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Junior Member (Idle past 5387 days) Posts: 24 From: Chorley, Lancs, UK Joined: |
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Author | Topic: Star Formation (Star Condensation) | |||||||||||||||||||||||||||||||||||||||
Parasomnium Member Posts: 2228 Joined: |
Sorry to interrupt, but I noticed you didn't use superscript. Sentences with expressions like the ones you used are much easier to read if you do. Here's how yours turns out:
The volume of a typical interstellar cloud is 4.43*1044 m3. Divide that by 1057 and you get 4.43*10-13 m3. Each hydrogen gas takes up a volume of 6.2*10-31 m3. I'd hardly call that condensed. It's a bit of a bore editing it, but your readers will thank you.
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CTD Member (Idle past 6128 days) Posts: 253 Joined: |
Can't help you there. Strictly speaking, I probably could go look up some things and study for a few days or weeks, but it's not that important.
It easy to see the history of the models. Way back when, they used to say gravity pulled the clouds in until stars formed. Then they discovered gravity wasn't enough, so they used shockwaves from supernova explosions. Could be somebody made a mistake - maybe gravity is enough all by itself. Last I knew, it was pretty well agreed that it isn't; but I haven't done all the calculations and I don't intend to. They don't appear to be very easy. I always get confused about how pressure emulates temperature, and I'll bet that's a factor somewhere in the mess. If people want to believe clouds can condense into stars without supernovas, I don't have a problem with it. I've tried to pitch in, and I may even be wrong about which model is now "preferred". If your model is newer, that's fine. If it's older but still correct, that's fine too. Now if it's always been common knowledge that gravity alone could get the job done, why was the supernova model even invented? I hardly think any YEC would invent such a thing. And I'm a tad curious just how many gas clouds should be present if it's a "done deal" and they're all busily condensing into new stars. There may be someone who would like to argue about this and mix numbers with you, but that would be someone other than myself. If it wasn't a very close thing, dark matter would've come into play long ago. Since it is a very close thing, and the math is complex, I see no point in arguing it. I cannot say at what point a gas reaches equilibrium and the pressure matches up with the gravity. Perhaps your gas wasn't condensed enough for that to happen yet. Maybe it never will... (at least maybe not prior to ignition!) Again, your model might be good. It might be the best. But it comes to a conclusion that is the opposite of what was commonly believed not long ago. I'm not going to argue. One way or another, under Big Bang cosmology the gas clouds become stars. I understood they needed something to jump-start the process, but I really don't care very much either way. I am not infallible, and neither are those who performed similar calculations in the past. My criticism of your model may have been erroneous. If it was, I am sorry. I was merely attempting to account for the discrepancy.
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Taz Member (Idle past 3550 days) Posts: 5069 From: Zerus Joined: |
CTD writes:
Why not both? At the beginning when there were only hydrogen and helium (right after the big bang event), certain already dense regions accumulated into interstellar clouds and gravity eventually contract these gas clouds into newly formed stars. The hydrogen burning (or fusion) that occur within these stars create helium, then helium burning creates heavier elements, and so on and so forth. Eventually, some stars run out of fuel and is massive enough that when they collapse under their own weight they become supernovas. During these short violent events, even heavier elements are created while the explosions themselves send these elements back into the interstellar medium. These materials eventually condense again and form another generation of stars. And so on and so forth. Now if it's always been common knowledge that gravity alone could get the job done, why was the supernova model even invented? I'm not trying to pick on you, but so far your responses have been little better than "I heard somewhere that Darwin doubted his own theory, therefore evolution is false..."
your model might be good.
I'm sorry, but I have not presented any model to speak of. You are making this harder than it is. Here's what happened so far. The thread started said that he thought gravity wasn't enough to overcome the gas's tendency to expand. I introduced honest to god math calculations that showed otherwise. You came in and said something like in the great scheme of things I'm wrong. I asked specifically why I was wrong and you answered that you heard somewhere that I was wrong, therefore I was wrong. It would really help if you could be a little more specific than simply repeating "It is very well known that you're wrong, therefore you're wrong..." I mean, throw me a bone here. Tell me what's wrong?
Last I knew, it was pretty well agreed that it isn't.
May I propose the following explanation? Please note that it is only a hypothesis. Is it possible that the community you refer to that "pretty well agreed" about this thing is the very same community that wants the young earth creationist model taught in school? I know from personal experience that it was pretty well agreed that if the earth was a few miles from its current orbit that all life on earth would end immediately, proving that this razor thin region of space that earth occupies must be proof of divine intervention. To me, this "fact" remained pretty well known until I stopped being a fundamentalist christian and someone pointed out to me that earth is several million miles farther away from the sun during summer than during winter. After that, this pretty well known fact stopped being so well known. What I'm saying is is it possible that, like me, you've been living a sheltered life?
