Through the force of gravity, dark matter sculpts the universe into a web of galaxies. Theorists now suspect that it may exert other forces as well. This image from the Millennium Simulation project in 2005 depicts a region roughly 1.6 billion light-years across.
Image: Courtesy of Volker Springel Max Planck Institute for Astrophysics and Heidelberg Institute for Theoretical Studies
In Brief
- Scientists have two independent reasons for thinking that the cosmos is filled with some unknown form of matter, dark matter. Not only do stars, galaxies and gas clouds move as if they are being tugged by the gravity of hidden material, but processes such as radioactivity present puzzles that can be solved by the existence of hitherto unknown particles.
- Dark matter is usually assumed to consist of WIMPs, a kind of particle that scarcely interacts with the visible world. Boringness is its sine qua non.
- Or at least that is the usual assumption. Might dark matter in fact have a rich inner life? Particle physicists striving to understand what makes up dark matter think it could interact through a full range of forces, including a form of light to which our eyes are totally blind.
On September 23, 1846, Johann Gottfried Galle, director of the Berlin Observatory, received a letter that would change the course of astronomical history. It came from a Frenchman, Urbain Le Verrier, who had been studying the motion of Uranus and concluded that its path could not be explained by the known gravitational forces acting on it. Le Verrier suggested the existence of a hitherto unobserved object whose gravitational pull was perturbing Uranus’s orbit in precisely the way required to account for the anomalous observations. Following Le Verrier’s directions, Galle went to his telescope that night and discovered the planet Neptune.
A similar drama—in which astronomers observe anomalous cosmic motions, deduce the presence of new matter and go out to hunt for it—is playing out again today in modern cosmology. In the role of Uranus, we see stars and galaxies moving in ways they should not; in the role of Neptune, we deduce the existence of hitherto unobserved substances, provisionally called dark matter and dark energy. From the types of anomalies we see, we can glean a few basic facts about them. Dark matter seems to be a sea of invisible particles that fills space unevenly; dark energy is spread out uniformly and acts as if it is woven into the fabric of space itself. Scientists have yet to repeat Galle’s accomplishment of pointing an instrument at the sky and glimpsing the unseen players definitively, but tantalizing inklings, such as blips in particle detectors, continue to accumulate.
This article was originally published with the title Dark Worlds.
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63 Comments
Add CommentDark Worlds is a fascinating article that raises several questions:
Reply | Report Abuse | Link to this1. What makes regular baryonic matter clump into disks-like galaxies while dark matter clumps spherically? Surely dark matter obeys the same laws of General Relativity, along with conservation of energy and angular momentum?
2. Since dark matter is 6 times more abundant than baryonic matter, how come those spherical halos have not collapsed into really super massive black holes?
3. Would there be any way of distinguishing a purely baryonic black hole with zero electric charge from a purely WIMPy black hole?
4. The article states that WIMPs where created with huge kinetic energies, then slowed down (i.e., losing their kinetic energy) while clumping into spheres (i.e., losing gravitational potential energy at the same time); where is the huge missing energy? If it has been radiated as "hidden photons" is there any way to check their gravitational impact?
Any insight would be appreciated.
Moshe Rozenblit
Q1. What makes regular baryonic matter clump into disks-like galaxies while dark matter clumps spherically? Surely dark matter obeys the same laws of General Relativity, along with conservation of energy and angular momentum?
Reply | Report Abuse | Link to thisA1. Regular baryonic matter can have physical interaction which converts kinematic energy into heat or light. Then moving directions change.
http://www.geocities.jp/imyfujita/galaxy/galaxy01.html
The image above "depicts a region roughly 1.6 billion light-years across." The observations upon which it is based represents light that was emitted over a period of 1.6 billion years, represented here as a contemporaneous spatial distribution of objects.
Reply | Report Abuse | Link to thisThese objects have never existed any moment as they are depicted here. No valid conclusions concerning large scale spatial relationships much less any expectations of gravitational effects can be drown from this temporally invalid spatial representation.
Only misperceptions can be drawn from this gross misrepresentation.
Undetected imaginary elements can always be useful in explaining misunderstood events and conditions.
Reply | Report Abuse | Link to thisIn the case of dark matter, during the 1970s Vera Rubin established through detailed observations that large spiral galaxies exhibit generally flat rotational velocities among stars throughout their galactic discs. She and others had expected that the orbital velocities of stars would diminish as distance from the galactic core increased, as in the Keplarian rotational curve derived from Kepler's laws of planetary motion.
This conflict, known as the Galaxy Rotation Problem, along with the failure to represent the gravitational effects of spiral galaxies in analytical models without their peripheral stars being expelled at high velocity, established the initial requirement for dark matter in the 1980s.
That Kepler's rotational curve, derived from observations of planets in the Solar system, represented only the characteristics of a highly centralized (98,8%) mass gravitational system, in contrast to the highly distributed mass of spiral galaxies was apparently not considered.
In any instance where the gravitational effects of a given distribution of mass is improperly estimated there will be a discrepancy with observed effects.
Applying the simple least-squares Law of Universal Gravitation equation to a complex distribution of mass misrepresents it as a centralized, spherically symmetrical distribution of mass; an invalid point-mass.
However, by now several generations of introductory physics students have learned all about dark matter in textbooks, literally thousand of papers have been published in scientific journals and careers have been devoted to its study. I probably just don't understand...
The studies of type Ia supernovae that concluded that universal expansion was accelerating (" Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant" , 1998, Riess, et al, http://arxiv.org/abs/astro-ph/9805201v1 ), determined that more accurate distance estimates based on SNe luminosity, for SN more than 5 billion light years away, greatly exceeded distance estimates derived from galactic redshifts using standard cosmological models.
Reply | Report Abuse | Link to thisHaving precisely determined that more distant galaxies are receding away from their observers at a greater rate than nearer galaxies, it was concluded by Riess et al. (1998) that the expansion of the universe is accelerating.
However, those more _ancient_ light emissions indicating greater rates of expansion reflect the expansion rate of the _earlier_ universe. I think those precise SNe observations actually confirmed the previously expected deceleration of the universe.
Since the luminosity of light emitted by most objects is variable, only for 'standard candles' such as Ia SNe that emit light of consistent peak luminosity can their light's observed luminosity be used to estimate the actual distance that light has traversed since emission.
In the cited report, observations of SNe estimated to be about 5Glya produced peak luminosity based distance estimates that were _consistent_ with the estimates of standard cosmological models based on the redshift of their galactic light.
