beecee Posted October 5, 2018 Posted October 5, 2018 https://phys.org/news/2018-10-era-quest-dark.html Since the 1970s, astronomers and physicists have been gathering evidence for the presence in the universe of dark matter: a mysterious substance that manifests itself through its gravitational pull. However, despite much effort, none of the new particles proposed to explain dark matter have been discovered. In a review that was published in Nature this week, physicists Gianfranco Bertone (UvA) and Tim Tait (UvA and UC Irvine) argue that the time has come to broaden and diversify the experimental effort, and to incorporate astronomical surveys and gravitational wave observations in the quest for the nature of dark matter.https://phys.org/news/2018-10-era-quest-dark.html the paper: https://www.nature.com/articles/s41586-018-0542-z A new era in the search for dark matter: Abstract There is a growing sense of ‘crisis’ in the dark-matter particle community, which arises from the absence of evidence for the most popular candidates for dark-matter particles—such as weakly interacting massive particles, axions and sterile neutrinos—despite the enormous effort that has gone into searching for these particles. Here we discuss what we have learned about the nature of dark matter from past experiments and the implications for planned dark-matter searches in the next decade. We argue that diversifying the experimental effort and incorporating astronomical surveys and gravitational-wave observations is our best hope of making progress on the dark-matter problem.
beecee Posted October 7, 2018 Author Posted October 7, 2018 (edited) http://chandra.harvard.edu/graphics/resources/handouts/lithos/bullet_lithos.pdf Bullet Cluster: Direct Proof of Dark Matter The “Bullet Cluster” is an extremely important object for astrophysical research including studies of dark matter. This cluster was formed after the violent collision of two large clusters of galaxies moving at great speeds. The Bullet Cluster is located about 3.8 billion light years from Earth. This composite image shows the galaxy cluster 1E 0657- 56, also known as the “Bullet Cluster.” This cluster was formed after the collision of two large clusters of galaxies, the most energetic event known in the Universe since the Big Bang. Hot gas detected by Chandra in X-rays is seen as two pink clumps in the image and contains most of the “normal,” or baryonic, matter in the two clusters. The bullet-shaped clump on the right is the hot gas from one cluster, which passed through the hot gas from the other larger cluster during the collision. An optical image from Magellan and the Hubble Space Telescope shows the galaxies in orange and white. The blue areas in this image show where astronomers find most of the mass in the clusters. The concentration of mass is determined using the effect of so-called gravitational lensing, where light from the distant objects is distorted by intervening matter. Most of the matter in the clusters (blue) is clearly separate from the normal matter (pink), giving direct evidence that nearly all of the matter in the clusters is dark. The hot gas in each cluster was slowed by a drag force, similar to air resistance, during the collision. In contrast, the dark matter was not slowed by the impact because it does not interact directly with itself or the gas except through gravity. Therefore, during the collision the dark matter clumps from the two clusters moved ahead of the hot gas, producing the separation of the dark and normal matter seen in the image. If hot gas was the most massive component in the clusters, as proposed by alternative theories of gravity, such an effect would not be seen. Instead, this result shows that dark matter is required. 24 minutes ago, JoeH said: The bullet cluster is evidence galaxies move through and displace the supersolid dark matter, analogous to boats passing by each other closely where their bow waves pile up and slosh back out. Hubble Finds Ghostly Ring of Dark Matter from your own link..... Hubble Finds Ghostly Ring of Dark Matter 05.15.07 The most common substance in the universe is called dark matter. It doesn’t shine or reflect light. We can’t even see it. Image right: This Hubble Space Telescope composite image shows a ghostly "ring" of dark matter in the galaxy cluster Cl 0024+17. The ring-like structure is evident in the blue map of the cluster's dark matter distribution. The map is superimposed on a Hubble image of the cluster. The ring is one of the strongest pieces of evidence to date for the existence of dark matter, an unknown substance that pervades the universe. Click image to enlarge. Credit: NASA, ESA, M.J. Jee and H. Ford (Johns Hopkins University) It is an invisible substance composed of atoms that are far different from those that make up the universe’s normal matter, such as stars and galaxies. In fact, if you drove into a wall made of dark matter, you wouldn’t crack a headlight or inflate an airbag. You wouldn’t even know it happened. But what happens to dark matter during a collision? Astronomers using NASA’s Hubble