COME OVER TO THE DARK SIDE: The presence of dark matter [purple] is inferred by its gravitational pull in this composite image of the Bullet Cluster.
Image: X-ray: NASA/CXC/M.Markevitch et al. Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al. Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/D.Clowe et al.
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Gravity's Engines
We’ve long understood black holes to be the points at which the universe as we know it comes to an end. Often billions of times more massive than the Sun, they...
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If current theories prove correct, ordinary matter—all that we can see, smell and touch—makes up just a fraction, maybe 4 percent, of the universe. The rest comes from the so-called dark sector: dark matter and dark energy, a mysterious and pervasive energy that is suspected of speeding the universe's expansion. Dark matter, so known because it refuses to emit or interact with light in a way that we can see, is nearly six times as prevalent as ordinary matter. But, for all its ubiquity, it is often tagged as being fairly bland, a sort of galactic deadweight that only reveals itself through its gravitational pull.
New theories about the hidden life of dark matter aim to shed this dull image once and for all. Whereas dark matter may not mix much with the ordinary kind, it may tango with other dark matter particles via some new force—one outside the purview of the Standard Model of particle physics.
A group of researchers at the California Institute of Technology proposes that dark matter could have its own force analogous to electromagnetism—mediated, naturally, by "dark photons". Just as in regular electromagnetism, the force would act over long ranges, and the photon (the discrete unit of light energy) would be massless. As noted by study co-author Sean Carroll, a Caltech physicist, on the blog Cosmic Variance, the theory opens the door to a rich, as yet unseen world of dark radiation, even dark magnetic and electric fields.
Such a proposal is not merely pie-in-the-sky conjecturing. "As astrophysical observations and simulations improve, we're doing increasingly precise comparisons between the models of how galaxies form and the observations of what galaxies actually look like," Carroll says. "And right now, there are some slight discrepancies." Those discrepancies, he adds, could result from imperfect measurements or "they might be because the idea of completely noninteracting dark matter isn't good enough, that there really are interactions that are affecting the shapes of galaxies."
"Particle physicists have at least known about the possibility of dark radiation for a long time," Carroll says, "but they haven't been taking seriously the idea that it could actually affect the dark matter in our universe." (As Carroll notes on Cosmic Variance, another recent paper, co-authored by physicist and cosmologist Jonathan Feng of the University of California, Irvine, also proposes the concept of dark photons, albeit in a different theoretical framework.)
In a separate paper, submitted to Physical Review D, a group of researchers at the Institute for Advanced Study in Princeton, N.J., Harvard University and New York University (N.Y.U.) also posits a new dark force, this one with a much smaller range, acting only on nuclear scales. Their theory first sought to account for a wealth of gamma rays emanating from the center of our galaxy, picked up by the European Space Agency's Integral satellite, that correspond to the annihilation of electrons with their antiparticle, positrons (positively charged counterparts to electrons).
Where those positrons were coming from was an open question. "Supernovae make positrons, but not nearly enough," says Harvard astronomer Douglas Finkbeiner, a study co-author. Under the right circumstances, he thought, dark matter could fit the bill. As it turned out, with the help of a new dark force, interacting particles could trade in some of their kinetic energy to produce a positron–electron pair, a proposal put forth by Finkbeiner and study co-author Neal Weiner, an N.Y.U. physicist, last year. But new data from the PAMELA instrument, which detects antimatter in cosmic radiation from on board a Russian satellite, revealed a still surprisingly high number of positrons. So Finkbeiner and his colleagues honed the theory to account for the PAMELA results, redefining how dark matter particles annihilate into other particles. Another space-borne observer, NASA's orbiting Fermi Gamma-ray Telescope (formerly known as GLAST) will provide further guidance in the near future by examining the types of gamma rays coming from areas where dark matter should be clumped. If the group's theory is correct, Fermi's results "really should be distinct from what people were expecting for other kinds of dark matter," Finkbeiner says.
The implications for such a model "go on and on," he says, pointing to the formation of black holes and the heating of galaxy clusters, for starters. "There are all these problems in astrophysics where it seems like you need a little bit more energy, almost as if there's energy coming out of nowhere, so we think this might be what's involved."
This is not the first time that new forces acting on the dark sector have been proposed. At the January 2007 meeting of the American Astronomical Society in Seattle, N.Y.U. professor of physics Glennys Farrar presented findings that pointed to the existence of a long-range force acting on dark matter that would have significant observable effects in the cosmos. Farrar later concluded that the figures on which the proposal was based, relating to the speed of a subcluster of galaxies in the Bullet Cluster, were inaccurate.
