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#21
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Critical Test for the Big Bang and Discrete Fractal Paradigms
On Feb 15, 6:44 am, "Kent Paul Dolan" wrote:
I read that the Hubble suffered some major breakdown just short of its expected lifespan. The main imaging camera, called ACS, failed. An older camera, the WFPC2, still remains in working condition, but it is less sensitive than ACS. What I want to know is, what was lost in terms of expected data that would have been settling or lending support/dismissal to some proposed solutions of some of the "big questions" here? What was "upcoming" that is now "indefinitely delayed"? Are other, planned tools going to provide this data later, or are we "back to square one" in some cases? Most proposals to take images with HST called for the ACS. Since it has failed, the Space Telescope Science Institute has put out a second call for revised proposals. Astronomers who were planning to use the ACS to take images of the faintest sources (which are in many ways the most important for cosmology) will probably change their projects, since WFPC2 can't reach those same faint objects. |
#22
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Critical Test for the Big Bang and Discrete Fractal Paradigms
On Feb 15, 12:11 pm, "Stupendous_Man" wrote:
This is a brief monthly update on the dark matter enigma/search and relevant publications on the critical test that is the subject of this thread. 1. A natural question is: if the Galaxy has a huge population of ultracompact objects, why don't we see them? Perhaps we do, but we don't know it yet. In astro-ph/0702578 the authors discuss X-ray emission results for M32, which are similar for M82 and the MWG. There is low-level X-ray emission in observed galaxies; in the case of M32 the authors report that "these results strongly suggest that weak discrete X-ray sources ..." are the origin of this emission. They hypothesize that the discrete sources are white dwarfs, CVs and ABs, but that is mainly because these classes of objects are the only ones we know about. However, weak X-ray and gamma ray emission is what you would expect from discrete ultracompact objects accreting small amounts of matter from the ISM. GLAST has the potential to enlighten us, so to speak, and should be launched in Oct of 2007. 2. In astro-ph/0703125 the authors mention that "several thousand microlensing events have been discovered". Why have we not seen comprehensive graphs displaying histograms of the event time scales, and even more importantly graphs showing estimated mass functions? With so many events, the large uncertainties in mass estimates must be whittled down somewhat and I would think that the results would be very important for dark matter research, SMF research, planet searches, etc. Does such a comprehensive analysis exist, but I do not know how to find it? Are there problems with such an analysis? What gives?? 3. I just read that a new putative globular cluster has found within about 4 kpc of the Galactic center, and near the disk. Seems like a very nice target for microlensing surveys! Thoughts on the questions above would be appreciated. Robert L. Oldershaw |
#23
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Critical Test for the Big Bang and Discrete Fractal Paradigms
1. A natural question is: if the Galaxy has a huge population of
ultracompact objects, why don't we see them? Perhaps we do, but we don't know it yet. In astro-ph/0702578 the authors discuss X-ray emission results for M32, which are similar for M82 and the MWG. There is low-level X-ray emission in observed galaxies; in the case of M32 the authors report that "these results strongly suggest that weak discrete X-ray sources ..." are the origin of this emission. They hypothesize that the discrete sources are white dwarfs, CVs and ABs, but that is mainly because these classes of objects are the only ones we know about. However, weak X-ray and gamma ray emission is what you would expect from discrete ultracompact objects accreting small amounts of matter from the ISM. Do the math, please. Estimate the luminosity of an isolated neutron strar or black hole which accretes material from the ISM. Start with the density of the ISM and the velocity of the compact object through it. Figure out the amount of mass per second (or year, or whatever) falls onto or near the compact object. Compute the gravitational potential energy lost by this material as it falls onto the object, and then assume some fraction of that energy is converted into X-rays. What luminosity do you get? Out to what distance would we be able to detect such sources? Once you can show that it is plausible for the X-ray background to come from such compact objects, everyone will listen more carefully to your other ideas. 2. In astro-ph/0703125 the authors mention that "several thousand microlensing events have been discovered". Why have we not seen comprehensive graphs displaying histograms of the event time scales, and even more importantly graphs showing estimated mass functions? With so many events, the large uncertainties in mass estimates must be whittled down somewhat and I would think that the results would be very important for dark matter research, SMF research, planet searches, etc. Does such a comprehensive analysis exist, but I do not know how to find it? Are there problems with such an analysis? What gives?? Most of the microlensing events have (probably) been noticed by the MACHO and OGLE groups. Go read their recent papers. Go to their web sites. The OGLE group has a very strong track record of making their data available to all. Spend a few weeks tracking it down. 3. I just read that a new putative globular cluster has found within about 4 kpc of the Galactic center, and near the disk. Seems like a very nice target for microlensing surveys! Indeed. Perhaps you should apply for time on a big telescope to do it. |
