pantheory Posted March 9, 2012 Posted March 9, 2012 For dark matter to be in fact the gravitational influence that explains the motions of spiral galaxies via gravitational influences therefore exonerating General Relativity and Newtonian gravity it would need to have a specific observable behavior. This dark matter hypothesis now seems to be in serious question based upon this link. Opponents of conventional gravity models have made such predictions since the advent of the dark matter hypothesis, my own model being one of them. http://www.redorbit.com/news/space/1112486232/hubble-findings-cast-doubt-on-dark-matter-theories/
The Observer Posted March 9, 2012 Posted March 9, 2012 Its specific observable behaviour is why we know its there. Its just a name we have given to the fact that the large scale gravitational effects of systems of galaxies doesn't agree with our current models. Its called dark matter cause we can't see it. Its a name for an observation, its not a theory in an of itself.
Spyman Posted March 9, 2012 Posted March 9, 2012 I agree with The Observer, the article points out that: Dark matter is not behaving as predicted, and it’s not obviously clear what is going on. It is difficult to explain this Hubble observation with the current theories of galaxy formation and dark matter. Nowhere in the article is it mentioned that the dark matter phenomena don't exists. Further down it is even stated: these new findings all but confirm that "without a doubt that there is a dark matter concentration in that piece of the sky."
pantheory Posted March 9, 2012 Author Posted March 9, 2012 (edited) Yes, I also agree. It would seem that there is something there that causes light to bend like the gravitational effects of matter. But since its behavior, according to this conclusion, is unlike matter -- the question becomes: is it really matter of some kind or something else? I have long proposed in my writings that what we now call dark matter is the primary substantive part of the ZPF which could then be called an aether. Light would accordingly bend based upon currents of aether flowing from high to low pressure areas which accordingly would also be the cause of all gravity rather than matter warping space. Of course these "preliminary findings" should be confirmed by others and in other locations. And of course there are seemingly many other possible explanations to explain these conclusions that might explain "dark matter," having many other possible characteristics explained by different reasoning. Many would also agree that the words "dark matter" may be just a place holder for something that is not understood and is not necessarily matter. My expectation and prediction is that what we now call dark matter behaves in a way that we will at sometime be able to equationally approximate by a form of modified Newtonian gravity not unlike Milgram's MOND. Of course such a formulation would also need to explain the inverse square law of gravity as well as the behavior of galaxies in a cluster, and I think also the related logic concerning all. Milgram's MOND cannot do any of these. It can only explain spiral disk stellar motions but another version of MOND with the appropriate logic, I believe will eventually explain it all. Edited March 9, 2012 by pantheory 1
Bart Posted March 22, 2012 Posted March 22, 2012 Yes, I also agree. It would seem that there is something there that causes light to bend like the gravitational effects of matter. But since its behavior, according to this conclusion, is unlike matter -- the question becomes: is it really matter of some kind or something else? I have long proposed in my writings that what we now call dark matter is the primary substantive part of the ZPF which could then be called an aether. Light would accordingly bend based upon currents of aether flowing from high to low pressure areas which accordingly would also be the cause of all gravity rather than matter warping space. Of course these "preliminary findings" should be confirmed by others and in other locations. And of course there are seemingly many other possible explanations to explain these conclusions that might explain "dark matter," having many other possible characteristics explained by different reasoning. Many would also agree that the words "dark matter" may be just a place holder for something that is not understood and is not necessarily matter. My expectation and prediction is that what we now call dark matter behaves in a way that we will at sometime be able to equationally approximate by a form of modified Newtonian gravity not unlike Milgram's MOND. Of course such a formulation would also need to explain the inverse square law of gravity as well as the behavior of galaxies in a cluster, and I think also the related logic concerning all. Milgram's MOND cannot do any of these. It can only explain spiral disk stellar motions but another version of MOND with the appropriate logic, I believe will eventually explain it all. Reliable physical explanation for the effects of dark matter is presented in the following link: link removed
swansont Posted March 23, 2012 Posted March 23, 2012 ! Moderator Note This is not the forum for discussing dark matter hypotheses — they belong in their own thread in Speculations.