However, in that report, observations of higher redshift SNe produced peak luminosity based distance estimates that were _much_greater_ than the estimates of standard cosmological models based on the redshift of their galactic light, at around 10Glya.
From this discrepancy it was determined that the light from more distant objects had been more greatly affected by the expansion of spacetime than nearer objects, thus the light from more distant objects were actually further away than their redshift indicated and 'were expanded away at a greater rate', indicating that the temporal rate of universal spacetime expansion was accelerating.
However, those 'more distant objects' are not contemporaneously observed objects: they are observations of photons emitted long ago into the very _early_universe_ that had been subjected to _increased_expansion_rates_.
The more _ancient_ light emissions, indicating that their light had traversed greater distances than more _recent_ light emissions, in relation to their redshifts, confirm the temporal _deceleration_ of universal expansion.
Decelerating Universe (continued)
Reply | Report Abuse | Link to thisIf I have misunderstood or misrepresented anything, _please_, anyone, explain my error. If not, the universe should be considered to be decelerating, as had been previously expected, consistent with the second law of thermodynamics.
You asked (Q3):
Reply | Report Abuse | Link to thisWould there be any way of distinguishing a purely baryonic black hole with zero electric charge from a purely WIMPy black hole?
I certainly can't answer your question, but as I understand there are some astrophysicists who consider that black holes contain no matter; that matter accelerated to extreme velocities falling into a black hole are materially disintegrated. In this scenario their residual component fundamental particles are ejected through the polar jets of active black holes, while their gravitational energy is integrated into the 'curved' (or radially contracted) spacetime of the black hole. This hypothesis avoids the issue of matter's spatial dimensional requirements being met by a singularity, or focal point of kinetic energy. In this case, I would expect that no matter what type matter contributes to the production of a black hole, its characteristics are consistent.
You asked (Q2):
Reply | Report Abuse | Link to this"Since dark matter is 6 times more abundant than baryonic matter, how come those spherical halos have not collapsed into really super massive black holes?"
Again, I cannot answer your excellent question but only raise another related question:
Since the spherical shell of dark matter presumedly encompassing spiral galaxies and containing most of their mass is gravitationally interacting with their normal matter, why isn't the galaxy's normal matter dispersed throughout the dark matter shell?
It seems the purpose of the dark matter shell is to validate the presumption that spiral galaxies can be represented as a single point-mass, which requires a spherically symmetrical distribution of mass.
Again, I suggest the presumed centralized mass gravitational model simply does not apply to spiral galaxies' complex distribution of self-gravitating mass.
Regarding the Bullet Cluster's proposed evidence for the existence of dark matter, why does not similar evidence of dark matter halos occur for other colliding galaxies? Even if the high velocity of the Bullet cluster's collision is unusual, if galaxies are contained by a massive halo of gravitationally interacting dark matter, wouldn't the normal matter of interacting galaxies be distorted by the encroachment of another galaxy's massive halo prior to the observed interactions among normal matter? This evidence seems to be missing.
Reply | Report Abuse | Link to thisDark matter and energy...still playing tennis without a net (or ball)!
Reply | Report Abuse | Link to thisRe: Dark Worlds
Reply | Report Abuse | Link to thisJonathan Feng and Mark Trodden have obviously spent a lot of time weaving their “Dark Matter” and “Dark Energy” hypothesis into a new age religion. All the possibilities presented here give not one concrete focus to their hypothesis. Just as in any religion we are asked to either ignore or remain ignorant to established theory. From metric tensors to recent M theory we are given a coherent direction to physical constraints in nature. The straw man presented as dark matter here does not make it any more real by placing an imaginary WIMP particle in its hand. Again, as in any religion increasing the number of believers does not strengthen the argument without proof. Any proof. I WANT to accept the postulate of dark energy as theory. I and many others still need something more substantial to grow on. I challenge the authors and any other scientist to proof their claims here in Scientific American. You have given us the grade school description; now give us the adult version.
S Runnels
Evergreen, Colorado
Am I the only one who believes that dark matter is among the strangest theory (competing with the inflationary Big Bang and dark energy) in cosmology? Here we have six universes of "matter" that no one can see despite all the resources of modern technology. Might it not be easier to adjust the laws of gravity rather than imagine six more invisible universes? (And we're not counting the mass-equivalent of dark energy.) This article takes science closer yet to science fiction as we are now to imagine phantom shadow worlds shimmering in the background of our perfectly normal daily lives. I tend to think that many of these theorists (including of course Stephen Hawking and his 10E500 universes) have lost sight of the logical priority of Occam's razor in scientific theorizing: we should be looking for simple theories, not complex ones. My own bet is that our observations will prove correct: dark matter really doesn't exist. There is another way to explain the missing mass problem.
Reply | Report Abuse | Link to thisNope - I agree. Perhaps my preceding comments didn't explain in terms that anyone can understand, but as a retired information systems analyst, I think I've identified the fundamental analytical errors that produced the observational discrepancies that seem to require the existence of imaginary dark elements.
Reply | Report Abuse | Link to thisThe motions of matter that do not seem to comply with those predicted by gravitational theories materialize when the well known gravitational characteristics of the Solar system (where 98.8% of all Solar system mass is contained within the Sun) are expected from complex widely distributed configurations of mass, such as large spiral galaxies. They seem just like the Solar system...
The error most commonly arises when applying Newton's inverse-square law of Universal Gravitation to large scale, complex distributions of massive objects. This law applies _only_ to two proper point-masses or (as established by Newton's Shell theorem) precisely spherically symmetrical distributions of mass, like (at sufficient distance) the Sun.
Not being a physicist, I find it impossible to explain in terms that physicists can accept, much less provide any mathematical proof. However, those so inclined may find a better explanation in the paper, "Newtonian mechanics & gravity fully model disk galaxy rotation curves without dark matter", Banhatti, 2008,
http://arxiv.org/abs/0806.1131
It would seem to me that if the original requirements for dark matter were invalidated, this Quixotic search could be abandoned. But then there's all those research papers published during the past forty years, and those careers spent researching Dark Matter...