Space Telescope got a first-hand view of how dark matter behaves during a titanic collision between two galaxy clusters. The wreck created a ripple of dark matter, which is somewhat similar to a ripple formed in a pond when a rock hits the water. The ring's discovery is among the strongest evidence yet that dark matter exists. Astronomers have long suspected the existence of the invisible substance as the source of additional gravity that holds together galaxy clusters. Such clusters would fly apart if they relied only on the gravity from their visible stars. Although astronomers don't know what dark matter is made of, they hypothesize that it is a type of elementary particle that pervades the universe. The ring-like structure is evident in a composite image of the cluster made from Hubble observations. The ring can be seen in the blue map of the cluster’s dark matter distribution, which is superimposed on an image of the cluster. The Hubble astronomers say it is the first time they have detected dark matter as having a unique structure that is different from the gas and galaxies in the cluster. The researchers spotted the ring unexpectedly while they were mapping the distribution of dark matter within the galaxy cluster Cl 0024+17 (ZwCl 0024+1652), located 5 billion light-years from Earth. The ring measures 2.6 million light-years across. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Nothing as yet you have posted even offers an inkling of evidence supporting your concept hypothetical. JoshH: While you are supporting the concept of DM, the model you are supporting was/is one I had not heard of. After doing some basic research it does appear as a model that is being discussed in scientific circles. So firstly, my apologies for my "pulled out of your rear end" comment. Still I would say it is still an alternative idea and highly speculative and as such I believe maybe you should raise it in a new thread in speculation. But that's up to the mods, and no I havn't reported it and very rarely do any reporting. Also, just to add, if I had been in your position, I would have commented that you had found a new model of DM and then linked to some reputable source, instead of letting people believe it was your idea. Finally the present concept of DM does not conflict with GR, and that certainly is a very important thing to consider. GR is now so well supported and evidenced backed, that it appears unlikely any other conflicting model of DM with GR would be taked seriously...unless some real empirical evidence was found. Edited October 7, 2018 by beecee
et pet Posted October 7, 2018 Posted October 7, 2018 (edited) 56 minutes ago, beecee said: 1 hour ago, JoeH said: The whole point of the article you referred to is that particle physicists need to revisit their underlying incorrect assumptions. No the whole point of the article is that physicists need to revisit the problem and broaden and diversify the experimental effort, and to incorporate astronomical surveys and gravitational wave observations in the quest for the nature of dark matter. https://arxiv.org/pdf/1810.01668.pdf "A New Era in the Quest for Dark Matter" by Gianfranco Bertone1 and Tim M.P. Tait : " The class of dark matter candidates that has attracted the most attention over the past four decades is weakly interacting massive particles (WIMPs). WIMPs appeared for a long time as a perfect dark matter candidate, as new particles at the weak scale would naturally be produced with the right relic abundance in the early universe8 , while at the same time they might alleviate the infamous hierarchy problem9 , that has been a main driver of particle physics for roughly four decades10. Despite much effort, no particle other than a Standard Model-like Higgs boson has been convincingly detected at the weak scale so far, a circumstance that, as long anticipated11, now raises the possibility that natural WIMPs may have been nothing more than an attractive red herring12 . " https://arxiv.org/pdf/1810.01668.pdf beecee, might it be " the possibility that natural WIMPs may have been nothing more than an attractive red herring " is what JoeH refers to as "underlying incorrect assumptions" ? Edited October 7, 2018 by et pet grammar
beecee Posted October 7, 2018 Author Posted October 7, 2018 (edited) 27 minutes ago, et pet said: beecee, is it possible that " the possibility that natural WIMPs may have been nothing more than an attractive red herring " is what JoeH refers to as "underlying incorrect assumptions" ? Perhaps my dear friend , neither you, I nor Joe can be certain at this time. But you miss the point. Science, all of science, is always open for new knowledge and discoveries and successful theories.....And as I have said to Joe, any new model I don't believe will gain too much traction at least and until some empirical evidence is found...particularly any model that does not align with GR and the BB which happen to go hand in hand, and are overwhelmingly evidenced. ps: How are you going over at the old place? 