pantheory Posted April 12, 2012 Author Posted April 12, 2012 (edited) Here is the latest on a dark-matter search. The brunt of most cosmic searches for a dark-matter particle is <b>based upon an assumption</b>: <b>that dark matter has an anti-particle that when interacting with its particle counterpart will produce gamma radiation</b>. Within the energy ranges tested from 200 million to 100 billion electron volts (GeV), when evaluating 10 of the roughly two dozen dwarf galaxies known to orbit the Milky Way, the LAT system did not detect any WHIMP gamma related radiation/ energies, based upon the given assumption http://www.nasa.gov/mission_pages/GLAST/news/dark-matter-insights.html Edited April 12, 2012 by pantheory
DrDNA Posted April 12, 2012 Posted April 12, 2012 I think things like this depend on definitions. For example, how you define "matter". Many definitions in science, especially this brand of science are rapidly evolving. For example, what is a particle is considered to be now compared to what a particle was thought to be 30 or 40 years ago are not the same. Agree? 2
pantheory Posted April 12, 2012 Author Posted April 12, 2012 (edited) I think things like this depend on definitions. For example, how you define "matter". Many definitions in science, especially this brand of science are rapidly evolving. For example, what is a particle is considered to be now compared to what a particle was thought to be 30 or 40 years ago are not the same. Agree? Yes, I agree. Not only might the particle be different from what we think, it may not even be matter. All we really known is that something is bending light more than what accepted lensing equations could allow, or equations involving orbital velocities at the galactic scale -- needing the assumption that something is there causing these effects other than baryonic matter -- or one or more equations could be wrong. // Edited April 12, 2012 by pantheory 1
imatfaal Posted April 12, 2012 Posted April 12, 2012 Yes, I agree. Not only might the particle be different from what we think, it may not even be matter. All we really known is that something is bending light more than what accepted lensing equations could allow, or equations involving orbital velocities at the galactic scale -- needing the assumption that something is there causing these effects other than baryonic matter -- or one or more equations could be wrong. // The equations could be wrong (that is always a possibility in an system) but, if I have the time line correct, it was noticed that angular velocities of galaxies and clusters did not match the amount of luminous material that we could observe, it was posited that a form of matter was around/about galaxies that was not interacting through emr but was gravitationally (and perhaps weakly). Subsequent to this it was realised that this matter should not only help our equations of motion work out, we should be able to detect it because of its gravitational lensing effect; this was born out in observation. The variance between centre(s) of mass of colliding galaxies/clusters as calculated by observation light-emitting matter and as alternatively calculated by gravitational lensing is further evidence; simplisitically, the normal matter of the two galaxies collides and interacts and forms a lump in the middle, the dark matter does not interact and has little way to disperse its KE and thus keeps going (on average). The expected centre of mass (by looking at the stars and normal matter) does not coincide with the data from gravitational lensing which shows that the mass not spherically spread around the colliding normal matter, but is an elongated dumbell sort of shape. the Bullet Cluster is worth reading up on - it is still hotly debated, but it is good reading. I put it like this as I see the gravitational lensing as part of the evidence rather than as part of the question 1
DrDNA Posted April 12, 2012 Posted April 12, 2012 (edited) At their essence, dark matter, dark energy, dark strings, etc....etc. are nothing more than cosmological (fudge) factors for things that we have absolutely no understanding of. They make our equations balance on both sides and look all pretty, but we really have no clue and no real evidence what they are, what they are composed of, and even if they actually exist. Agree? Disagree? Have a comment? This is one reason why I am a professional chemist....but I do like to read and dream of these speculations. All these speculative theories, equations and such that all require cosmological factors smell a lot more like religion and philosophy than science. Just because it makes an equation balance does not make it true. "Much later, when I was discussing cosmological problems with Einstein, he remarked that the introduction of the cosmological term was the biggest blunder of his life." -- George Gamow, My World Line, 1970 Seriously, in the end, quantum physics and cosmology require WAY too much FAITH for me to stake my professional integrity and financial future on them. And I'm a Christian. Go figure. Edited April 12, 2012 by DrDNA