Fritz Zwicky is the Father of Dark Matter and coined the term from the original German, Dunkle Materie. Jonathan Feng and Mark Trodden belabor the difficulty they and the entire scientific intelligentsia are having in discovering the secrets of Dark Matter and understanding its basic constitution. They fail, by design, to name the discoverer of Dark Matter. The brilliant mind of Fritz Zwicky is now lost to science and I believe only he would have unveiled the mystery of Dark Matter. Instead, he had to labor against hostility, professional incompetence, ignorance, rejection of the truth, suppression of his work and harassment by ignoramus of his time. The literary assaults continue commensurate with the failure of the scientific community. Despite the benefit of millions of dollars, the aid of supercomputers, and the support of world-renowned institutions, the failure of astronomers, astrophysicists, and cosmologists are visible for all the world to see while they continually fail to explain or even understand Dark Matter.
Reply | Report Abuse | Link to thisIn the interim, the Zwicky Family would appreciate a basic consideration and acknowledgment of the Father of Dark Matter in this and future discussions. Without Fritz, there would be no discussion at all and cosmologists would be blissfully unaware that they were missing 99% of the universe.
Barbarina Zwicky
Fritz Zwicky is the Father of Dark Matter and coined the term from the original German, Dunkle Materie. Jonathan Feng and Mark Trodden belabor the difficulty they and the entire scientific intelligentsia are having in discovering the secrets of Dark Matter and understanding its basic constitution. They fail, by design, to name the discoverer of Dark Matter. The brilliant mind of Fritz Zwicky is now lost to science and I believe only he would have unveiled the mystery of Dark Matter. Instead, he had to labor against hostility, professional incompetence, ignorance, rejection of the truth, suppression of his work and harassment by ignoramus of his time. The literary assaults continue commensurate with the failure of the scientific community. Despite the benefit of millions of dollars, the aid of supercomputers, and the support of world-renowned institutions, the failure of astronomers, astrophysicists, and cosmologists are visible for all the world to see while they continually fail to explain or even understand Dark Matter.
Reply | Report Abuse | Link to thisIn the interim, the Zwicky Family would appreciate a basic consideration and acknowledgment of the Father of Dark Matter in this and future discussions. Without Fritz, there would be no discussion at all and cosmologists would be blissfully unaware that they were missing 99% of the universe.
Barbarina Zwicky
I empathize the frustration Dr. Zwicky must have experienced, in this and other matters. Personally, I've been aware that Dr. Zwicky first identified an apparent gravitational discrepancy while studying the Coma cluster, suggesting that it may indicate the presence of missing mass. As I understand, Dr. Zwicky was unable to convince fellow scientists of the existence of dark matter.
Reply | Report Abuse | Link to thisHowever, the requirement for dark matter became widely established within the scientific community following Dr. Vera Rubin's many observations of spiral galaxies in the 1970s supporting the Galaxy Rotation Problem.
I find it personally difficult to address Dr. Zwiky's identified Coma cluster gravitational anomaly, as it was based on his estimations of the mass of the average galaxy within the cluster, analyzed using the virial theorem. I'm not capable of assessing Dr. Zwiky's sophisticated mathematical analysis.
Without knowing the specific events that occurred, perhaps Dr. Zwicky didn't consider his case for imaginary undetected mass to warrant further investigation.
I personally suspect that Dr. Zwicky's gravitational discrepancy was a product of the limitations of telescopic equipment. The Coma cluster contains mostly spiral galaxies which, when viewed with older equipment, the luminosity of the galactic discs was relatively low, since many stars are hidden within the dense, opaque molecular gas clouds within their spiral arms. Since mass estimates were based on luminosity, it would have been very difficult to correctly estimate the mass of spiral galaxies.
It is probably just me but I have great difficulty understanding why a topic like this is considered science. The whole concept of dark matter/energy is purely hypothetical and not based on a single measurement. But again, it's probably just me (being old-fashioned and stuff)... :)
Reply | Report Abuse | Link to thisCorrection - comment #4 paragraph 6 should state:
Reply | Report Abuse | Link to thisApplying the simple inverse-squares Law of Universal Gravitation equation to a complex distribution of mass misrepresents it as a centralized, spherically symmetrical distribution of mass; an invalid point-mass.
If the fundamental particles of an atom are much less than its overall mass and the rest is energy, so is the universe. I think the question is unless there is an outside source(like an effect of photon energy temporarily expanding the mass of an atom why the expansion continues (or emitting some energy somewhere outside so that it decelerates.
Reply | Report Abuse | Link to thisAs I understand, as spacetime expands its energy/matter is dispersed, diminishing thermal density. As a result, the expansion must decelerate.
Reply | Report Abuse | Link to thisAncient light from distant type Ia supernovae, emitted when the universe was about 4 billion years old, indicated greater expansion relative to its redshift than did light from nearer objects, emitted about 5 billion years ago when the universe was about 9 billion years old.
As a result, it was concluded that the inherent deceleration of spacetime expansion inexplicably changed to acceleration about 5 billion years ago.
The ancient light emissions of supernovae in distant galaxies indicate only that the expansion of the early universe was greater than the current expansion, indicating only that the universe continues to decelerate.
if we consider that the matter content (observable unit) of the universe is only 20% and the rest is unobservable dark energy, how do we know that it is expanding or decelerating? The observation that light from distant galaxies are moving faster than the ones nearer to us does not prove that the dark energy behaves accordingly.
Reply | Report Abuse | Link to thisIn around 10 on the posted comments I've tried to explain why reject the 'dark' assertions, so I can't fairly respond.
Reply | Report Abuse | Link to thisI am unable to accept your answer since you cannot simply reject natural forces by calling them imaginary. As in the case of gravity and electromagnetism some dimensions of natural reality is knowable only by their effects not by direct observation. So we still need an explanation.
Reply | Report Abuse | Link to thisE=MC2,which means mass is the light content of a particular object,since light is the only element that can act like a force (energy wave)and a particle (photon). However, as a particle it does not have any mass, so how come it becomes a matter (or what happens to the matter when the nucleus of plutonium blows up)?
Reply | Report Abuse | Link to thisMore than just labeling dark elements imaginary, I've attempted to explain how invalid interpretations of observational data produced the perceived effects that seem to require the presence of some undetected form of unidentified elements. Without direct evidence of their existence, the onus of proof is on those making extraordinary claims for the existence of undetected dark matter and dark energy.
Reply | Report Abuse | Link to thisWhy not object to specific issues I've raised with the methods used to analyze the observations that are thought to support dark elements?
Otherwise, continue futile attempts to explain the non-existent dark elements...
ok. you are saying that distant galaxies are moving faster than closer ones, therefore earlier acceleration is decelarating. however, this is based on the assumption that we are watching galaxies that have singular point of departure in time.
