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Well, if it is too difficult to offer the dark matter density formula for the milky way then let's move on.
Do you confirm that the dark matter can ONLY explain at its best case the orbital velocity at the galactic disc and no more than that?
If you can't do so, then how can we believe in the dark matter invention/imagination?
What would you want such a formula to say?
How the density of dark matter correlates with distance from the galactic center?
I'm not an astrophysicist. I haven't researched much into why the galaxy has the structure that it does. Just because I don't know the answer doesn't mean that no one does. If you want to know the answers to these questions, perhaps you should address them to an actual astrophysicist.
Well, I hope that you agree that such formula would say - what is needed from the dark matter in order to keep the orbital velocity of star at a fixed velocity while it is in the galactic disc (3KPC to 15KPC). That's all.Our astrophysicists can invent any sort of formula for that task as they wish.
Let's assume that we don't know how the gravity really works. If I will tell you that there is dark glue that holds the stars together, would you believe in this imagination?
Without being astrophysicist it is very clear that orbital velocity in the Bar (Below 3KPC) is totally different from that in the galactic disc as in this section the velocity is increasing dramatically and linearly as we move further away from the center (up to 3KPC).
Therefore, the invented formula for the dark matter in the galactic disc totally fail in the bar section.
I hope that by now you see the severe contradiction in the dark matter imagination..
The same formula for the imagination dark matter that can solve the fixed orbital velocity at the galactic disc can't solve the dramatically increasing in the same orbital velocity at the Bar.Therefore, the dark matter can't offer even one answer to all my questions as it isn't the correct solution
You won't find even one astrophysicist in the entire planet (or if you wish - in the entire universe) that can help you to solve my questions.
Ideally, they wouldn't "invent" a formula so much as derive one. They would need to take a look at how the rotation curve correlates with the mass of visible matter in the galaxy, then deduce from that what the needed distribution of dark matter would have to be in order to explain the rotation curve. Once you get that predicted distribution, you'd look for an equation that best matches it.
QuoteQuote from: Dave Lev on Today at 04:42:56Therefore, the invented formula for the dark matter in the galactic disc totally fail in the bar section.Please demonstrate this.
Quote from: Dave Lev on Today at 04:42:56Therefore, the invented formula for the dark matter in the galactic disc totally fail in the bar section.
Have you done the math?
Have you even asked an astrophysicist yet?
1. please specify the dark matter density formula that is invented for the Milky way.2. Galactic Disc -A. How this dark matter formula can set the disc only at the spiral arms (3KPC to 15KPC)?B. Why in the Bulge there is no Disc at all?C. Why the disc does not continue after 15KPC? Actually, do you confirm that when arm is ended, the stars after that point are ejected from the disc?D. Why the thickeners of the arm at the base is 3000LY while at the end it is 400LY? How Kepler law can explain this phenomenon3. Bar -Can you please explain how the same dark matter that aim to keep the orbital velocity of the stars in the galactic disc at a fixed velocity can suddenly increase so dramatically the orbital velocity of stars in this section? How the dark matter formula can justify that dramatic increase4. RingA. How the dark matter formula can justify the creation of the Ring?B. Why the ring is always created between the end of the bar to the base of the spiral arms?C. Why do you think that Kepler law works better with dark matter for this section?
How can I find that astrophysicist that had not been born yet.
take all the astrophysicists in the planet, and no one would be able to answer my following questions:
Is it for the section of the spiral arms where the velocity is more or less fixed at radius above 3KPC?Or is it for the section of the Bar where the velocity is increasing linearly and dramatically at radius below 3KPC?
How can I demonstrate it while you refuse to offer the dark matter density formula for the milky way?
Please offer the formula and I will prove by math that this formula is a pure nonsense.
Sorry - if you ask all the astrophysicists in the planet, no one would be able to answer my following questions:
If you think that they can do so, then would you kindly direct my questions to one of them?
QuoteQuote from: Dave Lev on Today at 13:25:00Sorry - if you ask all the astrophysicists in the planet, no one would be able to answer my following questions:Please demonstrate that no astrophysicist can answer those questions.
Quote from: Dave Lev on Today at 13:25:00Sorry - if you ask all the astrophysicists in the planet, no one would be able to answer my following questions:
Sorry, no one (including all the astrophysicists in the Universe) can answer those questions as the shape of the galaxy isn't part of the dark matter density formula and can't be.
Quote from: Dave Lev on 27/06/2022 20:30:01Sorry, no one (including all the astrophysicists in the Universe) can answer those questions as the shape of the galaxy isn't part of the dark matter density formula and can't be.Then don't ask it to explain something that it was never meant to explain in the first place.
That's like saying that the formula for Kepler's third law is wrong because it doesn't explain why the planets in the Solar System have the distances from the Sun that they have. It's a non-sequitur.
until someone has a better theory it is the best explanation for observations at the present moment.