pantheory Posted April 13, 2012 Author Posted April 13, 2012 (edited) DrDNA, At their essence, dark matter, dark energy, dark strings, etc....etc. are nothing more than cosmological (fudge) factors for things that we have absolutely no understanding of. They make our equations balance on both sides and look all pretty, but we really have no clue and no real evidence what they are, what they are composed of, and even if they actually exist. Agree? Disagree? Have a comment? .....in the end, quantum physics and cosmology require WAY too much FAITH for me to stake my professional integrity and financial future on them. I generally agree with your statements but your "professional integrity" could not be involved if you are a bio-chemist (hence DrDNA?) nor could your financial future be involved too much as a taxpayer unless you are also a betting man, and then it would probably require a substantial wager on your part, right? with some way to confirm such a bet. The best bet I think would involve a wager such as what percentage of technical papers, in Arxiv for instance, would have major theoretical changes or replacement of theory in either of the present models in quantum physics or cosmology? If more than 20% in either field might be a good bet concerning 20 years from now, in my opinion. If your bet instead would be more than 50% in both fields, then I think you better get pretty good odds or make the wager no more than a six pack If you also buy an extra one for yourself when you make the bet, then you can't lose // The equations could be wrong (that is always a possibility in an system) but, if I have the time line correct, it was noticed that angular velocities of galaxies and clusters did not match the amount of luminous material that we could observe, it was posited that a form of matter was around/about galaxies that was not interacting through emr but was gravitationally (and perhaps weakly). Subsequent to this it was realised that this matter should not only help our equations of motion work out, we should be able to detect it because of its gravitational lensing effect; this was born out in observation. The variance between centre(s) of mass of colliding galaxies/clusters as calculated by observation light-emitting matter and as alternatively calculated by gravitational lensing is further evidence; simplisitically, the normal matter of the two galaxies collides and interacts and forms a lump in the middle, the dark matter does not interact and has little way to disperse its KE and thus keeps going (on average). The expected centre of mass (by looking at the stars and normal matter) does not coincide with the data from gravitational lensing which shows that the mass not spherically spread around the colliding normal matter, but is an elongated dumbell sort of shape. the Bullet Cluster is worth reading up on - it is still hotly debated, but it is good reading. I put it like this as I see the gravitational lensing as part of the evidence rather than as part of the question Thanks imatfaal, I agree that your perspective generally agrees with today's consensus of theorists Edited April 13, 2012 by pantheory
DrDNA Posted April 13, 2012 Posted April 13, 2012 (edited) DrDNA,I generally agree with your statements but your "professional integrity" could not be involved if you are a bio-chemist (hence DrDNA?) nor could your financial future be involved too much as a taxpayer unless you are also a betting man, and then it would probably require a substantial wager on your part, right? with some way to confirm such a bet. I meant to infer that is one reason why it is not my chosen field of endeavor...too much speculation.....or maybe it is just too far over my head....which would be an even better bet Edited April 13, 2012 by DrDNA
pantheory Posted April 13, 2012 Author Posted April 13, 2012 (edited) I meant to infer that is one reason why it is not my chosen field of endeavor...too much speculation.....or maybe it is just too far over my head....which would be an even better bet Although present interpretations in both fields may be very difficult for anyone to understand concerning smacks of speculation but take heart, in less than 30 years most certainly more of it will make greater sense , or less of it Edited April 13, 2012 by pantheory
DrDNA Posted April 13, 2012 Posted April 13, 2012 Although present interpretations in both fields may be very difficult for anyone to understand concerning smacks of speculation but take heart, in less than 30 years maybe more of it will make sense , or not Since you got me to bettin.....I'll bet $1 not (it will make even less sense) and you can take the affirmative bet. Let's meet back here in 30 years so I can collect my dollar.