Reply | Report Abuse | Link to thisUnlike objects in our immediate environment that we observe in 'real' time, galaxies are so far away that it's more correct to consider that we detect their ancient light emissions rather than directly observe them. We must carefully analyze the characteristics of those detected photons to learn about the objects that emitted them.
Reply | Report Abuse | Link to thisFrom that perspective, we are detecting the most ancient light emissions from the most distant galaxies, representing the earliest conditions of the universe. Nearer galaxies more recently emitted their light, reflecting the conditions in effect more recently.
To modify your statement, we are not watching galaxies that have a singular point of departure time: we are detecting photons that were emitted throughout the history of the universe.
The more ancient photons were emitted from the more distant galaxies in the early universe. Their redshift indicates the conditions of the early universe, while the redshift of more recently emitted photons from nearer galaxies do not.
Since distant galaxies are further away than their redshift indicates, the expansion of the early universe exceeded more recent rates of expansion.
Stated yet another way:
Reply | Report Abuse | Link to thisAs it relates to the temporal variation in the expansion of spacetime, the spatial location or relative position or point of origin of any observed object is irrelevant. It is the period of the temporal history of the universe represented by the detected photons and their characteristic redshift indicating the effects of spacetime expansion imparted to it that are informative.
Initial studies observed that all of the light observed that indicated expansion exceeding the standard proportionality to redshift was emitted when the universe was less than about 4 billion years old. This clearly indicates only that the expansion of the universe has decelerated throughout its history.
Please let me know if these do not clarify - thanks.
thanks a lot for clarification. As I understood as in the case of dropping a rock in a still water the energy waves travel faster at the outside than inside the force field. therefore, earlier redshift corresponds to outside rim and later photons correspond to inside area. however, can we assume that outside acceleration has dropped by looking at nearer objects.
Reply | Report Abuse | Link to thismy real question is about the stuff that holds observable phenomena together. Is it fair to ignore it by calling that "thing" imaginary.
Reply | Report Abuse | Link to thisIt's just a matter of plotting expansion rate over time: as the universe has aged, the expansion rate indicated by light emission redshift has diminished.
Reply | Report Abuse | Link to thisWe have no data regarding the 'current' status of the spatial periphery of the observed universe, only its ancient status.
If you're referring to the effects of gravitation, they are very real. The issue is that astrophysicists have taken the gravitational characteristics of the centralized mass Solar system and applied them to all sorts of dispersed aggregations of massive objects.
Reply | Report Abuse | Link to thisTo say that gravitation generally acts as an attraction directed to the center of mass ignores the many other 'attractions' that exist in a distribution of massive objects. The reason spiral galaxies don't fly apart is that their peripheral stars are gravitationally bound to all of the other nearby massive stars, not just the central supermassive black hole that is up to 60,000 light years away.
Astronomers methods of gravitational evaluation tend to treat disperse aggregations of massive objects as a single object of mass - a point-mass; a centralized mass. In doing so, they are ignoring the local gravitational effects among dispersed objects of mass within the larger configuration.
As a result, they imagine that additional mass is necessary to produce observed effects - the unnecessary additional mass of the imagined dark matter. Please do not be upset by my calling it imaginary unless the procedural errors I refer to are nonexistent.
It's unfortunate that I cannot adequately prove my assertions, but they're more properly addressed in: "Newtonian mechanics & gravity fully model disk galaxy rotation curves without dark matter", Banhatti, 2008,
http://arxiv.org/abs/0806.1131
thank you for explaining. einstein's gravity model assumes that gravity distorts spatial fabric of the universe and causes temporal delays, ie. space and time interrelated. however, observations have yet failed to explain the material basis of the gravity. what is gravity that acts upon distant objects and through which medium?
Reply | Report Abuse | Link to thisI agree that the spacetime that is curved is not physically described in general relativity, except as an abstract system of dimensional coordinates. I don't accept that abstract dimensions produce the motions of objects: I think that some physical energy must be necessary, somewhat as Newton had imagined.
Reply | Report Abuse | Link to thisIt also occurs to me that spacetime is actually radially contracted by spherically symmetrical distributions of mass rather than curved; curvature instead best describes the trajectory of external objects of independently directed velocity interacting with gravitational fields of contracted spacetime.
I suspect that the classical description of the inverse-square law of Universal Gravitation with its imaginary attractive force actually describes the interaction of two external fields of contracted spacetime, representing the intersection of two external force vectors produced by two objects of mass.
IMO, the external field of contracted spacetime that is undefined by general relativity must be composed of some material or, as I suspect, some energy contained within all spacetime. I envision that the energy dispersal producing the intergalactic expansion of spacetime must be locally contracted by the mass of galaxies, producing a compression field of energy that is further locally contracted by objects of mass within the galactic field.
While these may seem conceptually reminiscent of dark energy and dark matter, I don't think, for the reasons described in prior comments, that the universe is accelerating or that additional mass is required to account for observed gravitational effects.
However, these are just my own imaginary conceptions of some the physical elements involved in the production of the gravitational effect. Then there is also the issue of quantum mass...
I think we have to present a physical model based on the mathematical formulation.
Reply | Report Abuse | Link to thisThen I propose a two-dimensionally localized gravity field.
http://www.geocities.jp/imyfujita/galaxy/galaxy01.html
I think that most agree with you regarding the requirement for a mathematical basis for a new theory. I can't fairly assess your your mathematics, but earlier attempts to represent galactic disks as two dimensional objects have been rejected as being non-physical.
Reply | Report Abuse | Link to thisHowever, I suggest that no new theory is required. One merely has to acknowledge the the inverse-square law of Universal Gravitation is valid only to determine the gravitational attraction between two point-masses, which according to Newton's Shell theorem, can apply to two objects of mass that can be considered to be spherically symmetrical distributions of mass. The inverse-square law directly applies only to a gravitational system dominated by a singular, central, spherically symmetrical object of mass with few sparse, effectively independent orbital bodies.
There is no proper theoretical basis I'm aware of for considering a large scale, diverse configuration of innumerable massive objects to be represented as a single point-mass. However, this invalid application of the inverse-square law of Universal Gravitation is commonly presumed to be valid, producing invalid results.
