Dark Matter vs. Aether

By Sean Carroll | June 8, 2012 9:35 am

This is an easier one than dark matter vs. modified gravity. As mentioned, I’m going to be on Science Friday today, and they asked me to contribute a guest blog post, which I’m cross-posting below. Old news, I’m sure, for longtime CV readers, but here you go.

——————–

Probably the biggest single misconception I come across in popular discussions of dark matter and dark energy is the accusation that these concepts are a return to the discredited idea of the aether. They are not — in fact, they are precisely the opposite.

Back in the later years of the 19th century, physicists had put together an incredibly successful synthesis of electricity and magnetism, topped by the work of James Clerk Maxwell. They had managed to show that these two apparently distinct phenomena were different manifestations of a single underlying “electromagnetism.” One of Maxwell’s personal triumphs was to show that this new theory implied the existence of waves traveling at the speed of light — indeed, these waves are light, not to mention radio waves and X-rays and the rest of the electromagnetic radiation spectrum.

The puzzle was that waves were supposed to represent oscillations in some underlying substance, like water waves on an ocean. If light was an electromagnetic wave, what was “waving”? The proposed answer was the aether, sometimes called the “luminiferous aether” to distinguish it from the classical element. This idea had a direct implication: that Maxwell’s description of electromagnetism would be appropriate as long as we were at rest with respect to the aether, but that its predictions (for the speed of light, for example) would change as we moved through the aether. The hunt was to find experimental evidence for this idea, but attempts came up short. The Michelson-Morley experiment, in particular, implied that the speed of light did not change as the Earth moved through space, in apparent contradiction with the aether idea.

So the aether was a theoretical idea that never found experimental support. In 1905 Einstein pointed out how to preserve the symmetries of Maxwell’s equations without referring to aether at all, in the special theory of relativity, and the idea was relegated to the trash bin of scientific history.

Aether was a concept introduced by physicists for theoretical reasons, which died because its experimental predictions were ruled out by observation. Dark matter and dark energy are the opposite: they are concepts that theoretical physicists never wanted, but which are forced on us by the observations.

Dark matter, in particular, is nothing at all like the aether. It’s something that seems to behave exactly like an ordinary particle of matter, just one with no electric charge or strong interaction with known matter particles. Those aren’t hard to invent; particle physicists have approximately a billion different candidate ideas, and experiments are making great progress in trying to detect them directly. But the idea didn’t come along because theorists had all sorts of irresistible ideas; we were dragged kicking and screaming into accepting dark matter after decades of observations of galaxies and clusters convinced people that regular matter simply wasn’t enough. And once that idea is accepted, you can go out and make new predictions based on the dark matter model, and they keep coming true — for example in studies of gravitational lensing and the cosmic microwave background. If the aether had this much experimental support, it would have been enshrined in textbooks years ago.

Dark energy is conceptually closer to the aether idea — like the aether, it’s not a particle, it’s a smooth component that fills space. Unlike the aether, it does not have a “frame of rest” (as far as we can tell); the dark energy looks the same no matter how you move through it. (Not to mention that it has nothing to do with electromagnetic radiation — it’s dark!) And of course, it was forced on us by observations, especially the 1998 discovery that the universe is accelerating, which ended up winning the Nobel Prize in 2011. That discovery took theoretical physicists around the world by surprise — we knew it was possible in principle, but almost nobody actually believed it was true. But when the data speak, a smart scientist listens. Subsequent to that amazing finding, cosmologists have made other predictions based on the dark energy idea, which (as with dark matter) keep coming true: for the cosmic microwave background again, as well as for the distribution of large-scale structure in the universe.

There is still much we don’t know about dark matter and dark energy; in particular, we certainly haven’t nailed down what exactly they are (although we have many plausible ideas), and the only way we’ve detected them is indirectly, through their effects on gravitational fields in the universe. But they are not arbitrary; both ideas make very specific predictions for what those gravitational effects should be, which astronomers have tested and verified. Unlike the aether, which shrunk and eventually disappeared under experimental scrutiny, the case for dark matter and dark energy continues to grow stronger.

CATEGORIZED UNDER: Science, Top Posts
  • AI

    “1998 discovery that the universe is accelerating”

    It’s probably better to clarify that it’s expansion of the universe that is accelerating.

  • http://scientopia.org/blogs/galacticinteractions Rob Knop
  • david

    It seems that another specific prediction of dark matter (as we currently hypothesize it) is that there should be no strong correlation between the distribution of visible matter in a galaxy and that galaxy’s rotation curve. However, there seems to be one. This appears to be a glaring failure of our current understanding of DM, and a strong hint that there’s something fundamental that we’re missing.

  • Meh

    You have to admit, the mistake is forgivable, they do have a lot in common. Aether is like the beautiful daughter who you really have to go out of your way to impress, while Dark Matter and Dark Energy are the butt ugly obese twins who have the hots for you; ugh, leave me alone and go tell your hot sister why she should hook up with me.

    I’m kind of a fan of the idea that Dark Energy, Dark Matter, and Gravity are conceptualized as different harmonic octaves of a string.

  • http://darkbuzz.blogspot.com/ Roger

    The aether was not necessarily thought to have a “frame of rest” in the 1800s. See Maxwell’s 1878 essay for a survey of aether theories. It was Lorentz who said in 1895, “It is not my intention to … express assumptions about the nature of the aether.” Something like the aether later became essential for quantum electrodynamics.

  • Meh

    Roger #5,

    What ‘something like the aether’ later became essential for quantum electrodynamics?

  • http://darkbuzz.blogspot.com/ Roger

    In quantum electrodynamics, the vacuum is not empty, but has something in it for the propagation of light. It is not usually called the aether, but it is a similar concept.

  • Hemo_jr

    There is still the possibility that both dark matter and dark energy are artifacts of observational deficiencies.

  • Charles

    david:
    Since dark mater has mass just like regular mater and is affected by gravity the quantum fluctuations in the very early universe that caused regular mater to come together would do the same for dark mater. The only difference is that dark mater doesn’t clump like regular mater does.

  • david

    OK, so if the observed correlation today is due to correlated initial conditions, then it should be possible to demonstrate it mathematically via numerical simulations or whatnot. While I don’t recall such a demonstration, maybe I’m ignorant or maybe groups are working now to show it?

  • Ben

    Charles, what david refers to is the observed *anti-correlation* (not correlation) between the surface density of baryons and that of dark matter in galaxies. Observations show that there exists a universal baryonic surface density of the order of 800 solar masses per parsec square, above which virtually no dark matter is ever present in galaxies, and below which it appears in exactly the right proportion as to give the baryonic Tully-Fisher relation between the visible mass and the fourth power of the asymptotic circular velocity. See e.g. Figure 4 of http://arxiv.org/pdf/astro-ph/0509305 . There is currently no understanding at all of this observation. It is really a kind of exclusion principle: if the baryonic surface density is large enough, there is apparently no room for dark matter. With our current understanding of dark matter as being the plain simple cold dark matter particle, one would not expect that at all: if the cold dark matter potential well is deep enough, nothing should prevent baryons to clump into that deep potential, with as high a baryonic surface density as they want, while still being subdominant to the even larger density of dark matter. But this is not what happens: wherever the baryonic surface density is high enough, observations say bye bye to the dark matter effect. So, where this anti-correlation comes from is still a complete mystery, except that it is predicted by MOND. Anyway, whatever the explanation for this phenomenology, we should always listen to Nature, and not pick and choose the observations. There are actually many other observations defying explanation in the cold dark matter context on galaxy scales. But of course, the same can be said about MOND: there clearly are observations fully disfavouring it on the largest scales. But that doesnt necessarily mean it is wrong on all scales.

