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About LinkBacksI'm no expert in physics, I'm actually just applying for university. But I was reading an article about the speed of light and nothing can exceed it. I was wondering, could dark energy be responsible for this?
November 24th, 2012, 07:56 PM
I'm no expert in physics, I'm actually just applying for university. But I was reading an article about the speed of light and nothing can exceed it. I was wondering, could dark energy be responsible for this?
Dark Energy refers to the expansion of the Universe; It's a hypothetical 'force' to balance the equation. To account for the accelerating expansion that we observe, until we have a more accurate working theory to explain it.
It's not related to c as a constant.
So basically we have no idea until we have some form of theory about dark energy?
Pretty much.... sucks, doesn't it?Originally Posted by marctowse
Dark energy - Wikipedia, the free encyclopedia
Yeah, but it's fascinating at the same time.
Very true, it's why we're all here.
Yes, it's a hypthetical force to balance the equations, as Neverfly explained. Maybe It's just a placeholder to explain observations until a better explanation comes along later. If so then its "discoverers" could count their lucky stars for the Million dollars, plus or minus, that went along with the Nobel Prize for its supposed discoveryIt's a hypothetical 'force' to balance the equation.
The universe is a strange place!
Maybe it's far simpler than present interpretations and theory might seem to indicate.
Or maybe it is even more complicated and strange than we can every imagine. Which would be way cooler.
If the universe is much simpler then we presently think then maybe in the not too distant future we may be able to do cool stuff, maybe something like star-trek, terraforming of extra-solar planets, etc.. But if it is complicated with dark energy, warped space, curved space, expanding space, extra dimensions, worm holes, multiverses,etc., then I don't expect anything much to happen in my lifetime. I would bet a case of beer on the former.
I don't see it that stranger is cooler concerning the universe, maybe a strange wild woman?
einstein_suresh_emre2.jpgIsn't that expanding force repulsive gravity. From what I know about Einstein theories say that you can have both types of gravities in the universe.
If it is a placeholder, would it remain a place holder?Yes, it's a hypthetical force to balance the equations, as Neverfly explained. Maybe It's just a placeholder to explain observations until a better explanation comes along later. If so then its "discoverers" could count their lucky stars for the Million dollars, plus or minus, that went along with the Nobel Prize for its supposed discoveryIt's a hypothetical 'force' to balance the equation.
If it does get more complicated it would mean schooling on Cosmology and other fields will also get more complicated.
No, it would only be a placeholder until we discover why we thought it existed in the first place, and if what we call dark energy now can properly be explained by a different explanation. Once we realized the problem we probably could correct it and properly identify dark energy as either being something different than we presently think, or just a misinterpretation or miscalculation of data -- which is my opinion based upon my related studies.If it is a placeholder, would it remain a place holder?Yes, it's a hypothetical force to balance the equations, as Neverfly explained. Maybe It's just a placeholder to explain observations until a better explanation comes along. If so then its "discoverers" could count their lucky stars for the Million dollars, plus or minus, that went along with the Nobel Prize for its supposed discoveryIt's a hypothetical 'force' to balance the equation.
Last edited by forrest noble; December 1st, 2012 at 11:33 PM.
...then we would have figured it out long ago.If the universe is much simpler then we presently think
I wonder if Dark Energy may not be an expression of Universal Potential.
IMO, the BB was preceeded by a single instant of Universal Potential compressed into a singularity. What if dark energy is the remnant of the BB of Potentials which did not become expressed in reality, but continues to expand as latent energy.
I disagree
Last edited by forrest noble; December 2nd, 2012 at 03:56 PM.
What is "Universal Potential"?I wonder if Dark Energy may not be an expression of Universal Potential.
IMO, the BB was preceeded by a single instant of Universal Potential compressed into a singularity. What if dark energy is the remnant of the BB of Potentials which did not become expressed in reality, but continues to expand as latent energy.
I expect he means that a beginning BB entity would have necessarily had to have the potential energy within it to create the universe as we now observe it.What is "Universal Potential"?I wonder if Dark Energy may not be an expression of Universal Potential.