Finkbeiner acknowledges that theories such as those of his group often fall short. But paraphrasing the late Princeton University cosmologist David Wilkinson, he says, "most all of your ideas are wrong, so you should find that out as quickly as possible so you can get on to the next one." Whatever the correct idea turns out to be, in whatever complex dance of particles and forces physicists find to best describe the universe, maybe dark matter won't be such a wallflower after all.
See what we're tweeting about
37 Comments
Add CommentDark energy is a false hypothesis based on the entropy-based fractional wave-elongation that both Hubble and Planck has misinterpreted in different ways.
Reply | Report Abuse | Link to thisDark matter is a false hypothesis based on the measurement of the galaxies' flat velocity curve that is misinterpreted as a stiff rotating plate.
The mistake is that the astronomers by autistic mathematics have mixed up orbital speed and angular velocity.
So, there is no need of dark matter or dark energy.
These apparent anomalies can be explained by intelligible logical physics.
Dark energy is a false hypothesis based on the entropy-based fractional wave-elongation that both Hubble and Planck have found but misinterpreted in different ways.
Reply | Report Abuse | Link to thisDark matter is a false hypothesis based on the measurement of the galaxies' flat velocity curve that is misinterpreted as a stiff rotating plate.
The mistake is that the astronomers by autistic mathematics have mixed up orbital speed and angular velocity.
So, there is no need of dark matter or dark energy.
These apparent anomalies can be explained by intelligible logical physics.
What I am about to ask is somewhat like questioning global warming, but here goes anyway: is it even remotely possible that there is something wrong, or missing, in the equations that are used in astrophysics, i.e. the equations that don't work unless one assumes the existence of dark energy and/or dark matter? To be able to predict only 4 or 5% of the mass of the universe is way beyond the incredible is it not? Are the equations absolutely accurate? Beyond question?
Reply | Report Abuse | Link to thisWhat needs to be discussed is how gravitational forces work over large distances with large mass. Einstein's and even Newtons gravitational theories need to be tweaked to reflect these ideas. They work well in the low mass and short distances of our solar system, even when you look at larger areas of several stars, but do we really know the exact math of a super massive black holes gravity over larger distances, i.e. a hundred thousand light year across galaxy with up to 100 billion stars, each with any number of planets. Newtons gravitational constant might not be correct at this scale. However with the large number of dull witted physicists who are getting large grants to investigate this extra gravity(the only proof of dark matter) Tackling General relativity is not going to bring the big money that the, however remote, possibility of some "dark" matter in the universe brings.
Reply | Report Abuse | Link to thisAnd don't even get me started on Dark energy....
I think nothing in science is beyond question... Science is not about absolut certainties, but about questioning and finding the most likely explanations. Today, it seems reasonable to propose and search something dark matter, but the answer may be in another hypothesis, such as "tacckling general relativity". However, only experiments and observations can say what works better.
Reply | Report Abuse | Link to thisoh lord! let me understand you.
Reply | Report Abuse | Link to thisThe universe was created inside a black hole and it's still in it.
Reply | Report Abuse | Link to thisCould it be that dark matter only exchanges force with other dark matter via dark energy becasue the dark matter is a virtual particle existing for a limited time?
Reply | Report Abuse | Link to thisMatter and dark matter"
Reply | Report Abuse | Link to thisFact and Speculation.
=========.
1.
Fact.
The detected material mass of the matter in the Universe is so small
(the average density of all substance in the Universe is approximately
p=10^-30 g/sm^3) that it cannot close the Universe and therefore
our Universe as whole is open , endless.
But what to do with the infinite Universe the physicists don't know.
The concept of infinite/ eternal means nothing
to a scientists. They do not understand how they could
draw any real, concrete conclusions from this characteristic.
A notions of "more", "less", "equally, "similar" could not
be conformed to a word infinity or eternity.
The Infinity/Eternity is something, that has no borders,
has no discontinuity; it could not be compared to anything.
Considering so, scientists came to conclusion that the
infinity/eternity defies to a physical and mathematical definition
and cannot be considered in real processes.
Therefore they have proclaimed the strict requirement
(on a level of censor of the law):
? If we want that the theory would be correct,
the infinity/eternity should be eliminated ?.
Thus they direct all their mathematical abilities,
all intellectual energy to the elimination of infinity.
Therefore they invented an abstract "dark matter" and " dark energy".
They say: " 90% or more of the matter in the Universe is unseen.
And nobody knows what it is.
2.
Speculation.
