Dark matter, apparently, is midichlorians

By Phil Plait | February 16, 2012 7:02 am

Dark matter, to re-interpret Obi Wan Kenobi, surrounds us and penetrates us. It binds the galaxy together.

At least that’s what a new scientific study seems to show. Dark matter appears to stretch well beyond the visible limits of galaxies, flowing through and filling even the vast, previously-thought empty space between galaxies. The researchers, led by Shogo Masaki of Nogoya University, used computer simulations to model how dark matter behaves over time as it helps form galaxies, and found that while it’s concentrated in and around galaxies, it doesn’t fade away into nothing with distance. It does get thinner, but still exists to a measurable degree well outside of galaxies. The model structure they found is actually quite lovely:

Remember, this is a model, and not an actual map. It does show concentrations of dark matter along galaxies and clusters of galaxies, but also shows how even "empty" space well outside of galaxies has pervasive dark matter in it.

OK, so what’s the deal then?

Dark matter was discovered a long time ago, when it was found that galaxies that live in clusters were moving way too fast to be held by the cluster gravity. They should just simply shoot away, and clusters would essentially evaporate. This implied that clusters of galaxies were either very young and hadn’t had time to dissolve — which we knew wasn’t true; they’re clearly old — or there must be a lot more gravity holding them together. We can add up all the light from the stars in the galaxies and estimate their total mass, but what you get is only about 5-10% of the mass needed to hold clusters together. So most of the matter making up the clusters must be dark. Otherwise we’d see it.

A lot of things are dark. Cold gas. Dust. Rogue planets. Burned out stars. Black holes. It’s hard to see how there could be more mass in any of these things then all the stars put together, let alone ten times as much! Still, over time, better observations started eliminating all the possibilities. Basically, everything made of normal matter was eliminated as a candidate. The Sherlockian conclusion is that something extraordinary makes up dark matter. The most likely possibility now is an exotic form of matter like axions, subatomic particles that have mass and gravity, but don’t emit light and don’t interact with normal matter. An axion could pass right through you, and like a ghost it would leave no trace.

But that doesn’t mean we can’t detect it. Just like we discovered it indirectly through its influence gravitationally, there is another way to "see" dark matter: gravitational lensing. In a nutshell, matter warps space, and light moving through that space follows the warped path. This can distort the shapes of distant galaxies, either strongly, really messing them up and bending them into long arcs and making multiple images of them (like in a recent and pretty Hubble picture of a galaxy), or it can be a weaker effect, gently smearing out the galaxy’s shape. Dark matter has mass, which means it has gravity… so it should create gravitational lensing.

In this illustration, imagine a bunch of background galaxies depicted by the points on the left. Plop a galaxy with dark matter between us and them, and the galaxy’s gravity warps the light from those more distant objects, bending the grid and also magnifying the background galaxies. All of this information can be used to map out the location and density of the dark matter doing the lensing.

Last year, astronomers made an incredibly detailed map of dark matter using an astonishing 24 million galaxies. By carefully measuring the shapes of these galaxies (using automated software) they could tell statistically how much the images were warped, and therefore how much dark matter there is, and where it’s located. Mind you, you can’t really point at any one galaxy and say it’s distorted by such and such an amount. But we know overall how they should be shaped, so by mapping millions of them (millions!) you can show statistically how they deviate from the expected shape. That in turn tells us about the dark matter between us and them, and this information was then used by the Japanese researchers as a test of their computer models of how dark matter behaved. That’s how they made the map above, and showed that dark matter extends well beyond the visible borders of galaxies.

And because dark matter outweighs normal matter in our Universe by so much, the researches involved have actually said that galaxies really don’t have boundaries. In a sense, they’re right. What we see is only a fraction of what’s really there. And since the dark matters extends so far past the limits of what we see, galaxies really don’t have borders. They just thin out over huge distances of space, overlapping. I picture it a bit like a mountain range: there are local peaks, but at their bases all the mountains merge together so it’s hard to tell where one ends and another begins. Amazing.

