like what are Elliptical galaxies, spiral galaxies and irregular galaxies. how do they form?
200961
Do you mean SPIRAL galaxies?\n\nCompare the Milky Way (our "spiral" galaxy) with others in the universe. There's a classification for spirals, so it shouldn't be that hard to write a paper on it (without be a physicist)
153026
Read;\n\nhttp://www.faqs.org/faqs/astronomy/faq/part4/section-14.html
7153
Conservation of angular momentum.  The odds are that anything being sucked into the center of the galaxy by the collective effect of gravity was moving with some degree of momentum not directly aimed at the center.  This would make it spiral inwards, as the angular momentum is conserved.  The closer it gets to the center, the faster it will rotate to preserve said momentum.  The aggregate direction of the angular momentum will sweep up the exceptions to the rule--the notion of a homogenous mass of uniform angular momentum would be statistically anamolous, and the result of a heterogeous mass with such angular momentum would be a spiral--any randon star between the "arms" of the spiral would be drawn towards the nearest arm, rather than toward the center of the galaxy, and this reinforces the effect.
27748
Interesting. I vaguely remember a "great attractor" from chaos theory, but what I find when I look it up now is that it refers to a cluster of galaxies, "in the direction of Centaurus and Hydra" where nobody is sure why they're grouped like that.\n\nHere's a direct quote from another source though which I think directly addresses what you're asking about: The galaxy rotational problem refers to the phenomenon of the descrepency between the observed rotational motion of the matter of the galactic disc from the predictions of Newtonian dynamics. (See links below and search for "12.25.I".)\n\nI think in layman's terms what they're boggling about is the "bar" shape that occurs in most galaxies, our own apparently included. A recent issue of Scientific American had a very good theory on how that occurs and why.\n\nIf I'm getting the gist of it right, they're not sure why clusters of stars occur in a semi-pinwheel pattern, since based on observed mass there simply isn't enough to cause such a structure to form or remain stable.  The theory in SciAm had something to do with a coincidence of travelling wave patterns rather than any deep dark mysteries of physics, filiments, or anything else.\n\nSee http://www.sciam.com/, October 2005 issue, p. 43, "Ripples in a Galactic Pond." Very nice article and they explained it more clearly than anything I could put together.
517969
Mushroom clouds form as a result of the sudden formation of a large mass of hot low-density gases near the ground creating a Rayleigh-Taylor instability. The mass of gas rises rapidly, resulting in turbulent vortices curling downward around its edges and drawing up a column of additional smoke and debris in the center to form its "stem". The mass of gas eventually reaches an altitude where it is no longer less dense than the surrounding air and disperses, the debris drawn upward from the ground scattering and drifting back down (see fallout).\nhello, use the link below to get more info.
183488
They're actually not perfect.\n\nBut check this link out:\n\nhttp://www.pa.msu.edu/~sciencet/ask_st/031198.html\n\nAnd this:\n\nhttp://www.sciam.com/askexpert_question.cfm?articleID=000D93E1-778C-1C72-9EB7809EC588F2D7&catID=3\n\nThey retain a spherical shape because of gravity.
138343
we have a hubble telescope. its actually a giant satellite that orbits in space. takes pictures. and sends them to computers on earth! neato!\n\nbut an intersting thing is, the pictures we get of other galaxies are what they looked like millions of years ago! thats because it takes millions of years for light to travel from THAT galaxy to THIS galaxy. :)
588262
WIMPS are "Weakly Interacting Massive Particles", which are hypothetical particles that have been invoked to solve the "dark matter" problem.  (Astronomical observations of things like the rotational speed of galaxies, and the interactions of galaxies in clusters can be explained if there is some form of matter, called "dark matter", that does not absorb or emit electromagnetic radiation, and thus cannot be detected by normal astronomical observations).\n\nWIMPS would only interact with other particles (and each other) via the weak and gravitational forces.  They would therefore be very hard to detect.  Because no one has yet detected them, and there are are not predicted by the "standard model" of particle physics, they remain simply an interesting conjecture.\n\nWIMPS are supposed to have large masses, and clumps of them could act as "gravitational nuclei" for the formation of galaxies in the early universe.  I do not know of any other connection between WIMPS and the inflationary scenario for the early universe.\n\nThe bubble theory of the universe is a variant on the currently favored inflationary theory for the early universe.  In this theory, instead of a single point expanding at a single time to form a single universe (ours) that constitutes all of physical reality, different portions of physical reality "decay" to form independent universes at differing times.  Physical reality would therefore correspond to a "foam" of independent universes, each of which is completely isolated from one another.\n\nI've never heard of the "hyperdimensional theory of the universe".