1 hour ago, JoeH said: The whole point of the article you referred to is that particle physicists need to revisit their underlying incorrect assumptions. This is what I meant JoeH..... https://physics.stackexchange.com/questions/428649/is-dark-matter-a-superfluid p vote7down vote Dark matter doesn't have to be a superfluid not to interact with itself. We know dark matter doesn't interact via the strong or EM forces because if it did we would have seen it by now. So at most it interacts via the weak force and the weak force is ... well ... weak. Having said that, it has been been suggested that dark matter forms a superfluid phase under the right circumstances. As far as I know this was first suggested by Berezhiani and Khoury in Theory of Dark Matter Superfluidity. However the motivation for this is not allowing dark matter to pass through itself in galaxy cluster collisions. Indeed in this theory the superfluid only forms in galaxies where the dark matter is relatively dense - the superfluid is not formed in lower density regions like galaxy clusters. The motivation is that when the superfluid forms it allows collective excitations that slightly modify the gravitational interaction in a way that matches the MOND theory. For completeness, we should note this is not considered a mainstream theory by most physcists ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: The highlighted bit by me is why I suggested you start a new thread in speculations. Let me add from the same link......... Quote "Dark matter is a supersolid that fills 'empty' space, strongly interacts with ordinary matter and is displaced by ordinary matter. What is referred to geometrically as curved spacetime physically exists in nature as the state of displacement of the supersolid dark matter. The state of displacement of the supersolid dark matter is gravity. The supersolid dark matter displaced by a galaxy pushes back, causing the stars in the outer arms of the galaxy to orbit the galactic center at the rate in which they do. Displaced supersolid dark matter is curved spacetime. There is evidence of the supersolid dark matter every time a double-slit experiment is performed, as it is the supersolid dark matter that waves. Wave-particle duality is a moving particle and its associated wave in the supersolid dark matter." Which is word for word what you also said.... but anyway again same link the reply..... Quote This is an exact duplicate of several deleted answers:physics.stackexchange.com/questions/377877 andphysics.stackexchange.com/review/low-quality-posts/227193, among others (must have 10k rep to view?) We've had several people putting up the same non-mainstream garbage about supersolid dark matter on Physics SE. – Chair Sep 14 at 14:43 highlights by me: Edited October 7, 2018 by beecee
et pet Posted October 7, 2018 Posted October 7, 2018 (edited) 3 hours ago, JoeH said: Dark matter is a supersolid that fills 'empty' space, strongly interacts with ordinary matter and is displaced by ordinary matter. What is referred to geometrically as curved spacetime physically exists in nature as the state of displacement of the supersolid dark matter. The state of displacement of the supersolid dark matter is gravity. The supersolid dark matter displaced by a galaxy pushes back, causing the stars in the outer arms of the galaxy to orbit the galactic center at the rate in which they do. Displaced supersolid dark matter is curved spacetime. JoeH, you seem to have plagiarized Paul Dover's answer from : https://physics.stackexchange.com/questions/428649/is-dark-matter-a-superfluid " Dark matter is a supersolid that fills 'empty' space, strongly interacts with ordinary matter and is displaced by ordinary matter. What is referred to geometrically as curved spacetime physically exists in nature as the state of displacement of the supersolid dark matter. The state of displacement of the supersolid dark matter is gravity. The supersolid dark matter displaced by a galaxy pushes back, causing the stars in the outer arms of the galaxy to orbit the galactic center at the rate in which they do. Displaced supersolid dark matter is curved spacetime. There is evidence of the supersolid dark matter every time a double-slit experiment is performed, as it is the supersolid dark matter that waves. Wave-particle duality is a moving particle and its associated wave in the supersolid dark matter. " https://physics.stackexchange.com/questions/428649/is-dark-matter-a-superfluid 1 hour ago, beecee said: Perhaps my dear friend , neither you, I nor Joe can be certain at this time. ps: How are you going over at the old place? "dear friend" ??? I can be certain, beecee, that the "...absence of evidence for the most popular candidates such as weakly interacting massive particles, axions, and sterile neutrinos, despite the enormous effort that has gone into searching for these particles." https://arxiv.org/pdf/1810.01668.pdf after 4 decades, might possibly be what JoeH means by "underlying incorrect assumptions". "ps: How are you going over at the old place?" beecee, why do you refer to arvix.org as "the old place" ? Edited October 7, 2018 by et pet clarification ?