The fundamental difficulty is properly representing the gravitational effects produced by extremely complex diverse configurations of massive objects. While mathematicians and physicists may feel it is necessary to produce a simple, generalized analytical model that can predict the observed gravitational effects. Please refer to: "Newtonian mechanics & gravity fully model disk galaxy rotation curves without dark matter", Banhatti, 2008,
http://arxiv.org/abs/0806.1131
Please also see:
Reply | Report Abuse | Link to this"General Relativity Resolves Galactic Rotation Without Exotic Dark Matter",Cooperstock & Tieu,2005,
http://arxiv.org/abs/astro-ph/0507619v1
That representaiton was critically reviewed below:
"Singular disk of matter in the Cooperstock-Tieu galaxy model",Korzynski,2005,
http://arxiv.org/abs/astro-ph/0508377
spacetime contraction is a valid argument as experiments show that time passes quickly the closer you live to mass. I wonder what happens inside a blackhole (does time vector approache infinity while space become non-existent). I am not a mathematician therefore I cannot challenge your idea that combined gravital effects of galactical mass is enough to explain deceleration without dark mass (actually I am a lawyer and used to an idea that dark side affects what we see!).
Reply | Report Abuse | Link to thisAs an old, very large computer system technical fellow, I found that the very difficult problems that could not be solved by subject area experts often required an 'outside the box' perspective even if less knowledgeable. I understand that even expert testimony can be refuted in court.
Reply | Report Abuse | Link to thisI find it interesting that large scale mass estimates used in gravitational estimations are derived from apparent luminosity even though luminosity can be obscured by massive opaque (to visible light) molecular clouds, especially in disperse spiral galaxies. I don't know how the mass of molecular clouds are estimated, but they repeatedly give rise to many new stars, so must be massive themselves.
I have no firm basis for questioning astronomers' estimates of galactic mass, since I too am not a mathematician, but it and the represented distribution of mass are the critical factors in comparing observed gravitational effects and those estimated using 'standard methods' of gravitational estimation. That alone is the only indirect 'evidence' for dark matter, that the observed gravitational effects exceed the estimated effects.
In my experience, if this dark matter problem was preventing the enterprise of astrophysics from collecting revenues, I suspect it could be solved in a matter of days with complete cooperation and assistance of all.
Sorry if I seemed to dismiss your representation of a spiral galaxy disk. Actually, I think you have the correct understanding of the basic required characteristics, except that the two dimensional representations seems to be unacceptable to physicists. This is understandable in that the planar disk is obviously a three dimensional structure, but if it behaves as a two dimensional structure it must be effectively rigid at local scales on the y-axis.
Reply | Report Abuse | Link to thisThe primary objective of efforts to produce an analytical model of spiral galaxies has been to produce the observed flat rotational curve; consistent disk rotational velocity regardless of distance from the rotational axis.
If the galactic disk was truly a solid (effectively) two dimensional structure, the rotational velocity along its radii would increase with distance from the axis of rotation.
As I understand, models representing spiral arms as being generally linearly bound structures wound around the axis of rotation (with no additional action) eventually wind so tight that they are effectively solid structures. However, this appears to generally represent the actual structure of the spiral arms within the disk.
Its seems that locations within the disk nearest the axis of rotation must receive a gravitational force produced by some collective mass within the galactic 'bulge'. It also seems that this same force must be effectively rigidly applied along the disk radii to the periphery of the disk, which rotates at nearly the same velocity as the inner disk region.
Given the obviously wound linear structure of the spiral arms within the disk region, I suggest that these are simply wound around the galactic 'bulge' by rotation, but that some linear structural extensibility prevents their being so tightly wound as to for an effectively solid disk structure which would produce rotational velocities increasing with distance from the axis of rotation.
I agree with you that the structural composition of the spiral arms and thus the semi-wound disk is primarily the local gravitational binding among discrete objects of mass. These bindings' flexibility should be able to produce the linear centrifugal extensibility required of the of the spiral arms.
If these are the principal compositional factors (local linear bindings producing spiral arms, centrifugal extension of arms) producing the observed flat galactic rotational curves, they may be acceptably simplified for mathematical representation within analytical model. Unfortunately I'm not capable of producing such a model.
Dark matter may be the neo-ether of the 20th and 21st century. Have the well-funded and overly reputation conscious scientists been able to detect it in the laboratory after years of looking for it? There is a group in Germany who rather doubt the Dark Matter hypothesis (http://www.scilogs.eu/en/blog/the-dark-matter-crisis).
Reply | Report Abuse | Link to thisThis dark matter dithering has been going on too long. Its time we raise the question that is right in from of our nose but do not see: "Does mass mediate the gravitational force or does the heat emanating from mass mediate the gravitational force".
A heat-based gravity theory is not a modification of Newtonian gravity as General Relativity and MOND are but it is a theory that is totally divorced from this idea that mass is related to gravity. Fortunately and not unsurprisingly, the idea that "heat mediates gravity" can be tested. I have placed four different test masses between a 1000 W heat source and and a cold source (copper containers filled with ice) and have found a 1.9%, 8.9%, 9.6% and 16% increase in weight. I also have a theory where I go on and on about how heat or sunlight or starlight can mediate the gravitational force. Just because Newton decided 300 years ago that it was the mass of the sun that attracts the planets and not the 10^26 joules of heat leaving it every second, is no reason with the present crisis due to the flat rotation curves to keep on believing in this magical power of some yet-to-be-identified property of mass that can somehow either attract other mass or warp space. Its time we face the fact that there is a lot of dumb ideas about this long standing idea that mass mediates gravity. Look at my experiments, read my paper, see for yourself whether "spreading heat" is or is not a viable possibility for explaining how gravity works.
http://vixra.org/abs/0907.0018
how about the idea that inside a blackhole due to infinite time vector mass is dissolved into a planck size and created anew each moment, like a fountain of youth!
Reply | Report Abuse | Link to thisI'm just an information systems analyst, but there are some issues that come to mind reviewing your tests.
Reply | Report Abuse | Link to thisAs I understand, effectively all small bodies are accelerated at the same rate within the Earth's gravitational field, since the acceleration is the product of the gravitational effect of total mass, most of which is provided by the Earth.
It would seem that any possible increase in the gravitational effect produced by a small body would not significantly increase the total gravitational effect (small body force of acceleration), most of which must still be provided by the Earth's mass, thermal density or whatever.
I'm not a physicist, but I think your experiments must not be controlling some other critical factors.