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anglagard Member (Idle past 1095 days) Posts: 2339 From: Socorro, New Mexico USA Joined: |
Taz writes: To me, this "fact" remained pretty well known until I stopped being a fundamentalist christian and someone pointed out to me that earth is several million miles farther away from the sun during summer than during winter. Watch out, I understand that there may be Australians around here.
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cavediver Member (Idle past 3902 days) Posts: 4129 From: UK Joined: |
Star formation - CreationWiki, the encyclopedia of creation science Nebula theory - CreationWiki, the encyclopedia of creation science The trouble with articles such as these is that is very difficult trying to ascertain the true propotions of stupidity, ignorance, lies by omission, and blatent falsehood that are fed into their creation. Regarding the ang mom of the solar system:
quote: Take a moment to admire the eloquence of the writing! And I think the word they are looking for is astrophysicists - not evolutionists. Or at least in my case, my first degree was in astrophysics, not evolution, which was when we sat around scratching our heads saying "wow, that's a lot of ang mom to remove from the system - how do you think that happens? - oh, who cares, it obviously just works - yeah, the first creationist websites aren't due to arrive on the scene for at least another twelve years so we've plenty of time to hide our ignorance - heh, heh, who wants to know anyway, science is boring - too right, let's go get pissed - by the way, what's a website???"
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CTD Member (Idle past 6128 days) Posts: 253 Joined: |
If anything, I'm feeling overexposed these days. There's only so much I can take of stuff that's obviously untrue. Fortunately this isn't a case of obvious untruth. The more I look at it, the more complex it grows.
Here's some more links I dug up. I know there's better somewhere, but how to find it!? Anyhow, here's a couple from a fairly pro-banger forum. You'll need to find the "flat" button to view the whole threads. Then "find" words from my quotes below if you care enough. http://uplink.space.com/showflat.php?Cat=&Board=sciastro&...http://uplink.space.com/showflat.php?Cat=&Board=askastron... "Star formation is usually thought to require a fairly good sized and energetic event such as a supernova, which can compress a gas cloud and begin the process of gravitational collapse." Then from the other: "The cloud started out spinning. This spin was very slow, in fact the same rate of rotation as the Galaxy as a whole. However, as the cloud collapses, it spins faster. The centrifugal force created by the spin counters gravity and this should prevent the cloud from collapsing, since it increases faster than gravitational force. This is called the 'angular momentum problem' and it was a vexing puzzle to astronomers throughout the 19th Century and into the earliest part of the 20th Century. In our solar system, the enormous Sun has over 98% of the mass of the system, and yet the planets orbiting around the sun have over 90% of the angular momentum (the spin). What mechanism could have carried away the spin?" As if we didn't have enough to deal with, they throw angular momentum into the mix. Oh, and the first guy's pretty much saying what I've was saying earlier. These guys probably aren't experts, but I'd say they represent pretty well what's taught in the mainstream. But here's a nice find for you! Ever hear of a fellow named James Hopwood Jeans? He worked out some relatively simple formulas about gas clouds collapsing. James Jeans - Wikipedia Be sure to take the links to Jeans Length and Jeans Instability while you're there. Good looking short-cuts, if you ask me. How's that for a bone? And if you just can't get enough Wiki, Molecular cloud - Wikipedia
The physics of molecular clouds are poorly understood and much debated. Their internal motions are governed by turbulence in a cold, magnetized gas, for which the turbulent motions are highly supersonic but comparable to the speeds of magnetic disturbances. This state is thought to lose energy rapidly, requiring either an overall collapse or a steady reinjection of energy. At the same time, the clouds are known to be disrupted by some process”most likely the effects of massive stars”before a significant fraction of their mass has become stars. Which is why I'll save my energy for something else. There just aren't too many areas where the big official brains so obviously don't know what's going on. I mean no insult by that. It's very much to their credit that they don't make more of an effort to hide it. I mean just after what little research I've done for my posts on this thread it's my opinion that anyone who just up and says "yes it will" or "no it won't" is probably not taking everything into consideration. At this point I would not be confident betting on either side, myself. Times are changing, and I don't consider you "wrong". Here's another bone: if some YEC wants to say you need the supernovas, just whip out a little magnetism & electricity on 'im. There are other not-so-obvious factors. You don't have to fall back on dark matter, not for a long time. But be prepared for some surprises the other way too, if he's sharp & up-to-date. Goodness! It's been a while since I learned so much about something I care so little about. But it was more fun than watching any Hollywood awards show. Good Luck, TD. I look forward to clashing with you on an issue I do care about sometime.
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Taz Member (Idle past 3550 days) Posts: 5069 From: Zerus Joined: |
CTD writes:
According to your own link...