Unknown dark matter it is matter which makes up the difference
between observed mass of a galaxies and calculated mass&&
which&.will & close &.the Universe, as &&.
as&&the astrophysicists want.
3.
The Dark Matter is another official dogma of our astronomy.
/ V. H. Vergon. /
==============..
Black hole and Big bang..
1.
A black hole is a theoretical region of space in which the
gravitational field is so powerful that nothing can escape.
2.
Hawking Radiation theorizes that black holes do not,
in fact, absorb all matter absolutely; they give off some
return matter.
3.
Once upon a time, 20 billions of years ago, all matter
(all elementary particles and all quarks and their
girlfriends- antiparticles and antiquarks, all kinds of
waves: electromagnetic, gravitational, muons&
gluons field &.. etc.) was assembled in a single point
The reason of this unity is gravitational force.
4.
How does this single point created if the matter
can escape from any strong gravitational force?
==========..
Best wishes.
Israel Sadovnik. / Socratus.
http://www.socratus.com
http://www.wbabin.net
http://www.wbabin.net/comments/sadovnik.htm
http://www.wbabin.net/physics/sadovnik.pdf
Matter and “dark matter"
Reply | Report Abuse | Link to thisFact and Speculation.
=========.
1.
Fact.
The detected material mass of the matter in the Universe is so small
(the average density of all substance in the Universe is approximately
p=10^-30 g/sm^3) that it cannot “ close “ the Universe and therefore
our Universe as whole is “ open”, endless.
But what to do with the infinite Universe the physicists don't know.
The concept of infinite/ eternal means nothing
to a scientists. They do not understand how they could
draw any real, concrete conclusions from this characteristic.
A notions of "more", "less", "equally, "similar" could not
be conformed to a word infinity or eternity.
The Infinity/Eternity is something, that has no borders,
has no discontinuity; it could not be compared to anything.
Considering so, scientists came to conclusion that the
infinity/eternity defies to a physical and mathematical definition
and cannot be considered in real processes.
Therefore they have proclaimed the strict requirement
(on a level of censor of the law):
« If we want that the theory would be correct,
the infinity/eternity should be eliminated ».
Thus they direct all their mathematical abilities,
all intellectual energy to the elimination of infinity.
Therefore they invented an abstract "dark matter" and " dark energy".
They say: " 90% or more of the matter in the Universe is unseen.
And nobody knows what it is.
2.
Speculation.
Unknown “dark matter “ it is matter which makes up the difference
between observed mass of a galaxies and calculated mass……
which….will …” close “ ….the Universe, as …….
as……the astrophysicists want.
3.
The Dark Matter is another official dogma of our astronomy.
/ V. H. Vergon. /
==============..
Black hole and Big bang..
1.
A black hole is a theoretical region of space in which the
gravitational field is so powerful that nothing can escape.
2.
Hawking Radiation theorizes that black holes do not,
in fact, absorb all matter absolutely; they give off some
return matter.
3.
Once upon a time, 20 billions of years ago, all matter
(all elementary particles and all quarks and their
girlfriends- antiparticles and antiquarks, all kinds of
waves: electromagnetic, gravitational, muons…
gluons field ….. etc.) – was assembled in a “single point”
The reason of this unity is gravitational force.
4.
How does this “single point” created if the matter
can escape from any strong gravitational force?
==========..
Best wishes.
Israel Sadovnik. / Socratus.
http://www.socratus.com
http://www.wbabin.net
http://www.wbabin.net/comments/sadovnik.htm
http://www.wbabin.net/physics/sadovnik.pdf
Your comment is not as daffy as you may have intended it to be. Your hypotheses is feasible.
Reply | Report Abuse | Link to thisDark energy and matter has a little more to it than just a way of explaining a boundary to our Universe. Dark energy/matter explains the missing mass as is calculated from, the expansion of the universe, the shape of galaxies and the required energy.
Reply | Report Abuse | Link to thisExpansion of the Universe:
We know it is getting bigger but if you calculate the expansion rate and use the mater/energy density of baryonic material then this only accounts for about 4% of the energy density as to be inferred by the measured expansion rate.
The shape of Galaxies:
If one was to calculate the positions (distribution) of all of the stars that we can see in a nearby galaxy, based on the estimated masses of the constituent stars, then the shape of that galaxy would not be what we see. The arms of the ‘bar’ type galaxies (bar galaxies are spiral) would be stretched outward more than we observe. There is something ‘pushing’ them in. There is an article showing this at http://en.wikipedia.org/wiki/Galaxy_rotation_problem
These ideas are not new. Jay Alfred has written a lot about dark plasma since 2006. He argues in his article Dark Matter Plasma of Super Particles (June 2008) that &dark matter consists of non-standard (or super) plasma which radiates energetic waves. These postulated "super" waves or "S-Waves" are currently not directly measurable by our scientific instruments. See http://ezinearticles.com/?Dark-Matter---Plasma-of-Super-Particles&id=1240357 Furthermore, Google dark plasma jay alfred and numerous links to articles and comments will appear.