So, did you catch all this? Let me explain… no, there is too much. Let me sum up.

Matter that we can’t see directly but we know exists but can’t be normal matter or even interact with it directly bends space which warps the path of light which can be used if you have millions of galaxies at your disposal to see the subtle distortions of background galaxy light which smears them out and lets you map the location and density of that invisible matter and see that it’s everywhere even well outside the visible boundaries of galaxies which means it fills the Universe in every direction and at all distances.

Got all that? Well, maybe I can be even more succinct:

It’s the Force.

Credits: Shogo Masaki (Department of Physics Nagoya University); NASA, ESA, J. Rigby (NASA Goddard Space Flight Center), K. Sharon (Kavli Institute for Cosmological Physics, University of Chicago), and M. Gladders and E. Wuyts (University of Chicago)


Related posts:

- Funhouse galaxy
- Dark matter detected?
- A small step toward dark matter

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Comments (70)

Links to this Post

  1. Dark Matter & The Force | February 16, 2012
  2. solar-salvage.com - Episode 1, Page 91 | February 20, 2012
  1. Eric TF Bat

    Ah, so dark matter is the ether. Knew they’d find it eventually!

    Either that (pardon the pun) or else the entire universe is just a story in a book, and dark matter is what the pages are printed on. And temporal paradoxes are typos. Or is that typoes? Oh bother, I just shot my own grandfather…

  2. Jeff

    I may be wrong, but wasn’t it Obi’s “mentor” who described midiclorians to a young Vader?

  3. Sum it up nice you have. Force strong within you is.

  4. Shamik

    To extend your mountain range analogy – Dark Matter and “normal” matter seems more akin to an archipelago of islands. All we see are small pretty islands dotting the surface of the ocean, but in reality they are huge mountains extending over a vast distance down to the ocean floor!

  5. david

    I’d say that dark matter was hypothesized a long time ago, not discovered. When someone figures out what it is and detects it directly, then they get their Nobel for the discovery. Or maybe some else figures out that GR is not quite right and the need for DM disappears, and then they get the Nobel instead.

  6. Tara Li

    @1 Eric – You know, it really *does* sound like that so-called mythical ether they kept nattering about in the 19th Century. That, or the Dirac Sea of virtual particles that fills all negative energy levels so that particles can’t fall to them…

    Modern Physics has falled down the White Rabbit’s hole, where the ether has been found, except it’s not, because it doesn’t let us transmit information faster than light, even though it seems something *does* get transmitted faster than light – because nothing actually happens until we see it happen.

    Anyone seen any neutrino-grams from 2069 yet? So far, I’ve yet to hear of a paper saying “Here’s your mistake – you multiplied when you should have divided” on that topic – just lots & lots of “Oh, here’s what you *COULD* have done wrong, even though you show how you took care of it” and “Oh, it’s impossible because our understanding of physics is perfect and this doesn’t fit that – even if Dirac taught us a lesson *ONCE* about ignoring ‘physically meaningless’ results of equations (damn those pesky positrons!)”

  7. Bob

    Researchers have produced simulations like the one above for over a decade and dark matter has been posited to exist in voids since it was first thought necessary to bind together clusters. This doesn’t seem like a new result…

  8. Bob

    Researchers have produced simulations like the one above for over a decade and dark matter has been posited to exist in voids since it was first thought necessary to bind together clusters. This doesn’t seem like a new result…

  9. Chris

    As I like to tell my gen chem students on the first day of class, we are just an impurity in the universe. All the elements heavier than helium make up about 0.04% of the universe’s energy. Just a smidgen.

  10. James

    That picture reminds me of a time I asked an astronomer what a 3D gravity well would look like. After a few minutes of thinking (staring into space) he said “I don’t know”.

  11. Jason

    Wait a sec. How can it have gravity and mass and not interact with us? Does it only interact with photons (hence the bending of light in gravitational lensing)? And, if so, how can it affect the expansion of the universe? I’m very confused.