  • Bob

    Sean, I don’t think it it correct that “dark matter and dark energy are concepts that theoretical physicists never wanted.” I think this is a common misunderstanding that astrophysicists have. They think that dark matter and dark energy are wild, crazy concepts that are completely disconnected from all our other ideas in physics. But its not true. For instance, when theorists hypothesized the axion to solve the strong CP problem, they wanted dark matter to found. When theorists hypothesized supersymmetry to obtain unification of the forces of nature, and to maximally unify relativity with quantum mechanics, they wanted dark matter to be found. And when theorists tried to compute zero point energy and always found it non-zero in any reasonable framework, such as QFT or string theory, etc, they really wanted dark energy to be found. On the other hand, astrophysicists were mainly unaware of progress in fundamental physics, so for them the discoveries of dark matter and dark energy were “unwanted”, if you like, because they had to start rewriting the astrophysics text books.

  • http://www.cstdbill.com/ Bill

    If dark matter feels gravity, then why doesn’t it clump?

    And if it doesn’t clump, then shouldn’t it be distributed uniformly? (In that red-and-blue picture that I’ve seen numerous times on various science-related Web sites (IIRC, of two galaxies colliding), it looks to me like there’s more of it some places than other places.)

    This non-scientist is very confused.

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  • Ben

    @Bob: indeed, there could be axions out there, LSSP too of course, as well as sterile neutrinos, and many other things… But in what exact proportion is the real question. Possible (or probable) existence doesnt mean being out there in exactly the right amount, both globally and locally. Globally, the WIMP miracle for the relic density of dark matter from the typical weak scale cross-section seemed to be an excellent argument, but is this argument still really alive with the latest results from direct detection XENON-CDMS constraints, as well as complementary LHC constraints?? If not, we could well have a mix of all these things out there, and an infrared modification of gravity on top of all this is still a real possibility too. By the way, my understanding was that the axion mass is varying as the temperature changes, due to the running of its couplings to matter during the process of symmetry breaking. And the effective consequence of the presence of such mass-varying DM could be an effective modification of gravity indeed, through the effective breaking of the weak equivalence principle due to the varying mass of DM itself. So both aspects are not necessarily mutually exclusive. Anyway, astrophysical observations of the relations between the gravitational field and the observed distribution of baryons in various different systems is still something very useful for giving us hints about the answer(s): these observations currently strongly point towards collisionless dark matter on cluster scales, but do not exclude (or even slightly favor) an infrared modification of gravity on galaxy scales, where coincidences of scales between the transition surface density I mentioned above (square root of the cosmological constant in natural units) and dark energy might still point towards something really interesting in linking the two supposedly separate dark sectors together. This might well all end up as “garbage in the sky” in the end, but let me perhaps be a bit biased in saying that I strongly doubt that it will actually end up as garbage.

  • Meh

    Roger #7,

    That doesn’t really answer my question. What is the concept you’re talking about? I’m just starting my study of electrodynamics, so you’ve got my mind hooked on this. If you can’t answer it, then I have to assume you have no idea what you’re talking about. Please don’t make me assume that.

  • Aiya-Oba

    Aether by any name, is absolute space; the oneness, resultant and equator of the relative pair of spaces. -Aiya-Oba (Philosopher)

  • Brad

    13. Bill Says:

    If dark matter feels gravity, then why doesn’t it clump?

    To clump into a more condensed form it has to lose energy somehow, that requires some sort of interaction. Interstellar gas clouds condense by becoming hotter and radiating electromagnetic energy up into the x-ray region. Dark matter can’t because it doesn’t interact with anything electromagnetically, and doesn’t collide with normal matter to lose momentum directly.

  • Gaston Moens

    Aether, dark matter, dark energy: different ‘things’, same function: save a theory. No direct empirical evidence.

  • s johnson

    #18 Brad says that dark matter must interact to lose energy to clump. By definition EM interactions are ruled out, as is cancellation of momentum by collision with baryonic matter. This leaves gravitational waves for one. Although they are weak, on cosmic scales, both spatial and temporal, wouldn’t this have visible effects?

    Also, wouldn’t there be a certain amount of random cancellation of momentum by collisions between dark matter particles? Or are dark matter particles imagined as not even interacting with each other? Also, wouldn’t there be the effects from the dark matter equivalent of decay? Why would we expect dark matter to be composed solely of stable particles, unlike baryonic matter?

    In view of these and similar considerations, does the concept of thermal equilibrium play any physicial role in cosmology? Shouldn’t all models of cosmic expansion default to dark energy and dark matter as the dominant factors?

  • martenvandijk

    Dark Matter vs. Aether: modern myth vs. antique myth.

  • Valatan

    @sjohnson #20: gravitational waves are not just weak, they are EXTREMELY weak. It would take the Earth several ages of the universe to have its orbit decay into the sun, for example. You’re not going to get significant clumping of galaxy-sized objects via gravitational radiation.

    @Hemo_jr #8: if DM is an artifact of observational deficiency, then it must be a defect across several different sets of observations, that all point toward the same DM abundance. You’re going to have to have some combination of DM and modified gravity in any model.

    @martenvandijk: if you hate them so much, come up with a better model.

  • http://www.cstdbill.com Bill

    Hmm…trying to process…

    I’m remembering that red-and-blue photo that appeared on various Web sites not too long ago (IIRC, of two galaxies colliding). I can’t remember whether the red or the blue is the dark matter; but whichever it is, it certainly looks like there’s more of it some places than other places. Is that just normal clustering rather than clumping due to gravitational attraction?

    And if dark matter can’t lose energy, does that mean that it’s in a state of maximum entropy?

    Or do I misunderstand so thoroughly that explaining it to me is hopeless (entirely possible)? 8-)

  • Christian Takacs

    Dark Matter and Energy are what you get when you have equations that can’t explain observation.
    Try working with three spatial dimensions (confirmed and measurable), and no point particles, since anything that is something enough to bump into something else has extension (NO VIRTUAL POINTS, PARTICLES, ANGELS DANCING ON VIRTUAL PINS ALLOWED!!)
    Some really big basic observations:
    1. Something with spin, like a thrown american football for example, or a particle, will have a wave like action if viewed two dimensionally.

    2. After all the “We wanna a unified field theory!! Waaaaaah! ” I’ve heard over the last several decades, I find it hilarious that physicists when confronted with the observational evidence that gravity alone ‘ain’t all that’s making things go round other things’ are surprised by this, and start making up stuff to save their ‘gravity only’ models. You want a damn unified field theory, start noticing gravity ain’t the only thing in it making stuff move a certain way.