IMO, the BB was preceeded by a single instant of Universal Potential compressed into a singularity. What if dark energy is the remnant of the BB of Potentials which did not become expressed in reality, but continues to expand as latent energy.
some kind of cosmological values that write4u is working on' i will advice him not to write things that don't exist.What is "Universal Potential"?I wonder if Dark Energy may not be an expression of Universal Potential.IMO, the BB was preceeded by a single instant of Universal Potential compressed into a singularity. What if dark energy is the remnant of the BB of Potentials which did not become expressed in reality, but continues to expand as latent energy.
Exactly,I expect he means that a beginning BB entity would have necessarily had to have the potential energy within it to create the universe as we now observe it.What is "Universal Potential"?I wonder if Dark Energy may not be an expression of Universal Potential.
IMO, the BB was preceeded by a single instant of Universal Potential compressed into a singularity. What if dark energy is the remnant of the BB of Potentials which did not become expressed in reality, but continues to expand as latent energy.
Moreover, not all this potential was physically expressed (yet) and continues to expand as a latent excellence.
I am a fan of David Bohm.
Lifework of quantum physicist David Bohm by Will Keepin
Bohm postulates that this Implicate order stems from a universal condition of "pure potential".Fullness Of Empty Space
Bohm's understanding of physical reality turns the commonplace notion of "empty space" completely on its head. For Bohm, space is not some giant vacuum through which matter moves; space is every bit as real as the matter that moves through it. Space and matter are intimately interconnected. Indeed, calculations of the quantity known as the zero-point energy suggest that a single cubic centimetre of empty space contains more energy than all of the matter in the known universe! From this result, Bohm (1980, 191) concludes that "space, which has so much energy, is full rather than empty." For Bohm, this enormous energy inherent in "empty" space can be viewed as theoretical evidence for the existence of a vast, yet hidden realm such as the implicate order.
what really do you mean by potentials? The one my dictionary tells me,or the write4u definition?Exactly,Moreover, not all this potential was physically expressed (yet) and continues to expand as a latent excellence.I am a fan of David Bohm. Lifework of quantum physicist David Bohm by Will KeepinI expect he means that a beginning BB entity would have necessarily had to have the potential energy within it to create the universe as we now observe it.What is "Universal Potential"?I wonder if Dark Energy may not be an expression of Universal Potential.IMO, the BB was preceeded by a single instant of Universal Potential compressed into a singularity. What if dark energy is the remnant of the BB of Potentials which did not become expressed in reality, but continues to expand as latent energy.
That would be really true. It probably isnt that complicated, the things that happen and why is complicated.
Be latently excellent to one another.
Firguring it out: maybe! Our evolve theories and intellingence was fueled by complex universe.
Firguring out: maybe. Our evolved theories and intelligence are base on the fact that the universe was complex...we cannot solve a problem with thesame level of thinking that created them--Albert einstein...if the universe were simpler our thinkings would be simpler...it still would appear complex by then.
A man never realize how strong he is! Before somethingelse makes him discover his inner strength.
I would urge you to really study the word "potential" and its implications as well as expressions.merumario,
What really do you mean by potentials? The one my dictionary tells me,or the write4u definition?
It is a word we use very casually and we kinda "know" what it means. I found the word potential to be one of the most profound and fundamentally pertinent symbols in human language.
btw. the reason why you will find the word everywhere is because it has universal utility and is applicable at all levels. It is the single common denominator in the universe. All things (past/present/future) (were/are/will be) preceeded by Potential.
Last edited by Write4U; December 2nd, 2012 at 04:05 PM.
I agree
Doesn't sound much like physics, though.
That is true, somewhere the concept of potential crosses from physical into meta-physical. It is the moment of the Implicate becoming Explicate in reality.Doesn't sound much like physics, though.
But considering the current great interest in String theory, I believe the term is very much appropriate at Planck scale, where apparently Dark Energy dwells.
and what would be the potential of the universe write4u? what implication thoes it make? in meta-physics or reality?......make a statement of formalism with respect to the universe and its intrinsic properties.
