'13-08-06, 13:38 Cuddles	Originally Posted by ben m CC did not waste our time by coming up with a model, trying to defend it, and making mistakes in the process. He wasted our time by misrepresenting his sources. But even that is something that can be learned from. After all, one of the most important parts of skepticism in general is to check the sources and not just blindly take someone's word for what they say. That's also an important part of reading, and especially reviewing, papers - are the references correct and relevant, and do the conclusions actually follow from the evidence?
'13-08-06, 16:40 ben m	Originally Posted by Cuddles But even that is something that can be learned from. After all, one of the most important parts of skepticism in general is to check the sources and not just blindly take someone's word for what they say. That's also an important part of reading, and especially reviewing, papers - are the references correct and relevant, and do the conclusions actually follow from the evidence? A normal scientific argument consists, indeed, of disagreements about what sources mean, whether conclusions follow, how strong those conclusions are. Scientists don't want to walk around like a skeptic at an ESP convention, looking for hidden radios and signs of fraud and deception. So, maybe CC's mistake teaches us something as skeptics, but by the standards of a science discussion it's ... well, it's outside the bounds of the honest-best-effort standards of the community.
'14-08-24, 01:29 Charles Chandler	Originally Posted by DeiRenDopa More critical review. From the "Heliosphere" section of CC's website: Originally Posted by CC There is also a lot that we can learn about the Sun's evolution and energy budget by studying the heliosphere. The Sun condensed from a dusty plasma with a volume of something like 7.48 × 1037 km3. The temperature would have been roughly 10 K. The volume of the Sun is 1.41 × 1018 km3, meaning that the dusty plasma was compressed by a factor of 5.31 × 1019. If we multiply the dusty plasma temperature (i.e., 10 K) by the same factor, we get an expected temperature of 5.31 × 1020 K. (my bold) Assuming, for now, that the values you give are correct, would you please explain the reasoning behind this, CC? Specifically, what 'laws of physics' are you applying here? I redid the relevant section, and came up with 7.76 × 108 K as an average temperature within the Sun, and 4.52 × 1015 Pa as an average pressure, which are still way too high for the standard model — the force of gravity is insufficient to keep such pressure contained. The calcs are all on my website.
'14-08-24, 05:52 edd	Originally Posted by Charles Chandler I redid the relevant section, and came up with 7.76 × 108 K as an average temperature within the Sun, and 4.52 × 1015 Pa as an average pressure, which are still way too high for the standard model — the force of gravity is insufficient to keep such pressure contained. The calcs are all on my website. We already know that such a naive calculation won't let the Sun collapse. See the calculation of the Jeans mass for the way we would normally do this. Of course we also have reason to think the formation wasn't adiabatic as you assume...
'14-08-24, 14:29 Charles Chandler	Originally Posted by edd Of course we also have reason to think the formation wasn't adiabatic as you assume... Why wouldn't it be adiabatic?
'14-08-24, 16:08 edd	It might radiate?
'14-08-24, 18:27 Reality Check	Originally Posted by Charles Chandler The calcs are all on my website. Calculation based on incorrect assumptions are always wrong, Charles Chandler. Star formation There is no "dusty plasma" in the molecular cloud that formed the Sun - it is a cloud of cold H and He with a trace of heavier elements - and yes some dust! A dusty plasma is a plasma with enough dust to influence its properties. Using the ideal gas law is just wrong. During the formation of a star both the pressure of the gas and its temperature varies as well as how much it radiates. Just guessing at an average pressure or temperature will not work. You have to actually use the real standard model of the formation of the Sun to do your calculations, not what you imagine it to be . This is really strange since you have "An Introduction to the Theory of Stellar Structure and Evolution" as a reference. Why are you not doing the calculations using the contents of this textbook? Your web page retains ignorance about the standard model of the formation of the stars - the model does include "both the thermal energy already contained in the original dusty plasma, plus the kinetic energy in the implosion".