    3. Instead of ‘pretend/virtual’ photons which are required to make current theory work, what would happen if “REAL” photons made it work? Last I checked, real photons are non baryonic, and do actually have mass for goodness sake, small as it may be, but there are lots and lots of them.

    4. Ummmm, about the whole accelerating universe thingy… Please consider for a moment, you are in an orbit, which is ellipitcial. As you are on certain locations along your orbit you notice other objects seem to speed up and slow down.. like say other planets. Would you think it likely that the other planets are actually speeding up or slowing down (due to dark matter/energy, entrophy, big bang, kitchen sink, etc. of course!)…. or perhaps… just perhaps… that other planets would APPEAR to speed up or slow down because of where you were in relation to them in your orbit? Whew, thank goodness our solar system doesn’t orbit anything ellipically… or our galaxy, or our galaxy cluster… I mean that would just suck if someone came up with an idea that WE were accelerating due to our location within an orbit inside of various stellar entities, not the universe.

    5. If first you don’t succeed, try not to make stuff up and complicate things further with magic, miracles, virtual anything, unicorns, endless dimensions, endless math designed to hide flaws and avoid criticism, or infinite anything.

    6. Read, rinse, repeat.

    from the collection “Space
    Child’s Mother Goose” by Frederick Winsor and Marian
    Parry (Simon and Schuster, 1956)

    This is the Theory Jack built.
    This is the Flaw
    That lay in the Theory Jack built.
    This is the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the Summary
    Based on the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the Constant K
    That saved the Summary
    Based on the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the Erudite Verbal Haze
    Cloaking Constant K
    That saved the Summary
    Based on the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the Turn of a Plausible Phrase
    That thickened the Erudite Verbal Haze
    Cloaking Constant K
    That saved the Summary
    Based on the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the Chaotic Confusion and Bluff
    That hung on the Turn of a Plausible Phrase
    That thickened the Erudite Verbal Haze
    Cloaking Constant K
    That saved the Summary
    Based on the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the Cybernetics and Stuff
    That covered Chaotic Confusion and Bluff
    That hung on the Turn of a Plausible Phrase
    That thickened the Erudite Verbal Haze
    Cloaking Constant K
    That saved the Summary
    Based on the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the button to Start the Machine
    To make with the Cybernetics and Stuff
    To cover Chaotic Confusion and Bluff
    That hung on the Turn of a Plausible Phrase
    That thickened the Erudite Verbal Haze
    Cloaking Constant K
    That saved the Summary
    Based on the Mummery
    Hiding the Flaw
    That lay in the Theory that Jack built.
    This is the Space Child with Brow Serene
    Who Pushed the Button to Start the Machine
    That made with the Cybernetics and Stuff
    Without Confusion, exposing the Bluff
    That hung on the Turn of a Plausible Phrase
    And, shredding the Erudite Verbal Haze
    Cloaking Constant K
    Wrecked the Summary
    Based on Mummery
    Hiding the Flaw
    And Demolished the Theory that Jack built.

  • Entropy

    Dark matter can lose energy, it just has to wait for something as weak as or weaker than the weak interactions in order to do it. It can also gain energy, through the same weak mechanisms. Basically, how would you add or subtract energy to/from a neutrino? It’d be very, very difficult, but it can be done in principle. Dark matter is in the same situation.

    The image you’re recalling is the bullet cluster.

    http://apod.nasa.gov/apod/ap060824.html

    The dark matter is the blue on the outside (detected indirectly via gravitational lensing by apparently empty space). What’s happened in that picture is the collision of two galaxies. Most of the visible mass of the galaxies has slowed down via friction and sits in the red areas. The dark matter halos, roughly spherical, have sailed through since dark matter basically does not interact. If one rejects dark matter, it must be explained how a typical galaxy warps light ~7 times as much as it should (ok, fine, modify GR), and how two galaxies that collide warp light exactly as much as they should in the collision region, but “empty space” on either side of them warps light many times more than the visible galaxies (uh…I’m pretty sure Occam’s Razor likes dark matter here).

  • martenvandijk

    @Valatan

    I do not hate them, I just critize them. There is no proof, no concrete empirical evidence and you expect me to come up with a better model? For a myth? You are pathetic. In fact I have come up with an other model. It is revolutionary and very controversial, but it is original , it is mine. I may be completely wrong, but at least I try to come up with something new. I invite you to try and do the same or stay put on the bandwagon and end up in the land of nowhere. I also invite you to try and find my model. You might learn something from it. You are welcome to try and critize me.

  • Entropy

    @ s johnson Dark matter should decay (which means it is unstable!), but slowly for the same reasons that it gains energy slowly. There’s a recent gamma ray line in the hundreds of GeV region (Higgs / Top mass area) that is a candidate for dark matter decay, but could turn out to be astrophysical. We hypothesize (nearly) stable dark matter because the observations indicate (nearly) stable dark matter. Supersymmetry, which is now basically dead but can serve as a representative case, hypothesized that dark matter was the Lightest Supersymmetric Particle, that Supersymmetric number was conserved or nearly conserved, and that this particle therefore could not decay, or at least not easily.

    Dark matter does not collide with itself for the same reason that neutrinos do not readily collide with each other: to collide, they need to get within the interaction distance of the weak force, or something comparably weak, which is very, very, very, very small. Weak force cross sections are in the picobarn range, which is 10^-36 cm^2, which is equivalent to a circle of roughly 10^-20 m. Compare this to the atomic nucleus size of ~10^-14 m. So, dark matter would collide with itself (perhaps annihilate if it’s its own antiparticle) very occasionally, but not often.

    Baryonic matter IS composed almost solely of stable particles, or particles so nearly stable that they may as well be (e.g., if the proton is unstable, its half life is > 10^34 years). Sure, strange quarks, muons, pions, etc can appear sporadically in particle detectors, but when we look out into the Universe, we don’t include strange quarks in our estimates of how much mass we should see. To create any possible hypothetical less stable versions of dark matter would be even harder than creating unstable versions of baryonic matter, since dark matter is much heavier and more energy, presumably, is necessary to reach the next highest particles (10s of GeV at least compared to a few MeV for baryonic particles).

  • Entropy

    @ martinvandijk

    I am wondering, what qualifies as concrete empirical evidence? Detection of the particle at the LHC or bust? We have as strong a circumstantial case for dark matter as it is possible to have. In fact, dare I say it, we have a stronger case for dark matter than we have for gluons if you accept nothing less than direct detection of the particle as proof. We have never directly detected a gluon and never will due to confinement, but have plenty of indirect evidence consistent with their existence. You will find gluons extensively discussed in introductory textbooks nonetheless.

  • http://darkbuzz.blogspot.com/ Roger

    Meh, you can read about the quantum vacuum on Wikipedia or in many textbooks.

  • martenvandijk

    @ Entropy

    Concrete empirical evidence is what you need to be able to take DM for granted. Do you take DM for granted?