I certainly agree with your assessment of dark matter. Please refer to my (amateur) essay, "Mass Distribution Characteristics Invalidate the Galaxy Rotation Problem", posted at:
http://sciencewithoutfiction.com/uploads/Mass_Distribution-_Galaxy_Rotation_Problem.pdf
It also occurs to me that if heat (thermal density) produced the gravitational effect, the established gravitational equations would not be effective using the same gravitational constant for both stars and planets. For example, I doubt they would be useful for determining the characteristics of both the Earth's orbit around the hot Sun and the moon's orbit around the relatively cold Earth.
Reply | Report Abuse | Link to thisI personally prefer simpler explanations - please refer to my comment #7 above for the conception of black hole mass I currently subscribe to.
Reply | Report Abuse | Link to thisDo you think it is possible that what we call dark energy is the residue of matter that was smashed into planck size during the big bang (like those inside a blackhole), therefore it has no spatial capacity but only gravitational effect that holds everything together. Universe is actually streching out because the greater gravitational energy of the outer rim of the universe is pulling us.
Reply | Report Abuse | Link to thisNo, I don't, since in comments 5, 6, 7, 20, 27 and 28 Ive tried to explain why the universe is actually not accelerating but rather continuing to decelerate.
Reply | Report Abuse | Link to thisAs I understand, the universe is expanding because an enormous amount of initial energy was not converted into matter. That residual energy release began the creation of and continued expansion of spacetime. As that energy is dispersed throughout expanding spacetime its density is diminished, reducing the rate of subsequent spacetime expansion.
IMO, whatever lies beyond the leading edge of expanding spacetime is outside the influence of our own discrete universe and its effects.
If some strange universe had an accelerating expanding external shell of dark matter producing a gravitational acceleration of its internal spacetime expansion, why wouldn't the proposed galactic dark matter shells produce the gravitational expansion of galaxies? IMO this reasoning leads down a rabbit hole.
jtdwyer said "It also occurs to me that if heat (thermal density) produced the gravitational effect, the established gravitational equations would not be effective using the same gravitational constant for both stars and planets."
Reply | Report Abuse | Link to thisBig G may explain gravitational phenomena found within the solar system but it does not explain gravitational phenomena found beyond the solar system. To keep the dogmas of astronomy before-the-satellites going, we must assume that 23% of the universe is composed of dark matter. [It has yet to be detected in the laboratory.] With the advent of Galileo's telescope we had to adopt whole new way of thinking about astronomy. We should then we expect with the advent of satellites and these new CCD telescopes a new way of thinking about cosmology and gravity.
The shape of galaxies are ideal for bending some of the light leaving its center and making that light fall in the outer reaches of the flat galaxy. Thus, the light in these regions tends to fall off as 1/r and not as 1/r^2. In my mind this 1/r fall-off of light in the outer regions of the galaxies is why we observe their flat rotation curves. But of course I have to assume that light (heat) is gravitationally attractive. My experiments show that light or heat is attractive. But you want to doubt my actual experiments and rely on your "thought" experiments and assume that they some how more valid.
I should point out the the luminosity from the sun (i.e its 10^26 Watts) falls off as 1/r^2 just the force of gravity that is thought to emanate from some yet-to-be-described property of the mass of the sun. Because of this inverse square fall-off of luminosity and this inverse square fall-off the gravitational force, we have a problem. We do not know whether it is the sun's mass or its luminosity that is doing the attracting of the planets. How can we keep on funding these dark matter studies unless we first address this fundamental question which should have been addressed 300 years ago when Newton first proposed this idea that mass mediates the gravitational force.
I hope you have heard of the Tully-Fisher relation which states that the luminosity of a galaxy is directly proportional to the highest orbital velocity raised to the fourth power (L = k*V^4). We do not know whether it is the light of a galaxy or its mass that is doing the attracting of its outer parts. More Under-the-table-top experiments like mine should be done in order to address this glaring, centuries-old, never-raised "mass or luminosity" question.
Thanks for your consideration, but back to your experiments, I don't see how heating the extremely trivial contributor to the gravitational effect between it and the extremely large Earth could make a measurable change in the actual gravitational effect meditated between the two.
Reply | Report Abuse | Link to thisSurely you agree that the Earth contributes nearly all of whatever energy produced the effect of gravitation, correct? Thanks.
By the way, I certainly want to commend you on your very detailed experiments and very nice, professional paper.
Reply | Report Abuse | Link to thisWell done!
Peter, you wrote "We do not know whether it is the sun's mass or its luminosity that is doing the attracting of the planets". Certainly it's mass. The moon orbits the Earth according to the exact same inverse square law, and the Earth has no luminosity (other than a little reflection of sunlight on the dayside). Are you really suggesting that scientists are not sure it it's Sun's mass or luminosity that's responsible for gravitation? If anything, the photons emitted from the Sun (as well as the particles forming the solar wind), produce a repulsive force.
Reply | Report Abuse | Link to thisScientists or anybody else cannot see infrared radiation. A new moon is not easily detected with a naked eye. I have experiments which show that 1000 W of infrared radiation is gravitationally attractive. I have observed a 1.9%, 8.9%, 9.6% and a 16% increase in weight of my test masses. Infrared radiation and radiation in general, just like the gravitational force, varies inversely as the square of the distance from the source. You ask, "Are you really suggesting that scientists are not sure if it's Sun's mass or luminosity that's responsible for gravitation?" They only know of the radiation pressure studies which tend to be done with collimated beams of light or lasers. They have not studied in detail, as I have, as to whether or not spreading radiation is attractive or repulsive. They are smugly sure, as apparently you are, that the mass of sun attracts the planets because they, like Newton and everyone since him, have never seriously asked the important and vital question: Is it the sun's MASS or its HEAT that is doing the attracting of the planets? Infrared radiation excites the vibratory modes of a molecules, if an infrared-produced gravitational force aligns the vibratory modes of molecules in a collection of molecules, we have a simple and visualizable explanation for how the relatively weak gravitational force works. See http://vixra.org/abs/0907.0018 for more detail.
Reply | Report Abuse | Link to thisWhat would you prefer: A gravitational theory based on spreading infrared radiation or a highly-mathematical, mind-boggling, gravitational theory based on non-Euclidean geometry where mass has a mysterious ability to warp space and which needs two entities that comprise 95% that to date have not been detected in the laboratory despite millions of dollars and years of effort expended?
Hi Peter
Reply | Report Abuse | Link to thisI mean no offense, but I just don't agree with your heat gravitation theory. Your 1000 W experiments sound very interesting, although to be honest I seriously doubt the results. Such an effect would have been discovered ages ago, and could not have escaped thousands of scientists for centuries. However, if you can persuade other scientists to repeat and confirm your experiments, then it's obviously a different matter. Have you thought about getting the results published and peer reviewed?