Reply | Report Abuse | Link to thisThese ideas are not new. Jay Alfred has written a lot about “dark plasma” since 2006. He argues in his article “Dark Matter – Plasma of Super Particles” (June 2008) that “…dark matter consists of non-standard (or super) plasma which radiates energetic waves. These postulated "super" waves or "S-Waves" are currently not directly measurable by our scientific instruments.” See http://ezinearticles.com/?Dark-Matter---Plasma-of-Super-Particles&id=1240357 Furthermore, Google “dark plasma jay alfred” and numerous links to articles and comments will appear.
Reply | Report Abuse | Link to thisI am not a scientist. But I am curious. Is it possible that 'dark matter' is created by black holes?
Reply | Report Abuse | Link to thisDon't be ridiculous. It's turtles, all the way down.
Reply | Report Abuse | Link to thisMeasurements of cosmic microwave background (CMB) anisotropies, most recently by the WMAP satellite, indicate that the universe is very close to flat. For the shape of the universe to be flat, the mass/energy density of the universe must be equal to a certain critical density. The existence of dark energy, in whatever form, is needed to reconcile the measured geometry of space with the total amount of matter in the universe. The total amount of matter in the universe (including baryons and dark matter), as measured by the CMB, accounts for only about 30% of the critical density. This implies the existence of an additional form of energy to account for the remaining 70%. The most recent WMAP observations are consistent with a universe made up of only 4% ordinary matter, 23% dark matter, and 73% dark energy.
Reply | Report Abuse | Link to thisEver since the presentation of Einstein’s theories of both special and general relativity with the many earth shaking scientific advances based upon the precepts, there are still many unanswered questions. Both Maxwell’s hypothetical “ether,” suggested to facilitate the propagation of electromagnetic energy, and Newton’s gravitation theory based on observed laws of motion, have fallen into disregard based on Einstein’s suggestions of no need for an ether if you abandon the necessity for absolute time and that gravity is not a force like other forces but that mass follows a geodesic path in a “curved space,” based on the suppositionthat space-time is not flat as had been previously surmised, but is curved, or “warped,” by the distribution of mass and energy in it.
Constrained by those accepted precepts we have never discovered the actual means by which light is propagated or the quantum mechanics of gravitational force, and we have no proven origin of matter or shape of the universe theories. And now we have measured evidence of dark matter with the question of what is the substance of dark matter, and what is the composition of an implied necessary form of dark energy. I suggest the answers are all causal related.
Based upon an in-depth analysis using all proven data of now known properties of radiated EM energy, I propose the composition and functionality of Maxwell’s ether can now be defined, consistent with all experiments testing the phenomena of special relativity, general relativity and relativistic quantum mechanics,. As scientifically defined the ether is the “dark energy” glue that ties all four interaction forces in Nature together, bonding all atomic components in atomic masses in a quantum entropy pattern of motion that sustains their composition and interdependent coexistence; facilitates all the propagation principles of EM radiation, and accounts for the ongoing formation of new matter to maintain an unending “steady state” continuance of the universe. The atomic components thus formed constitute the substance of “dark matter.”
A Library of Congress copyrighted full disclosure 11 page paper is available for all interested.
A 1970s study of the orbital velocities of stars in spiral galaxies empirically expected that they would decline with distance from the galactic center of mass, as do planets in our solar system. The observation results clearly demonstrated that, except for those nearest the galactic core, the orbital velocity of stars in spiral galaxies remained generally constant regardless of distance. Based on application of established gravitational theory, it appeared that the peripheral stars were orbiting so fast that they should be flung out of the galaxy. This reported discrepancy between expected orbital velocities and observational results was the original basis for the Dark Matter hypothesis. While many subsequent observations of apparent gravitational anomalies have been attributed to it, no form of matter has ever been identified that can satisfy the requirements specified for dark matter.
