break-spiral-arm-Milky-Way-stretches-3-000-light-years.html

That splinter which looks like piece of wood is a clear indication that the spiral arms are gravitational arms.

Actually, our scientists fully confirm that in the bar stars are locked with each other (I call it gravitational arm):

NASA - Barred Spiral Galaxies Are Latecomers to the Universe

"Bars form when stellar orbits in a spiral galaxy become unstable and deviate from a circular path. The tiny elongations in the stars' orbits grow and they get locked into place, making a bar,"

As we observe that the Bar funnels those stars outwards to the spiral arm, then we should understand that those stars should also be locked at the base of the spiral arms and extend the length of the spiral arm from inside.

So far so good.

However, I really wonder why it is stated that "a bar can act as a highway to funnel gas and dust from the outer parts of the galaxy into the core,"

https://cosmoquest.org/x/2021/05/galactic-bars-may-funnel-material-and-trigger-star-formation/

"In a new study appearing in Astronomy & Astrophysics, researchers led by Eduardo González-Alfonso have switched to using infrared light. What we’re learning now is that a bar can act as a highway to funnel gas and dust from the outer parts of the galaxy into the core, where it can trigger star formation and feed the central supermassive black hole."

How could they claim that a bar can act as a highway to funnel gas and dust from the outer parts of the galaxy into the core while they clearly observe that the bar acts as a highway to funnel gas and dust from the core into the outer parts of the galaxy?

Why they mislead us with wrong information/facts?

It is quite clear that base on the current theory the SMBH at the core of the MY galaxy must eat stars. Therefore, somehow stars should be delivered from outside to the core.

Unfortunately, the observation fully contradicts this theory.

Therefore, instead of reconsider the theory, while the observation proves that the bar act as a highway to funnel gas and dust outwards, they change the facts and claim that the Bar CAN act as a highway to funnel gas and dust inwards to the core.

Why they say "Can"?

Is it a wishful thinking or just a nice way to change the real facts?

I don't know if it was Einstein or someone else who had stated that: "if the facts do not fit the theory, then the facts must be changed"

https://quotepark.com/quotes/1786579-albert-einstein-if-the-facts-dont-fit-the-theory-change-the-fact/

However, do you agree that no one - not even our scientists in the name of any sort of theory - should change the facts?

How can we trust those scientists while they clearly offer incorrect facts?

Edited December 29, 2022 by Dandav

[Dandav]

Star transformation from the Bar to the spiral arms.

This is an important activity in the spiral galaxy.

Unfortunately, I don't have data about this process, therefor I will try to estimate how it should work:

1. Due to tidal impact the Bulge is squeezed and is forced to eject stars into the bar structure. During this process, the stars in the bars are locked to each other and form a gravitational arm. As the stars drifts outwards in the bar, they increase their velocity linearity and dramatically. 

2. The base of the spiral arms is at 3KPC from the galaxy center, which means 10,000LY away. The Diameter of the spiral arms at the base is about 3000Ly. As more and more stars flow from the Bulge to the bar, the edge of the Bar arm would get closer and closer to the base of the spiral arm.  At some point, the gravity force of the spiral arm base would be strong enough to pull the edge of the bar. However, in order to maintain the size of the spiral arm base, at 3000LY, the minimal size of the splinter/broken bar arm that is transformed from the bar to the spiral arm must be 3000LY (or more). 

3. Therefore, it is expected to see that the bar is increasing its length to almost 10,000ly. At this distance it would be connected to the base of the arm and then the bar would be cut sharply at about 7000LY. Hence, it is expected to see some sort of Hysteresis in the length of the Bar.

Please look at the following diagram:

The red line at Thigh represents the maximal Bar length (when the edge of the bar is connected by gravity with the base of the spiral arm). Let's assume that it is 10,000Ly

The blue line at Tlow represents the cutoff bar length. Let's assume that it is 7,000LY.

Hence, it is expected to see that the length of the bar is changing over time based on this Hysteresis diagram.

4. However, due to tidal, the bar must be fully symmetrical. Therefore, the total members of stars in both bar arm MUST be identical. Therefore, at any given moment, the total length of both arms must also be identical. Hence, Both Bar arms must obey the to the same Hysteresis diagram at the same time.

Ok.

This is my personal estimation. I hope that it would meet the observation of the Bar length that we might find in the future.

Edited December 30, 2022 by Dandav

[Dandav]

"The tidal mechanism for spiral galaxy"

The spiral Galaxy "Mirrorlike Symmetry" Image proves that it is there ONLY due to tidal force.

Once we accept the existence of tidal force between the spiral arms to the Bulge, we can clearly understand the simple mechanism of spiral galaxy.

This mechanism would be called: "The tidal mechanism for spiral galaxy" and It works as follow:

1. Due to tidal force, the Bulge would be squeezed and be forced to eject stars into the two Symmetrical bar arms. Any star in the bar arm would be locked by gravity to the nearby stars and therefore it must orbit around a local center of mass. From outside, we would see that the star is wobbling.

2. Those locked stars in the Bar would increase their motion linearity as they move further away from the Bulge due to the linear shape of the Bar. At some point they would be pushed outwards from the edge of the bar as splinter of stars directly to the base of the spiral arms. Therefore, the Bar increases the length of the spiral arms from inside and transform the spherical motion of stars in the bulge to disc motion in the ring.

3. Therefore, although, the edge of the bar looks constantly connected to the base of the spiral arm, each arm would rotate/spin around the galaxy at different velocity. This solves the "winding problem".

4. The Spiral arm is formed by splinters of stars that had been delivered from the Bar. All those splinters are locked together in a row by gravity and form the long spiral arm shape. The arm gets narrower as we move further away from its base (3000LY at the base, 1000LY at our location, 400Ly at the edge). However, there is a possibility for narrower/wider spots in the arm at different location. There could be also gateways and bridges between the arms. However, in any local section of the arm the density of stars should be quite fixed (in our location - 512 G stars per 100LY sphere). 

 5. Any star in the galactic disc is locked by gravity to the local nearby stars group and therefore it has a "local orbital motion" which seems as wobbling motion from outside. If the star would go out from the nearby group of stars, it would be ejected from the galactic disc as a rocket (hypervelocity” star). The total velocity of star is a sum of: Local motion + Outwards motion in the arm + Motion of the arm. The star will go with the arm wherever it goes. 

6. After long journey, from the bulge though the bar to the spiral arm, any star in the spiral arm would get to the edge of the spiral arm. At that point, the stretch force on the arm is maximal. Therefore, the diameter of the edge of the spiral arm is so narrow (400LY) comparing to its base (3000LY).

7. The bars and spiral arms are long living objects. they would keep their shape for unlimited time. However, the time living of any given star in the arms is limited.

8. At some moment, the star at the edge of the spiral arm would be ejected outwards from the spiral arm with its nearby stars group. once they do so, this group of stars would be disconnected also from the galactic disc.  Hence, the group of stars that had been called "splinter" while they have ejected from the edge of the Bar arm into the base of the spiral arm, would be transformed into globular cluster as they are ejected from the edge of the spiral arm.

9 Spiral galaxy is the biggest star sprinkler in the nature. Therefore, there are so many stars & globular clusters outside the galaxies.

10. There is no need for dark matter to explain the motion of stars in the spiral arms. it is all about tidal gravity force and ONLY tidal force!!!

Edited January 1, 2023 by Dandav

[Dandav]

I have a simple question:

How do we know if a theory is correct or imagination?

Don't you agree that it must be realistic and should cover 100% of all the observations?

The "tidal mechanism for spiral galaxy" is realistic as it all about real gravity impact.

It also covers 100% of the spiral galaxy observation with all its features as follow:

1. Orbital rotation curve (In the Bars and in the Spiral arms)

2. Long living arms

3. "Mirrorlike Symmetry" 

4. The thickness of the spiral arm - (3000Ly at the base - 3KPC , 400LYLY at the edge -15KPC)

5. Splinters in the disc that looks as a piece of wood.

6. Wobbling motion of stars in the arms

7. Disc shape.

However, the current dark matter had not been observed.

The idea that the total mass of the dark matter is at least 10 times the mass of ordinary matter and it should be in the galaxy at a very specific density (for each galaxy - different density) is not realistic

As long as we can't find a clear observation of that dark matter, how can we accept it as realistic idea?

Even if it was there, at its best case the dark matter can only give an answer for the orbital motion of stars in the disc. That's all.

It can't explain any of the other observations. None of them, not even the spiral structure.

It can't also explain why at 3KPC from the center the orbital motion in the spiral arm is affected by the dark matter, while the bar that also gets to almost this distance is not affected.

In order to explain the spiral shape our scientists have invented other imagination that is called density wave.

However, the density wave can't explain the disc shape. In order to get the spiral shape, our scientists had to start their simulation while they set stars in a disc (which is also not realistic). Even so, they clearly admit that at the best case, the density wave can keep the spiral structure for just few rotations. Therefore, this theory can't explain the long living structure of the spiral galaxy.

For all the other features, our scientists have no clue.

The key two issue that kills the Dark matter and the density wave imaginations are - "Mirrorlike Symmetry" and the thickness of the spiral arms (get narrower as we move further away from the center)  

Hence, it's time to accept the "The tidal mechanism for spiral galaxy" as it is the ONLY real theory for spiral galaxy.

It seems to me that if Einstein would come back to life and tell you that this tidal mechanism is correct, you would accept it. However, as I offer this breakthrough understanding, then it's not good enough for you.

Why is it?