  • Entropy

    What does it mean “to take DM for granted?” The evidence is strongly in favor of the existence of DM, by which I mean that it is far, far more difficult and implausible to explain observations in favor of it away than to accept its existence. If the only observation in favor of dark matter were galactic rotation curves, I would say we need to rethink our models, but those are by now a minor footnote on the dark matter theory’s explanatory power, although they were its original inspiration. Even if anomalous gravitational lensing is added in, I would still not prefer DM to an altered theory of gravity, but again, the theory explains more phenomena than overly massive galaxies. My question stands, what, by your definition, is sufficient evidence? Am I absolutely sure DM exists? Well, no, but I am as sure DM exists as I am sure quarks exist.

  • martenvandijk

    @ Entropy

    I am not going to repeat my answer. “Sufficient evidence” are your words, not mine.You are relatively sure about the existence of DM. That answers my question. Thank you.

  • amphiox

    Aether, dark matter, dark energy: different ‘things’, same function: save a theory. No direct empirical evidence.

    Um, no. And this is specifically what the OP is trying to explain.

    Dark matter and dark energy are labels for something that was observed, which theory did not predict.

    Aether is something theory predicted, but was never observed. Aether was NEVER used to “save” a theory. When aether failed to be detected, the theory that predicted it was killed.

    Dark matter and dark energy also are not used to “save” a theory. When they were discovered, they forced the existing theory to be changed to accommodate them.

    And now we are working on trying to figure out exactly what dark matter and dark energy are, and are testing hypotheses about them.

    And trying to say that there is no direct empirical evidence for dark matter is like saying that watching you fall off a cliff is not direct empirical evidence for the existence of the earth.

    There’s been no direct empirical observation of dark matter. Observation is not the only kind of direct evidence there is.

  • Meh

    Amphiox #33, Man, Dark Matter is certainly a hot button topic. It’s such a big topic because it proves that we are missing something. For those who sit on the fringe with radically different ideas, it presents the opportunity to say “HA! I told you so!”, which drives physicists crazy. The reason is because this one single thing that we admit we need more evidence to understand, brings out the physics hobbyist who thinks they have the answer in their internet posted theory of everything. So in summation, I totally agree with you, though I’m sure our opinions of what exactly dark matter is may vary.

    Roger #29, OH! you mean Hawking Radiation? The cosmic microwave background radiation? Was it really that hard to type that? And you’re statement is pretty inaccurate. The ‘aether-like substance’ you’re talking about in which electromagnetic radiation is produced…is electromagnetic radiation…I wouldn’t classify Electromagnetism as an aether-like substance because that would be totally wrong.

  • http://darkbuzz.blogspot.com/ Roger

    Meh, just click on the link. It does not say anything about Hawking radiation. Or just google it.

  • Tony

    @Meh #34, If you truely understand where Hawking radiation comes from, then you know about the aether-like-stuff Roger is talking about. My understanding (and I’m SO not a physicist) is that in the vacuum of space, there’s actually a rippling sea of “things” (again, not a physicist – not sure whether to use the term “particles” or “quarks” or what here) and paired “anti-things” popping into existence together, then annihilating each other (thus popping back out of existence). Hawking radiation occurs when, near a black hole, one of this pair gets diverted into the blackhole, leaving the other of the pair to carry on its merry way – the remaining of the pair being Hawking Radiation.

    The “rippling sea” I mentioned is Roger’s aether-like-stuff. It’s not the same as Hawking Radiation (and definitely not Cosmic Microwave Background Radiation) but “Aether-like-stuff + Black-Hole produces Hawking Radiation”.

  • Tony

    .

  • Pinger

    In #13 Bill actually asked two questions.

    The first one, “If dark matter feels gravity, then why doesn it clump?”, was addressed in #18 by Brad, but I’m not sure I find the answer satisfying.

    I don’t because of Bill’s second question: “And if it doesn clump, then shouldn’t it be distributed uniformly?” He mentions that in the Bullet Cluster picture, some parts of the dark matter region seem more concentrated than others. It looks like that to me too.

    Also, if dark matter doesn’t clump, why doesn’t it spread uniformly all over the universe?

    So the question still strikes me as a good one. I’m probably even less of a physicist than Tony above, so there’s no way I’m even close to being able to answer. Anybody want to take a crack at it?

  • mpc755

    ‘Was the universe born spinning?’
    http://physicsworld.com/cws/article/news/46688

    “The universe was born spinning and continues to do so around a preferred axis”

    The Universe spins around a preferred axis because the Universe is, or the local Universe we exist in is in, a jet; analogous to the polar jet of a black hole.

    ‘Mysterious Cosmic ‘Dark Flow’ Tracked Deeper into Universe’
    http://www.nasa.gov/centers/goddard/news/releases/2010/10-023.html

    ‘The clusters appear to be moving along a line extending from our solar system toward Centaurus/Hydra, but the direction of this motion is less certain. Evidence indicates that the clusters are headed outward along this path, away from Earth, but the team cannot yet rule out the opposite flow. “We detect motion along this axis, but right now our data cannot state as strongly as we’d like whether the clusters are coming or going,” Kashlinsky said.’

    The clusters are headed along this path because the Universe is, or the local Universe we exist in is in, a jet.

    The following is an image analogous of the Universal jet.

    http://aether.lbl.gov/image_all.html

    The reason for the ‘expansion’ of the universe is the continual emission of aether into the Universal jet. Three dimensional space associated with the Universe itself is not expanding. What we see in our telescopes is the matter associated with the Universe moving outward and away from the Universal jet emission point. In the image above, ’1st Stars’ is where aether condenses into matter.

    The following is an image analogous of the Universe, or the local Universe, we exist in.

    http://www.astro.ucla.edu/planetarium/graphics/st_images/BlackHole.jpg

    The following is an image analogous of the Universal spin.

    http://i.space.com/images/i/612/i02/040817_quasar_illo_02.jpg?1292259454

    Dark energy is aether emitted into the Universal jet.

    It’s not the Big Bang. It’s the Big Ongoing.

  • mpc755

    What is presently postulated as non-baryonic dark matter is aether. Aether has mass. Aether physically occupies three dimensional space. Aether is physically displaced by matter.

    Non-baryonic dark matter does not travel with matter. Matter moves through and displaces the aether.

    It is the aether which is displaced external to the matter which the Milky Way consists of which is pushing back and exerting inward pressure toward the Milky Way which causes the Milky Way to rotate at a speed which can not be accounted for by the matter the Milky Way consists of itself.

  • http://darkbuzz.blogspot.com/ Roger

    Yes, Tony, the cosmic background radiation is not the same as the luminiferous aether. But the CBR does give a rest frame for the universe. Some physicists in the 1800s thought that the aether might provide such a rest frame, until Lorentz showed in 1895 that such an assumption is unnecessary.

  • david

    The new “Critical Opalescence” blog at Scientific American has an interesting piece on dark matter, MOND, and Erik Verlinde’s work.

    http://blogs.scientificamerican.com/critical-opalescence/

  • http://alexpavellas.wordpress.com Alex

    The important question isn’t whether Dark Matter exists, it’s what can we use Dark Matter for if it does?

