Spiral galaxies are among the most beautiful and familiar objects in the
heavens, but a working explanation as to why galaxies evolve into
spirals has eluded astronomers for decades. Now, two independent
researchers have published a compelling solution to this eighty year old
problem, which appears in the November 2009 issue of Proceedings of the
Royal Society A. Consequently, the Milky Way must be remapped. This
newly emerging picture of our galaxy is being released online today as a
high-resolution digital image. The Milky Way is revealed as tightly
wound “grand design” two-armed spiral – not a four-armed spiral as has
previously been supposed.
Download the new map of the Milky Way @ http://astrostudio.org/milkyway.
html
Independent mathematician Charles Francis of Hastings, U.K., and
amateur astronomer Erik Anderson of Ashland, Oregon, had been working
on a quite different problem when the discovery was made. Anderson had
compiled data from existing sky surveys on more than 20,000 Milky Way
stars with accurately known positions and velocities. By treating orbits
as precessing ellipses, Francis found that mutual gravitation naturally
leads to orbital alignments that generate spiral patterns. Orbital
motions follow spiral arms over large distances.
Watch an animation of the galaxy in motion @ http://rqgravity.net/Spiral
Structure
Francis likens the gravitational potential of a spiral galaxy to a giant
funnel with spiral grooves. Stars, like rolling marbles, are channeled
along the grooves until they build enough momentum to escape. Escaping
stars migrate away from the galactic center, crossing over the next
highest groove, and falling back into the same groove they came from.
See the spiral funnel diagram @ http://rqgravity.net/images/spiralmotion
s/funnel2.gif
Francis and Anderson’s model also explains why spiral patterns are
stable. As an arm accumulates stars, its gravitational field grows
stronger, making its “groove” deeper and drawing greater numbers of
stars into it. Thus, mutual gravity between stars reinforces spiral
structure. The gravity of the arms locks the rate of orbital precession
to spiral pattern speed (which rotates slowly backwards) for a wide
range of orbits. Interstellar gas, following similar motions, also
contributes to the formation of “grand
design” two-armed spirals.
“The idea is so simple that I had initially rejected it,” Francis
confesses. “I thought that if it were right, it would already be known;
but when I compared it to data, it worked straight away, giving a
perfect fit.”
Astronomer Rainer Klement, at the Max Planck Institute for Astronomy in
Heidelberg, Germany, agrees. “It is a very nice paper with very good
ideas and explanations for the kinematic structures we observe,” Klement
remarks. “It comes up with an elegant way of explaining the velocity
distribution in the solar neighborhood.” Klement believes that future
observations, covering even broader regions of the galaxy with even
greater precision, will support the paper’s conclusions.
The introduction of a working model for spiral galaxies will
revolutionize the study of galactic dynamics. “It comes as a surprise to
most people that galactic orbits of stars are still treated in textbooks
using a model of epicycles introduced in the 1920s,” Francis notes.
“Epicycles are generally believed to have been banished from astronomy
over three hundred years ago, when Newton explained Kepler's discovery
that planetary orbits are ellipses. In popular culture, ‘adding
epicycles’ refers to the process of introducing fudges to make a theory
fit data, when actually the theory needs to be replaced in its
entirety.”
Learn about epicycles in modern astrophysics @ http://rqgravity.net/Ptol
emyIsDead
Regards
--
Charles Francis
moderator sci.physics.foundations.
charles (dot) e (dot) h (dot) francis (at) googlemail.com (remove spaces and
braces)
Congratulations, Charles, on what sounds like some real physics.
Incidentally, none of your links here worked. Also, Ptolemy's
technique was a mathematical method of finite Fourier transforms to
calculate relative motion between two points (e.g. Earth, Mars) each
moving on a slowly precessing ellipse. It is easier to CALCULATE with
circular motion than to try to use elliptical functions directly. He
was NOT proposing that this technique represented the actual motion of
the planets - that came later, from his more religious (& less
philosophical) followers.
http://astrostudio.org/milkyway.html
>> Independent mathematician Charles Francis of Hastings, U.K., and
>> amateur astronomer Erik Anderson of Ashland, Oregon, had been working
>> on a quite different problem when the discovery was made. Anderson had
>> compiled data from existing sky surveys on more than 20,000 Milky Way
>> stars with accurately known positions and velocities. By treating orbits
>> as precessing ellipses, Francis found that mutual gravitation naturally
>> leads to orbital alignments that generate spiral patterns. Orbital
>> motions follow spiral arms over large distances.