  12. Daffy

    Paraphrasing Dylan: “Something’s happening and we don’t know what it is.”

  13. Peter Davey

    Some of you may have read Stephen Baxter’s “Xeelee” sequence, in which a race of dark matter beings – “photino birds” – start remodelling the universe to make it more hospital to their own kind of life; triggering supernovae, in order to “age” the Universe, reducing the risk to their “nests”.

    In the course of this action, they are making the universe far less hospitable to our kind of – Baryonic – life.

    I trust this will not turn out to be nature imitating art.

  14. Jess Tauber

    Nobody doesn’t like Tara Li… couldn’t resist :)

    Could Dark Matter be affecting properties of atoms or subatomic particles as they supposedly pass through each other? If the former has mass, then what is felt by anything overlapping or adjacent will be altered. This might then cause certain properties to shift slightly in value- say, for example, the Fine Structure Constant, which seems to change (still controversially) depending on what direction of the sky one looks at. So perhaps the local shape of the Dark Matter web, with changes in density, could be to blame, assuming the effect is real? I can imagine a number of different properties of matter that might change if a Dark Matter background has to be taken into account.

  15. This is all well and good, but how does Dark Energy, which drives the galaxies apart, fit into your Jedi cosmo-theology? I will tell you, as a Sith Master, that the real power in the universe comes from Dark Energy, which Luciferians call the Black Flame. You may think of Dark Energy as the power of Satan made manifest, for it is that which drives the Light of all Creation into the infinite, eternal Darkness of the universal Void.

    May the Dark Energy be with you.

  16. Robin Byron

    Looks like ‘cosmic foam’. ;) Where bubbles touch, there be galaxies. The rest is invisible.

  17. ctj

    if you’re going to reference the princess bride, you may as well call it true love.

  18. Dave

    Not that the whole article wasn’t interesting (it was), but I just wanted to say I liked “The Princess Bride” reference. :-)

    Well played sir, well played.

  19. steve

    Fascinating stuff! This is the best explanation I’ve ever read on dark matter and the map is gorgeous.

    I love the Star Wars reference and the far more subtle Princess Bride :)

  20. Relativity

    @12 Aye! True love, indeed!

  21. fractalEDGEpress

    The 2D universe of Flatlanders is contained within the 3D universe of the spheres and cubes. They only see evidence of, say a sphere, when the sphere intersects with the plane of their universe – and they freak because first there’s a point at the first moment of intersection, which becomes a tiny circle, the radius of which increases until it equals the radius of the sphere, and then (assuming here that the circle is just passing through) decreases to a point and vanishes – nothing “native” to Flatland acts like that. BUT within Flatland, if they bothered to measure gravity, they would be able to detect the presence of the inhabitants of 3D world even though they couldn’t see them. A sphere, near to, but not intersecting with Flatland, would still exert a gravitational influence on Flatland.

    OK, bump that story up a dimension or two. We cannot see matter in the dimension one beyond where we are [remember superstring theory requires 11 dimensions], but we would be able to measure and witness the effects of the gravity of the matter in all dimensions beyond the ones we can see. And it may be that, because we would suspect that the laws of physics would be consistent throughout all those dimension [all of them are part of "our" physics now], dark matter that we cannot see but can measure the effects of may just be “regular matter” that we cannot see because we cannot see into the next dimension up, even though all of our dimensions are completely contained in each of the higher order dimensions.

  22. PdlJmpr


    If DM changes the direction light travels, does it change light’s speed?

  23. Ahh, this is one of the coolest posts I’ve read on BA in quite some time! Excellently written with great images to illustrate the ideas. Dark matter is a fascinating subject… How bout a deep dive on dark energy next?

  24. Mike

    To PdlJmpr:

    No, the speed of light is a constant, regardless of the motion of the observer.

  25. Erin

    I like the Princess Bride reference.