    Consider a hypothetical super-dense material, laid out in a thin sheet with a thickness of one or two molecules. This material would be dense enough to reflect a non-negligible amount of Dark Matter hitting it. Since the Dark Matter in the galaxy must have some angular momentum in the direction of the rotation of the galaxy, locally there is a “Dark Matter Wind” in a single direction.

    This super-dense material can then be used as a “Dark Matter Sail” and can be used for cheap interstellar travel. Even better, since it makes no difference if there is an atmosphere around, when the wind is blowing away from the surface of the Earth, this sail could be used as a super cheap way to achieve orbit.

    The only drawback I can think of this is that excessive use would slow the rotation of the galaxy, but that would require an awful lot of excessive use.

  • Jimdotz

    We always seem to assume that matter preceeds gravity: Without matter to generate it, the assumption goes, there would be no gravity. Should we not question that assumption? Is it not possible that gravity waves (including their extreme version, singularities) existed in the moments before matter did?

    In the Dark Matter vs. Modified Gravity trialogue from the other day, I made an argument that before matter precipitated into existence, the Big Bang might simply have generated more gravity in some regions of spacetime than there would come to exist matter with which to fill that spacetime.

    That “excess gravity” is what we see today as Dark Matter.

    Here’s the post: http://blogs.discovermagazine.com/cosmicvariance/2012/05/09/dark-matter-vs-modified-gravity-a-trialogue/#comment-240711

  • Entropy

    @ Alex

    In order to stop a dark matter particle, the equivalent of 10000 light years of lead (assuming dark matter interacts with strength comparable to the neutrino) is required. Compressing 10000 light years of lead down into a sail would create a black hole many times over. In short, collecting any reasonable fraction of a dark matter wind is utterly impossible without somehow altering the strength of the weak force (or whatever dark matter couples through).

  • http://alexpavellas.wordpress.com Alex

    @Entropy,
    yea, I was afraid that the density required would create a black hole. I was just entertaining a wacky possibility. A more serious question would be: is there any potential use for DM? Or is the difficulty in detecting it too high, even for hypothetical future technologies?

  • Entropy

    It’s difficult to conceive of a direct use for dark matter. Its density is too low (sure, it dominates the mass of galaxies, but that’s only because it fills space relatively evenly while baryonic matter is packed into tiny clumps of high density). Even 100% efficient collection wouldn’t do much. That said, dark matter could be the clue to new physics that is more useful, and understanding the formation of the Universe’s large scale structure can’t hurt.

    Always remember with these things that, for instance, Maxwell discovered the light was an electromagnetic wave 34 years before the first practical radio was built using his discoveries. Maxwell’s discovery at the time could fairly have been greeted with the same “so what?” attitude as some greet modern discoveries. Who cares if light is an electromagnetic wave? That’s great trivia but not *useful*. ;)

    On the flip side, we discovered that the Universe is expanding in the 20s, and that hasn’t led to any direct benefits (plenty of spinoffs, but no direct applications). The point is, we just don’t know, the knowledge is benefit enough, and useful applications are bonuses.

  • http://alexpavellas.wordpress.com Alex

    Don’t get me wrong, I do think that the search for how the universe works and even possibly how it came to be is something that is more than worthwhile.
    I read this blog because I find these sorts of questions fascinating, despite what I said in my first post, which was written a bit tongue in cheek.
    When I think about how much information we have gleaned about the universe from our tiny vantage point here on Planet Earth, I am awestruck, to put it mildly.
    I simply also enjoy thinking about what we could possibly do with these discoveries.

  • mpc755

    Q. Why is the particle always detected entering, traveling through and exiting a single slit in a double slit experiment?
    A. The particle always enters, travels through and exits a single slit. It is the associated aether wave which passes through both.

    What ripples when galaxy clusters collide is what waves in a double slit experiment; the aether. The ripple is a gravitational wave.

    Einstein’s gravitational wave is de Broglie’s pilot-wave.

    They are both aether displacement waves.

  • mpc755

    ‘Interpretation of quantum mechanics by the double solution theory – Louis de BROGLIE’
    http://aflb.ensmp.fr/AFLB-classiques/aflb124p001.pdf

    “When in 1923-1924 I had my first ideas about Wave Mechanics I was looking for a truly concrete physical image, valid for all particles, of the wave and particle coexistence discovered by Albert Einstein in his “Theory of light quanta”. I had no doubt whatsoever about the physical reality of waves and particles.”

    “any particle, even isolated, has to be imagined as in continuous “energetic contact” with a hidden medium”

    The hidden medium of de Broglie wave mechanics is the aether. The “energetic contact” is the state of displacement of the aether.

    A moving particle has an associated aether displacement wave.

    In a double slit experiment the particle travels a well defined path which takes it through one slit. The associated aether wave passes through both. As the aether wave exits the slits it creates wave interference. As the particle exits a single slit the direction it travels is altered by the wave interference. This is the wave piloting the particle of pilot-wave theory. Detecting the particle strongly exiting a single slit turns the associated aether wave into chop. The aether waves exiting the slits interact with the detectors and become many short waves with irregular motion. The waves become disorderly. The waves are disorganized. There is no wave interference. The particle pitches and rolls through the chop. The particle gets knocked around by the chop and it no longer creates an interference pattern.

    ‘Surprise! IBEX Finds No Bow ‘Shock’ Outside our Solar System’
    http://www.universetoday.com/95094/surprise-ibex-finds-no-bow-shock-outside-our-solar-system/

    ‘“While bow shocks certainly exist ahead of many other stars, we’re finding that our Sun’s interaction doesn’t reach the critical threshold to form a shock,” said Dr. David McComas, principal investigator of the IBEX mission, “so a wave is a more accurate depiction of what’s happening ahead of our heliosphere — much like the wave made by the bow of a boat as it glides through the water.”’

    The wave ahead of our heliosphere is an aether displacement wave. This is evidence of a moving ‘particle’, the solar system, having an associated aether wave.

    ‘Hubble Finds Ghostly Ring of Dark Matter’
    http://www.nasa.gov/mission_pages/hubble/news/dark_matter_ring_feature.html

    “Astronomers using NASA’s Hubble Space Telescope got a first-hand view of how dark matter behaves during a titanic collision between two galaxy clusters. The wreck created a ripple of dark mater, which is somewhat similar to a ripple formed in a pond when a rock hits the water.”

    The ‘pond’ consists of aether. The moving ‘particles’ are the galaxy clusters. The ripple is an aether displacement wave. The ripple is a gravitational wave. This is also evidence of a moving ‘particle’, the galaxy clusters, having an associated aether wave.

    ‘Giant black hole kicked out of home galaxy’
    http://www.astronomy.com/en/News-Observing/News/2012/06/Giant%20black%20hole%20kicked%20out%20of%20home%20galaxy.aspx

    “But these new data support the idea that gravitational waves — ripples in the fabric of space first predicted by Albert Einstein but never detected directly — can exert an extremely powerful force.”

    The fabric of space is the aether.

    Gravitational waves are ripples in the aether.

    What ripples when galaxy clusters collide is what waves in a double slit experiment; the aether.

    Einstein’s gravitational wave is de Broglie’s pilot-wave.

    They are both aether displacement waves.