>>
>> Watch an animation of the galaxy in motion
http://rqgravity.net/SpiralStructure
>> Francis likens the gravitational potential of a spiral galaxy to a giant
>> funnel with spiral grooves. Stars, like rolling marbles, are channeled
>> along the grooves until they build enough momentum to escape. Escaping
>> stars migrate away from the galactic center, crossing over the next
>> highest groove, and falling back into the same groove they came from.
>>
>> See the spiral funnel diagram
http://rqgravity.net/images/spiralmotions/funnel2.gif
>> Francis and Anderson’s model also explains why spiral patterns are
>> stable. As an arm accumulates stars, its gravitational field grows
>> stronger, making its “groove” deeper and drawing greater numbers of
>> stars into it. Thus, mutual gravity between stars reinforces spiral
>> structure. The gravity of the arms locks the rate of orbital precession
>> to spiral pattern speed (which rotates slowly backwards) for a wide
>> range of orbits. Interstellar gas, following similar motions, also
>> contributes to the formation of “grand
>> design” two-armed spirals.
>>
>> “The idea is so simple that I had initially rejected it,” Francis
>> confesses. “I thought that if it were right, it would already be known;
>> but when I compared it to data, it worked straight away, giving a
>> perfect fit.”
>>
>> Astronomer Rainer Klement, at the Max Planck Institute for Astronomy in
>> Heidelberg, Germany, agrees. “It is a very nice paper with very good
>> ideas and explanations for the kinematic structures we observe,” Klement
>> remarks. “It comes up with an elegant way of explaining the velocity
>> distribution in the solar neighborhood.” Klement believes that future
>> observations, covering even broader regions of the galaxy with even
>> greater precision, will support the paper’s conclusions.
>>
>> The introduction of a working model for spiral galaxies will
>> revolutionize the study of galactic dynamics. “It comes as a surprise to
>> most people that galactic orbits of stars are still treated in textbooks
>> using a model of epicycles introduced in the 1920s,” Francis notes.
>> “Epicycles are generally believed to have been banished from astronomy
>> over three hundred years ago, when Newton explained Kepler's discovery
>> that planetary orbits are ellipses. In popular culture, ‘adding
>> epicycles’ refers to the process of introducing fudges to make a theory
>> fit data, when actually the theory needs to be replaced in its
>> entirety.”
>>
>> Learn about epicycles in modern astrophysics @
http://rqgravity.net/PtolemyIsDead
>Congratulations, Charles, on what sounds like some real physics.
Thanks
>Incidentally, none of your links here worked.
Sorry. Hopefully they are fixed in above.
>Also, Ptolemy's
>technique was a mathematical method of finite Fourier transforms to
>calculate relative motion between two points (e.g. Earth, Mars) each
>moving on a slowly precessing ellipse.
Except of course that Fourier analysis wasn't known at the time.
> It is easier to CALCULATE with
>circular motion than to try to use elliptical functions directly.
Actually, I don't think it is. Actually planetary orbits are just
ellipses. Elliptic functions are something else.
http://en.wikipedia.org/wiki/Elliptic_function
> He
>was NOT proposing that this technique represented the actual motion of
>the planets - that came later, from his more religious (& less
>philosophical) followers.
Strictly speaking, they do approximate the motion, but not the mechanism
underlying the motion.
Best,
Fred Diether
"Oh No" <No...@charlesfrancis.wanadoo.co.uk> wrote in message
news:k6smKrBG...@charlesfrancis.wanadoo.co.uk...
If you don't (mean theory) then the answer is obvious. It is given by
the quoted website links. And there isn't anything wrong with that, in
principle. However, it is a bit unfortunate that Charles exhibited a
(slightly embarasing) 'premature ejaculation' in this respect, by
publishing the announcement before the links existed.
If you mean theory, Proceedings of the Royal Society, A , which you
can discover by following the "analysis" link in
http://www.astrostudio.org/milkyway.html