Reply | Report Abuse | Link to thisThe observed orbital characteristics of stars in disperse spiral and elliptical galaxies most closely resembles the rotation of a loosely bound massive object rather than those of relatively independent, smaller bodies orbiting the stellar mass of planetary systems. This contrast in gravitational characteristics seems to be consistent with the apparent distribution of galactic mass throughout the orbital plane of disperse galaxies in comparison to the highly centralized mass of stellar planetary systems. The simplest possible solution to the disperse galaxy orbital velocity problem is that they are exactly what they appear to be: rotating loosely bound massive objects.
The existence of large scale structures within spiral galaxies is clear evidence of gravitational bindings among neighboring stars. At sufficient distance from the galactic center of mass these structures persist despite galactic gravitational influences. Spiral galaxies should be gravitationally evaluated not as individual stars but as large scale bound stellar structures orbiting the galactic center of mass. While less apparent, similar large scale stellar binding may also occur within elliptical galaxies.
This interpretation of evidence suggests that more complete investigations should be made into the gravitational effects of mass distribution in disperse galaxies. The simple central mass planetary model is an inadequate representation of these complex gravitational systems.
If better understanding of gravitational interactions within disperse galaxies can eliminate the original requirement for the dark matter hypothesis, perhaps similarly complex disperse gravitational interactions can account for all the other observed gravitational anomalies conveniently attributed to dark matter.
The observations of apparent large scale gravitational anomalies may be best understood through more complete consideration of component regional gravitational interactions. This more straightforward explanation of observed large scale gravitational effects may eliminate the extraordinary demands imposed on the material composition of the universe by the dark matter hypothesis.
Sunsphere at 08:39 PM on 03/25/09
Reply | Report Abuse | Link to thisIt appears that the concept of curved space has never been clearly defined, as no physical medium of curvature has been described.
Predictive mathematical models require only accurate and correct representation of essential factors to produce accurate results. This does not necessarily require complete physical description of all components of the predicted process.
While the equations of general relativity successfully describe the relative motions of matter, complete understanding of physical processes may require a more complete determination of the physical nature of spacetime.
Perhaps space contains or consists of an energy which imparts velocity to matter, and mass represents a contraction or lensing of space-energy by matter.
Velocity is required to produce distance, or space , and time: motion, distance/space and time are all effects/artifacts of velocity.
Even a disperse force of velocity may result in expansion of spacetime or, contracted by matter, the localized gravitational effect of mass. Space-energy may have even originated in conjunction with creation matter from unified energy.
These simplistic conceptualizations, conceived independently, appear to be consistent with the described concept of ether.
The inverse squares rule perfectly represents the shape and resulting gravitational effects of spacetime curved by a single, dominatingly massive, spherical object. However, it cannot possibly represent the complex shape or large scale effects of spacetime curved by many massive objects, such as disperse spiral and elliptical galaxies.
Reply | Report Abuse | Link to thisThe original assumptions and expectations for the orbital velocities of stars in spiral galaxies were invalid. This invalidates the resulting discrepancy and the original Dark Matter hypothesis intended to resolve it.
maybe "dark matter" is in the another dimention and that's the reaso it does not react to "our" world
Reply | Report Abuse | Link to thisScientists Keep Chasing Their Selfmade Gibbering Tail
Reply | Report Abuse | Link to thisA. "Dark Matter May be Easier to Detect than Previously Thought"
http://www.physorg.com/news169121408.html
And
"Dark Energy From the Ground Up: Make Way for BigBOSS"
http://www.physorg.com/news168858441.html
B. On The Origin Of Origins
http://www.the-scientist.com/community/posts/list/160/122.page#2753
http://www.physforum.com/index.php?showtopic=14988&st=525&#entry420991
Enough Is Enough!
Beyond Einstein-Hubble And Beyond Darwin
Dark Matter-Energy And Higgs Particle?
Energy-Mass Superposition
The Fractal Oneness Of The Universe
All Earth Life Creates and Maintains Genes
Dov Henis
(Comments from 22nd century)
http://profiles.yahoo.com/blog/2SF3CJJM5OU6T27OC4MFQSDYEU
Reply | Report Abuse | Link to thisThe perceived requirement for Dark Matter arose from the erroneous presumption of astronomers and others that the well proven standard method of determining the gravitational attraction between two discrete objects of mass would naturally and correctly apply directly to large scale aggregations of innumerable massive objects.
The critical distinction between these two disparate classes of mass configurations is in their characteristic spatial distributions. Discrete objects are most often spherical in form whereas larger scale aggregations of many discrete massive objects are more often non-spherical formations. By its definition, the equation describing gravitational attraction correctly applies only to point masses. The point mass construct can represent either an object separated from its attraction partner by a significant distance, relative to its spatial dimensions, or a nearer spherically symmetrical distribution of mass.