#24
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Critical Test for the Big Bang and Discrete Fractal Paradigms
On Mar 17, 5:16 pm, "Stupendous_Man" wrote:
1. A natural question is: if the Galaxy has a huge population of ultracompact objects, why don't we see them? Perhaps we do, but we don't know it yet. In astro-ph/0702578 the authors discuss X-ray emission results for M32, which are similar for M82 and the MWG. There is low-level X-ray emission in observed galaxies; in the case of M32 the authors report that "these results strongly suggest that weak discrete X-ray sources ..." are the origin of this emission. They hypothesize that the discrete sources are white dwarfs, CVs and ABs, but that is mainly because these classes of objects are the only ones we know about. However, weak X-ray and gamma ray emission is what you would expect from discrete ultracompact objects accreting small amounts of matter from the ISM. Do the math, please. Estimate the luminosity of an isolated neutron strar or black hole which accretes material from the ISM. Start with the density of the ISM and the velocity of the compact object through it. Figure out the amount of mass per second (or year, or whatever) falls onto or near the compact object. Compute the gravitational potential energy lost by this material as it falls onto the object, and then assume some fraction of that energy is converted into X-rays. What luminosity do you get? Out to what distance would we be able to detect such sources? In Astrophysical Journal 322, 34-36, 1987 I reported my estimates, which I believe were in the 10^24 to 10^28 ergs/sec range. Surprised? Maybe you should read that paper. Two things are important to mention he (1) very large populations with these levels of X-ray luminosity do not appear to violate current observations and (2) my estimates were based on the models of other astrophysicists publishing in about 1986. Their models, and my estimates, might be need to be re-evaulated based on theoretical progress in the intervening years. Once you can show that it is plausible for the X-ray background to come from such compact objects, everyone will listen more carefully to your other ideas. Well, I certainly appreciate your optimism, but they did not listen in 1987 and I do not think they listen now either, *unless the population is detected*. Then they will probably say they predicted such a result all along. 2. In astro-ph/0703125 the authors mention that "several thousand microlensing events have been discovered". Why have we not seen comprehensive graphs displaying histograms of the event time scales, and even more importantly graphs showing estimated mass functions? With so many events, the large uncertainties in mass estimates must be whittled down somewhat and I would think that the results would be very important for dark matter research, SMF research, planet searches, etc. Does such a comprehensive analysis exist, but I do not know how to find it? Are there problems with such an analysis? What gives?? Most of the microlensing events have (probably) been noticed by the MACHO and OGLE groups. Go read their recent papers. Go to their web sites. The OGLE group has a very strong track record of making their data available to all. Spend a few weeks tracking it down. But why would no one have done the obvious and publish simple and comprehensive histograms of the time scales and mass estimates? Now that so much data exists, it is a no-brainer. Surely the data summaries must exist somewhere (unpublished?), and hopefully someone will save me "a few weeks" of frustration a steer me to them. Or create them, if no one else has. 3. I just read that a new putative globular cluster has found within about 4 kpc of the Galactic center, and near the disk. Seems like a very nice target for microlensing surveys! Indeed. Perhaps you should apply for time on a big telescope to do it. Dream on. As an uppity maverick with a subscription to Science News as my credentials, they would probably not even let me wash dishes in the commisary! But seriously, there are limited areas where I can potentially contribute something, and many other areas where I totally rely on others to do *their* thing. The days when an Einstein could do just about everything by himself are long gone (and even he would have had very serious troubles without the 3 increasingly important things done for him by Grossman, and then of course there was Minkowski, Planck, Lorentz, Poincare, Faraday, Maxwell, Riemann,..., I guess science is a communal effort and always has been) . Robert L. Oldershaw www.amherst.edu/~rloldershaw |
#25