pantheory Posted April 13, 2012 Author Posted April 13, 2012 (edited) Since you got me to bettin.....I'll bet $1 not (it will make even less sense) and you can take the affirmative bet. Let's meet back here in 30 years so I can collect my dollar. I think it would be better to bet a six pack (or its equivalent in wine or strong spirits) and hopefully meet in 10 years to collect. I would be 99 years old in 30 years. But in ten years regardless of the outcome of who buys, if we both show up we would both be winners in one way or another It appears that we may be in the same time zone PST? even a better chance for me to pay off the wager -- and if I should luckily win the bet then we both must imbibe the wager, hard to beat that bet btw, is your avetar Ming the Merciless from the planet Mongo? Edited April 13, 2012 by pantheory
imatfaal Posted April 13, 2012 Posted April 13, 2012 I wish we could go back and use a different placeholder name for "Dark Energy". Dark Matter was a good name - and personally I think we are well on the way to having this as settled piece of cosmology and later of particle physics. Dark Energy was a fun riff on that name - but I think has back fired; it's mystical with no good reason, it links back to Dark matter in people's heads, and causes real problems in understanding.
pantheory Posted April 13, 2012 Author Posted April 13, 2012 (edited) inadvertent posting Edited April 13, 2012 by pantheory
DrDNA Posted April 13, 2012 Posted April 13, 2012 (edited) btw, is your avetar Ming the Merciless from the planet Mongo? Tim the Enchanter from Monty Python. In Search of the Holy Grail. Hit link for video Edited April 13, 2012 by DrDNA
pantheory Posted April 13, 2012 Author Posted April 13, 2012 Tim the Enchanter from Monty Python. In Search of the Holy Grail. Hit link for video Missed that one. He certainly is "Enchanting"
juanrga Posted April 14, 2012 Posted April 14, 2012 (edited) For dark matter to be in fact the gravitational influence that explains the motions of spiral galaxies via gravitational influences therefore exonerating General Relativity and Newtonian gravity it would need to have a specific observable behavior. This dark matter hypothesis now seems to be in serious question based upon this link. Opponents of conventional gravity models have made such predictions since the advent of the dark matter hypothesis, my own model being one of them. http://www.redorbit....atter-theories/ Dark matter is the Vulcan planet of the 21st century All the direct searches of dark matter have found nothing during the last decades. And all the 'indirect evidence' of the existence of dark matter has been discredited in recent years as well. For example the Bullet Cluster cannot be explained by dark matter, although some years ago it was considered the best 'evidence' of its existence. The past year a new galactic test resulted in another fiasco for the dark matter hypothesis http://blogs.nature....02/post_73.html http://www.bbc.co.uk...onment-12571965 Edited April 14, 2012 by juanrga
pantheory Posted April 15, 2012 Author Posted April 15, 2012 (edited) Dark matter is the Vulcan planet of the 21st century All the direct searches of dark matter have found nothing during the last decades. And all the 'indirect evidence' of the existence of dark matter has been discredited in recent years as well. For example the Bullet Cluster cannot be explained by dark matter, although some years ago it was considered the best 'evidence' of its existence. The past year a new galactic test resulted in another fiasco for the dark matter hypothesis http://blogs.nature....02/post_73.html http://www.bbc.co.uk...onment-12571965 Thanks for the informative/ news links concerning both some of the latest on MOND and the struggle to find dark matter. As I said in my opening post, MOND is most certainly not the last word on gravity but I think it might eventually contribute to solving the puzzle. Since there are a number of galactic effects and motions that MOND seemingly does not explain, most astronomers and theorists believe there is something physical there to explain these effects, hence dark matter. But the question then becomes "is that something really matter of some kind," or maybe it could be instead energy based like EM radiation, and/ or etherial in nature which could be particulates that might be mass-less at rest, a variation on the dark matter idea? -- that a Modified Newton Gravity Model of some kind, might eventually be a part of? // Edited April 15, 2012 by pantheory