'14-08-24, 23:43 Charles Chandler	Originally Posted by edd It might radiate? Given the opacity of dust clouds, once they get dense enough to be hot enough to radiate, I'd like to see numbers in support of the contention that they radiate fast enough to drop the pressure by 2 orders of magnitude during the final aggregation.
'14-08-25, 00:57 ben m	Originally Posted by Charles Chandler Given the opacity of dust clouds, once they get dense enough to be hot enough to radiate, I'd like to see numbers in support of the contention that they radiate fast enough to drop the pressure by 2 orders of magnitude during the final aggregation. What's "hot enough to radiate" in your mind? What wavelengths are emitted at that temperature? And: what's the opacity of dust to that wavelength? Given the power allowed to escape with this combination of temperature/wavelength/opacity, what's the cooling timescale, and what makes that "fast enough" in your mind? (Hint #1: the answer will change over the course of the collapse.) (Hint #2: The standard theory of star formation has worked through this---using actual opacity numbers---in full detail, from Jeans-mass-primordial-material to protostellar cloud to protostar. Though the details are complicated I am not aware of any problems so obvious as to be identifiable in an argument that doesn't include any actual opacity numbers.)
'14-08-25, 01:58 Charles Chandler	Originally Posted by ben m The standard theory of star formation has worked through this---using actual opacity numbers---in full detail, from Jeans-mass-primordial-material to protostellar cloud to protostar. Link please.
'14-08-25, 03:53 edd	http://articles.adsabs.harvard.edu/c...&filetype=.pdf Hayashi 1966 - a good review of this particular field early on, I guess. Note that this is a huge and important field of astrophysics and there has been lots of work in the near 50 years since incorporating all sorts of additional things not included here. It's literally textbook stuff and you shouldn't really find it difficult to find your own references.
'14-08-25, 05:39 Charles Chandler	Originally Posted by edd It's literally textbook stuff and you shouldn't really find it difficult to find your own references. Can you provide a link to work that demonstrates with laboratory physics that collapsing gas clouds do, indeed, undergo the variations in opacity that are invoked to facilitate the assumed diabatic cooling due to radiation? I don't accept assumed conclusions. We know that stars form from gas clouds. We know that if the collapse was fully adiabatic, the collapse would never happen, because the gas pressure would prevent it. It is widely accepted that this necessitates diabatic cooling, and the only option is heat loss due to radiation. So we could just work backwards from there, and assert the conditions necessary to allow it. But I'm challenging the assumption that diabatic cooling is the only option. As a consequence, I would only find it convincing if it was actually tied into laboratory physics. Otherwise the whole diabatic thing is just a hunch, no matter how elaborate the math. And as concerns the more modern literature, asking for laboratory physics is a bit laughable. The force causing the implosion is gravity coming from CDM, which is merely a math construct, and which (pretty much by definition) cannot be demonstrated any other way. In a framework that's already non-physical, how could there be a tie-in with laboratory evidence? Still, I consider these things to be physical, and if they don't obey demonstrable physical laws, we're missing something. I know that such is not the widely accepted view. As James Jeans said, speaking for proponents of the Idealist movement, "the Universe is looking less and less like a great machine, and more and more like a great thought." Well, I don't consider assumed conclusions and non-physical rationalizations to be such great thoughts. So I'm looking for fully mechanistic constructs. Sorry.
'14-08-25, 06:01 edd	It all is. It's how we know that we can explain it for high metallicity stars like the Sun, but for Pop III systems we expect to require higher mass stars to have to form. It's because we know how the atoms and molecules behave from laboratory experiments. As for Quote: The force causing the implosion is gravity coming from CDM No it isn't. On the scales involved in star formation, dark matter isn't involved in any significant way. It doesn't form stellar scale objects precisely because of the lack of baryonic physics we're supposedly discussing here.
