Is dark matter all it's cracked up to be?

bonzelite · Mar 3, 2006

As I said, the galaxy simulations work when you throw in dark matter. again, yeah, but the simulations are based upon a model that is in all likelihood incorrect. thus the need to implement "dark matter" in order to make everything "work" = bad model.

yevaud · Mar 3, 2006

Not at all. All models are somewhat imperfect at first. In this case, an addition was required to explain the anomolous rotational dynamics of galaxies we've observed. This wasn't even realized until Vera Rubin and a few others noticed it. Jury's still out though. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

drwayne · Mar 3, 2006

This sort of "what would it take to make things work" postulate has worked before - the neutrino pops to mind. Granted - postulating something that allows conservation of momentum is on a different ground that a simulation, but it is a valid method, as long as one has any means of determining whether the postulated fix is really there (such as detecting a neutrino). Wayne <div class="Discussion_UserSignature"> "1) Give no quarter; 2) Take no prisoners; 3) Sink everything." Admiral Jackie Fisher </div>

bonzelite · Mar 3, 2006

i will meet Yevaud half-way and agree that the jury is still out. in some way that i do not understand, i will bet that the flat rotational velocities inherent in galactic rotations have something to do with non-locality of gravity, ie, geometric gravity acting as one "unit" across vast distances all at once, as if it "knows" or is "thinking" as one "thing." like a giant school of fish. can you dig that?

bonzelite · Mar 4, 2006

more like a giant wagon wheel whose spokes are the geometric "fabric" that begets the flat radial velocity that is observed. exactly how it does this, i have no clue. but the spokes' origin at the "hub", extending out to their very extremities at the outer rim of the galaxy, are connected in such a way that the material or information at the hub is acting in accord and simultaneously with the material at the outer edges --acting as one unit across light years-- instantly. from this perspective, we can address full-on the phenomenon of non-locality of space and time. and for this i have reason to believe that such a thing is acting within galaxies, if not over the entire universe. but, hey, i'm merely supposing.

Saiph · Mar 4, 2006

Well...the easier solution is (if you want to mess with gravity) adding on a "constant" term, so that gravity never goes below a minimum value... That can give you flatter radial velocity curves...but it doesn't really work elsewhere. Otherwise...I've no real clue what you're saying or trying to get at, let alone how giant spoke patterns of "geometric fabric" (I'm assuming spacetime?), or this hub (which you haven't said where it is), can, by communicating instantly (something we've never seen beyond quantum entanglement) orchestrate the motions of the entire galaxy. Especially since we see anamolies in non-spiral galaxies, so a straight "wheel" shape has problems generalizing to a more spherical shape...and I've no idea why you want spokes. I'd think throwing in matter we haven't seen yet, and must be electrically neutral in charge...would be easier to swallow. Especially since I can list two particles off the top of my head that have similar properties: neutrons and neutrinos. Problem with neutrons: decay very rapidly unless they're in a nucleus with a proton. Problem with Neutrinos: Move to bloody fast to stay where they're needed. So a more massive particle (like a neutron) that's stable (like a neutrino) doesn't seem that far fetched. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

colesakick · Mar 4, 2006

"What is the nature of “missing matter”, and does it even exist in truth? It is interesting to note that astronomers cannot answer the first question, but do not doubt the answer to the second. We see the contradiction ratified daily in the popular scientific media. A story at the Universe Today website begins, “Dark matter is a mystery. Astronomers know it's there because they can measure the effect of its gravity on stars and galaxies, but they can't see it”. Perhaps the author does not realize that the confidence he exudes rests entirely on the astronomers’ conjectures. Their equations “work” only in an abstract world, and only because the mathematicians have systematically excluded electricity. The diagram at the top of the page shows the universal confusion between matter and mass. (It's a pity both words begin with "m", say the electrical theorists; otherwise mathematicians might not have gotten away with this sleight of hand). Everyone recognizes the equation relating energy and mass (E = mc2), but no one knows what gives matter its apparent mass. One of the foundational principles of physics states that matter cannot be created or destroyed. Matter cannot be converted into energy or vice versa. In other words, energy and matter are not equivalent and cannot be lumped together as in the above diagram. The truth is that we have no real idea of the relationship between matter, mass, and gravity. It is our ignorance of this relationship that has permitted the big bang theory to flourish and has created the “problem” of missing mass. Dark matter was invented to rescue a gravity-driven universe and to make the big bang work, even if the theory requires “creation from nothing" and must violate, in its first principles, every fundamental law of physics. Is there an alternative? Yes, plasma cosmologists are waiting in the wings for working scientists to tire of the theorists’ mathematical escapades, and to think first of the things we actu <div class="Discussion_UserSignature"> Intellectual honesty means being willing to challenge yourself instead of others </div>