beecee Posted October 7, 2018 Author Posted October 7, 2018 (edited) 1 hour ago, et pet said: "dear friend" ??? I can be certain, beecee, that the "...absence of evidence for the most popular candidates such as weakly interacting massive particles, axions, and sterile neutrinos, despite the enormous effort that has gone into searching for these particles." https://arxiv.org/pdf/1810.01668.pdf after 4 decades, might possibly be what JoeH means by "underlying incorrect assumptions". The assumptions are yet to be determined incorrect, and of course the search continues. Quote "ps: How are you going over at the old place?" beecee, why do you refer to arvix.org as "the old place" ? What one thing we are certainly able to learn from the OP article and paper, is that science and scientific theories and models, will always be improved, corrected, and/or changed when necessary, due to further science based on observational and/or experimental data from and by science itself. It will not stagnate because the many thousands of young up and comers, will be doing their best to over turn or invalidate the status quo and get that feather in their cap ....Like I say many times, the scientific methodology makes certain that science is always self correcting when needed and a discipline in eternal progress. The paper in the OP and the Abstract summary, highlights that, and the main part that interests me, is the possibility of the relatively new discovery of gravitational waves, we may have a new method of refining and improving the search for these elusive critters. Let's hope so. https://www.nature.com/articles/s41586-018-0542-z A new era in the search for dark matter: Abstract There is a growing sense of ‘crisis’ in the dark-matter particle community, which arises from the absence of evidence for the most popular candidates for dark-matter particles—such as weakly interacting massive particles, axions and sterile neutrinos—despite the enormous effort that has gone into searching for these particles. Here we discuss what we have learned about the nature of dark matter from past experiments and the implications for planned dark-matter searches in the next decade. We argue that diversifying the experimental effort and incorporating astronomical surveys and gravitational-wave observations is our best hope of making progress on the dark-matter problem. Edited October 7, 2018 by beecee
et pet Posted October 7, 2018 Posted October 7, 2018 (edited) 1 hour ago, beecee said: The assumptions are yet to be determined incorrect, and of course the search continues. ???? It might also be said that after 4 decades of concerted effort that the assumptions are yet to be determined correct, but that is not what I asked. I simply asked : might it be the " the possibility that natural WIMPs may have been nothing more than an attractive red herring " from : https://arxiv.org/pdf/1810.01668.pdf "A New Era in the Quest for Dark Matter" by Gianfranco Bertone1 and Tim M.P. Tait, is what JoeH refers to as "underlying incorrect assumptions" ? Your response was : "Perhaps my dear friend , neither you, I nor Joe can be certain at this time." ???? Dude!!! If you simply read : https://arxiv.org/pdf/1810.01668.pdf : " The class of dark matter candidates that has attracted the most attention over the past four decades is weakly interacting massive particles (WIMPs). WIMPs appeared for a long time as a perfect dark matter candidate, as new particles at the weak scale would naturally be produced with the right relic abundance in the early universe8 , while at the same time they might alleviate the infamous hierarchy problem9 , that has been a main driver of particle physics for roughly four decades10. Despite much effort, no particle other than a Standard Model-like Higgs boson has been convincingly detected at the weak scale so far, a circumstance that, as long anticipated11, now raises the possibility that natural WIMPs may have been nothing more than an attractive red herring12 . " https://arxiv.org/pdf/1810.01668.pdf How is it not easy to understand that JoeH might read the above and see it as, or paraphrase it as "underlying incorrect assumptions". As I said, I can be certain that it might possibly be what JoeH means by "underlying incorrect assumptions". Why can't you just allow that that is what JoeH is possibly referring to and move on? So much more knowledge can be attained while enjoying a discussion than can be gained by forcing an arguement. beecee, why do you refer to arvix.org as "the old place" ? Edited October 7, 2018 by et pet addition
beecee Posted October 7, 2018 Author Posted October 7, 2018 (edited) 12 minutes ago, et pet said: How is it not easy to understand that JoeH might read the above and see it as, or paraphrase it as "underlying incorrect assumptions". I understand Joe. I repeat.....The assumptions are yet to be determined incorrect, and of course the search continues. Quote As I said, I can be certain that it might possibly be what JoeH means by "underlying incorrect assumptions". And I said, The assumptions are yet to be determined incorrect, and of course the search continues. Quote Why can't you just allow that that is what JoeH is possibly referring to and move on? I did. Quote So much more can be learned while enjoying a discussion than can be garnered by forcing an arguement. Well in your 40 posts so far on this forum, everyone is addressed to me or at least reference to me. Yes, you need to move on and forget the old days. Edited October 7, 2018 by beecee