'14-08-25, 06:49 Charles Chandler	Originally Posted by edd It all is. It's how we know that we can explain it for high metallicity stars like the Sun, but for Pop III systems we expect to require higher mass stars to have to form. It's because we know how the atoms and molecules behave from laboratory experiments. Link please. Originally Posted by edd On the scales involved in star formation, dark matter isn't involved in any significant way. It doesn't form stellar scale objects precisely because of the lack of baryonic physics we're supposedly discussing here. From the Royal Astronomical Society (2003): The history of star formation in a Λ cold dark matter universe Perhaps that doesn't speak for everybody, but it seemed to be representative of what I've been reading.
'14-08-25, 07:00 edd	Originally Posted by Charles Chandler Link please. I'm not your tutor, nor your research assistant. This is a huge field, and references are abundant. Quote: From the Royal Astronomical Society (2003): The history of star formation in a Λ cold dark matter universe This does not disagree with what I said about the scales with which you are concerned.
'14-08-25, 09:40 Charles Chandler	Originally Posted by edd I'm not your tutor, nor your research assistant. This is a huge field, and references are abundant. If you make the statement, you provide the support. The onus is not on me to assume that you are correct, and to do the leg work for you. Even if I knew your real name, and respected your credentials, I wouldn't necessarily give you every benefit of the doubt. Sorry. Call me skeptical, but that's just the way I am. De omnibus dubitandum est.
'14-08-25, 09:52 thedopefishlives	Originally Posted by Charles Chandler If you make the statement, you provide the support. The onus is not on me to assume that you are correct, and to do the leg work for you. Even if I knew your real name, and respected your credentials, I wouldn't necessarily give you every benefit of the doubt. Sorry. Call me skeptical, but that's just the way I am. De omnibus dubitandum est. Actually, it is, because the currently accepted model is being treated as the null hypothesis for the purposes of this discussion; the burden of proof is on you to prove your own theory correct, not on mainstream science to prove ours. You seem to be laboring under the misapprehension that any failure on our part to produce evidence for the mainstream theory means that your alternative must, of necessity, be correct.
'14-08-25, 10:13 ctamblyn	Originally Posted by Charles Chandler If you make the statement, you provide the support. No-one here is obliged to defend the accepted models of star formation unless they, for some reason, want you in particular to change your mind. On the other hand, if you want people here to believe that things can be usefully modelled in the way that you suggest, you indeed need to provide support for that claim. ETA: Sorry, thedopefishlives, I was busy with background tasks while composing that post, and missed yours.
'14-08-25, 10:23 ben m	Originally Posted by Charles Chandler If you make the statement, you provide the support. The onus is not on me to assume that you are correct, and to do the leg work for you. Done. Detailed theoretical, laboratory, observational, and other evidentiary support for star-formation theory has been provided to thousands of astrophysicists, journal editors, peer-reviewers, colloquium audiences, funding agency panels, and students over the past 100 years. That was a lot of leg work! The onus was on the proponents, that's right, and the proponents came through. Oh, wait, you meant "spoon-feed the evidence to me personally". Um, why? Everyone else interested in this question has put the onus on themselves by going to college and attending a series of rigorous astronomy courses. Why are you different? It looks like what you are doing is the following: a) I bet star formation research is fundamentally mistaken somehow ... b) ... but I don't know where or how, I just want that to be the answer. c) So I want you to give me a free lecture series ... d) ... so I have something to sift through to find the flaw I want to find.
'14-08-25, 11:08 tusenfem	Just to be nice, I was raised with Bowers & Deeming - Astrophysics I & II
'14-08-25, 11:30 ben m	I'm amused by "link please". Charles, please note that many people have knowledge astrophysics which is not acquired via random Google searches conducted while composing their forum posts.
'14-08-25, 11:42 Charles Chandler	Originally Posted by thedopefishlives You seem to be laboring under the misapprehension that any failure on our part to produce evidence for the mainstream theory means that your alternative must, of necessity, be correct. No, there is no false dichotomy in what I'm saying. I'm just challenging an assumption in the widely accepted view. But OK, if nobody is going to defend the mainstream (except with rhetorical argumentativeness), I'll be back in a few more months, after I've done a bunch more reading.