  26. Artor

    @PdlJmpr
    No, the speed remains constant, but the energy levels & frequency change. The resulting Doppler shift is how we determine how fast & how far things are.

  27. Bigfoot

    Please, can somebody just tell me, what’s the matter?

  28. Bart

    I’m waiting for the claim that this explains how astrology works.

  29. Ezza

    Sounds pretty bang on to me.

  30. David Brown

    “… it’s everywhere even well outside the visible boundaries of galaxies which means it fills the Universe in every direction and at all distances.” If M-theory with the infinite nature hypothesis is correct, then dark matter should be the manifestation of one or more exotic particles. If M-theory with the finite nature hypothesis is correct, then dark matter should be the manifestation of the Rañada-Milgrom effect.
    http://en.wikipedia.org/wiki/A_New_Kind_of_Science

  31. That’s one hell of a sentence… ;)

  32. Andy B

    Interesting as always, and I lol’d at the Princess Bride reference!

  33. Mike

    Well, we really don’t know what dark matter is, so it might as well be “the force”.

  34. harry

    Great article.

    People should note that there are currently experiments deep underground (to remove the influence of the sun) designed to detect dark matter directly. We do not necessarily have to depend on indirect observation.

    Wikipedia has a brief synopsis, although you can find some data on how the experiments are going from other sources. Once they have been run long enough, we hope to have good evidence as to the nature of dark matter.

    Dark energy is the real mystery. Either is it real and we have no clue what it is, or general relativity needs some serious adjustment.

  35. Jazz

    Dark matter is a silly attempt to theorize thru something that we simply cannot understand. It must be pointed out that just like quantum physics, the dark matter/energy junk is theory Only. Try this one out- GRAVITY IS NOT A CONSTANT. All the questions left by the theoretical stuff fall away when one understands that Newton and maybe even Einstein didn’t understand gravity as it applies to the vastness of the universe(s).
    No, it is not my bit of scientific work; this was published in Discover magazine about a decade ago.

  36. Jay T.

    Beautifully written!! Mind blown!

  37. Captn Tommy

    Let me understand this … I am either a wave pattern, or a particle, or both… AND I am being held in a jar/balloon/fishbowl 26 billion light years accross. Which is being expanded by an Energy I can’t feel… AND yet is also being held together by Matter I can not see NOR feel
    Yes… but what is the terminal velocity of an unincombered African swallow? Or was it European?

    Captn Tommy, who matters darkly, and seems to be full of dark energy ……………………………..and it’s only Thursday.

  38. truthspeaker

    Tara Li Says:
    February 16th, 2012 at 7:42 am

    even though it seems something *does* get transmitted faster than light – because nothing actually happens until we see it happen.

    Um, what?

  39. amphiox

    No, the speed of light is a constant, regardless of the motion of the observer.

    In a vacuum.

  40. James Evans

    Dark matter, to re-interpret Obi Wan Kenobi, surrounds us and penetrates us. It binds the galaxy together.

    While this is indeed a paraphrase of Obi Wan speaking about the Force in Episode IV, we have only a doting, prequel-minded Lucas and Qui-Gon Jinn to thank for midichlorians. We can’t blame that hopeless disaster on Old Ben, even if as a youth he’s still guilty of not deciding to do us all a big favor and cut Jar Jar in half with his lightsaber.

    I’m jussayin’…

  41. harry

    I think the person is referring to the results indicating a neutrino may have exceeded the speed of light in the measurement reference frame.

    However, even the scientists that did the experiment will be the first to tell you it needs to be repeated many times at other locations before the results would be meaningful. Science does not jump to conclusions based on one set of observations. In fact, most prominent particle physicists agree that the results are most likely in error.

    Popular science articles in the media sort of oversimplify what is going on in any case. Even if the results are true, physicists have stated that there are explanations that do not involve violating our current models of the universe.

