what is black matter/dark matter?
401680
The theory of dark matter has been developed to try and explain the observed characteristics of large-scale celestial objects, like galaxies. Mass (matter) causes gravity which in turn effects the shape and motions of things like spiral galaxies. However, the observed shape and motions of spiral galaxies can't be explained by the amount of matter known to be there. Some other kind of matter must be present, and that's called "dark matter."\n\nDon't confuse "dark matter" with "dark energy." The latter is another mysterious feature of the universe that is thought to be causing the expansion rate of the universe to be increasing.\n\nHere's the theorized percentages of dark matter, dark energy, and regular matter for the universe --\nDark matter.....23%\nDark energy.....73%\nRegular matter..4%\n\nYou could almost say that 97% of the universe appears to be missing :)
241767
In cosmology, dark matter refers to hypothetical matter particles, of unknown composition, that do not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence can be inferred from gravitational effects on visible matter such as stars and galaxies. The dark matter hypothesis aims to explain several anomalous astronomical observations, such as anomalies in the rotational speed of galaxies (the galaxy rotation problem). Estimates of the amount of matter present in galaxies, based on gravitational effects, consistently suggest that there is far more matter than is directly observable. The existence of dark matter would also resolve a number of inconsistencies in the Big Bang theory, and is crucial for structure formation.
179527
No, neither. When matter and anti-matter get together you get a lot of gamma rays, and assorted other known particles. This has been observed many times in the larger particle accelerators. Nobody knows what dark matter or dark energy are made of, but we do know they aren't made of the things we've detected in our accelerators yet.
611919
depends on who you ask, you could probably find all percentages because we are not capable of measuring black matter throughout the whole universe.
277935
A galaxy is a huge gravitationally bound system of stars, interstellar gas and dust, plasma, and (possibly) unseen dark matter. Typical galaxies contain 10 million to one trillion (107 to 1012) stars, all orbiting a common center of gravity. In addition to single stars and a tenuous interstellar medium, most galaxies contain a large number of multiple star systems and star clusters as well as various types of nebulae. Most galaxies are several thousand to several hundred thousand light years in diameter and are usually separated from one another by distances on the order of millions of light years.\n\nAlthough so-called dark matter appears to account around 90% of the mass of most galaxies, the nature of this unseen components is not well understood. There is some evidence that supermassive black holes may exist at the center of many, if not all, galaxies.\n\nIntergalactic space, the space between galaxies, is filled with a tenuous plasma with an average density less than one atom per cubic meter. There are probably more than a hundred billion (1011) galaxies in the visible universe.
477879
Well, the one is matter and the other is energy.\n\n=====\n\nIn cosmology, dark matter refers to hypothetical matter particles, of unknown composition, that do not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence can be inferred from gravitational effects on visible matter such as stars and galaxies. The dark matter hypothesis aims to explain several anomalous astronomical observations, such as anomalies in the rotational speed of galaxies (the galaxy rotation problem). Estimates of the amount of matter present in galaxies, based on gravitational effects, consistently suggest that there is far more matter than is directly observable. The existence of dark matter would also resolve a number of inconsistencies in the Big Bang theory, and is crucial for structure formation.\n\nIf dark matter does exist, it has vastly more mass than the "visible" part of the universe [1]. Only about 4% of the total mass in the universe (as inferred from gravitational effects) can be seen directly. About 22% is thought to be composed of dark matter. The remaining 74% is thought to consist of dark energy, an even stranger component, distributed diffusely in space, that probably cannot be thought of as ordinary particles. Determining the nature of this missing mass is one of the most important problems in modern cosmology and particle physics. Its urgency is underlined by David B. Cline in a 2003 article in Scientific American, in which he writes: "The terms . . . 'dark matter' and 'dark energy,' serve mainly as expressions of our ignorance." [2]\n\n=====\n\nIn cosmology, dark energy is a hypothetical form of energy which permeates all of space and has strong negative pressure. According to the theory of relativity, the effect of such a negative pressure is qualitatively similar to a force acting in opposition to gravity at large scales. Invoking such an effect is currently the most popular method for explaining recent observations that the universe appears to be expanding at an accelerating rate, as well as accounting for a significant portion of the missing mass in the universe.\n\nTwo proposed forms for dark energy are the cosmological constant, a constant energy density filling space homogeneously, and quintessence, a dynamic field whose energy density can vary in time and space. Distinguishing between the alternatives requires high-precision measurements of the expansion of the universe to understand how the speed of the expansion changes over time. The rate of expansion is parameterized by the cosmological equation of state. Measuring the equation of state of dark energy is one of the biggest efforts in observational cosmology today.\n\nAdding a cosmological constant to the standard theory of cosmology (i.e. the FLRW metric) has led to a model for cosmology known as the Lambda-CDM model. This model agrees closely with established cosmological observations.\n\nThe term dark energy was coined by Michael Turner.\n\n=====\n\nZack,\n\nDark matter is not detectable.  It can't be seen with visible light, or astronomers would see fuzzy halos around galaxies.\n\nDark energy is a force that is causing the expansion of the Universe to accelerate.  Instead of holding the Universe together, dark energy is blowing it apart.