That is how science works and it is futile "throwing stones" at a theory unless you have better concept complete with full mathematical description.
I have just found an excellent article about the Bar:https://scitechdaily.com/galactic-bar-paradox-a-mysterious-and-long-standing-cosmic-conundrum-resolved-in-cosmic-dance/It is stated:"The bar pulsations result from its regular encounters with the Galactic spiral arms, in what can be described as a “cosmic dance”. As the bar and spiral arm approach each other, their mutual attraction due to gravity makes the bar slow down and the spiral speed up.Once connected, the two structures move as one and the bar appears much longer and slower than it actually is. As the dancers split apart, the bar speeds up while the spiral slows back down."It is specifically stated: "their mutual attraction due to gravity makes the bar slow down and the spiral speed up."It is also stated: "Once connected, the two structures move as one"So it is all about gravity that connects the stars in the Bar to those in the spiral arm so they all become one.Wow!!!What a great information!!!I was looking for that information for years.This is the smoking gun of the spiral galaxy!Not gravity between dark matter to ordinary matter but gravity between two key elements (Bar and spiral arms) in the spiral galaxy that are all based on ordinary matter as stars.If our scientists would understand the real meaning of this explanation, they would verify that there is no need for dark matter. The stars (ordinary matter) in each element in the galaxy are good enough to maintain its full structure (Bulge, Bar, Ring, Spiral arms...) without any need for even one particle of dark matter!Take out one element from that complex and you break down the galaxy.Nothing would help - not even dark matter.
Quote from: Dave Lev on 21/06/2022 18:31:45The Bar and the spiral arms are connected (or their motions are associated with each other) by mutual attraction due to gravity as one temporarily object?That does seem to be the case.
The Bar and the spiral arms are connected (or their motions are associated with each other) by mutual attraction due to gravity as one temporarily object?
I have found a breakthrough literature that fully supports my understanding:http://pubs.sciepub.com/ijp/7/3/2/index.html#Figure4"New Formulas and Mechanism for the Spiral Arm Formation of Galaxies"It is stated:"This model is the first attempt to think the spiral arm formation with the hydrogen originated from inside of the galactic center to outside. The proposed mechanism of the hydrogen production seems highly speculative, but the result of the simulations is very satisfactory, this indicates that the idea for the hydrogens originated from inside the bar is a promising approach, may lead us to re-think about the property of the black holes and hope to serve as a trigger to promote the future research in this direction."It is stated clearly:"This model is the first attempt to think the spiral arm formation with the hydrogen originated from inside of the galactic center to outside""this indicates that the idea for the hydrogens originated from inside the bar is a promising approach"WowWhat a great literature!!!Remember please - "from inside of the galactic center to outside"I don't need to add even one more word.
There is no need for dark matter to explain the anomalous galactic rotation curve.Please look again at the rotation curve:https://www.astronomy.ohio-state.edu/thompson.1847/1101/RotCurve2.gif1. Bar - Below 3KPCI have already explained how this segment works.There is no need for dark matter as gravity that funnels the stars from the Bulge into the inwards side of the spiral arms is good enough:Quote from: Dave Lev on 23/06/2022 19:50:59http://pubs.sciepub.com/ijp/7/3/2/figure/4The yellow line represents stars as they migrate outwards from the Bulge directly into the spiral arms.We see that the Bar looks as a propeller of an airplane.Let's assume that a star in a radius of 1KPC (R1) orbits at velocity V1 and try to verify the velocity of a star at different radius at this Bar (propeller)It is clear that:V = V1 (R / R1).If R = R2 = 2KPCV2 (at 2KPC) = 2 V1 (at 1KPC)V3 (at 3KPC) = 3 V1That linear increase in the calculated orbital velocity is fully correlated with the orbital velocity observations at the Bar section (Below 3KPC):https://www.astronomy.ohio-state.edu/thompson.1847/1101/RotCurve2.gifIf you agree with that we can move on to the spiral arms.2. Spiral arm segment 3KPC to 15 KPCWe already know that as the bar spines faster than the spiral arm, it adds new stars to the most inwards side of the arm and therefore it increases the spiral arm size (from inside).In order to keep the spiral shape of the arm while new stars are added from inside, the stars that are already there must drift backwards and keep on with their current fixed velocity.So, please look at the following image and focus on the connection point between the Bar and the spiral arm.http://pubs.sciepub.com/ijp/7/3/2/figure/4Let's assume that in this point there is a star (Let's call it Star A) which had just been delivered by the bar and is connected now to the spiral arm.So, technically, star A is currently the most inwards star in the spiral arm and its orbital velocity might represent the maximal velocity of the spiral arm.However, as the spin velocity of the bar is faster than the spin velocity of the spiral arm, than let's assume that after a given time frame (T) the Bar would move upwards and new star (let's call it star B) would be delivered from the bar to the arm.Now star B is located at the most inwards side of the arm, while star A is second one in the yellow line.As the Bar keeps its motion, new stars are coming and are connected to the most inwards side of the spiral arm.After 100 new stars, Star A is already located 100 stars away from the most inwards point of the spiral arm.Therefore, star A could keep its orbital velocity while new stars are added from inwards by the bar.The key idea is that the spiral arm isn't a solid object where a star in the top would stay there forever.It is a temporary structure of stars that constantly drift backwards while maintaining their fixed orbital velocity.However, as new stars are constantly added from inside, the spiral arm shape is maintained over time.So, if a star moves backwards at distance of D at a given time T then after 100T star A had already drifted backwards is the arm by a distance of 100D.Hence, while new stars are added constantly at the most inwards side of the arm, all the millions or billions stars in this arm can maintain a fixed orbital velocity of about 220 Km/s without breaking the spiral arm shape.However, that means that stars can't hold themselves in the arm for indefinitely.Sooner or later a star which had been delivered by the bar at the most inwards side of the arm would be eventually ejected from the most outwards side of the arm.In this way the orbital velocity of all the stars in the arm would be fixed and the temporary structure of the spiral arm would be stable.Is it clear?
