Of course I would expect a simulation using simple newton's gravity to yield the correct shape for a galaxy if given enough time. According to Wikipedia the sun completes one orbit around the galactic center in 200 million years. If the Milky Way is assumed to be 10 billion years of age, then at most, stars at the sun's distance have only made 50 complete orbits during that time. It just seems like this would not be enough passes for the entire galaxy to stabilize into a well defined form. But, if others have simulated the behavior in a reasonable manner and achieve good results then my intuition may just be incorrect.
I also have trouble thinking of the Big Bang as being an accurate model of the creation of our universe. Lets hope that proof is soon obtained one way or the other. Dave -----Original Message----- From: Jouni Valkonen <[email protected]> To: vortex-l <[email protected]> Sent: Thu, Oct 18, 2012 6:40 pm Subject: Re: [Vo]:Planet discovered at Alpha Cantauri B On Oct 18, 2012, at 8:07 PM, David Roberson <[email protected]> wrote: In light of the fact that a galaxy is geometrically immense, I have long wondered why most of those seen through telescopes are so well formed. This is quite easy to find out. Just running simulations and see what Newton wants from the Galaxy evolution. Galaxy evolution is quite easy to simulate, because Newton's law of gravity is so simple. Short answer is that spiral galaxies are formed in collisions of smaller elliptical protogalaxies. The collisions will drive the starformation, when clouds are disturbed and stardust is compressing into large stars. And as galactic interactions are violent, they will happen fast, in few billion years. Milky way is approximately 10 billion years old, so the formation of the large spiral galaxy happened in just few billion years. However, spiral galaxies are not stable structures and eventually Milky way will deform into shapeless elliptical galaxy that is reddening when star formation rate diminishes and old red and yellow stars are becoming dominant. However as two spiral giants Andromeda and Milky way are colliding in not too distant future, there will be lots of star and planet formation and hence things will get bright again. However with this scale of collision and merging end result will be mostly large and shapeles elliptical galaxy with twin core. Personally I would speculate that we need to alter big bang theory quite a lot although the age of univese is properly calculated. It is verified with so many distinct ways and all dating methods are pointing into same point of origin. My idea would be that expanding cosmos is gravitationally balanced, i.e. it is finite although it has no borders, similarly to that of Earth's surface. As cosmos is gravitationally balanced, we do not need to worry how cosmos can expand, because the expansion of cosmos is indifferent from gravity or energy density. Therefore cosmos also appears as flat in cosmic microwave background. I hope that Planck satellite data will verify that cosmos is indeed flat and hence it will disprove inflation hypothesis and naïve dynamic models of cosmos. This model of gravitationally balanced cosmos will solve almost all current major problems in Big Bang model. —Jouni Ps. Jed, thanks for correcting me. I had and still have horrible head ache due to cold. Therefore my English was worse than usually.