I'm sorry, I do not have the formal knowledge of physics to formulate a proposition. But intuitively I feel comfortable with the following.
One of the most impressive theories emerging out of scientific cosmology respecting these ancient truths was set forth by the late physicist, David Bohm in his book, Wholeness and the Implicate Order. Using the language of mathematics, Bohm set out to describe the transcendent reality and its graded energetic hierarchy in four basic states or orders of energy beginning with the physical world, which he called the Explicate Order.
'The Explicate Order, weakest of all energy systems, resonates out of and is an expression of an infinitely more powerful order of energy called the Implicate order. It is the precursor of the Explicate, the dreamlike vision or the ideal presentation of that which is to become manifest as a physical object. The Implicate order implies within it all physical universes. However, it resonates from an energy field which is yet greater, the realm of pure potential. It is pure potential because nothing is implied within it; implications form in the implicate order and then express themselves in the explicate order. Bohm goes on to postulate a final state of infinite [zero point] energy which he calls the realm of insight intelligence. The creative process springs from this realm. Energy is generated there, gathers its pure potential, and implies within its eventual expression as the explicate order.' Will Keepin, David Bohm, Noetic Science Journal.When Bohm's resonant fields are arranged in a vibrational hierarchy they represent energy in successive states of manifestation from infinitely subtle to the gross physical reality
The Quantum Brahman by Robert Wilkinson
The point is that regardless of what it is we call dark matter or dark energy, it was, is, and will be preceeded by potential.
David bohm was a wonderful physicist. I thought he took same side with me in the quantum mind-body problem.
you mean potential of the universe! Its possible to be,but not yet actual.
The universe can be considered complicated, where complicated would mean many details involved with its contents. But, I think, it is relatively easy to understand concerning the entities involved to explain the parts and mechanisms of its details. Of course to be "simple," such details and mechanisms would need to be far simpler and different from present theory.That would be really true. It probably isnt that complicated, the things that happen and why is complicated.
Last edited by forrest noble; December 2nd, 2012 at 06:05 PM.
Yep, the Implicate which may become reality.you mean potential of the universe! Its possible to be,but not yet actual.
There is a difference between dark energy and dark matter. Dark matter is believed to be the infamous neutrino. Which is simplest terms is a particle with no charge and has very little interaction with any matter. They are everywhere. It is also believed that this could also be involved when light bent through space. While dark energy is the rest of space that we have no clue about.
Well it depends on how you look at it. If you think about a set of ideas; it's complicated. If think about another set of ideas; it's simple.
There are no neutrino proposals for dark matter that I know of. Instead they believe dark matter involves neutral, uncharged and unknown particles.There is a difference between dark energy and dark matter. Dark matter is believed to be the infamous neutrino.
Yes, dark matter is a hypothetical particle and dark energy is a hypothetical force.Which is simplest terms is a particle with no charge and has very little interaction with any matter. They are everywhere. It is also believed that this could also be involved when light bent through space. While dark energy is the rest of space that we have no clue about.
Keep your heads up and your eyes fixed.
Black holes suck energy/matter from this dimension then regurgitate, in the form of dark matter/energy. The universe is accelerating in expansion, but will not continue to. Implosion will eventually bring about the eternal pulse of existance.
Succinct and wrong.
Wrong?, what's your take on it, oh learned one?
Black holes do not produce dark energy, there's no reason or indication that accelerating expansion is going slow down and your last sense is meaningless woo.
Do you honestly think that science is just whatever you make up? If so, aren't you amazed your computer works at all?
Black holes do produce dark energy. Via extra dimentia, the energy is reintroduced. The great expansion will abate because the fuel
will expire, thus starving dark energy/matter driving acceleration.
Please stop posting crank nonsense in the physics threads. We have a trash subfourm for you to use.
Evidence?
Neverfly, thats a really macho image you choose to represent yourself by footsoldier.
Do you have anything to say on this thread, or are you going to carry on with your continually, unimaginative, banal, vacuous posts?.