While the affects of gravitation are identical at all scales, the spherical formation of masses is much less frequent at very large scales. Correct and accurate determination of gravitational affects for relatively proximal non-spherical masses requires a much more complex procedure than simply solving a single equation. Dark Matter most simply provided the additional mass necessary to compensate for the resulting estimation error, allowing the standard attraction estimation method to be erroneously considered correct for all configurations of mass. As defined, its conveniently simple equation produces correct results only for sufficiently separated or spherically symmetrical distributions of mass.
Illuminating Dark Matter
Reply | Report Abuse | Link to thisThe perception of Dark Matter simply arose from the erroneous presumption of astronomers and others that the well proven standard method of determining the gravitational attraction between two discrete objects of mass would naturally and correctly apply directly to large scale aggregations of innumerable massive objects.
The critical distinction between these two disparate classes of mass configurations is their characteristic spatial distributions. Discrete objects are most often spherical in form whereas larger scale aggregations of many discrete massive objects are more often non-spherical formations. While the affects of gravitation tend to aggregate mass into its most efficient spherical formation, loosely bound large scale aggregations of massive objects are highly susceptible to permutational influences.
By its definition, the equation describing gravitational attraction correctly applies only to point masses. The point mass construct can represent either an object separated from its attraction partner by a significant distance, relative to its spatial dimensions, appearing as a point or a nearer spherically symmetrical distribution of mass. This restriction is too often ignored in practical applications, producing incorrect results. The planar disc formation of spiral galaxies is an extreme deviation from the required spherical distribution of mass.
While the affects of gravitation are identical at all scales, the spherical formation of masses is much less frequent at very large scales. Correct and accurate determination of gravitational affects for relatively proximal non-spherical masses requires a much more complex procedure than simply solving a single equation. Dark Matter most simply provided the additional mass necessary to compensate for the resulting estimation error, allowing the standard attraction estimation method to be erroneously considered correct for all configurations of mass. As defined, its conveniently simple equation produces correct results only for sufficiently separated or spherically symmetrical distributions of mass.
comment
Reply | Report Abuse | Link to thisProblems: (1) Why the universal expansion is accelerating, and (2) The anomalously high rotation speed of the galaxies.
Reply | Report Abuse | Link to thisI have a part qualitative, part quantitative idea for a cosmology that might explain both.
Consider that our entire universe is the inside of a gigantic black hole of the order of 14b light years diameter (measured in external coordinates.). Outside the event horizon, the Schwarzschild metric applies where dr has a + sign and dt has a -sign. Inside, the signs reverse. That means dr takes on the role of time and dt becomes a spatial coordinate - so I switch the notation for a start. Now do a transformation R=R(r,t), T=T(t,r) so that the new metric just has dT^2 alone in it, and you will see it is of the Robertson-Walker form with an bathtub-shaped expansion factor versus time. It starts at infinite expansion rate at the big bang, falls to a plateau, then rises again ultimately to infinity at finite T (the Big Rip). To fix the parameters of this curve, two measurements of the Hubble factor are needed at widely spaced epochs. Using around 100km/sec/megaparsec now and 50km/megaparsec much earlier, I get a curve that predicts where we are on it (i.e. the age of the universe) and also gives the diameter of the black hole and the total mass of the universe, which seems be close to other estimates.
How does this help with Galactic rotation?
Well, normally the Roberston-Walker metric arises when a uniform distribution of matter permeates space; but with this model, I get it in-vacuo, and it arises due to the influence of the mass at the central singularity. Now you have to understand that, due to the reversal of roles of r and t, the central singularity is not a place, but a time in the future - maybe about 10B years in our future.
To recap: A huge mass that is displaced 10B years in time to our future has the capability to affect what we observe now, and appears exactly as if there were a uniform distribution of (intangible) matter permeating our space in our time.
If this is our cosmology, what we need to do to predict the trajectory of stars rotating around galaxies is to revisit the calculation of orbits by computing a new version of the Schwarzschild metric with the constraints that:
(a) It's a spherically symmetric solution of Einsteins equation
(b) At infinity, it reduces, not to the Minkowski metric, but to the above "Roberston-Walker" metric.
If the geodesics of this new metric yield the obServed galactic rotations, Q.E.D.
Paul Dent
I agree with you about difficulties in computing gravitational effects for non-spherically-symmetric mass distributions. This was really glossed over and never mentioned in undergraduate physics, where it was stated that "mass at smaller radius than the orbiting body can be aggregated to a central point" and "mass at a larger radius has no effect". That begs a big question: Where are you measuign radius from?