224794
DARK energy and dark matter, two of the greatest mysteries confronting physicists, may be two sides of the same coin. A new and as yet undiscovered kind of star could explain both phenomena and, in turn, remove black holes from the lexicon of cosmology.\n\nThe audacious idea comes from George Chapline, a physicist at Lawrence Livermore National Laboratory in California, and Nobel laureate Robert Laughlin of Stanford University and their colleagues. Last week at the 22nd Pacific Coast Gravity Meeting in Santa Barbara, California, Chapline suggested that the objects that till now have been thought of as black holes could in fact be dead stars that form as a result of an obscure quantum phenomenon. These stars could explain both dark energy and dark matter.\n\nThis radical suggestion would get round some fundamental problems posed by the existence of black holes. One such problem arises from the idea that once matter crosses a black hole's event horizon - the point beyond which not even light can escape - it will be destroyed by the space-time "singularity" at the centre of the black hole. Because information about the matter is lost forever, this conflicts with the laws of quantum mechanics, which state that information can never disappear from the universe.\n\nAnother problem is that light from an object falling into a black hole is stretched so dramatically by the immense gravity there that observers outside will see time freeze: the object will appear to sit at the event horizon for ever. This freezing of time also violates quantum mechanics. "People have been vaguely uncomfortable about these problems for a while, but they figured they'd get solved someday," says Chapline. "But that hasn't happened and I'm sure when historians look back, they'll wonder why people didn't question these contradictions."\n\n“People have been uneasy about these problems with black holes, but figured they'd get solved. That hasn't happened”While looking for ways to avoid these physical paradoxes, Chapline and Laughlin found some answers in an unrelated phenomenon: the bizarre behaviour of superconducting crystals as they go through something called "quantum critical phase transition" (New Scientist, 28 January, p 40). During this transition, the spin of the electrons in the crystals is predicted to fluctuate wildly, but this prediction is not borne out by observation. Instead, the fluctuations appear to slow down, and even become still, as if time itself has slowed down.\n\n"That was when we had our epiphany," Chapline says. He and Laughlin realised that if a quantum critical phase transition happened on the surface of a star, it would slow down time and the surface would behave just like a black hole's event horizon. Quantum mechanics would not be violated because in this scenario time would never freeze entirely. "We start with effects actually seen in the lab, which I think gives it more credibility than black holes," says Chapline.\n\nWith this idea in mind, they - along with Emil Mottola at the Los Alamos National Laboratory in New Mexico, Pawel Mazur of the University of South Carolina in Columbia and colleagues - analysed the collapse of massive stars in a way that did not allow any violation of quantum mechanics. Sure enough, in place of black holes their analysis predicts a phase transition that creates a thin quantum critical shell. The size of this shell is determined by the star's mass and, crucially, does not contain a space-time singularity. Instead, the shell contains a vacuum, just like the energy-containing vacuum of free space. As the star's mass collapses through the shell, it is converted to energy that contributes to the energy of the vacuum.\n\nThe team's calculations show that the vacuum energy inside the shell has a powerful anti-gravity effect, just like the dark energy that appears to be causing the expansion o
394958
Sorry, but we've ruled out the majority of dark matter being massive concentrations of mass (small black holes etc).  Things like that can be detected in gravitational lens searches, and the numbers of lensing events that we have detected pretty much rules out any type of "massive compact" dark matter being the bulk of what is out there.  This leaves us looking for even more exotic stuff - there is likely a nobel out there for someone who figures it out.\n\nAs for directly answering the question... I'm really at a loss to even begin to understand what is being said there.
