kenel Posted July 22, 2002 Share Posted July 22, 2002 I was reading an article in a magazine at the dentist's office the other day on how galaxies were formed, but I wasn't able to finish. So, my question is...how are galaxies created? Link to comment Share on other sites More sharing options...
chris Posted July 28, 2002 Share Posted July 28, 2002 weren't all galaxies created when the universe was created, but right now there either expanding/imploading on themselves? maybe im wrong. Link to comment Share on other sites More sharing options...
JaKiri Posted July 28, 2002 Share Posted July 28, 2002 iirc slight varations in the density of areas in space time just after the big bang caused matter to condense, at least by current thinking. Link to comment Share on other sites More sharing options...
Radical Edward Posted July 28, 2002 Share Posted July 28, 2002 yup, fluctuations caused in the inflationary period, thought to have occurred during a phase change as the strong force separated out of the mix. the think I've always wondered is how come more of the matter didn't overcome the chandrasekhar limit, since this presribes a really low density when given enough matter.... Link to comment Share on other sites More sharing options...
fafalone Posted July 28, 2002 Share Posted July 28, 2002 Most of the matter created was destroyed by antimatter, since equal amounts were created. Link to comment Share on other sites More sharing options...
Radical Edward Posted July 28, 2002 Share Posted July 28, 2002 still doesn't deal with the chandrasekhar limit though... there is probably an easy enough answer, but I've not seen it. Link to comment Share on other sites More sharing options...
fafalone Posted July 28, 2002 Share Posted July 28, 2002 More matter didn't escape because there was't too much more matter to escape. Link to comment Share on other sites More sharing options...
blike Posted July 28, 2002 Share Posted July 28, 2002 More matter didn't escape because there was't too much more matter to escape. Link to comment Share on other sites More sharing options...
fafalone Posted July 28, 2002 Share Posted July 28, 2002 escape the chandrasekar limit "to" should be emphasized.. think about it, makes sense Link to comment Share on other sites More sharing options...
Radical Edward Posted July 28, 2002 Share Posted July 28, 2002 I get it.. depends how big the universe was at the time when it was all destroyed really.... I guess it would be after the inflationary period. Link to comment Share on other sites More sharing options...
chris Posted July 28, 2002 Share Posted July 28, 2002 chandrasekhar limit... what is that? Link to comment Share on other sites More sharing options...
Morat Posted July 29, 2002 Share Posted July 29, 2002 Originally posted by chris chandrasekhar limit... what is that? I don't know the mathematical formulation, but iirc it's a limit how dense a certain amount of matter can be (or vice versa, how much matter of a certain density there can be) before its gravity causes it to collapse into a black hole. ed - do you know how, if at all, the initial condition of the matter affects this? would it matter that the matter in the big bang would have been incredibly hot and fast moving? and does the expansion of space have any bearing on it? Link to comment Share on other sites More sharing options...
fafalone Posted July 29, 2002 Share Posted July 29, 2002 M = (5.87/µ²)*Mo where Mo is solar masses, mu is nucleons per electron. Link to comment Share on other sites More sharing options...
chris Posted July 29, 2002 Share Posted July 29, 2002 Link to comment Share on other sites More sharing options...
Radical Edward Posted July 29, 2002 Share Posted July 29, 2002 here's me again, I meant swartzchild radius..... chandrasekhar limit is the maximum mass that can be supported as a white dwarf. anyway. I did a crude calculation (really crude - I don't have a calculator) for the mean density of the contents of a black hole the size of the one in the galaxy M87, which is about a billion solar masses, and it gave a mean density of about 10kg/m^3* which while high when compared to the mean density of the galaxy, could well have occured an awful lot in a young universe. I'll have to check up on the mean density of the universe when it was in equilibrium though. it might be interesting to work out the probability of different sizes of black hole occuring (some statistics... how banal) and see if it matched up to anything, such as the distribution of hypothesised black holes in the centre of galaxies. calculation consisted of the following: R=2GM/(c^2) R is the swartzchild radius - the radius of the event horizon of a black hole of mass M G is the gravitational constant c = speed of light. and density=mass/volume solar mass = 1.9x10^30 kg/m_3 G = 6.7x10^-11 c = 3x10^8 -------------- If anyone knows much about statistics, that would be a help. I hate it and have avoided it wherever possible. Link to comment Share on other sites More sharing options...