h9c2 · Mar 4, 2006

While I am certainly not against entertaining alternative theories, I find the above quote from thunderbolts to be a typical populist pasage from them; Bold claims, no references. I believe that both Wallace Thornhill and David Talbot are as much plasma cosmologists as Erich von Daniken is an archeologist. A much better source is of course wiki http://en.wikipedia.org/wiki/Plasma_cosmology But be sure to read the talk page for a good discussion on the subject. http://en.wikipedia.org/wiki/Talk

lasma_cosmology

Saiph · Mar 4, 2006

First of all, I'm not flogging here, I'm discussing. And I see lots of rather questionable statements in this expert: it is correct, we cannot definitively describe the nature of dark matter. However, if it is there, we do have a couple very good properties it should have, and have a few ideas of what it might be (MACHOs and WIMPs). It is incorrect that, "astronomers do not doubt" it's existence. A large majority either believe that it is, or are willing to work on the material assuming it is (to see if the results then match observation). I.e. they're going, If this is true then so this other testable thing must be true...and lets go check it out. Now, if that's a complaint about how the media tends to exagerate how sure scientists are of things...that's fine. I often believe the media is over-stating the case. <blockquote>In reply to:<hr />only because the mathematicians have systematically excluded electricity<hr /></blockquote> I don't think anything of the sort has happened. Astronomers take lots of E&M courses, many also learn/teach plasma sciences. Electricity isn't addressed on the large scale yet, because of two things. 1) It's much, much harder to do, so less people are able to do it. 2) Not much need has been seen for it. No solid indications of vast streams of current for instance. I've seen papers in APJ discussing the role of magnetic fields in star formation. While gravity is still the primary contributor, magnetic fields can significantly affect where, how large and how fast, protostars form. So it isn't being ignored, it's just not a huge area of work right now. It's a shame, true, but there is only so much funding and manpower to go around. Do you know that there are only ~5000 professional astronomical researchers? And they are the only people to really study everything above the earth's atmosphere. That's a lot of stuff <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

colesakick · Mar 4, 2006

Thank's for the wiki link, nice treatment of the subject <div class="Discussion_UserSignature"> Intellectual honesty means being willing to challenge yourself instead of others </div>

colesakick · Mar 4, 2006

Thank you for such a reasoned answer. Did you stay in the "New Foundation of Physics" thread long enough to read Volantis say: "Mass and energy are not the same thing. Energy is time dependent, mass is not. Mass is merely the dimension of inertia, energy is a unit of work. Energy is *composed* of mass, yes, but mass is not composed of energy. Also, if mass and energy are the same thing, then why does the mass change value? Where is the energy and what is it that it can be massless? You are confusing photons with energy. Energy is not photons. Photons have net zero mass, yes, but E=mc^2 does not claim that mass is converted to photons (or is the same thing as photons). Also, you are flat wrong to say that gravity affects photons. Photons curve around massive objects because the space-time is curved, not because gravity exerts a force on photons. GR completely replaces the concept of force with geometric curvature. Since gravity is a force, it has nothing to do with GR. You are trying to say that geometric curvature and gravity are the same thing, but that is not what the math shows. There is no equation anywhere that says curvature equals force. You use one system or the other, but you can't mix them unless you can provide an equality that shows them to be equal. And further still, GR does not work at the quantum scale. The force of gravity in the nucleus is practically non-existent. There is no way that GR can apply to the nucleus. In reply to: -------------------------------------------------------------------------------- A fissioning nucleus does not gain mass due to the release of energy, it was always there. -------------------------------------------------------------------------------- If the mass was always there, then why isn't it measured? If the mass was in the form of energy, then why can't we measure or observe the energy and how does tim <div class="Discussion_UserSignature"> Intellectual honesty means being willing to challenge yourself instead of others </div>