  42. SoupNazi

    Maybe Julian Barbour is right and we don’t have a need for Dark Matter , Dark Energy or String Theory :)

    http://discovermagazine.com/2000/dec/cover/?searchterm=universe%20theory

  43. peter

    I don’t understand this, if dark matter is so evenly distributed, why doesn’t ‘normal’ matter show the same behaviour? What exactly is holding the galaxies together? Obviously not gravity, since if this was the case, we would surely expect similar patterns to occur with both dark matter and ‘normal’ matter.

  44. Pam

    Fun article. I’ve been waiting for someone to say that dark matter = the Force.

  45. Mike

    Just to clarify – I think Tara Li’s comment about things travelling faster than light referred to the Copenhagen Interpretation of quantum mechanics, which seems to imply the famous “spooky action at a distance”. I am not a physicist but from what I have read I prefer the “Many Worlds Interpretation”, which circumvents this issue (but doesn’t explain absolutely everything) in that it re-interprets the so-called “collapse of the wave function upon observation” by assuming that nothing collapses and that all possible outcomes factor out and are enacted in physically separated worlds. Because our brains (and hence our minds) are also split into different worlds, we perform the measurement in multiple worlds, and multiple copies of us discover different outcomes of the experiment. Unsurprisingly, many people find this hard to accept, but many physicists think it is elegant and more likely… all I can say is that it’s certainly more elegant and likely to me than the alternative, which seems to give consciousness special powers over the universe.

  46. Gary Ansorge

    21. fractalEDGEpress

    Cool! Best hypothesis goes to you,,,

    Ah, Dark Mater, I knew thee well,,,

    ,,,oh,Phil, you meant,,,well, that’s DIFFERENT,,,never mind,,,

    Gary 7

  47. zandperl

    “Dark matter was discovered a long time ago, when it was found that galaxies that live in clusters were moving way too fast to be held by the cluster gravity.”

    I am under the impression that the original discovery of (or evidence for) dark mater was not due to galaxy clusters but due to galaxy rotation curves, by Vera Rubin.

  48. Brian Too

    I still suspect that that the theorists are whistling past the metaphorical graveyard, physics-wise. They confidently announce that DM/DE is this, that or the other, and equally confidently announce what it is not.

    The truth is that they have a crashing lack of data, just a measurement discrepancy and a bunch of hypotheses that might explain it all. Maybe.

    One day we’ll learn what is going on. I would not be surprised if, on that day, the theorists are mildly embarrassed and looking for cover as to why their favorite hypothesis was out to lunch. “Oh well, it seemed perfectly reasonable to suggest that 90% of the universe was an unknown and undetectable something-or-other. Hey, look over there, an aardvark!!”.

  49. After all is said and done when we come to greater understandings concerning the observations that have lead us down the “wrong paths,” I think that both the dark matter and dark energy conclusions will be enlightened :) by new understandings and formulations which will eliminate the need for either.

  50. Paul Hannah

    In what way is Dark Matter different from the ‘ether’ that pre Einsteinian physicists imagined?

  51. @Paul Hannah,

    I think you are making a good point. The almost universally accepted aether of the last century was also called a luminiferous aether, meaning it was the theorized carrier of light and energy waves. The dark matter hypothesis does not propose a luminiferous medium in the ZPF. Instead it proposes that the substance must be a form of matter, not something too small to be measured as a single entity, as prior aether theory proposed.

    But yes, I think there is something there. In my opinion, however, it is probably more like the aether of the last century than the dark matter idea today. The same aether could be both the carrier of EM radiation as well as the sole cause/source of gravity. Both aspects/ explanations for light and gravity could be solely mechanical based upon an aether. I believe the Michelson Morley experiment of the last century, and others since then, could not detect an aether because the experiments were not sensitive enough to detect a gravity centered, slow moving aether.

  52. So aardvarks are responsible for dark matter? Wouldn’t it be much less expensive and much more efficient to spend science dollars learning to communicate with aardvarks?

  53. Jeff

    Catn tommy. . . It’s an “unladen” swallow, not “unincumbered”, followed by Arthur’s question “African, or European?”

    sorry, I only contribute to what I know, and DM isn’t one of those.