Be sure to take the links to Jeans Length and Jeans Instability while you're there. Good looking short-cuts, if you ask me. How's that for a bone?
quote: Here's the calculation... k = 1.38066 * 10-23 J/KT = 20K G = 6.67 * 10’11 N m2 /kg2 m = 1.7*1030 kg p = m/((4/3)*pi*r3) r = 4.73 * 1014 meters = .05 LY = ((5*k*T*r3)/(G*m2)).5 Which comes out to be 2.75*10-14m So... what's the problem?
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NosyNed Member Posts: 9012 From: Canada Joined: |
I'm not checking the actual calculation but I find the result surprising.
We are discussing intersteller gas clouds and the crucial "length" with resonable parameters comes out to a jillion times less than a billionth of a meter?? This doesn't seem to make sense. I'd have expected this to result in numbers that would actually separate "too small" clouds from large enough. Answers in 100,000's or much, much more meters is more like what I'd expect to see. I don't get it at all is the probable conclusion I should arrive at.
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Taz Member (Idle past 3550 days) Posts: 5069 From: Zerus Joined: |
NosyNed writes:
My mistake. I blindly trusted that wiki article, which is wrong. If you know how to edit that wiki, you should do it. m refers to the mass of the particle, not the mass of the whole thing. So, the equation cannot be combined like that. We are discussing intersteller gas clouds and the crucial "length" with resonable parameters comes out to a jillion times less than a billionth of a meter?? This doesn't seem to make sense. So, = 8.7*1014 m, which is I guess what he has been talking about. My mistake. Edited by Tazmanian Devil, : No reason given.
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Son Goku Inactive Member |
Which is why I'll save my energy for something else. There just aren't too many areas where the big official brains so obviously don't know what's going on. I mean no insult by that. It's very much to their credit that they don't make more of an effort to hide it.
The quote you provided refers to how difficult it is to model the internal fluid dynamics of interstellar clouds, which does not cast any doubt on their ability to form Stars. Stellar formation is a much more generic feature.
I mean just after what little research I've done for my posts on this thread it's my opinion that anyone who just up and says "yes it will" or "no it won't" is probably not taking everything into consideration. At this point I would not be confident betting on either side, myself. Times are changing, and I don't consider you "wrong".
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Prototype Junior Member (Idle past 4547 days) Posts: 1 Joined: |
I come in a little late on this, but there is an important point that got missed in the discussion so far that must be mentioned.
Taz estimated the force on a hydrogen atom on the OUTER RIM of a gas cloud. In other words, he starts off with an extremely inhomogeneous gas distribution in space, where in one region of space is concentrated (astronomically speaking) all the matter, which is surrounded by vast regions of perfect vacuum. The original question however was: How can we get from a uniform gas distribution to such an extremely clumpy system in the first place? This puzzling question has not be addressed here yet, at all.
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Dr Adequate Member Posts: 16113 Joined: |
The original question however was: How can we get from a uniform gas distribution to such an extremely clumpy system in the first place? This puzzling question has not be addressed here yet, at all. I think it has --- see message #3. I am not a physicist (don't worry, I'm sure several of 'em will turn up any minute now). But I think the point is this: a perfectly uniform distribution of gas would indeed never become "clumpy". But this state is unstable: that is, any small deviation from perfect uniformity will be accentuated rather than reduced over time. Edited by Dr Adequate, : No reason given.
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Alfred Maddenstein Member (Idle past 4225 days) Posts: 565 Joined: |
The whole nebular idea even to be considered depends on taking the big bunk creationism for granted. That includes re-ification of the notion the Universe which means treating the Universe as a single, finite object uniformly evolving in linear time. That is, starting from a singularity that is everywhere, going next to the cloud of the simplest elements which in its turn collapses into the first stars and so on.
No reason to take that for granted. That is not possible at all. Cosmologically, time is another measurement of distance. That means distance in every direction as measured from any possible relative location. No common shared past for each and every location and no uniform evolution is implied by that at all.
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NoNukes Inactive Member
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The whole nebular idea even to be considered depends on taking the big bunk creationism for granted. No, the nebular idea does not depend on any particular theory for the universe. Regardless of whether you believe the universal is eternal, the sun and earth quite obviously are not. An endless, eternal universe might still include the birth and death of stars and galaxies.Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) The apathy of the people is enough to make every statue leap from its pedestal and hasten the resurrection of the dead. William Lloyd Garrison
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Alfred Maddenstein Member (Idle past 4225 days) Posts: 565 Joined: |
The stars and planets indeed may be recycled in any case so you are right to an extent. Though the actual process may never have started and its mechanism might have nothing to do with gravitational collapse.
Not so long ago, I have stumbled on an alternative hypothesis of planet formation that really impressed me. The hypothesis is very rough and might be off in many details but its general direction of thought is very interesting. It proposes that stars and planets are the same thing at different stages. That is, that planets are nothing but cooled stars. That would mean that giants like Jupiter are on their way of becoming earth-like and so on. Jeffrey Wolynski is the guy who came up with the conjecture.
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