Reply | Report Abuse | Link to thisHowever, the anomalous rotation speeds of the galaxies are much larger than any such error - we are talking about a factor of two or more.
Way to go man! See my explanation exactly along these lines!
Reply | Report Abuse | Link to thisThe Coney Island Green Theory is a relativistic based theory that explains Dark Matter, Dark Energy, quantifies a mass unit into a spatial quantity, brings physical meaning to E=mc2, combines the spacetime continuum with the mass-energy equation (MT=S), predicts Red Shift while solving Red Shift anomalies, combines gravity with the other forces, and offers a firm solution to the Horizon Problem (though the later is not in the theory, one can extrapolate the solution out of it, namely that the temperature homogeneity is self promulgated from the MT=S manifestation; the horizons do not have to talk to one another for there to be homogeneity). The initial postulate still remains "Believe it or Not"! The theory may be found by Googling, "The Coney Island Green Theory". Hopefully, there will soon be a web site dedicated exclusively to the Coney Island Green Theory. Researchers who are serious about Dark Matter are highly encouraged to understand this theory. Dark matter enthusiasts are encouraged to read the theory as well. Best of all, there is little to no math!
Reply | Report Abuse | Link to thisIn short, as regards Dark Matter specifically, the theory shows how matter manifests it self into becoming space as it approaches the speed of light (the quantification is in the theory). In accordance with relativity, at various speeds, there are various corresponding 'times". Where there is a different time there must be a different place. Where there is a different place, there is a different space. Where there are different spaces, there are different volumes. CIG theory attempts to explain the creation of new volumes of space created as the result of different times imparted onto the world universe; which, in turn, are a direct result of the diffrent rates of traveling massive particles. These rates are limited by "c", and are often simply a percentage of "c". The Michelson-Morley, Lorentz, Einstein work should appear apparent in CIG, at least to those that have a Wikipedia knowledge of them. It also appears justifiable that Bohr orbitals, Planck, and quantum theory have some common ground within CIG, especially where newly formed discrete orbits can now be considered new space, in accordance with MT=S. The accumulated new space adds up to an expanding Universe (historically, it was the Red Shift data that preceded the concept of expansion - then, following the expansion in reverse, to the concept of the Big Bang). Not only is CIG theory experimentally verifiable, it is believable. The space between the stars comes from the stars! See CIG Theory today!
You have to have pretty good estimates of the total 3D mass distribution of a galaxy in order to compute its rotation curve. It will be totally different for a spherical distribution compared to a discoidal distribution. Both give velocity curves curves that rise as root(r) (disc) or as r (sphere) for uniform matter density. A matter distribution that thins out towards the edge gives a flat curve. We have to have strong evidence that a galaxy thins out faster than this to predict a falling velocity curve. Therefore, unless we have really good estimates of the matter distribution, its hard to see why a flat velocity curve would be a surprise. I am looking for such data to test another theory.
Reply | Report Abuse | Link to thisIf we really have good enough data on the 3D mass distribution to predict a falling velocity curve, when in fact it is flat, then I am close to a candidate theory that explains both accelerating expansion and the galactic rotations. Indpendent estimates of the mass and size of the universe place it entirely within its own Schwarzchild radius. The implications, that we are in a Black Hole, have not been seriously recognized or discussed. The main implication is reversal of the roles of time and the radial dimension compared to the outside. The inexorable chute to the central singularity becomes the inexorable passage of time, while the exterior time dimension(s) become the interior space dimensions and are unbounded. The metric of the universe exhibits a bathtub-shaped curve of the Hubble factor. It starts at infinite expansion rate at the Big Bang, settles down to a plateau phase of around 70Km/sec/Mpc, then acceerates to inifinity again at the Big Rip, which is when we hit the central singularity. This metric is a Robertson-Walker type metric, which one normally associates with a matter-fluid-filled universe.
Reply | Report Abuse | Link to thisPlanetary and galactic orbits follow the geodesics of the spacetime. These are entirely determined by the metric. They will therefore be the same as if the universe really was filled with a perfect fluid (but it's not!). Where I am at right now is solving Einstein's equation to get the spherically-symmetric metric aroud a gravitating point partical in a universe filled with a perfect virtual fluid. Then I will compute orbital period versus radius, given an assumed galactic matter distribution.
Un contrast to Newtonian calculations, a uniformly distributed matter-fluid DOES affect orbits, so the assumption that "Dark Matter" has to be clumping around galaxies is not essential to obtain an effect on rotation curves.