Quote from: Dave Lev on 24/06/2022 20:51:59Is it clear?Clearly wrong. Orbital velocity is determined by gravity.
Is it clear?
Quote from: Dave Lev on 25/06/2022 09:09:17There is no violation of any physical law by the Bar (including the Kepler's third law).If it's orbiting faster than Kepler's third law allows, then it is.
I am not an astrophysicist, not even a physicist.
So you fully confirm that the dark matter can't give any sort of indication about the shape of the spiral galaxy.
No it is notIf you run the kepler law on the computer you would get a perfect match to the observation with regards to the velocity and shape.
As it doesn't cover the shape, then it can't be used as a theory for the spiral galaxy.
Actually I have a theory that meets the observation by 100%.
The real theory is all about gravity between ordinary matter.
We have clear observation that proves the gravity forces in the armsIt is stated:” As the bar and spiral arm approach each other, their mutual attraction due to gravity makes the bar slow down and the spiral speed up Once connected"
As an example, let me use the idea of a person that is crossing the air in an airplane.So, by simple calculation, there is no way for a person by itself to fly at so high velocity in the air.However, once you understand that this person holds itself in the airplane, then you can understand how it gets its high velocity.In the same token, once you understand that the star holds itself in the arm, then you can understand how it gets its high velocity.Why is it so complicate to understand so simple observation?
Hence, from now on we must set the calculation on the arm that holds the stars and not on individual star.
Therefore, the sun holds itself to the Orion arm and not to the center of the galaxy.
The dark matter imagination can't help to any star that is moving away from the arm.
Therefore, if you want a real theory – then you must consider the arm (the bar arms and the spiral arms) as a temporary connected stars structures by gravity, and you already have full understanding on how spiral galaxy really works without a need for one particle of dark matter.
So which theory is more realistic?Is it the one that can explain the full structure of spiral galaxy including velocities and shape at each segment of the galaxy (Bulge, Bar, Ring, spiral arms...) without any need for extra gravity, or is it a theory that is based on imagination dark matter while it can't give us any indication about the galaxy shape/structure?
That does seem to be the case.
So as the gravity force holds the two arms in one structure, why do you refuse to accept that the same gravity force helps the arm to holds its stars together?
QuoteQuote from: Dave Lev on Today at 15:25:01So as the gravity force holds the two arms in one structure, why do you refuse to accept that the same gravity force helps the arm to holds its stars together?I don't.
Quote from: Dave Lev on Today at 15:25:01So as the gravity force holds the two arms in one structure, why do you refuse to accept that the same gravity force helps the arm to holds its stars together?
What I don't accept is your claim that it somehow results in an overall speed increase that violates Kepler's third law.
Quote from: Dave Lev on 28/06/2022 03:24:18Actually I have a theory that meets the observation by 100%.There are 2 options here:1. You are lying.2. You don't know what a theory is.
The two options are not mutually exclusive.
You fully accept that the bar arm (and spiral arm) are made out of stars that are bonded by gravity force.
However, you claim that this Bar arm that is all about stars that are bonded by gravity can't increase its orbital velocity as it violates Kepler's third law.
Quote from: Dave Lev on 28/06/2022 16:59:27You fully accept that the bar arm (and spiral arm) are made out of stars that are bonded by gravity force.And dark matter too.
As long as you confirm that the stars are bonded to the arms it is perfectly OK with me.