'14-08-25, 12:33 DeiRenDopa	Originally Posted by Charles Chandler No, there is no false dichotomy in what I'm saying. I'm just challenging an assumption in the widely accepted view what I think is an assumption (but I haven't done the work needed to find out if it's actually more of a conclusion). FTFY Quote: But OK, if nobody is going to defend the mainstream (except with rhetorical argumentativeness), I'll be back in a few more months, after I've done a bunch more reading. Oh? Is "Bowers & Deeming - Astrophysics I & II" rhetorical argumentativeness? You have a strange idea of "rhetorical argumentativeness", Charles Chandler; I could have sworn they were rather heavy, multi-hundred page tomes ...
'14-08-25, 12:50 Captain_Swoop	Originally Posted by Charles Chandler No, there is no false dichotomy in what I'm saying. I'm just challenging an assumption in the widely accepted view. But OK, if nobody is going to defend the mainstream (except with rhetorical argumentativeness), I'll be back in a few more months, after I've done a bunch more reading. Why not go to College and learn it properly?
'14-08-25, 15:14 Charles Chandler	One more thing that I forgot to mention is that even if a collapsing dusty plasma started radiating energy, that doesn't exactly solve the problem of relieving the hydrostatic pressure. Compressive heating is actually the smaller part of the problem. The bigger part is that there is a direct relationship between volume and pressure, which has nothing to do with heat. This is known as Boyle's Law, which I read about on Wikipedia: The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system. I won't know until I run the numbers all of the way through, but if I had to guess, the force of gravity is insufficient to cause a dusty plasma to collapse all of the way into a star or planet. (Anybody care to publicly lay down their bets on what I'll find?) While gravity obeys the inverse square law, hydrostatic pressure increases by a cubic function, since it's based on volume. So the pressure increases faster than the density of the gravity field, and then you hit the equilibrium. Where is that point? I'll let you know. Oh and by the way, there's the other implication of momentum, again having nothing to do with heat, that is problematic. If a dusty plasma implodes, it has momentum. This means that it will overshoot the hydrostatic equilibrium, whereupon there will be more hydrostatic potential than gravity to keep it contained. What happens to that potential? It gets converted to motion in the opposite direction, just like a bouncing basketball. So why don't dusty plasmas just bounce off of themselves, back out to the original dimensions? To my knowledge, there is no physical answer to that question. So even if compressive heating simply wasn't a factor, nor the rate of radiative heat loss, steady-state aggregates are an unlikely consequence of dusty plasma implosion. I'll let you know what I find, but please feel free to publicly register your predictions. Don't worry, you're not using your real names, so it won't hurt your reputations if you're wrong.
'14-08-25, 15:36 Reality Check	Originally Posted by Charles Chandler I'm just challenging an assumption in the widely accepted view.) No, Charles Chandler. You are stating without any evidence that the standard theory of the formation of stars is wrong. This is an assertion, not a challenge. It is up to you to provide credible evidence that your assertion is correct. Endlessly repeating your assertion is not evidence ! Evidence is taking the standard theory of the formation of stars and showing that it is wrong somehow. That means doing calculations within the standard theory of the formation of stars.
'14-08-25, 15:41 Reality Check	Originally Posted by Charles Chandler One more thing that I forgot to mention is.... This one problem is ignorance of the models of the formation of stars leading you to assume that astronomers do not know basic physics such as Boyles Law, Charles Chandler . Your guesses are wrong - the formation of stars from molecular clouds works.
'14-08-25, 15:46 Reality Check	Originally Posted by Charles Chandler ..., I'll be back in a few more months, after I've done a bunch more reading. Oh dear, Charles Chandler, what looks like an admission of ignorance about astronomy ! What matters is what you are going to understand and unfortunately starting by saying that the formation of stars is wrong from simplistic and inappropriate calculations is not promising. But there is a possibility that a few months of reading about the actual models of star formation and how they reflect the real universe will convenience you that they are correct.