So, my answer to "What is Dark Matter" looks like being: It's mass that's ahead of us in time on its chute to the central singularity, or already there, from where its exerts its influence to create the metric of an apparent fluid-filled universe. However, given that matter is not in our time, it's not surprising we don't interact with it.
I agree Dave... The math and science leads us to that conclusion.. I am not a smart man ,but I know sometimes the solution to things is a simple one.. They all agree that it started from a singularity...What if singularity's had a limit as to how much mass they could hold before exploding.. In doing so you have an outer shell of the explosion that still has pieces of the singularity in them flying out just ahead of our universe pulling on our universe as it fly's out from that massive explosion... Gamma ray bursts have perplexed many fine minds until math proved it can happen... Maybe a simple solution can do it again....
Reply | Report Abuse | Link to thisdark matter and the resultant NEED for dark energy are necessary to make the math work. perhaps the math is wrong, we have only recently figured out super massive black holes that basically are the heart of galaxies...gravitational forces at that level may simply not fit in the gravitational constant...beyond that the expansion theory again is predicated on we "our perceived universe" is all there is...how presumptuous, gravity may not behave as predicted because it is not bound by the constraints of the "known" universe and dark matter and energy may be great to make the math work inside this man-made boundary but what, as I believe this is but one of many universes resulting from the results of the "galaxies" of others creating singularities that eventually expand in one of an infinite number of big bangs all within the grasp of a shared gravity...of course this would require a lot of new equations and challenge the millions spend chasing whimps that could by their own definition, not be detectable?
Reply | Report Abuse | Link to thisI suggest a new theroy ..Gamma Ray burts surprised science for awhile.. I think they are in for another.. I think the initial explosion from our Universe was a more focused event similar to a gamma ray burst... I also think it was caused by a black hole that could not hold anymore matter .. Science throws out Dark matter as something because they can't understand the speeding up of the expansion... I would bet that the shell of the intial explosion "Black hole matter", was thrown out ahead of the universe and is pulling the universe with it and since it is composed of more than the univese itself ,it's only a matter of time before we catch up to it and dissapear once again..Till enough matter gets collected and another black hole cannot take the input and boom... A new Universe is created....
Reply | Report Abuse | Link to thisThe Coney Island Green Theory (CIG) is my best effort to explain Dark Matter. Interestly, as a single theory, it also explains Dark Energy at the same time. But wait, there's more. Add: Horizon Problem, Red Shift Anomalies, Red Shift, Expanding Universe, a Varying Cosmological Constant, Vacuum Energy, a Quantification of an atomic mass unit into a Spatial Quantity, Virtual Particles, and it combines the spacetime continuum with the mass energy equation. Lets not stop just yet. The theory is based on relativity and buils upon its concepts. It also explains the wave particle duality. Lets also discuss Youngs double slit, as follows:
Reply | Report Abuse | Link to thisCIG Theory allows for a three dimensional small particle such as an electron to become much more spatial. It does this as it travels at faster and faster rates. Without getting into too much detail, note that different "times" are imparted on particles traveling at different rates (realtivity - Einstein et al). Different "times" result in different spaces, different spaces mean different volumes. These new volumes allow a small particle to become much much more spatial. The percentage of the rate of the traveling massive particle dictates the percentage the mass manifests itself into: Dark Matter (for slower rates) to Dark Energy (at rate "c"). But, back to the grand-daddy of all experiments, the double slit:
The now spatial manifestation of the electron/photon/etc. can go through both slits. The current incorrect confusion suggests that the single particle be in "two places at once", which is impossible. Part of the particle, now spatial, goes through one slit, part through another, and the wave interferrence pattern appears on the back screen. When only one slit is open, the same spatial entity goes through the slit, but there is no other spayial wave that it interfers with, so the pattern is the single band we are so accustomed to.
In this manner, CIG not only explains Dark Matter and Dark Energy, and further combines the fundamentals (space, time, matter), but it removes the confusion of the double slit experiment.
CIG does not support non-locality of entanglement but does support the idea that everything is a manifestation of evrything else. The CUPI (should be Kewpie after my wife) represents that spatial quantity associated with one atonic mass unit. CIG offers the quantification based on loss of mass and the resultant gain of volume in the fusion process.
I sent CIG out for comment and attempted to publish to no avail. E-mail author at lippfamily@earthlink.net Douglas Lipp
Who FIRST thought up the idea of dark matter. I want to shake his hand
Reply | Report Abuse | Link to thisIm sorry, I want to shake HIS OR HER hand. Some of the smartest people in the world are women and we men should acgknolage this with dignity.
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