et pet Posted October 7, 2018 Posted October 7, 2018 19 minutes ago, beecee said: I understand Joe. I repeat.....The assumptions are yet to be determined incorrect, and of course the search continues. And I said, The assumptions are yet to be determined incorrect, and of course the search continues. I did. Well in your 40 posts so far on this forum, everyone is addressed to me or at least reference to me. Yes, you need to move on and forget the old days. I do not understand you, beecee You start a thread, seemingly to invite discussion People read your OP and follow the Links and actually read the referenced article People (myself included) try to participate in the discussion, but you seem to just want to force an arguement beecee, why is it that you have to consistently go 'Off Topic' towards me? Just stick with the thread topic. This wierd "old days" schtick, gimmick or whatever it is that you are peddling has nothing to do with either me or "A new era in the quest for dark matter".
beecee Posted October 7, 2018 Author Posted October 7, 2018 (edited) 1 hour ago, et pet said: People (myself included) try to participate in the discussion, but you seem to just want to force an arguement I have no problem with any genuine science adherents on this forum or even non mainstream suggestions as Joe put as long as there is evidence that may support said non mainstream idea. Joe of course has no argument against the existence of DM. 41 and counting. Quote Just stick with the thread topic Pot, kettle? .......anyway, just one question for you...Do you have a problem with the existence of DM? or how it applies with GR? With DM other lines of evidence that does support and continues to support the concept is the gravitational lensing by galactic clusters and the CMBR itself.... see..... http://chandra.harvard.edu/xray_astro/dark_matter/index3.html Gravitational Lensing by Clusters of Galaxies Yet another independent line of evidence points to the dominance of dark matter in galaxy clusters. According to Einstein's theory of general relativity, space is curved in the vicinity of strong gravitational fields. One consequence of the warping of space by gravity is that the path of light from background galaxies is bent when it passes near a cluster, in much the same way that a glass lens will bend light. The images of the galaxies are distorted by this "gravitational lensing" effect, by an amount that depends on the mass of the cluster. This method gives estimates for the amount of dark matter in galaxy clusters that is in good agreement with X-ray observations. Fluctuations in the Cosmic Microwave Background Radiation The cosmic microwave background radiation reveals what the universe was like when it was only a few hundred thousand years old, long before galaxies and clusters of galaxies were formed. At this time the universe was an expanding gas composed primarily of protons, electrons, photons, neutrinos, and dark matter. The intensity of the cosmic microwave background radiation is very nearly the same in all directions, but not quite. Small variations of a fraction of a percent have been detected. These variations, or fluctuations, are due to clumps of matter that are either hotter or cooler than the average. The rate at which clumps would grow in a hot, expanding gas can be calculated for different mixtures of photons, protons, neutrinos and dark matter. Comparison of such calculations with observations of the microwave background (especially with the Wilkinson Microwave Anisotropy Probe, or WMAP) and other data indicate that the universe contains about 6 times more dark matter than normal matter. Summary: Amount of Dark Matter: Many different lines of evidence suggest that the mass of dark matter in galaxies, clusters of galaxies, and the universe as a whole is about 5 or 6 times greater than the mass of ordinary baryonic matter such as the protons and neutrons. This chart represents the census of the Universe only 380,000 years after the Big Bang. (Illustration: NASA/CXC/M.Weiss) Revised: November 01, 2017 Edited October 7, 2018 by beecee
Strange Posted October 7, 2018 Posted October 7, 2018 5 hours ago, et pet said: is what JoeH refers to as "underlying incorrect assumptions" ? Note that “JoeH” is a serial sock-puppet and crackpot. He is incapable of rational discussion (I have tried a couple of times years ago). All he does is repeat the same statements over and over, getting angrier and angrier when challenged. He has nothing useful to contribute. Despite being banned multiple times from here and many (all?) other science forums he keeps coming back. I think he is unwell.