juanrga Posted April 15, 2012 Posted April 15, 2012 Thanks for the informative/ news links concerning both some of the latest on MOND and the struggle to find dark matter. As I said in my opening post, MOND is most certainly not the last word on gravity but I think it might eventually contribute to solving the puzzle. Since there are a number of galactic effects and motions that MOND seemingly does not explain, most astronomers and theorists believe there is something physical there to explain these effects, hence dark matter. But the question then becomes "is that something really matter of some kind," or maybe it could be instead energy based like EM radiation, and/ or etherial in nature which could be particulates that might be mass-less at rest, a variation on the dark matter idea? -- that a Modified Newton Gravity Model of some kind, might eventually be a part of? // Nobody is proposing MOND as "the last word on gravity" and extensions to MOND are under active research. Yes, most astronomers and theorists believe that there is something physical there out and name it "dark matter", somewhat as in the past most astronomers and physicists believed that Vulcan existed. The Modified Newton Gravity Models show that you can explain the observed phenomena without any need to introduce the hypothesis of a new and mysterious kind of matter with odd properties. And this is in agreement with the null results of the hundred of experiments that have searched the hypothetical "dark matter" and have not found it... just as Vulcan, the hypothetical planet, was never found
pantheory Posted April 16, 2012 Author Posted April 16, 2012 (edited) Nobody is proposing MOND as "the last word on gravity" and extensions to MOND are under active research. Yes, most astronomers and theorists believe that there is something physical there out and name it "dark matter", somewhat as in the past most astronomers and physicists believed that Vulcan existed. The Modified Newton Gravity Models show that you can explain the observed phenomena without any need to introduce the hypothesis of a new and mysterious kind of matter with odd properties. And this is in agreement with the null results of the hundred of experiments that have searched the hypothetical "dark matter" and have not found it... just as Vulcan, the hypothetical planet, was never found Since this is a news site we should not discuss details of particular possibilities but I generally agree with most of your statements. I will now comment on your statements, but not necessarily in apposition The Modified Newton Gravity Models show that you can explain the observed phenomena without any need to introduce the hypothesis of a new and mysterious kind of matter with odd properties. A "good" MOND model, in my opinion, must have reasoning to it -- like Einstein's model where he proposed that matter warped space to explain the logic of his equations, whether valid or not. In retrospect, Newton's mathematical model of the inverse square law of gravity provided an intuitive understanding of gravity mechanics in that the same inverse square law equally applies to magnetism and light, concerning the dissipation of a "force/ power" from its source. I think Milgram should receive Kudos for his MOND, but on the other hand, there is a recognition of the discrepancy concerning the failings in a logic /vision/ approach to explain why his model does not work in the galaxy cluster arena, and also the other venues that GR/ Newton can better explain with the inclusion of dark matter. I know you used the plural when you said MOND model"s" implying there are other versions. The success of Milgram's MOND concerning retrodictions is considered by some to be much better than the retrodictions of Dark Matter concerning stellar orbital velocities in spiral galaxies. I'm also a fan of Modified Newtonian Gravity possibilities but realize that any final model of gravity, both mathematical and otherwise, must ultimately explain all observations in all arenas. Based upon this same reasoning, Milgram's MOND also needs similar modification to explain other arenas. Of course in the same way Dark Matter might also be looked at as the logical basis needed to explain changes to the mainstream equations. Not just Migram's MOND, but in my opinion all new and all existing mathematically based hypothesis/ theories in all of physics that may be lacking in logic and reasoning, will likewise ultimately fail to accurately predict in all venues and circumstances, resulting in them respectively being dismissed, changed, or replaced. // Edited April 16, 2012 by pantheory
pantheory Posted April 18, 2012 Author Posted April 18, 2012 (edited) Saw this in the science news today. The article is entitled "Serious Blow to Dark Matter Theories? http://www.eso.org/p...c/news/eso1217/ The purpose of the study was to find dark matter around the sun and its surrounding mass relating to gravitational influences within our solar system. According to their observations and conclusions, none was found. Edited April 18, 2012 by pantheory
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