Concerning the Sun's gravitational force: I don't believe photons - no matter what their wavelengths and/or beam topology - have any gravitational effect. Simply compare for example the Sun, Earth and Jupiter and the gravitational pull on their respective satellites, and you will find that they all obey the GMm/r^2 law. So other properties, such as photon emission has no effect on gravity.
If photons produced gravity, space probes based on solar sails would not work, contrary to what experiments show (the Planetary Society will soon launch such a probe, btw). I'm of course aware that heat increases mass because higher temperatures means higher kinetic energies, which again cause an increase in particle masses (according to the special theory of relativity). But you need relativistic speeds in order to notice any considerable mass increase.
Concerning the dark matter/energy theory: I agree it is currently entirely unsubstantiated, and there seems no hope of experimental verification any time soon. At best it is a hypothesis rather than a theory, so I'm definitely not a believer. Still, science is all about trying to explain nature, proposing new ideas (and having some of them shot down!). The problem with dark matter/energy is imho not that scientists have suggested this, but that it has been elevated to status of a confirmed theory.
Hi olebole
Reply | Report Abuse | Link to thisThe gravitational heat effect that I have observed with my experiments is elusive. Without a cold source for the heat to flow into the effect is difficult to produce and repeat.
With the Caloric theory it was thought that heat did have weight. This theory had a long life. Count Rumford did a series of studies that finally killed the heat=weight theory. In those studies he did not sandwich the test mass between a hot source and a cold sink as I have done in four of the five experiments.
The Nobel laureate Marice Allais found a diurnal variation in the earth's surface gravity. Do you think our esteemed scientific commumity has made an effort to repeat his study. Instead they have spent a considerable amount of resources studying the "Allais effect" where Allais found a "weight change" during a solar eclipse which occurs far more rarely than when the earth rotates on its axis. This diurnal variation in g is critical for my theory. Just a slight variation in the surface gravity is needed to effect a pressure difference of 10^22 Newtons between earth's dayside and nightside solid hemispheres that would be needed to account for earth's 0.006 m/s^2 centripetal acceleration around the sun.
There is the Tully-Fisher relation where the total luminosity of a galaxy is directly related to its highest orbital velocity (L=k*V^4). Astronomers know of this relation but do they ever think that this relation a direct indication that light (heat) is gravitationally attractive? No they use mass-to-light ratios to come up with a baryonic Tully-Fisher relation and go on confidently thinking that it is the mass of a galaxy that keeps it gravitationally bound.
I hope you are aware that there is high correlation between a mass of a star and its luminosity. Hence astronomers routinely use mass-to-light ratios to determine the mass of a star by observing its luminosity. They do this with galaxies also. The mass of a galaxy is determined by its light output. So when they study the gravitational effects of a galaxy. They do not know whether it is a galaxy's mass or it luminosity that is causing the gravitational phenomena. I have tried to get my paper published. But our esteemed scientists are just like you: they doubt my experimental results. There are plenty of good logical and theoretical reasons why we should think of light (=heat) as gravitationally attractive. In my mind there are not many good reasons why mass is attractive. Like: What exactly is the property of mass that is doing the attracting or warping of space?
I agree that there is some unidentified physical entity producing/mediating the effect of gravitation; that an imaginary attractive force or a system of imaginary spacetime coordinates can be effectively employed to describe aspects of the effects of gravitation, but not its physical causation.
Reply | Report Abuse | Link to thisHowever, I think that the effect of gravitation, even if it was a product of thermal density, would be proportionally produced by the Earth for small objects on its surface; that heating a small object could not change the majority of gravitational effect provided by the Earth: increasing the gravitational effect provided by a small object would not produce any measurable effect produced by the small object and the Earth.
From a sufficient distance, a coin is accelerated towards the Earth's surface at the same velocity as a bowling ball because their masses are insignificant in relation to the mass of the Earth. The Earth's mass produces essentially all of the gravitational effects observed near its surface.
So why would light or heat produce attraction? Why do cold moons orbit cold planets in accordance with established methods of estimating gravitational effects?
Reply | Report Abuse | Link to thisIt's unfortunate that no remotely detectable surrogate for object mass exists other than luminosity, since there are plenty of massive molecular gas clouds that spawn many stars without depletion. Not only is their galactic mass not included in luminosity based estimations of galactic mass, but in many cases the obscure many stars whose mass is also not included in estimations of galactic mass.
I suggest that you evaluate how the heat expansion of your copper ball might affect your measurement device.
jtdwyer: You are obfuscating my 30-year effort to make the physics of gravity a physics that is more close-to experience than this surrealistic, non-Euclidean, multidimensional world we presently live in where all physical phenomena is couched in a space-time warp. My experimental results offer this hope. In addition we have a chance to stop this multi-million dollar search for dark matter and dark energy that have such similarities to the ether concept. However this hope depends on whether or not "spreading heat" is gravitationally attractive. My experiments give some decent credence to this possibility. Special Relativity killed the search for the ether. MOND which is only a modification of Newtonian gravity--as is General Relativity--can only hope to "kill" the dark matter search. My heat-based gravity theory which is a replacement of a Newtonian mass-based gravity theory has the potential to stop both the hectic hunt for the dark matter and dark energy. A heat-based gravity theory holds out a lot of promise. A mass-based theory, which may in part rest on the high correlation between a star's light and its mass, does seem to be going any where. Or not anywhere other than where the 1500 year old earth-centered Ptolemaic theory, which was based on the earth rotating on its axis every 24 hours, went.
Reply | Report Abuse | Link to thisI'm really sorry. There definitely is a correlation between mass and luminosity/heat for stars, as the mass of stars is their source of energy used to gravitationally produce luminosity/heat through its fusion.
Reply | Report Abuse | Link to thisThat there seems to be no significant EM radiation emitted by still fairly massive planets, especially in relation to their observed gravitational effects, seems to mitigate against a luminosity/heat hypothesis for the causation of the gravitational effect.
Personally, I favor the idea that kinetic energy was released during the initiation of the universe producing the one and only continuing, diminishing, production/expansion of spacetime. While this fundamental energy (as does all energy) disperses in space, the potential energy of mass locally contracts this kinetic energy of spacetime just as linear momentum linearly contracts the kinetic energy of spacetime. You may see this as conceptually identical to ether, I don't know. I'm still thinking about it.