Saiph · Mar 4, 2006

Unfortunately I didn't keep up with that thread. When it got shifted I was busy, and failed to notice. When I found it again...it was huge, and others of similar opinions to mine were present. BTW, how much of that post is a quote? it isn't really that clear. I'm assuming the whole thing? You've got the opening quotes, but I don't see closing ones. Perhaps an easier to notice seperation would help (like ________________ above and below or something) Anyway, I disagree with volantis here. <blockquote>In reply to:<hr />"Mass and energy are not the same thing. Energy is time dependent, mass is not. Mass is merely the dimension of inertia, energy is a unit of work. Energy is *composed* of mass, yes, but mass is not composed of energy.<hr /></blockquote> Mass and energy are not the same thing, true. But they can be converted from one, to another. This is shown in fusion experiments. Four hydrogen are turned into 1 helium. The problem is, the mass of 4 H is slightly more than that of He. During the process energy is released, the material can be observed to heat up, and radiate light. The energy released is found to agree with E=mc^2 when one considers the mass difference. I.e. the amount of mass that is not conserved is proportional to the amount of energy that is not conserved. Photons, btw, are energy (though not the only form of energy). <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

Saiph · Mar 4, 2006

The rest of my reply...since my reply text box just mysteriously disappeared: GR says gravity isn't a force...it is a curvature in space-time. Now, Volantis is correct in saying you can't go between the two pictures, but both pictures are valid. This is similar to how you can solve a physics problems using various forces or by using energy conservation. So, it isn't invalid to say gravity, as a curvature in spacetime, is affecting photons. As for there being no equation to convert the curvature into a force...the results for describing the motion of two bodies using the curvature picture are the same for those using newtionian gravity, if the speeds and masses aren't huge. This is what people mean when they say you can derive newtons gravity from GR (they are even equivalent mathematically as various terms go to 1 or 0 in the more complicated GR equations). Now, for the concept of Energy itself. It's a rather strange idea. But energy is the ability for things to do work. This energy is really stored in various ways. It can be stored by an objects relative position (a book high on the shelf has more potential to do work, than one on the floor), their relative motion (faster objects can do more work than slower ones), or their mass (according to GR). Binding energies, electron orbital energies, planetary orbits, etc, fall into the "relative position" form. Photons, moving objects, fall into the relative motion form. And anything that has mass, is storing some energy that way. So really, when you measure mass, you're measuring energy, just as when you figure the energy avialable in a book on a shelf, or a falling rock. Volantis is correct in saying that GR doesn't explain gravity at a quantum level...and that's a known flaw in GR, and one that hasn't been rectified yet (and is a major area of research). <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

volantis · Mar 4, 2006

<blockquote>In reply to:<hr />Mass and energy are not the same thing, true. But they can be converted from one, to another. This is shown in fusion experiments. Four hydrogen are turned into 1 helium. The problem is, the mass of 4 H is slightly more than that of He. During the process energy is released, the material can be observed to heat up, and radiate light. The energy released is found to agree with E=mc^2 when one considers the mass difference. I.e. the amount of mass that is not conserved is proportional to the amount of energy that is not conserved. <hr /></blockquote> Hi Saiph, Mass is merely a dimension. Matter has mass, but it has other dimensions as well. Hydrogen and helium are matter, not mass. The matter of hydrogen is not converted to helium. Besides, helium is composed of two protons and two neutrons, not four hydrogens. E=mc^2 is strictly interpreted to say that *mass* is converted into energy. It says nothing about *matter* being converted to energy. As for your presentation that mass is converted to energy as an explanation for the "mass defect," and that the mass was radiated away, where does the mass then come from when helium is ripped apart to produce two protons and two neutrons again? Are you saying that a fission reaction would absorb energy? Because this is obviously not true. That is the big problem with trying to explain nuclear reactions with E=mc^2. In fact, the US Navy tells us in their training manuals that fission and fusion are explained much better without resorting to E=mc^2. There is no conversion of the mass dimension (m) into the unit of energy (E) in a fusion reaction. In fact, energy is a unit that is composed of the mass dimension. That is the literal meaning of E=mv^2. Energy is equal to mass times velocity squared. Energy already has mass, but mass does not have energy. As for potential energy, potential energy is