  • knov

    Well, my favorite theory of everything is Mills’ Grand Unified Theory of Classical Physics.

    http://www.blacklightpower.com/theory-2/theory/

    Gets rid of almost all the goofiness of quantum theory (particles acting instantaneously over great distances, a single photon existing in many places at the same time, etc…), and restores physics to something deterministic again, with real physical meaning and not mathematical nonsense.

    He says dark matter is hydrogen with the electron orbiting below the “ground state” predicted by current quantum mechanics; he calls such an entity a hydrino. He claims a new energy source from hydrogen reducing to this lower energy state that does not interact much with other matter. So yes, there are HUGE potential uses for dark matter – nearly unlimited energy, new chemistry and new properties of matter not even dreamed of yet, all of course if one believes dark matter is a hydrino as Mills theorizes.

  • knov

    @mpc, a simpler explanation of the double slit experiment is given by Mills:

    http://www.blacklightpower.com/theory-2/theory/double-slit/

    There is no aether.

  • mpc755

    @knov, the following is simpler and correct.

    Aether has mass. Aether physically occupies three dimensional space. Aether is physically displaced by matter.

    A moving particle has an associated aether displacement wave; analogous to the bow wave of a boat.

    In a double slit experiment the particle travels a well defined path which takes it through one slit. The associated aether wave passes through both. As the aether wave exits the slits it creates wave interference. As the particle exits a single slit the direction it travels is altered by the wave interference. This is the wave piloting the particle of pilot-wave theory. Detecting the particle strongly exiting a single slit turns the associated aether wave into chop. The aether waves exiting the slits interact with the detectors and become many short waves with irregular motion. The waves become disorderly. The waves are disorganized. There is no wave interference. The particle pitches and rolls through the chop. The particle gets knocked around by the chop and it no longer creates an interference pattern.

  • Ann Kittenplan

    As a layperson who naively/instinctively sees strong parallels between luminiferous aether and dark matter I think the whole basis of this article is wrong:

    In both cases there is a theory at odds with observation, the proposal is to magic up out of thin air a compensatory mechanism.

    In the case of the aether this mechanism has been discredited, in the case of the dark matter it is under review.

    Maybe the evidence for the existence of dark matter is becoming overwhelming but as a lay observer I don’t yet get this sense.

  • http://www.astro.multivax.de:8000/helbig/helbig.html Phillip Helbig

    “It’s probably better to clarify that it’s expansion of the universe that is accelerating.”

    Why? If a car is accelerating, I say the car is accelerating. I don’t say the motion of the car is accelerating, nor that the velocity of the car is accelerating, neither of which make any sense.

  • mpc755

    Ann Kittenplan: What has been disproven is a stationary aether and a completely entrained aehter. The aether is neither. Aether is displaced by matter.

    Don’t fall for the lazy nonsense of mainstream physics.

  • martenvandijk

    @ Philip Helbig

    An accelerating car does not expand. Its length decreases.

  • mpc755

    The following is an animation of a moving particle and its associated aether wave.

    http://www.youtube.com/watch?v=iWRNZNemQyY

  • http://dispatchesfromturtleisland.blogspot.com ohwilleke

    The original post is a very narrow view of the “aether” concept, limiting it to a specific and rejected version of it with a fixed frame of reference considered in relation to Maxwell’s equations.

    But, a broader sense of the term “aether” is also possible. In a broad sense, it represents the conclusion that “empty space” is not just “nothing,” but has definable properties like local space-time curvature, a possible minimum scale (perhaps the Planck scale), dimensionality, a speed limit for contained particles, vacuum energy, dark energy, locality (or non-locality), causality (or select exceptions to causality), an arrow of time, etc.

    It is quite possible, within the range of observational data, that another property of space-time may be maximum local energy density (nothing ever observed has had more mass-energy density than a neutron star, if one is willing to acknowledge a certain amount of quantum uncertain that “smears” the effective matter-energy density of point particles over sub-Planck distances, and to assign an average value based on total mass divided by volume within event horizons to singularities).

    A difference of opinion regarding aether pretty much boils down to different people using different definitions of the term, both of which are admitted as viable in the ever pliable English language, without acknowledging this fact.

    General relativity, standard model quantum mechanics, dark energy cosmology, loop quantum gravity, string theory, modified gravity theories, and almost every other remotely mainstream theory in physics established or seriously examined by physicists, assigns some sort of properties to “empty space”, even if a fixed frame of reference turns out not to be one of those properties, and hence adopt aether-like concepts in the broader sense. In modern physics, vacuums aren’t truly empty.

    I prefer the broader definition and would be inclined to say that a certain kind of aether was rejected – the kind with a fixed reference frame, rather than the notion that empty space itself is something that has properties itself, that is at the real core of the term. But, your preferences may vary, and wouldn’t cause conflict if all participants disclosed the sense in which they were using the term.

  • Thomas Larsson

    The following analogues seem to me much more relevant:

    Aether and SUSY: A purely theoretical construct that theorists cling to, despite mounting experimental counter-evidence. Never, never, never give up.

    Dark matter/energy and epicycles: Fudge factors necessary to reconcile experiments with the prevailing theoretical paradigm.

  • http://www.astro.multivax.de:8000/helbig/helbig.html Phillip Helbig

    @60: Show us a better theory which fits the observations.

  • mpc755

    @Phillip Helbig: Aether has mass and physically occupies three dimensional space. Aether is physically displaced by matter. There is no such thing as non-baryonic dark matter traveling with matter. Matter moves through and displaces the aether.

    Einstein’s definition of the state of the aether:

    “the state of the [ether] is at every place determined by connections with the matter and the state of the ether in neighbouring places”

    The state of the aether at every place determined by connections with the matter and the state of the aether in neighboring places is the state of displacement of the aether.

    Displaced aether pushing back and exerting inward pressure toward matter is gravity.

    A moving particle has an associated aether displacement wave. In a double-slit experiment, the particle travels a well defined path which takes it through one slit while the associated aether wave passes through both.

    The Michelson-Morley experiment disproved a stationary aether the Earth moved through. The Sagnac effect disproved a completely entrained aether. The aether is neither stationary nor completely entrained by the Earth. Aether is displaced by matter.

    ‘NASA’s Voyager Hits New Region at Solar System Edge’
    http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-402_AGU_Voyager.html

    “Voyager is showing that what is outside is pushing back. … Like cars piling up at a clogged freeway off-ramp, the increased intensity of the magnetic field shows that inward pressure from interstellar space is compacting it.”

    It is the aether which is displaced by the matter the solar system consists of which is pushing back and exerting inward pressure toward the solar system.

    ‘Surprise! IBEX Finds No Bow ‘Shock’ Outside our Solar System’
    http://www.universetoday.com/95094/surprise-ibex-finds-no-bow-shock-outside-our-solar-system/

    ‘“While bow shocks certainly exist ahead of many other stars, we’re finding that our Sun’s interaction doesn’t reach the critical threshold to form a shock,” said Dr. David McComas, principal investigator of the IBEX mission, “so a wave is a more accurate depiction of what’s happening ahead of our heliosphere — much like the wave made by the bow of a boat as it glides through the water.”’

    The wave ahead of our heliosphere is an aether displacement wave. This is evidence of a moving ‘particle’, the solar system, having an associated aether wave.

    ‘Hubble Finds Ghostly Ring of Dark Matter’
    http://www.nasa.gov/mission_pages/hubble/news/dark_matter_ring_feature.html

    “Astronomers using NASA’s Hubble Space Telescope got a first-hand view of how dark matter behaves during a titanic collision between two galaxy clusters. The wreck created a ripple of dark mater, which is somewhat similar to a ripple formed in a pond when a rock hits the water.”

    The ‘pond’ consists of aether. The moving ‘particles’ are the galaxy clusters. The ripple is an aether displacement wave. The ripple is a gravitational wave. This is also evidence of a moving ‘particle’, the galaxy clusters, having an associated aether wave.

    ‘Giant black hole kicked out of home galaxy’
    http://www.astronomy.com/en/News-Observing/News/2012/06/Giant%20black%20hole%20kicked%20out%20of%20home%20galaxy.aspx

    “But these new data support the idea that gravitational waves — ripples in the fabric of space first predicted by Albert Einstein but never detected directly — can exert an extremely powerful force.”

    The fabric of space is the aether.

    Gravitational waves are ripples in the aether.

    What ripples when galaxy clusters collide is what waves in a double slit experiment; the aether.

    Einstein’s gravitational wave is de Broglie’s pilot-wave.

    They are both aether displacement waves.

  • http://juanrga.com Juan Ramón González Álvarez

    The common astrophysicists/astronomers’ claim that dark matter is the aether of the 21st century is rather accurate.

    The aether was theoretically postulated to account for certain observations. It was never found in direct experiments. In fact, experimental results were in contradiction with aether predictions.

    Dark matter was theoretically postulated to account for certain observations. It has been never found in despite of hundred of direct experiments made up to the date. There exists a broad range of experimental results and observations in disagreement with the dark matter model.

    Indirect observations as gravitational lensing do not count as “experiments that support dark matter”, because the same lensing is explained by theories without appealing to any hypothetical dark matter.

  • MNichols

    @Pinger & Bill
    I may get some details wrong (and I apologise in advance if I overly simplify the issue), but if I understand your question, you are asking why the Bullet Cluster (and other galaxies and clusters) have some structure to the dark matter in them (ie they aren’t uniform or points)?
    The universe isn’t uniform because dark matter does clump. It still experiences gravity (and maybe the weak force). This means any slight deviations from a uniform background in how it is was distributed originally gets amplified over time.
    However, it isn’t uniform because it gets angular momentum from these same deviations.
    If you have a piece of dark matter, it moves towards these already denser regions as they have stronger gravity. However, as it falls the attraction to rest of the dark matter gives it angular momentum, which means it misses the center slightly. Normal matter does this as well, however, it can get rid of some of this angular momentum through radiation and by colliding with other bits of material. Dark matter doesn’t collide, and doesn’t give off radiation so it keeps on orbiting this dark matter clump. This is similar to the planets around the sun (although we are in a disk because we were able to collide and radiate some of this energy away before the planets formed, so it is like a set of planets without a disk) or stars inside an elliptical galaxy.

    The too long; didn’t read summary is: It does clump, however, it can’t get rid of what angular momentum it gets when it first starts clumping so it doesn’t collapse into a black hole.
    Possibly the best visual examples of (simulations of) this clumping are available here http://www.mpa-garching.mpg.de/galform/data_vis/ which shows the Millennium Simulation and how we think the dark matter will look in these structures.

  • mpc755

    @MNichols Dark matter does not clump. Dark matter has been shown to be smoothly distributed throughout dwarf galaxies.

    What is mistaken as the clumping of dark matter is the state of displacement of the aether.

  • Jim

    Maxwell equations predict correct speed of light only when it is assumed that light is traveling through a medium with characteristics of a perfect solid. Am I correct in thinking that this should inform us regarding the nature of dark matter?

  • mpc755

    It informs you regarding the nature of the aether. Maxwell’s displacement current is a displacement of the aether.

    Aether has mass. Aether physically occupies three dimensional space. There is no such thing as non-baryonic dark matter traveling with matter. Matter moves through and displaces the aether.

    ‘Superfluid Is Shown To Have Property Of A Solid’
    http://www.sciencedaily.com/releases/1999/07/990730072958.htm

    “Northwestern University physicists have for the first time shown that superfluid helium-3 — the lighter isotope of helium, which is a liquid that has lost all internal friction, allowing it to flow without resistance and ooze through tiny spaces that normal liquids cannot penetrate — actually behaves like a solid in its ability to conduct sound waves.”

    The aether is, or behaves similar to, a superfliud with properties of a solid; an incompressible fluid.

  • Jim

    Perhaps the Mill’s hydrino referred to by Knov above has the necessary characteristics; dark, superfluid, and properties of perfect solid.

  • prasad

    “But the CBR does give a rest frame for the universe. ”

    Misleading. The issue of preferred frames is whether you have the same laws in all frames, or whether your laws in their form pick out one of them. It has nothing to do with whether (for example) you can identify a center of momentum frame for the visible universe.

  • mpc755

    Superfluid with properties of a perfect solid is the definition of the aether.

    There is no such thing as non-baryonic dark matter traveling with matter.

    Matter moves through and displaces the aether.

  • meh

    Why don’t you take the theory of an “aether” ( I hate that spelling ) and just use a different name if you really believe in it that much? You know the scientific community will never, ever, ever, ever, ever accept an aether. So why are you still calling it that?

    Do you know when you can spot a crackpot? When they say the exact same comment over and over again. Physics crackpots tend to hijack a remedial level popular science blog while claiming that they have the answers to all our problems; if only someone would listen. mpc755, if you believe so deeply in it, then why are you not professionally pursuing it? Why aren’t you a physicist? why aren’t you writing detailed scientific papers about it and proving it beyond a shadow of a doubt? because your a crackpot, and unfortunately, any crackpot can post a comment online free for anyone to post to. I’m doing it right now.

  • mpc755

    @meh Why aren’t you able to understand what is presently postulated as non-baryonic dark matter is aether? Why aren’t you able to understand there is no such thing as non-baryonic dark matter traveling with matter? Why aren’t you able to understand matter moves through and displaces the aether.

    From the ‘sloshing’ back and forth detected when galaxy clusters collide to the offset between light lensing through the space neighboring moving galaxy clusters and the galaxy clusters themselves, to the wave out ahead of our heliosphere being analgous to the bow wave of a boat, and on and on and on is the evidence of the aether.

    Einstein stated, “According to the general theory of relativity space without ether is unthinkable”. How are you able to interpret that to mean there isn’t an aether? What if Einstein had said ‘space with ether is unthinkable’. Would that have meant there is an aether in relativity? Of course not. How is it when Einstein specifically states there is an aether in relativity you are able to interpret that as there is no aether?

    How did mainstream physics get so screwed up as to insist there is no aether when ALL of the evidence IS evidence of the aether?

  • Meh

    Only someone who has been completely intellectually and logically defeated answers questions with questions. Do you know how many people like you there are on all the science blogs out there? I didn’t say I don’t accept an aether, I asked why are you so hell bent on picking a fight about it? because the way you are presenting the case for an aether, draws zero interest. When has the following argument ever persuaded anyone: You know that thing you absolutely refuse to believe, well I believe it, so you should too.

    DUDE, they refuse to believe it for one reason or another. You don’t understand how simple human communication works; THAT’s why you’re a crackpot!

    Another way to tell you’re a crackpot is because you’re assuming that everyone is arguing with you. I’m telling you that 99% of physicists don’t believe in an aether. I’m not saying I don’t believe in it, I’m stating facts.

    AND AGAIN, if you believe in it so much, why aren’t you pursuing it professionally? The answer is because you know you don’t have the guts or the intellect to do so. You probably know nothing about math and what you know about physics you read online. Yet despite your gross ignorance of the basics, you think that typing a comment on a popular science blog will definitely convince everyone who matters; these words you type will certainly change the world and it will be forever imbedded to a hard drive on a server. What could possibly change about our technology in 100 years? We’ll certainly always use the same method of data storage linked to the internet, right? Our method of transmitting information over the internet to various computers all over the world will certainly never ever change.

  • mpc755

    DUDE, why are you unable to understand there is no such thing as non-baryonic dark matter which travels with matter? Why are you unable to understand matter moves through and displaces the aether?

    AND AGAIN, why are you unable to understand displaced aether pushing back and exerting inward pressure toward matter is gravity, a moving particle has an associated aether displacement wave and in a double slit experiment the moving particle travels a well defined path which takes it through one slit while the associated aether wave passes through both?

  • Michael J. Brouillette

    You know, back in the 1970′s there was a musical group with the name “5th Dimension”…

    “Pay no attention to the man behind the curtain!” – OZ the Incredible

  • What’s It?

    Matter (all observed particles including photons) are density waves in “Aether” …

  • mpc755

    ‘Density waves’ is incorrect. As far as we know, aether is, or behaves similar to, a superfluid with properties of a solid; an incompressible fluid.

    A moving particle has an associated aether displacement wave. The aether displacement wave is the particle’s bow wave.

  • don’t feed the trolls

    Aether exists. Okay. Please write down a Lagrangian description and let us pick it to pieces.

    Don’t feel bad about that, lots of people have written down their proposed Lagrangians for Dark Matter and/or Dark Energy and they’ve been picked to pieces too.

    Perhaps yours will be more effective.

    Here’s a recent example.

    http://arxiv.org/abs/1201.3608

  • mpc755

    http://en.wikipedia.org/wiki/Lagrangian#General_relativistic_test_particle

    ‘Ether and the Theory of Relativity by Albert Einstein’
    http://www-groups.dcs.st-and.ac.uk/~history/Extras/Einstein_ether.html

    “the state of the [ether] is at every place determined by connections with the matter and the state of the ether in neighbouring places, … disregarding the causes which condition its state.”

    The PHYSICAL state of the aether at every place determined by PHYSICAL connections with the matter and the PHYSICAL state of the aether in neighboring places is the state of displacement of the aether.

  • mpc755

    ‘Interpretation of quantum mechanics by the double solution theory – Louis de BROGLIE’
    http://aflb.ensmp.fr/AFLB-classiques/aflb124p001.pdf

    “If a hidden sub-quantum medium is assumed, knowledge of its nature would seem desirable. It certainly is of quite complex character. It could not serve as a universal reference medium, as this would be contrary to relativity theory.”

    de Broglie is referring to a relativistic aether. The same aether as Einstein.

    ‘Ether and the Theory of Relativity – Albert Einstein’
    http://www.tu-harburg.de/rzt/rzt/it/Ether.html

    “As to the mechanical nature of the Lorentzian ether, it may be said of it, in a somewhat playful spirit, that immobility is the only mechanical property of which it has not been deprived by H. A. Lorentz. It may be added that the whole change in the conception of the ether which the special theory of relativity brought about, consisted in taking away from the ether its last mechanical quality, namely, its immobility.”

    An immobile aether is a universal reference medium. Both de Broglie and Einstein are stating the aether is not an immobile universal reference medium.

    “It is ironic that Einstein’s most creative work, the general theory of relativity, should boil down to conceptualizing space as a medium when his original premise [in special relativity] was that no such medium existed [..] The word ‘ether’ has extremely negative connotations in theoretical physics because of its past association with opposition to relativity. This is unfortunate because, stripped of these connotations, it rather nicely captures the way most physicists actually think about the vacuum. . . . Relativity actually says nothing about the existence or nonexistence of matter pervading the universe, only that any such matter must have relativistic symmetry. [..] It turns out that such matter exists. About the time relativity was becoming accepted, studies of radioactivity began showing that the empty vacuum of space had spectroscopic structure similar to that of ordinary quantum solids and fluids. Subsequent studies with large particle accelerators have now led us to understand that space is more like a piece of window glass than ideal Newtonian emptiness. It is filled with ‘stuff’ that is normally transparent but can be made visible by hitting it sufficiently hard to knock out a part. The modern concept of the vacuum of space, confirmed every day by experiment, is a relativistic ether. But we do not call it this because it is taboo.” – Robert B. Laughlin, Nobel Laureate in Physics, endowed chair in physics, Stanford University

  • mpc755

    “Relativity actually says nothing about the existence or nonexistence of matter pervading the universe, only that any such matter must have relativistic symmetry. [..] It turns out that such matter exists.”

    Matter has mass.

    “Subsequent studies with large particle accelerators have now led us to understand that space is more like a piece of window glass than ideal Newtonian emptiness. It is filled with ‘stuff’ that is normally transparent but can be made visible by hitting it sufficiently hard to knock out a part.”

    ‘Stuff’ has mass.

    Aether has mass.

    There is no such thing as non-baryonic dark matter traveling with matter. Matter moves through and displaces the aether.

  • Sir richard

    Wouldn’t force carrier particles be dark matter?

  • http://www.facebook.com/people/Kevin-Thomas-Nixon/1202481434 Kevin Thomas Nixon

    There is no dark matter. The expanding universe can be explained else-wise. There were two big bangs. The first was significantly larger than the second. Most of the mass (or pre-mass) of the first big bang escaped. Mass nearest the origin collapsed back to a new singularity and exploded again, the second big bang. We are part of that second event. No light was generated by the material of the first event for some time. The total mass of the first event was great enough for it to eventually collapse, which is what it is doing now. Our second event “universe” is being drawn out, faster and faster, by the gravity of this encroaching shell. The light from this “Outerverse” has not reached us yet, but it will, and suddenly. Then there will be a new sky, unlike anything we could have imagined. There is no dark matter.

    – gearpile

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Cosmic Variance

Random samplings from a universe of ideas.

About Sean Carroll

Sean Carroll is a Senior Research Associate in the Department of Physics at the California Institute of Technology. His research interests include theoretical aspects of cosmology, field theory, and gravitation. His most recent book is The Particle at the End of the Universe, about the Large Hadron Collider and the search for the Higgs boson. Here are some of his favorite blog posts, home page, and email: carroll [at] cosmicvariance.com .

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