aman Posted August 2, 2002 Share Posted August 2, 2002 Without sentience to observe a galaxy, there is no galaxy. That is a derivitive of Schroedingers cat in the box theory. Without the formation of galaxies there would be no sentience. For a galaxy to form there must have been something that interfered with the homogenous expansion of the original big bang mass. It seems to have all the elements of seeding life since we find so much positive enforcment in our solar systems materials. Somehow, some force diverted large amounts of mass to take individual paths that are contrary to a homogenous state. I'm just postulating the universe can't be unless somebody realizes it is. That might be the reason for the galaxies but I'm going to need pages to explain my postulation of how. I guess my assistance was only worth a nickle so far. Just aman Link to comment Share on other sites More sharing options...
Radical Edward Posted August 3, 2002 Share Posted August 3, 2002 the universe can still be around icen if we aren't. if all life ended tomorrow, the universe would still be here. the initial inhomogeneities only need to be very slight, and I believe they are a possible consequence of the inflationary period, though I don't know enough about cosmology to tell you why it is thought that this is the case. Link to comment Share on other sites More sharing options...
Zarkov Posted August 3, 2002 Share Posted August 3, 2002 Spin gravity in the ether of Magnetism, would interpret all the observations differently. The interpretations used to describe the observations above are mostly not held in spin gravity theory. Link to comment Share on other sites More sharing options...
Radical Edward Posted August 6, 2002 Share Posted August 6, 2002 keep it in pseudoscience. Link to comment Share on other sites More sharing options...
aman Posted August 6, 2002 Share Posted August 6, 2002 We have a small model of galaxy development in the planet saturn. If you want to build a scale model and do the math you can learn a lot from Saturn and its rings. Extrapolate how it collected. Then come the analmolies. How come the heaviest elements are in the center. Are there any heavy metals in the rings? That might be a clue also. Just for thought. Just aman Link to comment Share on other sites More sharing options...
DocBill Posted March 18, 2003 Share Posted March 18, 2003 Originally posted by fafalone M = (5.87/µ²)*Mo where Mo is solar masses, mu is nucleons per electron. Blackhole formation is inevitable if the remnant of a Type II supernova which leaves a core of greater than 3 solar masses. Generally (although not always) a star that is large enough to form heavier elements (via Proton capture) will begin "onion skin" burning, expand, collapse and then, if the outer shell retains a mass of more than 2.99 solar masses it becomes a black hole. If the solar m,ass is less than 1.4 solar masses, you get a white dwarf. 1.5 and you get an unstable star that will detonate as a Type I novae leaving begind a Neutron star (ussually as a pulsar until all angukar conservation has been depleted). Bill Link to comment Share on other sites More sharing options...
Guest NuHertz Posted March 19, 2003 Share Posted March 19, 2003 Originally posted by fafalone M = (5.87/µ²)*Mo where Mo is solar masses, mu is nucleons per electron. I thought µ (Mu) was the co-efficient of friction, or does it have other purposes throughout physics that I am unaware? Like nucleons per electron? Link to comment Share on other sites More sharing options...
fafalone Posted March 20, 2003 Share Posted March 20, 2003 It's not. The coefficient of friction is either µs or µk. Link to comment Share on other sites More sharing options...
JaKiri Posted March 21, 2003 Share Posted March 21, 2003 Originally posted by fafalone It's not. The coefficient of friction is either µs or µk. Written as :mu: because in context there's nothing else that it could be. Link to comment Share on other sites More sharing options...
YoungStrife Posted March 22, 2003 Share Posted March 22, 2003 Spiral galaxies form from giant clouds of gas, which in the center a black hole forms from *your guessed it* a GIANT supernova, and the gas/matter around it spins counter-clockwise. I don't know how eliptical galaxies form but I do know that our galaxy will turn into one when it collides with our negihbor and the 2 black holes form to 1 even bigger one. The reason they come together in the first place...the obvious: Gravity. Link to comment Share on other sites More sharing options...
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