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Critical Test for the Big Bang and Discrete Fractal Paradigms
1. A natural question is: if the Galaxy has a huge population of
ultracompact objects, why don't we see them? Perhaps we do, but we don't know it yet. In astro-ph/0702578 the authors discuss X-ray emission results for M32, which are similar for M82 and the MWG. There is low-level X-ray emission in observed galaxies; in the case of M32 the authors report that "these results strongly suggest that weak discrete X-ray sources ..." are the origin of this emission. They hypothesize that the discrete sources are white dwarfs, CVs and ABs, but that is mainly because these classes of objects are the only ones we know about. However, weak X-ray and gamma ray emission is what you would expect from discrete ultracompact objects accreting small amounts of matter from the ISM. Do the math, please. Estimate the luminosity of an isolated neutron strar or black hole which accretes material from the ISM. Start with the density of the ISM and the velocity of the compact object through it. Figure out the amount of mass per second (or year, or whatever) falls onto or near the compact object. Compute the gravitational potential energy lost by this material as it falls onto the object, and then assume some fraction of that energy is converted into X-rays. What luminosity do you get? Out to what distance would we be able to detect such sources? In Astrophysical Journal 322, 34-36, 1987 I reported my estimates, which I believe were in the 10^24 to 10^28 ergs/sec range. Surprised? Maybe you should read that paper. Thanks for the reference. I have just read the paper. It does not provide any estimates for the luminosity of an isolated compact object accreting material from the ISM. 2. In astro-ph/0703125 the authors mention that "several thousand microlensing events have been discovered". Why have we not seen comprehensive graphs displaying histograms of the event time scales, and even more importantly graphs showing estimated mass functions? With so many events, the large uncertainties in mass estimates must be whittled down somewhat and I would think that the results would be very important for dark matter research, SMF research, planet searches, etc. Does such a comprehensive analysis exist, but I do not know how to find it? Are there problems with such an analysis? What gives?? Most of the microlensing events have (probably) been noticed by the MACHO and OGLE groups. Go read their recent papers. Go to their web sites. The OGLE group has a very strong track record of making their data available to all. Spend a few weeks tracking it down. But why would no one have done the obvious and publish simple and comprehensive histograms of the time scales and mass estimates? Now that so much data exists, it is a no-brainer. Surely the data summaries must exist somewhere (unpublished?), and hopefully someone will save me "a few weeks" of frustration a steer me to them. Or create them, if no one else has. I am not going to track the data down for you. Perhaps someone else reading this thread will. 3. I just read that a new putative globular cluster has found within about 4 kpc of the Galactic center, and near the disk. Seems like a very nice target for microlensing surveys! Indeed. Perhaps you should apply for time on a big telescope to do it. Dream on. Well, I was trying to help you, but your reply isn't polite. I'm not going to help you any more. Perhaps there is a reason few people are stepping up to work with you. Good luck. |
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Critical Test for the Big Bang and Discrete Fractal Paradigms
On Mar 18, 10:02 am, "Stupendous_Man" wrote:
Thanks for the reference. I have just read the paper. It does not provide any estimates for the luminosity of an isolated compact object accreting material from the ISM. If you go to www.amherst.edu/~rloldershaw and click on "Selected Papers", then click on Paper #2, then go to section 2.5 "The Enigmatic Dark Matter", the X-ray estimates for the 0.145 solar mass population are given (10^26 to 10^29 ergs/sec for disk and halo locations) and there is a reference to my original published calculations (based I think on an ApJ paper by Heygi et al?). But why would no one have done the obvious and publish simple and comprehensive histograms of the time scales and mass estimates? Now that so much data exists, it is a no-brainer. Surely the data summaries must exist somewhere (unpublished?), and hopefully someone will save me "a few weeks" of frustration a steer me to them. Or create them, if no one else has. I am not going to track the data down for you. Perhaps someone else reading this thread will. Or maybe explain why it has not been done. Well, I was trying to help you, but your reply isn't polite. I'm not going to help you any more. I treat others with the same respect, or sarcasm, that they offer to me. Nothing in my most recent post was intended to be offensive and neither was it any more or less polite than your preceeding post. Perhaps you feel that there is some unexplained reason that you should receive preferential treatment. I do believe that science is a communal activity, and should ideally be based on cooperation rather than competition. But I also strongly believe in Galileo's famous dictum about the "authority of a thousand" and the "humble reasoning of a single individual". To end on an empirical note (since that is what science is all about); readers might want to take a look at astro-ph/0702621 at www.arxiv.org. This preprint describes a "tantalizing hint" of populations of gamma ray emmiters in the bulge and halo of the Galaxy. Very preliminary, but interesting. GLAST may pull back the veil enough for a first look at the putative populations. Robert L. Oldershaw www.amherst.edu/~rloldershaw |