388852
Stars (our Sun included) form inside large nebulas of gas and dust in space.  A single nebula forms tens to hundreds of stars, so our Sun did form with other stars.  The stars that form together in a nebula eventually go there separate ways, so to speak, but systems of two, three, or more stars are quite common.\n\nHere's a nebula where stars are forming right now:\nhttp://www.seds.org/messier/m/m042.html
571626
Read this: http://outreach.atnf.csiro.au/education/senior/astrophysics/stellarevolution_postmain.html\n\nThe "onion" layer is because the core contains different layers like an onion.
642678
The planets in this solar system are in stable orbits and get no farther away from each other than their orbits allow.\n\nYou are thinking of things like galaxies moving away from eachother, indicating that the universe is expanding.\n\nFirst off, to correct a misconception, some galaxies are moving towards one another, for example, the Andromeda Galaxy, and our own galaxy the Milky Way. \n\nCertain galaxies also seem to be "clumping" together, traveling towards something called "the geat attractor".\n\nDistant galaxies and quasars seem to be moving away.\n\nTo answer your question, some speculate that the expansion of the universe will continue forever and that gravity will lose in the long run. Eventually clusters of matter will become so seperated from eachother that the possability of any productive interactions approaches zero and stars will eventually die, and their remnants will be spread to thin to form into new ones. The universe, will essentially be a cold, dark, corpse. This is called the "cold death" theory. Depressing isn't it?\n\nBut never fear! There are other theories out there! Perhaps the universe will eventually implode into a big crunch, and the force of this implosion will create a new universe! Scientists aren't yet sure exactly how the universe will end. Hopefully none of us will be around to find out by example.
290662
Your question has two parts. First, there isn't a "center" to the universe. I know that sounds strange, but it is true nonetheless.\n\nAs to what pulls, as you noted, everything pulls. However, some things are more massive and pull harder. There is a good book that shows the history of the discovery of what was called the "Great Attractor" IIRC, the book was Journey to the Great Attractor. \n\nThe Great Attractor is a supercluster of galaxies. Since then, we have discovered more about what is around us and exerting the stronger gravitional pull.\n\nA quick Internet search for galaxies + "great attractor" should give you plenty of reading material.\n\nIf you are interested in space, try\nhttp://groups.yahoo.com/group/lunar-observing/\n\nHope this helps\n\nChuck
115713
gravity.\n\nany shape of mass that is not spherical is gravitationally unstable
449912
i don't think in terms of the universe being massive compared to the size of galaxies,but minuscule compared to that which is outside the universe, that way there is an endless supply of material on hand.here at the"center of the universe"it's all relative to our thinking everything is so large but since all we can do is theorize about whats out there,why cant we theorize outside the box,way outside the box. where did science get this idea ? i believe that a chaotic set of galaxies brings about an ordered universe that is a single organism of a larger set of chaotic universes,which in turn forms ordered groups of galactic multiverses which is a small component of a megaverse ,and so on
490900
Whee, uh, I doubt if this is something you heard about in high school, but here it goes:  A modular form is a complex analytic function on the upper half-plane satisfying a number of conditions, and defined by two complex axes, so that they exist in hyperbolic space. They exhibit infinite symmetry under transformations of the type f(z) -> f[(az+b)/(cz+d)].  Related to elliptic functions, they appear in algebraic topology, string theory, and even in Mandelbrot sets. Here's the website about this last aspect, check out the color pictures:
412023
galaxies like our own and others emit radiation in different wavelength. specific elements like hydrogene can be identified with their radiation for example\nscientists now often call it the 'galaxies music' for the multitude of signals they receive. for them this is a kind of music.
541777
It is false. An "active" galaxy is one which is emitting larger than average amounts of radiation, generally in the infrared and radio frequencies. It could also apply to one active in the X-ray spectrum. The causes for these emissions can be several: The effects of two galaxies in collision(when they collide, the stars don't collide but the clouds of gas and dust do) A galaxy with a large and growing black hole at its center, A galaxy which is undergoing a large amount of new stellar formation ( now thought to be caused by gravity waves in the gas and dust clouds.