Yeah ok- Evidence to support your claims?
AlexG, when you refer to 'we', who are you talking about?. I mean are you sitting there, next to your laptop, with a posse of bona fide,
certifiable 'scientists', or are you, as I suspect, pedalling the hocum of your particular university of indoctrination?.
Maybe the best take on it should be that dark matter and dark energy are still hypothetical entities. We do not really know anything about them other than observations may be better explained by their existence. It may turn out that neither really exists. To draw any conclusions as to what else they might do or cause, presently is generally speculative........what's your take on it.............?
Last edited by forrest noble; December 3rd, 2012 at 12:15 AM.
Ah, yes, the typical crank disdain for an actual education. Did you flunk out, or just never attend?
Do know how the universe is? You think it was so easy and a priest from vatican hav'nt won a nobel yet...what do you know about black holes? CAN SOMEONE TAKE IT TO THE TRASH CAN!!! PLZ
Science is not about who can come up with the "most creative" idea. It is about evidence and testing ideas to destruction. As your claim that black holes "regurgitate dark matter/energy" is not supported by any evidence and flies in the face of established (i'e. well-tested) theory, I think we can safely ignore it.
Dementia, maybe.
Neutrinos have been ruled out as a possibility. One of the observed properties of dark matter is that it is "cold"; i.e. has relatively low velocity. Neutrinos, because of their small mass, always travel at something very close to the speed of light.
Okay, I have to be fair here. Dark Energy? The effects have been hypothesized by Wheeler in the sixties in his article 'On the nature of quantum geometrodynamics' Albeit nog so observable.Neutrinos have been ruled out as a possibility. One of the observed properties of dark matter is that it is "cold"; i.e. has relatively low velocity. Neutrinos, because of their small mass, always travel at something very close to the speed of light.
And Dark matter? Well, me, and nobody else in my department here really gets the big deal. As it is our jobs to make matter dark. It is a form of stability in quantum states where they no longer decay into a lower state. Since space i relatively cold, it isn't at all surprising that such a state can be achieved for simple molecules. And then it would be electromagnetically inert. Honestly, I don't see the big idea. I'd like to know what it is, so we don't have to think of other forms of dark matter. Dark matter in my opinion is just simple.
What other things could it possibly be?Neutrinos have been ruled out as a possibility. One of the observed properties of dark matter is that it is "cold"; i.e. has relatively low velocity. Neutrinos, because of their small mass, always travel at something very close to the speed of light.
So you assume that at one point it will stop and fall back into itself? I think not.
Well, if you take an entangled state, when properly prepared, it can decay naturally in the 'dark state' an energy state where it can't get out of (without perturbation) Then this applies to all the properties of 'Dark matter'
http://en.wikipedia.org/wiki/Dark_state
The general consensus is the dark matter consists of an unknown neutral particle of some kind. Another idea is that it could be some kind of so-far undetectable baryonic matter of some kind. Another idea proposes large unseen quantities of black holes etc. An alternative hypothesis is that General Relativity is not the correct model of gravity and therefore dark matter would not really exist.
Last edited by forrest noble; December 4th, 2012 at 10:58 AM.
how many of us here want to think that general relativity is wrong?
It would be inconvenient, but it doesn't matter much. If GR was in error, I think most people would want to know about it.
Since GR holds up against testing quite well, it's reasonable to say it's a good theory but it may need corrections or tweaking with new observations.
If a theory that is more accurate and explains observation better comes along, I highly doubt there will be any tears.
there really won't be tears,or did anyone cry over newtons big blow,given to him by einstein!
Quite the reverse, if anything. I imagine there would be quite a bit of excitement, even in the popular press. Look at the fuss that was made about the "faster than light neutrinos" story.
buh that is still hypothetical,base on the neutrino.