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Critical Test for the Big Bang and Discrete Fractal Paradigms
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Critical Test for the Big Bang and Discrete Fractal Paradigms
In article ,
" writes: If you go to www.amherst.edu/~rloldershaw and click on "Selected Papers", then click on Paper #2, then go to section 2.5 "The Enigmatic Dark Matter", the X-ray estimates for the 0.145 solar mass population are given (10^26 to 10^29 ergs/sec for disk and halo locations) and there is a reference to my original published calculations (based I think on an ApJ paper by Heygi et al?). Do you think that Omega = 0.3 (approximately) is in objects of 0.145 solar masses? If so, then can you explain why high-redshift QSOs do not show the expected microlensing signal? ------------------------------------------------------------------------------- A man does not attain the status of Galileo merely because he is persecuted; he must also be right. ---Stephen Jay Gould |
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Critical Test for the Big Bang and Discrete Fractal Paradigms
On Apr 2, 2:43 am, (Phillip Helbig---
remove Do you think that Omega =3D 0.3 (approximately) is in objects of 0.145 solar masses? If so, then can you explain why high-redshift QSOs do not show the expected microlensing signal? -------------------------------------------------------------------------= --=AD---- A man does not attain the status of Galileo merely because he is persecuted; he must also be right. ---Stephen Jay= Gould I think you should explicitly explain what you mean by "the expected microlensing signal". What specific assumptions go into the calculation of "the expected microlensing signal"? Do you assume a homogeneous distribution of stellar-mass dark matter objects? If so, you are merely setting up a "straw man" so that you can easily knock it down. Assuming that the distribution of the stellar-mass dark matter objects roughly follows the distribution of luminous matter, what exactly (in numbers and units) is "the expected microlensing signal" that you are referring to? And regarding the dark matter distribution, how do you explain the fact that Richard Massey and his team at CIT find very surprising results in their 3D map of the dark matter that are in contradiction with CDM predictions? Here's a quote from Massey: "The first thing that strikes me is the voids. Vast expanses of space are completely empty." CDM proponents have traditionally argued that the particle-mass dark matter should be spread out much more homogeneously than luminous matter. The SSCP ( www.amherst.edu/~rloldershaw ) predicted that the stellar-mass dark matter should roughly follow the luminous matter. Looks to me like nature is trying to tell us something, and fudging the CDM hypothesis once again until it is forced to agree with observations seems like a dubious strategy, from the point of view of science anyway. Robert L. Oldershaw www.amherst.edu~rloldershaw ...=2E............................................ ...........................= ...=2E.................................... "Why should one not be able to live contentedly as a member of the service personnel in the lunatic asylum? After all, one respects the lunatics as the ones for whom the building in which one lives exists. Albert Einstein |
#30
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Critical Test for the Big Bang and Discrete Fractal Paradigms
In article ,
" writes: I think you should explicitly explain what you mean by "the expected microlensing signal". What specific assumptions go into the calculation of "the expected microlensing signal"? Do you assume a homogeneous distribution of stellar-mass dark matter objects? If so, you are merely setting up a "straw man" so that you can easily knock it down. QSOs are very far away. If the nearby distribution is not somehow magically correlated with the QSO position, than homogeneity is a reasonable assumption. Assuming that the distribution of the stellar-mass dark matter objects roughly follows the distribution of luminous matter, what exactly (in numbers and units) is "the expected microlensing signal" that you are referring to? Even in this case, averaged along the line of sight to a QSO, the distribution should be homogeneous. And regarding the dark matter distribution, how do you explain the fact that Richard Massey and his team at CIT find very surprising results in their 3D map of the dark matter that are in contradiction with CDM predictions? Just because something else is in conflict with CDM predictions doesn't mean that your theory, which is also in conflict with standard predictions, must be right. |
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