IMO, an external kinetic energy source pushing smaller objects towards massive objects could be effectively described as an attractive force. External fields of kinetic energy (for spherically symmetrical objects of mass) directed to singular focal point encompassing massive objects could, for the intersection of two opposingly directed force vectors, produce a net attraction effect as described by Newton.
IMO the interaction of the external kinetic energy fields of (spherically symmetrical) material objects and their independent relative velocity could produce the curvature affect applied to their relative motions as described by general relativity.
It would seem that a heat based gravitational effect would cause a heated barbell to weigh more than a cold barbell. I don't find any empirical evidence of that effect, while there is plenty of evidence that weight increases proportional to increasing mass, by adding weights to a scale, for example.
After forty years, I think only the simple truth simply explained has a chance of clearing up the dark matter debacle. I'm afraid that the correct solution does not lie in the relationship between stellar mass, heat and luminosity. However, I think you have done a really good job of explaining and illustrating that idea!
Now that the dust is settled, let me summarize:
Reply | Report Abuse | Link to this1. Newton's gravity is the real cake. Einstein's gravity is the icing on the cake and
MOND gravity is the missing part of the cake.
2. As for the Heat gravity theory:
Mass and momentum of mass is kinetic energy. Kinetic energy of matter is what
constitutes heat. Kinetic energy and therefore heat has no relation with gravity.
3. Einstein's geometric space and gravity explanation is very much the reality, but
is a little incomplete because it does not explain for how mass is coupled with space.
4. MOND is basically correct but empirical without an underlying basis.
5. I give a realistic natural reason for gravity and MOND at my web.
Tissa Perera
ktperera: Nice summary, except that I don't agree that Modified Newtonian dynamics (MOND) is necessary, since I assert that the Galaxy Rotation Problem it was intended to address is merely a misconception and does not describe a real problem. The only problem identified by the GRP is that galaxies' highly distibuted mass does not produce the same gravitational effects (based on required inverse-square solution for all actual point-masses) as the highly centralized mass of the Solar system.
Reply | Report Abuse | Link to thisFor a better scientific description than I can present, please see: "Newtonian mechanics & gravity fully model disk galaxy rotation curves without dark matter"
http://arxiv.org/abs/0806.1131
The Nature of dark matter is that it is due to extreme gravity. The reason why dark matter is detected at the centres of galaxies is quite straight forward. It is because that is where a supermassive black hole lurks, and that is the scource of the extreme gravity.
Reply | Report Abuse | Link to thisThese observations have already been published. Essentially the extreme gravity causes an increase in the apparent gravity close to the black hole over and above that normally measured from a distance.
The prediction is that that increase in gravity reaches a factor of exactly 6.25 at the Shwarschild radius
References available online
1.An advanced dynamic adaptation of Newtonian equations of gravity. Physics Essays 21: 222-228.
http://dx.doi.org/10.4006/1.3027501
2. String quintessence and the formulation of advanced quantum gravity. Physics Essays 22: 364-377. http://dx.doi.org/10.4006/1.3182733
P.S. Physics Essays offers free membership for a year- so you be able to get to read the articles for free
I think one should start speaking of hidden mass instead of dark matter,since gravitational mass and inertial mass equivalence is revealed experimentally and quantum mechanically to breakdown under conditions of charged particles and their motion in strong electromagnetic fields. A part of the gravitational mass is now attributable to charge coupling in strong electromagnetic fields interacting with charged particles.This is so because a fraction of energy density is predicted to be captured from the field to form a gravitational mass density,when a charged particle enters a region of strong electromagnetism,from a region of no mass. similarly a charged particle will appear to lose a part of its gravitational mass as it emerges from a strong field to a no field region. As a result there is an hidden mass potential in strong electromagnetic fields for low mass charged particles ,because of assumptions like equivalence of gravitational and inertial mass ,which is the base for newtonian and relativistic physics.Newton`s second law includes proportionality of inertial and gravitational masses which underlie all determinations of dynamical mass within galaxies and galaxy systems. Dynamical masses determined on the basis of above relation are overestimated in terms of gravitational mass due to breakdown of the NEWTONIAN law,as above.
Reply | Report Abuse | Link to thisUnder conditions of the effects of strong electromagnetic fields on charged particles the above law no longer describes the motion of low mass charged objects since the inertia term is rendered not proportional to acceleration. When a part of the charged particle`s field exists as gravitational mass ,as shown to be the case in strong electromagnetic fields,this causes discrepancies in gravitational mass from being equal to inertial mass,since the former is now larger than the latter.On a rough estimate about 50 percent of energy density is derived in universe from strong electromagnetic fields,and the discrepancies due to mass divergences can be as high as 100-150 percent which implies that the hidden mass potential can be 4-6 times the baryonic mass densities. this also tallies with the current estimates for dark matter in universe.
Similarly dark energy can also be derived from ZERO POTENTIAL FIELD of electromagnetic spectrum ,as per published literature. presence of a temporal electromagnetic field on a cosmological scale generates an effective cosmological constant.In quantum scales Cscimir force has repulsive gravity,and is derived from ZPF.
SURESHKUMAR.S,SCIENTIST,ADVISER,NIIST,CSIR,INDIA
The problem with scientific american, as most of my Physics professors remarked, is that they do not focus on contemporary physics, nor do they publish things that simply reaffirm the well-accepted theories of astrophysics. Editors insist on sensationalizing physics, and make the ideas sound far more tantalizing and provocative than they actually are. The world of physics moves much slower than scientific american would like it to. The Higgs boson was 'discovered' long before scientists were willing to say they had enough data to confirm that they had found it at the LHC (Large Hadron Collider). I do not know much about dark matter, but the fact is that there is still much data to be collected before a grandiose restructuring of astrophysics can be made. I have read scientific american for years, but when I started studying physics (it was my major after all) I realized that much of the content is conceptual, theoretical formulations with nothing more than a scintilla of evidence to substantiate the claims. I think it is thought provoking, and insightful, but as far as contemporary physics goes, read Physics today or something - read Scientific American if you want a look at the creativity of theoretical physicists. I am not saying this isn't correct, but you should not infer anything from broad statements like "This work hints that the WIMP is just the tip of the iceberg. Lurking under the surface could be hidden worlds, complete with their own matter particles and forces." These sort of banal, overly broad statements are simply restating the obvious: there are things that physicists cannot explain. The great thing about science is that the more we know, the more we learn there is to know. To infer anything beyond that is to be presumptuous and naively optimistic.
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