swansont Posted October 7, 2018 Posted October 7, 2018 4 hours ago, et pet said: JoeH, you seem to have plagiarized Paul Dover's answer from : https://physics.stackexchange.com/questions/428649/is-dark-matter-a-superfluid " Dark matter is a supersolid that fills 'empty' space, strongly interacts with ordinary matter and is displaced by ordinary matter. What is referred to geometrically as curved spacetime physically exists in nature as the state of displacement of the supersolid dark matter. The state of displacement of the supersolid dark matter is gravity. ! Moderator Note JoeH is a sockpuppet of a formerly banned user and his account has been deactivated (and apologies to all for not doing it sooner). Probably the same person as Paul Dover, hence not actually plagiarism. Do not pay his posts any attention. Please get back to discussing the science of the OP
et pet Posted October 7, 2018 Posted October 7, 2018 20 minutes ago, Strange said: Note that “JoeH” is a serial sock-puppet and crackpot. He is incapable of rational discussion (I have tried a couple of times years ago). All he does is repeat the same statements over and over, getting angrier and angrier when challenged. He has nothing useful to contribute. Despite being banned multiple times from here and many (all?) other science forums he keeps coming back. I think he is unwell. Thanks for the 'Heads Up', Strange.
beecee Posted October 7, 2018 Author Posted October 7, 2018 19 minutes ago, swansont said: ! Moderator Note JoeH is a sockpuppet of a formerly banned user and his account has been deactivated (and apologies to all for not doing it sooner). Probably the same person as Paul Dover, hence not actually plagiarism. Do not pay his posts any attention. Please get back to discussing the science of the OP 5 hours ago, beecee said: p voLet me add from the same link......... "Dark matter is a supersolid that fills 'empty' space, strongly interacts with ordinary matter and is displaced by ordinary matter. What is referred to geometrically as curved spacetime physically exists in nature as the state of displacement of the supersolid dark matter. The state of displacement of the supersolid dark matter is gravity. The supersolid dark matter displaced by a galaxy pushes back, causing the stars in the outer arms of the galaxy to orbit the galactic center at the rate in which they do. Displaced supersolid dark matter is curved spacetime. There is evidence of the supersolid dark matter every time a double-slit experiment is performed, as it is the supersolid dark matter that waves. Wave-particle duality is a moving particle and its associated wave in the supersolid dark matter." Which is word for word what you also said.... Yeah, I actually picked up something was wrong after reading the above, word for word with what he said here in two other places...He must be getting around! 26 minutes ago, Strange said: Note that “JoeH” is a serial sock-puppet and crackpot. He is incapable of rational discussion (I have tried a couple of times years ago). All he does is repeat the same statements over and over, getting angrier and angrier when challenged. He has nothing useful to contribute. Despite being banned multiple times from here and many (all?) other science forums he keeps coming back. I think he is unwell. He actually PMed me on the matter.
et pet Posted October 7, 2018 Posted October 7, 2018 (edited) 36 minutes ago, swansont said: ! Moderator Note JoeH is a sockpuppet of a formerly banned user and his account has been deactivated (and apologies to all for not doing it sooner). Probably the same person as Paul Dover, hence not actually plagiarism. Do not pay his posts any attention. Please get back to discussing the science of the OP Just read that from Strange, swansont. It seems that I must Thank You for the 'Heads Up' also. So, I 'googled' : "Ted Watson" - https://www.scienceforums.net/topic/115861-the-notion-of-wimps-incorrect-dark-matter-is-displaced-by-ordinary-where-displaced-dark-matter-is-curved-spacetime/ "ALGreenwood" - https://www.reddit.com/r/space/comments/91dz9q/what_is_dark_matter_a_new_clue_nova_pbs/ "Mitch13" - https://phys.org/news/2018-10-era-quest-dark.html Seems to be somewhat prolific at any rate. Edited October 7, 2018 by et pet
beecee Posted October 7, 2018 Author Posted October 7, 2018 (edited) It still appears that at this stage, the general opinion/s is that DM exists. http://chandra.harvard.edu/xray_astro/dark_matter/index3.html That hasn't changed. The gist of the OP article was "that diversifying the experimental effort and incorporating astronomical surveys and gravitational-wave observations is our best hope of making progress on the dark-matter problem". Let's add another competitor to the equation. I just found the following article.....https://phys.org/news/2017-12-machos-dead-wimps-no-showsay-simps.html SIMPs or Strongly Interactive Massive Particles. Some pertinent extracts from the article......"Murayama says that recent observations of a nearby galactic pile-up could be evidence for the existence of SIMPs, and he anticipates that future particle physics experiments will discover one of them". "Yet so-called massive compact halo objects - MACHOs - eluded discovery, and earlier this year a survey of the Andromeda galaxy by the Subaru Telescope basically ruled out any significant undiscovered population of black holes. The researchers searched for black holes left over from the very early universe, so-called primordial black holes, by looking for sudden brightenings produced when they pass in front of background stars and act like a weak lens. They found exactly one" -and finally the real difference with this new hypothesis" SIMPs interact with themselves, but not others" a couple of papers on the subject....... https://arxiv.org/pdf/1803.07518.pdf Mar 20, 2018 "We consider dark matter as Strongly Interacting Massive Particles (SIMPs) in a hidden sector, thermally decoupled from the Standard Model heat bath. Due to its strong interactions, the number-changing processes of the SIMP lead to its thermalization at temperature TD different from the visible sector temperature T, and subsequent decoupling as the Universe expands. We study the evolution of the dark SIMP abundance in detail and find that a hidden SIMP provides for a consistent framework for self-interacting dark matter. Thermalization and decoupling of a composite SIMP can be treated within the domain of validity of chiral perturbation theory unlike the simplest realizations of the SIMP, where the SIMP is in thermal equilibrium with the Standard Model" and............................... https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.021301 ABSTRACT A recent proposal is that dark matter could be a thermal relic of 3→2scatterings in a strongly coupled hidden sector. We present explicit classes of strongly coupled gauge theories that admit this behavior. These are QCD-like theories of dynamical chiral symmetry breaking, where the pions play the role of dark matter. The number-changing 3→2 process, which sets the dark matter relic abundance, arises from the Wess-Zumino-Witten term. The theories give an explicit relationship between the 3→2 annihilation rate and the 2→2 self-scattering rate, which alters predictions for structure formation. This is a simple calculable realization of the strongly interacting massive-particle mechanism. ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Whatever their nature, they appear to be going to be elusive little buggers to pinpoint. Perhaps the recent validation of gravitational waves, or more research into the CMBR as per the gist of the OP may help to facilitate eventual success in this field. Edited October 7, 2018 by beecee
LaurieAG Posted October 8, 2018 Posted October 8, 2018 20 hours ago, beecee said: I have no problem with any genuine science adherents on this forum or even non mainstream suggestions as Joe put as long as there is evidence that may support said non mainstream idea. I have an Applied Science degree and must say that the only real facts that we know about the LambdaCDM model and 'dm' is that the ratio of TOTAL CALCULATED UNIVERSAL MATTER (i.e. DM & OM) to TOTAL CALCULATED ORDINARY MATTER equals 2 * Pi +/- 1.1 % in both the WMAP and PLANCK data. Our gravitational models only operate inside a sphere and our visible universe is similarly limited so lets stop perpetually wrangling unicorns etc while bleating numerology at the only thing that makes any sense and understand that the universe may actually exist beyond the realms of our limited scientific models and the mathematics that describe them!
beecee Posted October 8, 2018 Author Posted October 8, 2018 (edited) 4 hours ago, LaurieAG said: I have an Applied Science degree and must say that the only real facts that we know about the LambdaCDM model and 'dm' is that the ratio of TOTAL CALCULATED UNIVERSAL MATTER (i.e. DM & OM) to TOTAL CALCULATED ORDINARY MATTER equals 2 * Pi +/- 1.1 % in both the WMAP and PLANCK data. Our gravitational models only operate inside a sphere and our visible universe is similarly limited so lets stop perpetually wrangling unicorns etc while bleating numerology at the only thing that makes any sense and understand that the universe may actually exist beyond the realms of our limited scientific models and the mathematics that describe them! Hi Laurie: Not sure what you are trying to say, but the comment of mine you quoted was meant for any science in general. And as yet I havn't seen anyone raise numerology...something who's validity I class as analogous with Astrology...pseudoscience in other words. And while certainly there is much as yet we are ignorant of, [DM being one of them] I'm not sure we can class them yet as being beyond the realms of our models. Some things simply take more time and ingenuity then others. The visible universe is also around 95 billion L/years in diameter which is a sizable chunk albeit still only small portion of the universe as a whole. At this stage with the lack of success in searching for WIMPS in the necessary quantity, I see the research into SIMPs as worthwhile and whatever new line of research can be learnt from gravitational waves and further study of the CMBR. Edited October 8, 2018 by beecee
swansont Posted October 8, 2018 Posted October 8, 2018 7 hours ago, LaurieAG said: I have an Applied Science degree and must say that the only real facts that we know about the LambdaCDM model and 'dm' is that the ratio of TOTAL CALCULATED UNIVERSAL MATTER (i.e. DM & OM) to TOTAL CALCULATED ORDINARY MATTER equals 2 * Pi +/- 1.1 % in both the WMAP and PLANCK data. Our gravitational models only operate inside a sphere and our visible universe is similarly limited so lets stop perpetually wrangling unicorns etc while bleating numerology at the only thing that makes any sense and understand that the universe may actually exist beyond the realms of our limited scientific models and the mathematics that describe them! ! Moderator Note This is off-topic. Either discuss the news given in the OP, or open a new thread to discuss anything tangential.
beecee Posted October 11, 2018 Author Posted October 11, 2018 https://phys.org/news/2018-10-galaxy-ngc-substantial-amounts-dark.html Galaxy NGC 3256 contains substantial amounts of dark matter, study suggests: A new research recently carried out by astronomers suggests that the galaxy NGC 3256 has substantial amounts of dark matter in its central region. The finding, presented in a paper published October 2 on arXiv.org, might pose a challenge to the modified Newtonian dynamics theory. extract: "The analysis of the available data allowed the team to determine the mass distribution in NGC 3256. They found that there is a significant amount of invisible dynamical mass (around 48 billion solar masses) in the central region of the galaxy. The fraction of the invisible mass was calculated to be about 87 percent of the dynamical mass. According to the authors of the paper, such huge amount of invisible mass, cannot be explained by the molecular mass and the stellar mass within the central region. Therefore, they suggest that invisible mass is likely caused by dark matter. "The amount of dark matter is about 4.84 ± 0.42 × 1010 solar masses, which is significantly larger than the stellar mass. It is clear that even the velocity was not circular, the dynamical mass that would be required to account for the observed velocity dispersion is still much larger than the baryonic mass, and thus the existence of a huge amount of dark matter in the central region of the galaxy is necessary," the researchers concluded" Read more at: https://phys.org/news/2018-10-galaxy-ngc-substantial-amounts-dark.html#jCp <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> the paper: http://www.ukm.my/jsm/pdf_files/SM-PDF-47-6-2018/20 Israa Abdulqasim Mohammed Ali.pdf Dark Matter in the Central Region of NGC 3256 ABSTRACT We investigated the central mass distribution of the luminous infrared galaxy NGC 3256 at a distance of 35 Mpc by using CO(1-0) observations of the Atacama Large Millimeter and sub-millimeter Array (ALMA) and near-IR data of the Two Micron Sky Survey (2MASS). We found that there is a huge amount of invisible dynamical mass (4.48 × 1010 ) in the central region of the galaxy. The invisible mass is likely caused by some dark matter, which might have a cuspy dark matter profile. We note that this dark matter is difficult to explain with the conventional Modified Newtonian Dynamics (MOND) model, which is only applicable at a low acceleration regime, whereas the acceleration at the central region of the galaxy is relatively strong. Therefore, this discovery might pose a challenge to the conventional MOND models.
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