967381
new research show that galaxies are held together by dark matter which until recently there was little or no evidence of,however i believe the massiveness of the entire universe is actually exerting pressure ever so slightly upon the galaxies and that force is squeezing them upon a tightly wound black hole which appears to be a gravitational force, but i compare it to all the water in a tub pressing itself gently into a whirlpool as it goes down the drain...yes it is gravity pulling it down the drain but if that same whirlpool was in space it would have more similarities to a black hole
268153
Three cosmic enigmas, one audacious answer\n09 March 2006 \nExclusive from New Scientist Print Edition \nZeeya Merali \n\n \n\n \n\n  \nDARK energy and dark matter, two of the greatest mysteries confronting physicists, may be two sides of the same coin. A new and as yet undiscovered kind of star could explain both phenomena and, in turn, remove black holes from the lexicon of cosmology.\n\nThe audacious idea comes from George Chapline, a physicist at Lawrence Livermore National Laboratory in California, and Nobel laureate Robert Laughlin of Stanford University and their colleagues. Last week at the 22nd Pacific Coast Gravity Meeting in Santa Barbara, California, Chapline suggested that the objects that till now have been thought of as black holes could in fact be dead stars that form as a result of an obscure quantum phenomenon. These stars could explain both dark energy and dark matter.\n\nThis radical suggestion would get round some fundamental problems posed by the existence of black holes. One such problem arises from the idea that once matter crosses a black hole's event horizon - the point beyond which not even light can escape - it will be destroyed by the space-time "singularity" at the centre of the black hole. Because information about the matter is lost forever, this conflicts with the laws of quantum mechanics, which state that information can never disappear from the universe.\n\nAnother problem is that light from an object falling into a black hole is stretched so dramatically by the immense gravity there that observers outside will see time freeze: the object will appear to sit at the event horizon for ever. This freezing of time also violates quantum mechanics. "People have been vaguely uncomfortable about these problems for a while, but they figured they'd get solved someday," says Chapline. "But that hasn't happened and I'm sure when historians look back, they'll wonder why people didn't question these contradictions."\n\n“People have been uneasy about these problems with black holes, but figured they'd get solved. That hasn't happened”While looking for ways to avoid these physical paradoxes, Chapline and Laughlin found some answers in an unrelated phenomenon: the bizarre behaviour of superconducting crystals as they go through something called "quantum critical phase transition" (New Scientist, 28 January, p 40). During this transition, the spin of the electrons in the crystals is predicted to fluctuate wildly, but this prediction is not borne out by observation. Instead, the fluctuations appear to slow down, and even become still, as if time itself has slowed down.\n\n"That was when we had our epiphany," Chapline says. He and Laughlin realised that if a quantum critical phase transition happened on the surface of a star, it would slow down time and the surface would behave just like a black hole's event horizon. Quantum mechanics would not be violated because in this scenario time would never freeze entirely. "We start with effects actually seen in the lab, which I think gives it more credibility than black holes," says Chapline.\n\nWith this idea in mind, they - along with Emil Mottola at the Los Alamos National Laboratory in New Mexico, Pawel Mazur of the University of South Carolina in Columbia and colleagues - analysed the collapse of massive stars in a way that did not allow any violation of quantum mechanics. Sure enough, in place of black holes their analysis predicts a phase transition that creates a thin quantum critical shell. The size of this shell is determined by the star's mass and, crucially, does not contain a space-time singularity. Instead, the shell contains a vacuum, just like the energy-containing vacuum of free space. As the star's mass collapses through the shell, it is converted to energy that contributes to the energy of the vacuum.\n\nThe team's calculations show that the
230733
In cosmology, dark matter refers to hypothetical matter particles, of unknown composition, that do not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence can be inferred from gravitational effects on visible matter such as stars and galaxies. The dark matter hypothesis aims to explain several anomalous astronomical observations, such as anomalies in the rotational speed of galaxies (the galaxy rotation problem). Estimates of the amount of matter present in galaxies, based on gravitational effects, consistently suggest that there is far more matter than is directly observable. The existence of dark matter would also resolve a number of inconsistencies in the Big Bang theory, and is crucial for structure formation.\n\nIf dark matter does exist, it has vastly more mass than the "visible" part of the universe. Only about 4% of the total mass in the universe (as inferred from gravitational effects) can be seen directly. About 23% is thought to be composed of dark matter. The remaining 73% is thought to consist of dark energy, an even stranger component, distributed diffusely in space, that probably cannot be thought of as ordinary particles. Determining the nature of this missing mass is one of the most important problems in modern cosmology and particle physics.
696222
According to the world's best brains(Scientists) 80% of the universe is dark matter(read unknown). So it will take ages before we get any idea to your question.
391370
Not really, a solid is usually atoms packed closely enough together so that they bond and form a structure that is resistant to change. Blackhole cores are of collapsed matter: there are no atoms, protons or even quarks. Just like plasma isn't "gas," blackhole material isn't solid
97653
Actually the "missing mass" percentage is more like 96%. Science is pretty sure that there has to be something else present in the universe to cause the motions and velocities of large-scale structures like galaxies and galactic clusters. Based on recent research and analyses, it now looks like the universe is composed of about 4% "regular" matter, stuff we can see or infer is present, 23% "dark" matter that we can't as yet see or detect, and 73% "dark energy", the mysterious force(s) that is causing the universe's expansion rate to increase.
564206
are you asking about "dark matter"?  dark matter is an unknown kind of matter that only interacts with ordinary matter gravitationally.  about 85 percent of the matter in the universe is dark matter.  swiss astronomer fritz zwicky originated the term 'dark matter'.\n\nread these pages.  they will help.\nhttp://en.wikipedia.org/wiki/Dark_matter\nhttp://map.gsfc.nasa.gov/m_uni.html
1153702
Dark energy comprises 70% of the universe and dark matter comprises 26% of the universe. Ordinary baryonic matter, in the form of gas and stars, only makes up 4%.\n\nDark matter refers to matter particles, of unknown composition, that do not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence may be inferred from gravitational effects on visible matter such as stars and galaxies. Dark matter is explained as being cold, non-baryonic, collision-less dust.\n\nDark energy is a hypothetical form of energy which permeates all of space and has strong negative pressure. According to the theory of relativity, the effect of such a negative pressure is qualitatively similar to a force acting in opposition to gravity at large scales. In other words, dark energy acts as a repulsive force or anti-gravitation and is responsible for the acceleration of the universe.
803363
dark matter and dark energy and debris