  54. SoupNazi

    @ Brian Too

    Agreed – I am not a physicist but am an enthusiast, but It has always seemed to me like this whole DM/DE and string theory business are really complicated ways of attempting to reconcile Einstein’s relativity with the very large and the very small. Occam’s Razor should apply here. It seems far more reasonable to me to assume that Einstein may not have been completely correct as his models don’t work completely at the very large and very small scales. I’m sure he would have thought so…

    I am excited by Julian Barbour’s work. We may gain a much better understanding of and become MUCH better at manipulating our environment if he turns out to be correct.

  55. prianikoff

    The classic ether was proposed to be a static medium through which light waves propagate. This theory was disproved when experiments showed that the speed of light wasn’t changed by the direction, or the velocity of the light source.

    However, the speed of light *is* changed by its passage through a transparent medium if it’s composed of particles that have electrons.
    Dark matter can’t be made of something like this;
    It isn’t a medium through which light propagates. It must be something that has no electrons. Something which doesn’t emit, scatter or reflect light, but which has a gravitational effect.

    This strongly implies some form of sub-atomic particle.

  56. truthspeaker

    Mike, I don’t see how the Copenhagen inerpretation or any other one gives consciousness special powers, or even has anything to do with consciousness. Remember, an observer doesn’t have to be conscious.

  57. Does dark matter interact with itself?
    Even if not, what prevents large amounts of it from coming together, like nebulae come together to form stars?
    What prevents macroscopic objects of dark matter to exist?
    Can it fall into a black hole, and would there be any radiation like from regular matter infall?

  58. Andrei

    Since I heard and read about it, I’m more attracted by MOND than DM / DE.
    You can always regard these kind of maps as some error maps between MOND and accepted gravity. And if gravity decreases only with inverse of the distance for large scale structures like in MOND, then I guess that you’ll get quite large errors for the “voids” in the Univers’ superstructures – i.e. the map will be grey like in the main image and not pitch black.

  59. CB

    Does dark matter interact with itself?

    To explain its behavior it would have to not interact with itself any more than it interacts with normal matter. This isn’t that odd; neutrinos aren’t any more likely to interact with each other than they are with other things relative to their cross-section.

    Even if not, what prevents large amounts of it from coming together, like nebulae come together to form stars?

    Friction plays an important role in causing nebulae to collapse. Without it, the particles that are accelerated towards each other would continue right on past each other, slowing down but perhaps being dragged off by other gravitational sources. There clearly is some structure in the Dark Matter map, though.

    Since I heard and read about it, I’m more attracted by MOND than DM / DE.
    You can always regard these kind of maps as some error maps between MOND and accepted gravity.

    The original map is a simulation of how DM might behave, it isn’t an ‘error’ in anything. The map of where actual DM is suspected to be based on gravitational lensing is just that — a map of gravitational lensing. To explain that without DM, MOND has to explain how we get lensing in the absence of mass-energy.

    MOND did a pretty good job of explaining galactic rotation curves, but doesn’t do so well at explaining many of the other observations that support DM. In order to fit all the evidence, MOND has to essentially adopt DM or something close enough to be philosophically equivalent (and philosophical objects seem to be common ones).

    MOND doesn’t even come close (or try AFAIK) to replacing the need for DE. If gravity was decreasing linearly on large scales the expectation would be greater deceleration of the expansion than if decreasing quadratically. Accelerating expansion runs counter to any theory of a universe dominated by gravity.

  60. Andrei

    Yes, MOND is not 100% correct and does not explain everything, but the beauty of MOND is that sometimes is better to think outside of the box and don’t take for granted what it’s “established” knowledge. Maybe, sometimes, it’s better and far more productive to allow your imagination to go further with ideas that seem crazy – like the idea that the Earth revovlves around the Sun was some centuries ago.
    About error maps – you can always regard DM maps as error maps – in fact that’s exactly what they are.
    If you discard DM from the models, you’ll have error terms that must be acounted for – graph them and you’ll get a map simillar with DM maps – the more error you have, the more DM you need to account for it, so the more densier the map will be.
    So DM IS an error term as DM is assumed to explain why we have deviations between our models and reality.