darahred · Mar 5, 2006

I have a few questions related to this subject that maybe someone can help me with. 1) If dark matter exists in the amount predicted by believers, would it not create a distortion when viewing distant objects? I would think it would create a haze somewhere in the spectrum similar to smog over a large city. 2) If there is no resistance in space, why would we expect the arms of a spiral galaxy to be traveling that much slower than the center? 3) Not counting the black holes at the center of the galaxies, could others be located at strategic points along the spirals account for the arms? Maybe to one day pull the arms off to create new galaxies. And finally just for the fun of it, has anyone ever attempted to weigh light?

nova_explored · Mar 6, 2006

argh. here we go again. shame on you. Should we refer to that other post of yours... it is a real conversion, a very real one. <div class="Discussion_UserSignature"> </div>

CalliArcale · Mar 8, 2006

By all means, but you might want to do it in that thread, not this one, or it gets rather confusing for people trying to follow along. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

cosmictalk · Mar 8, 2006

mass = dimension energy= the ability for matter to do work gravity= possibly a curvature in space/time (not a force) Has energy ever been considered a form of matter? CosmicTalk

nova_explored · Mar 9, 2006

actually yes. plasma. <div class="Discussion_UserSignature"> </div>

nova_explored · Mar 9, 2006

http://uplink.space.com/showflat.php?Cat=&Board=phenomena&Number=447376&fpart=1&PHPSESSID= this is the link to the thread, on going, with respects to energy and matter and Einstein and QM. Thought we got far enough along to discern suedoscience. <div class="Discussion_UserSignature"> </div>

CalliArcale · Mar 9, 2006

Actually, plasma is not energy. It is matter. Plasma is the fourth state of matter (the others being solid, liquid, and gas). Sometimes described as a superheated or ionized gas, plasmas actually don't have to be hot -- they just have to be ionized. It's like a gas, except that the electrons have become dissociated from the protons. Plasmas are conductive, so that may be the source of your confusion about plasma being energy. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

cosmictalk · Mar 9, 2006

If there are states of matter considered to be solid, liquid, and gas, than why is energy in itself not considered to be a state of matter?

Saiph · Mar 9, 2006

because the energy in matter (that's described by E=mc^2) is present in all the phases, and doesn't fit well onto a PVT diagram. It also doesn't follow the same thermodynamic laws the other states do (phase changes etc). So it doesn't really fit the definition of a "state" or "phase" of matter. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Mar 9, 2006

aren't we a bit haste to subscribe to rigid terminologies that are really describing things that are highly unknown? have you considered that in nature there are no such divisive boundaries? have we considered that just maybe plasma is energy, too? how can we say we know what all states of matter really are? perhaps liquid is energy as well? yes? what prevents it from being so? gravitation may be energy. why the johnny-on-the-spot denial of such a possibility? matter IS energy.

bonzelite · Mar 9, 2006

because the energy in matter (that's described by E=mc^2) is present in all the phases, and doesn't fit well onto a PVT diagram. It also doesn't follow the same thermodynamic laws the other states do (phase changes etc). So it doesn't really fit the definition of a "state" or "phase" of matter. isn't this a bit pseudo-intellecutually dismissive? even evasive? if the energy in matter is present in all phases, that would lead to the conclusion that all matter is then pure energy itself, in different manifestations. states of matter can be phase changes of energy. this is too much of a stretch for you?

Is dark matter all it's cracked up to be?

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