If it is that simple, why hasn't it been considered? Or wouldn't you think it has been considered, but eliminated as a candidate? Also, even atoms in dark states can still collide with other matter, no?Okay, I have to be fair here. Dark Energy? The effects have been hypothesized by Wheeler in the sixties in his article 'On the nature of quantum geometrodynamics' Albeit nog so observable.Neutrinos have been ruled out as a possibility. One of the observed properties of dark matter is that it is "cold"; i.e. has relatively low velocity. Neutrinos, because of their small mass, always travel at something very close to the speed of light.
And Dark matter? Well, me, and nobody else in my department here really gets the big deal. As it is our jobs to make matter dark. It is a form of stability in quantum states where they no longer decay into a lower state. Since space i relatively cold, it isn't at all surprising that such a state can be achieved for simple molecules. And then it would be electromagnetically inert. Honestly, I don't see the big idea. I'd like to know what it is, so we don't have to think of other forms of dark matter. Dark matter in my opinion is just simple.
kerling,
Concerning dark matter:I didn't get your meaning in your explanation. Are you saying that dark matter is just undetectable cold matter. Is this the way, in your opinion, that the dark matter hypothesis is "just simple?" I think the problem is more in the distribution of dark matter and the source of its supposed angular momentum surronding a galaxy......I don't see the big idea. I'd like to know what it is, so we don't have to think of other forms of dark matter. Dark matter in my opinion is just simple.
In my opinion dark matter is also just simple, because non-existence is a relatively simple concept to comprehend. I have the same opinion of the hypothesis of dark energy, Nobel Prize and all
Last edited by forrest noble; December 4th, 2012 at 11:25 PM.
dark matter accounts for 90% of the observable universe,...forrest are we sharing the prize in physics?
Yes, it is just simple because (dark matter, not dark energy, I didn't look into that yet) Dark matter, is just that, matter that isn't optically active. And this is very important. Especially in star forming. It is not completely unlikely that my hypothesis is true. And that it is just a normal kind of molecular set-up with an entangled dark state that is stable. This would simply mean that it is not optically active. This could easily be derived to be for all possible wavelengths (except perhaps one very specific one, finding that one isn't easy but the lack of it would disprove my hypothesis)I didn't get your meaning in your explanation. Are you saying that dark matter is just undetectable cold matter. Is this the way, in your opinion, that the dark matter hypothesis is "just simple?" I think the problem is more in the distribution of dark matter and the source of its supposed angular momentum surronding a galaxy.
In my opinion dark matter is also just simple, because non-existence is a relatively simple concept to comprehend. I have the same opinion of the hypothesis of dark energy, Nobel Prize and all
Now in star forming we are talking fusion, nuclei, this is not an optical process, just put mass in a furnace and it works. So dark matter would contribute to larger sun's. But, unlike with optical matter, it is optically inactive and so not dependend on optical pressure. That would mean that in a 'dark matter cloud' all the matter that can fall into a star will do so, and all those orbiting around it, won't get blown away. This would basically mean that optically seen a planetary system and its sun would be the same. But mysteriously much heavier. Because there is not physical system to blow the cloud away.
So yes, im my perspective it is very easily explained. And disproved for that matter. Basically it would mean that 70 percent of the universe is shielding us from one specific colour of light. Which one is the big question!
I can understand the concept of Dark Energy being of a certain (as yet unknown) wavelength.
But Dark Matter should have mass, no?
I don't think wavelength is relevant to dark energy.
It does. That is how it is detected, by its gravitational effects (affecting the orbital velocity of stars in galaxies, gravitational lensing ...)But Dark Matter should have mass, no?
I am no expert, but I think this is where you idea falls down. If matter in this dark state still engages in electromagnetic interactions then it cannot be a dark matter candidate. The distribution of dark matter suggests that it only interacts gravitationally.
and via the weak force or other interactions no stronger than that. if they are wimps of course.The distribution of dark matter suggests that it only interacts gravitationally.
and that is exactly why they are called dark matters,only gravitational effect...absorbs no light and gives out no light...not even reflect.its like it is too dark......hahaha
The definition and general hypothesis is that dark matter is a kind of matter that via its mass creates the gravity needed to explain the behaviors of stars in spiral galaxies, and galaxies within a cluster. I lean the other way believing that "dark matter" has no mass to it but instead influences other matter by pushing it via its currents. To be mass-less does not necessarily mean it has no substance, it just means that it would "float" within a gravitational field, something like an atmosphere "floats" around a planet. The particulates might be vastly smaller than matter particulates. This kind of hypothetical dark matter might be better described as a background field, and/or an aether. If this is the characteristics of dark matter then we probably discovered it many decades ago and now call it the Zero Point Field.
Present beliefs are that we will discover the nature of dark matter particles within maybe four years from now since it is running out of places to hide. If within a decade or so if they still cannot find it I expect there will be a number of other hypothesis, maybe one like the one I mentioned above, concerning a mass-less dark matter. This kind of dark matter also might require another theory of gravity.
There seems to be another dark matter problem seldom discussed. Adding a great deal of unseen mass/matter surrounding spiral galaxies would not by itself cause the outer stars of the galaxy to orbit more rapidly, that new matter would also need the energy of motion concerning a large angular momentum to it.Yes, it is just simple because (dark matter, not dark energy, I didn't look into that yet) Dark matter, is just that, matter that isn't optically active. And this is very important. Especially in star forming. It is not completely unlikely that my hypothesis is true. And that it is just a normal kind of molecular set-up with an entangled dark state that is stable. This would simply mean that it is not optically active. This could easily be derived to be for all possible wavelengths (except perhaps one very specific one, finding that one isn't easy but the lack of it would disprove my hypothesis)..................
I'm not sure I understand that. Why wouldn't the increased mass in the galaxy affect the orbital velocity? And how would the angular momentum of the dark matter be relevant?
Perhaps we enter this world at the Planck scale. A dynamic field (Higgs?) from whence particles form and sometimes disappear. If the formation of stable particles is sufficiently large but diffused throughout the universe, we might never see the creation itself, but the accumulated effect is DM gravityThe definition and general hypothesis is that dark matter is a kind of matter that via its mass creates the gravity needed to explain the behaviors of stars in spiral galaxies, and galaxies within a cluster. I lean the other way believing that "dark matter" has no mass to it but instead influences other matter by pushing it via its currents. To be mass-less does not necessarily mean it has no substance, it just means that it would "float" within a gravitational field, something like an atmosphere "floats" around a planet. The particulates might be vastly smaller than matter particulates. This kind of hypothetical dark matter might be better described as a background field, and/or an aether. If this is the characteristics of dark matter then we probably discovered it many decades ago and now call it the Zero Point Field.
Present beliefs are that we will discover the nature of dark matter particles within maybe four years from now since it is running out of places to hide. If within a decade or so if they still cannot find it I expect there will be a number of other hypothesis, maybe one like the one I mentioned above, concerning a mass-less dark matter. This kind of dark matter also might require another theory of gravity.
that would put it in a special class of particle and if it was massless it would travel at lightspeed i believe, and so is probably ruled out by what we know os the standard model. also, even the massless photon creates gravity so there is no need for "currents" pushing on anything.I lean the other way believing that "dark matter" has no mass...
I have a real problem with visualizing Dark Energy being stronger than the total gravity of Entire Mass of the universe.
What could cause this unequal function in context of the universal constants of gravity and the conservation of energy?
Is it possible that the answer lies outside (below Planck) our universe. Perhaps Universal Gravity is creating space! Spacetime is stretched in the vicinity of a massive body. Perhaps what we perceive as expansion is in fact a constant collapse of infinitely stretched nothingness into spacetime.
Perhaps we should treat this at GR and the observation of "expansion" is relative to the observation of "contraction". That would solve any apparent conflicts or paradoxes.
Why? Gravity is, after all, a comparatively weak force, as forces go. For example, it's over 40 orders of magnitude weaker than the electric force.
I see no logical connection between your first sentence and this one. For example, the conservation of energy has no apparent connection with what's under discussion. Ditto for the "universal constants of gravity," whatever they may be.[/QUOTE]What could cause this unequal function in context of the universal constants of gravity and the conservation of energy?
You keep using the phrase 'optically active'. This implies that it interacts with the electromagnetic spectrum somewhere outside the range of visible light. That's not what Dark Matter does. It does not interact electromagnetically at all. Which means that you don't find it clumping. You don't find it in stars contributing to fusion. Aside from gravitationally, it doesn't interact with normal matter at all.
Think of it this way. Throw a huge amount of matter outside the galaxy. What would the galaxy's orbital momentum be different from a galaxy without this dark matter disk? It would take matter that has a great orbital velocity faster than the interior galaxy for the momentum of the outer galaxy to effect the orbital momentum of the internal galaxy, resulting in a galaxy rotating fasten than one without this dark matter exterior.I'm not sure I understand that. Why wouldn't the increased mass in the galaxy affect the orbital velocity? And how would the angular momentum of the dark matter be relevant?
Ehm, no that is not what I am implying. In Quantum physics matter has so called optical transitions. When I say optical I mean the entire range of the electro magnetic scale. I don't see why you would interpret it otherwise as the field its named optics for a reason. Now I theorize that dark matter is in a sharp dark state with a very broad exited state. What that means is that all decay, even natural will fall its population of a state into the dark state and all other dynamics being to slow to give reasonable contributions.Then you have a perfect dark state. It is normal matter, but it does apply to all the observational data.I think it is the best theory because of Occam's razor, it is the simplest solution.
And therefore it would sustain fusion. As the optical effects of nuclei is tiny with respect to atomical optical effects. And fusion is a nuclear effect, and not atomic.
Hmmm... I kinda see what you mean but ... why outside the galaxy?
And what do you see as the mechanism for the transfer of angular momentum?
I haven't studied optics in detail yet, but wouldn't there still be Compton scattering if dark matter was "normal" baryonic matter ? And wouldn't that aforementioned scattering be detectable ?
You are operating under a misconception about dark matter. It isn't something that just surrounds the galaxy it permeates it too. Think of the visible disk of the galaxy imbedded in a large spherical "cloud" of DM. I realize that this misconception is pretty common and likely arises from the fact that we talk about the "halo" of DM surrounding the Galaxy. The thing is that the word "halo" in astronomy doesn't refer to the common image that forms in most people's of a doughnut shaped ring.Think of it this way. Throw a huge amount of matter outside the galaxy. What would the galaxy's orbital momentum be different from a galaxy without this dark matter disk? It would take matter that has a great orbital velocity faster than the interior galaxy for the momentum of the outer galaxy to effect the orbital momentum of the internal galaxy, resulting in a galaxy rotating fasten than one without this dark matter exterior.I'm not sure I understand that. Why wouldn't the increased mass in the galaxy affect the orbital velocity? And how would the angular momentum of the dark matter be relevant?
So why does this effect the speed of the outer stars of the galaxy? To determine how fast they should orbit we take the distance they are from the center of the galaxy and the total mass of everything closer to the center than they are. So if you are just considering the visible matter, you count all the stars in the galactic disk closer in to the center. DM on the other hand isn't confined to just the disk, to calculate its gravitational effect on the outer stars you have to total up the its mass in the whole spherical volume with a radius less than the stars radial distance. This is a much larger volume that that which contains the visible disk of the galaxy. So even though the overall density of the DM in this volume is less than the density of the visible disk, the vastly greater volume allows for it to contribute significantly in terms of gravitation effect on those stars.
Yes, fusion is a nuclear effect, as is nucleosynthesis. Studies have shown that the percentage of DM that can be baryonic is small. Essentially it works like this: If there was significantly more baryonic matter in the universe than what we see, then the relative abundances of the elements would be different than what we measure.
dark matter is dark,so dark in nature also....lets take a break...or what do you think?
It could lie inside the galaxy too but the majority of it would need to lie outside the galaxy to control galaxy orbital momentum. I think of it as roughly similar to the lever principle, whereby the farther out the dark matter extends form the visible galaxy, and the greater the mass and angular momentum of this dark matter, the greater influence it would have on the momentum of the stars in the galaxy in general, and the stars in the outer galaxy in particular. Humorously something like the tail wagging the dog.Hmmm... I kinda see what you mean but ... why outside the galaxy?
In dark matter models in general, it is though to be the gravitational pulling effect/ the change in the configuration of space. In my own model it would be the vortex currents of this dark matter material as a background field carrying matter with it as it enters and orbits the lower pressure galaxy while pushing with an average directional vector upon all matter.And what do you see as the mechanism for the transfer of angular momentum?
Last edited by forrest noble; December 6th, 2012 at 04:27 PM.
As Janus has nicely explained, that isn't how it works.
But any dark matter outside the galaxy will have no gravitational effect on matter inside the galaxy (assuming a roughly even distribution). That is why I wondered what mechanism you thought would be responsible for the transfer of angular momentum.Generically in dark matter models in general, it is though to be the gravitational pulling effect/ the change in the configuration of space.
Yes, well. I think we can safely ignore that. Unless you are able to show how this would quantitatively explain rotation curves?In my own model ...
Larger volumes of mass does not create larger angular momentum. The largest galaxies, elliptical galaxies, are often much greater in mass than spiral galaxies yet most do not generally rotate. For a galaxy or solar system to rotate it takes objects of varying relative motions to come together to form a vortex. A torus or vortex of material trying to spiral inward toward the gravitational center of the galaxy.I'm not sure I understand that. Why wouldn't the increased mass in the galaxy affect the orbital velocity? And how would the angular momentum of the dark matter be relevant?
(my quote)Think of it this way. Throw a huge amount of matter outside the galaxy. What would the galaxy's orbital momentum be different from a galaxy without this dark matter disk? It would take matter that has a great orbital velocity faster than the interior galaxy for the momentum of the outer galaxy to effect the orbital momentum of the internal galaxy, resulting in a galaxy rotating fasten than one without this dark matter exterior.Yes, dark matter is theorized to exist within the galaxy as well but it would seemingly have not much more momentum to it than the galaxy itself. So it would seem that the dark matter outside the galaxy is where the increased momentum must come from.You are operating under a misconception about dark matter. It isn't something that just surrounds the galaxy it permeates it too. Think of the visible disk of the galaxy imbedded in a large spherical "cloud" of DM. I realize that this misconception is pretty common and likely arises from the fact that we talk about the "halo" of DM surrounding the Galaxy. The thing is that the word "halo" in astronomy doesn't refer to the common image that forms in most people's of a doughnut shaped ring.
The outer dark matter halo, orb, or torus would need a source of momentum to effect the inner galaxy. Again, stationary mass could not cause a galaxy to rotate.So why does this effect the speed of the outer stars of the galaxy? To determine how fast they should orbit we take the distance they are from the center of the galaxy and the total mass of everything closer to the center than they are. So if you are just considering the visible matter, you count all the stars in the galactic disk closer in to the center. DM on the other hand isn't confined to just the disk, to calculate its gravitational effect on the outer stars you have to total up the its mass in the whole spherical volume with a radius less than the stars radial distance. This is a much larger volume that that which contains the visible disk of the galaxy. So even though the overall density of the DM in this volume is less than the density of the visible disk, the vastly greater volume allows for it to contribute significantly in terms of gravitation effect on those stars.
Dark energy, on the other hand, is even more problematic.
Last edited by forrest noble; December 6th, 2012 at 04:22 PM.
Strange,
(my quote)In my own model ...In my model a background field of minuscule particulates spiral in a vortex form, into a spiral galaxy. The field according carries a higher rotation velocity/ momentum than the galaxy itself and imparts this increased momentum on the outer stars first while its influence of pushing would slowly decrease as it would spread inward toward the mass of the galaxy. Of course this is just my model. What I think is missing from the standard model is the source the momentum of the dark matter, since it would have to be greater on the exterior of the galaxy to explain the observed galaxy rotation curves.Yes, well. I think we can safely ignore that. Unless you are able to show how this would quantitatively explain rotation curves?
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