  61. Dr.Sid

    IMHO midichlorians are actually mitochondria. The have independent DNA, and so they are a symbiotic organism in a way .. they indeed provide energy to our bodies .. Lucas just added some mysticism around it ..

  62. Captn Tommy

    54. Jeff Says:

    Unladen it is! Thank you.
    ___________________
    What Matters Darkly,
    Simply cannot be seen,
    Save in the imaginations
    Of the night.
    And the laughter of Children

  63. Clark

    Perhaps instead of DM, the gravitational effects we are observing are caused by “holes” in the space-time continuum. A “hole” in space might have a similar impact on the space-time continuum as a gravitational well. Holes in space may be all around us, but might not be detected unless they have clustered enough to produce noticeable gravitational-like effects.

  64. MNP

    As non-science person, what I don’t understand is how Dark Matter can be detected at all. If it can’t interact with normal matter, how can it exert a gravitation force on normal matter?

  65. Collin

    I second Tara Li on #6. Dark matter has all the properties that would be expected of an ether.

    However, that’s not the same thing as the Dirac sea. If the Dirac sea exists, its amplitude would be an infinite non-sortable product of anticommuting variables. And that’s impossible.

    Clark #65, what would keep these holes open? What would keep them from “filling in” and becoming ordinary black holes?

    MNP #66, it does interact. We can see light because it interacts differently with positive and negative charges. All mechanical and chemical forces are caused by moving charges. They are actually the electromagnetic force being “rigged” by the structure of atoms, like the arrangement of sails on a ship rigs the wind. However, dark matter hits all particles equally, regardless of their charge. Theoretically, this could be measured directly by something similar to a gravity wave detector. However, nobody’s ever figured out how to make that either.

    Light travels through the vacuum at speed c, at which the dilation factor (which goes from absolute to relative) is infinite. Since light imparts a finite relative energy density on whatever it hits, its absolute energy density is zero (finite divided by infinite). Therefore it has no mass. Dark matter is presumably a form of energy that travels through the vacuum slower than c, so this argument doesn’t apply.

  66. Clark

    Collin #67, I’m thinking of a hole in the space-time continuum. Matter could not “fall into it” because matter is a part of the space time continuum. If it acts as a gravity well, matter could accumulate around it if it is big enough and may form something similar to a black hole, but a small hole might be right in front of your face and you wouldn’t see it. A small hole might have the same effect on the matter around it as the gravitational effect of an atom.

    So where does the hole go? Perhaps our universe is encompassed in a much larger metaverse that is continually expanding. This expansion could be dragging our universe along with it in all directions, which accounts for dark energy. The holes in our universe could be gaps in the space-time continuum that are a part of this metaverse.

    What’s the current thinking on the giant black holes found at the centers of galaxies? Are they considered to be the accumulation of thousands of black holes from former stars? Perhaps they are just vast gaps in the space-time continuum that have gathered clouds of stars and matter around them, like soap suds around a drain.

    If there is an ever expanding metaverse outside of our universe, perhaps this explains the effects of gravity. Perhaps the expanding of this metaverse has a greater drag on matter than on the surrounding space-time continuum, which creates the effect of a gravitational well within the space-time continuum.

    Or perhaps not.

  67. How come no one has pointed out that the dark matter distribution pictured looks a lot like the large scale structure of the Universe?

    What is the scale of that picture/model? I would like to see it’s relative size next to a model of the large scale structure of the Universe.

  68. Checkmate1

    It’s metaverses and turtles all the way down. (Why do you think electron energy levels in an atom are called shells?) Just beware of the Phlogiston; it turns really dark down there at the Particle Turtle level…

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »