[Dave Lev (OP)]

Hence, as long as the star is interacted by gravity to the arm, it would go with the arm wherever it goes.

Only to an extent.

Agree!

[Dave Lev (OP)]

Dear Kryptid

Let's try to understand the impact of that statement:
"Hence, as long as the star is interacted by gravity to the arm, it would go with the arm wherever it goes."

Do you agree with the following:
1. The Orion arm is a gravitational arm.
2. The Sun is interacted by gravity to the Orion and it would go with this arm wherever it goes.

To get better understanding about this issue let me use the Sun/Earth/Moon system:
The Moon is interacted by gravity to the Earth and it would go with it wherever the earth goes.
The Earth (or actually the Com of the Earth/moon) is interacted by gravity to the sun and it would go with it wherever the sun goes.
Therefore, the moon and the earth are not directly interacted by the center of the galaxy
Their "Gravitational job" is to keep themselves under the gravity interaction with the Sun.
In the same token, the Sun is not directly interacted with the center of the galaxy.
Its "gravitational job" is to keep itself under the gravity interaction with the Orion arm and as the Orion arm orbits around the galaxy, the sun will follow.

If you agree with the above message, why do we insist that the Sun should be under a direct gravity interaction with the center of the galaxy?
Could it be that the assumption that the sun should interact directly by gravity to the center of the galaxy leads us to the wrong understanding that the SMBH mass isn't enough and there is a need for dark matter?

[Kryptid]

You are wandering dangerously close to things you have discussed in closed threads. Compare this statement of yours...

"Hence, as long as the star is interacted by gravity to the arm, it would go with the arm wherever it goes."

,,,with this previous statement of yours in a closed thread...

In the same token the spiral arm would keep them all in the galactic disc and they would have to go wherever the spiral arm goes.

And compare this...

To get better understanding about this issue let me use the Sun/Earth/Moon system:
The Moon is interacted by gravity to the Earth and it would go with it wherever the earth goes.
The Earth (or actually the Com of the Earth/moon) is interacted by gravity to the sun and it would go with it wherever the sun goes.
Therefore, the moon and the earth are not directly interacted by the center of the galaxy
Their "Gravitational job" is to keep themselves under the gravity interaction with the Sun.
In the same token, the Sun is not directly interacted with the center of the galaxy.
Its "gravitational job" is to keep itself under the gravity interaction with the Orion arm and as the Orion arm orbits around the galaxy, the sun will follow.

...with this...

We think that the Moon orbits around the Earth, but in reality it orbits around a common center of mass with the Earth. Let's call this point as ComE.
This ComE orbits around a common center of mass with the Sun. Let's call this point as ComS
Therefore, we already see two stages of gravity bonding.
Hence, while the moon is bonded locally with ComE and this comE is bonded with ComS, then although the moon orbits locally around a common center of mass, it goes wherever the Sun goes.
In the same token, we can claim that each star in bonded locally to a center of mass that is integrated in the arm and it goes wherever the arm goes.

...and you're using it all as an argument that there is no need for dark matter (which is exactly what you did in a previous thread). If you keep going with this argument, this thread will be closed as that would make it an attempt to bypass a thread lock.

[Dave Lev (OP)]

Dear Kryptid

You are the one that fully confirmed that spiral arm is gravitational arm:

Quote from: Dave Lev on Yesterday at 05:32:39
What kind of force can keep spiral arms in their spiral structure for so long time except of gravity force?
I'm not aware of any astrophysicists who claimed that it wasn't gravity that held the arms together.

So, you fully agree that gravity held the arms together.
You also confirmed that as long as the star is interacted by gravity to the arm, it would go with the arm wherever it goes:

Hence, as long as the star is interacted by gravity to the arm, it would go with the arm wherever it goes.

Only to an extent.

This breakthrough understanding is based on an important work/simulation that have done by Drs. Brant Robertson and Lars Hernquist:

"The scientific theoretical model and the computational data output were developed by Drs. Brant Robertson and Lars Hernquist. AVL rendered more than 80 gigabytes of this data using in-house rendering software and Virtual Director for camera choreography."
Do you trust this work by Drs. Brant Robertson and Lars Hernquist?

Therefore, do you claim now that all the above is incorrect?
If it is correct, why do you refuse to agree that:

1. The Orion arm is a gravitational arm.
2. The Sun is interacted by gravity to the Orion and it would go with this arm wherever it goes.

Why do you insist that there is a need for dark matter gravity interaction with Sun, while it is 100% clear to all of us that the sun is interacted by gravity to the spiral arm?

Would you kindly explain what is the mission of this forum?
Do you need to protect the main stream concept even if you clearly understand that there is a fatal error in their theory?

You know, 500 Years ago the main stream concept was that the Earth is the center of the Universe.
Anyone that dare to claim differently could lose his life.
Now nobody is going to lose his life if he proves that there is a fatal error in the current mainstream.
However, his tread would be closed.

Therefore, I want to thank you all (including Halc & Evan_au) for your excellent support that helped me to understand how gravitational spiral arm really works.

Now you are more than welcome to close the tread in order to protect the mainstream concept from a contradiction that had been proved as a real science.

[Kryptid]

So, you fully agree that gravity held the arms together.

And the gravitational contribution from dark matter is an important part of that.

You also confirmed that as long as the star is interacted by gravity to the arm, it would go with the arm wherever it goes:

You say that despite quoting me where I said, "Only to an extent". The gravitational attraction between the stars alone isn't enough.

Therefore, do you claim now that all the above is incorrect?

No, what I claim is incorrect is your misrepresentation of it.

If it is correct, why do you refuse to agree that:

1. The Orion arm is a gravitational arm.
2. The Sun is interacted by gravity to the Orion and it would go with this arm wherever it goes.

The Sun doesn't orbit the arm, it orbits the center of the galaxy.

Why do you insist that there is a need for dark matter gravity interaction with Sun, while it is 100% clear to all of us that the sun is interacted by gravity to the spiral arm?

Who is "all of us"? You're the only one I've seen here insisting, incorrectly, that the Sun's attraction to the spiral arm is enough to eliminate the need for dark matter.

Would you kindly explain what is the mission of this forum?

To discuss science, which is one reason why threads get closed when the original poster insists on ignoring scientific evidence despite being corrected over and over again to no avail.

Do you need to protect the main stream concept even if you clearly understand that there is a fatal error in their theory?

Your misunderstandings are not evidence of a "fatal error" in mainstream science.

You know, 500 Years ago the main stream concept was that the Earth is the center of the Universe.
Anyone that dare to claim differently could lose his life.
Now nobody is going to lose his life if he proves that there is a fatal error in the current mainstream.
However, his tread would be closed.

That's a false analogy. One scientific idea being wrong in the past is not evidence that the concept of dark matter is wrong in the present.

Therefore, I want to thank you all (including Halc & Evan_au) for your excellent support that helped me to understand how gravitational spiral arm really works.

You don't. If you did, you wouldn't be insisting on this idea that defies the law of gravity.

Now you are more than welcome to close the tread in order to protect the mainstream concept from a contradiction that had been proved as a real science.

You have not demonstrated a contradiction in a mainstream concept, let alone proven it "as a real science".

Since you have pretty much owned up to trying to bypass a thread lock, then this thread will be locked as well.

Please, don't try it again.