• mpc755
    10
    Is our visible Universe in a larger version of the following?

    Black holes banish matter into cosmic voids

    Some of the matter falling towards the [supermassive black] holes is converted into energy. This energy is delivered to the surrounding gas, and leads to large outflows of matter, which stretch for hundreds of thousands of light years from the black holes, reaching far beyond the extent of their host galaxies.

    Is the energy described above at the scale of a Universal black hole dark energy?

    Our being in the outflow of a Universal black hole would explain the following directionality.

    New evidence for a preferred direction in spacetime challenges the cosmological principle
  • apokrisis
    6.8k
    Nope.

    Whatever dark energy is, it would have to be distributed absolutely evenly across every point of space (to match with the astronomical observations that identified its existence as a faint repulsive pressure present in the fabric of the void itself).
  • mpc755
    10


    Our being in the outflow of a Universal black hole would explain the following directionality.

    New evidence for a preferred direction in spacetime challenges the cosmological principle

    Note: also added above to original comment
  • apokrisis
    6.8k
    How is that particular claim bearing up?

    Thus, we conclude that there is no significant evidence for anomalous dipole anisotropy in the LSS....

    https://arxiv.org/pdf/1606.06751.pdf
  • mpc755
    10


    Low multipoles and other anomalies

    With the increasingly precise data provided by WMAP, there have been a number of claims that the CMB exhibits anomalies, such as very large scale anisotropies, anomalous alignments, and non-Gaussian distributions. The most longstanding of these is the low-l multipole controversy. Even in the COBE map, it was observed that the quadrupole (l = 2, spherical harmonic) has a low amplitude compared to the predictions of the Big Bang. In particular, the quadrupole and octupole (l = 3) modes appear to have an unexplained alignment with each other and with both the ecliptic plane and equinoxes, A number of groups have suggested that this could be the signature of new physics at the greatest observable scales
  • apokrisis
    6.8k
    Yep. So at best, this is an ongoing controversy. The consensus continues to advise caution.

    chief scientist from WMAP, Charles L. Bennett suggested coincidence and human psychology were involved, "I do think there is a bit of a psychological effect; people want to find unusual things."

    Sorry to be harsh, but the title of your OP suggests some half-baked thinking.

    "Is dark energy the outflow of dark matter from a universal black hole?"

    You might need to refine your terms. What is this dark matter such that its outflow would cause a general cosmic acceleration rather than a localised gravitational deceleration?

    If it is powerful enough to account for "70% of the missing mass", why does its flow from one place to another create such a remarkably insignificant cosmic anisotropy?

    What is a universal black hole here? Supermassive black holes are located in places within the universe. It sounds as you may be wanting to make some kind of "we are trapped inside a white hole" story that explains cosmic dark energy acceleration ... with a faint anisotropy. But why would that generalised hole even have an anisotropy?

    If you can put all the bits of the puzzle together, that would be interesting. So far I'm not seeing a well-motivated thought at the back of your OP.

    I'd be happy enough to be proved wrong, of course.
  • mpc755
    10
    , read the article linked to in my original post. The question being asked is why can't dark energy be a larger version of the energy descibed, leaving open the possibility that our Universe is anisotropic.
  • apokrisis
    6.8k
    But blasting dark matter out to create "cosmic voids" doesn't connect with a dark energy story of a faint added accelerative repulsion that is part of the void itself.

    It just spreads the gravitating mass about. It doesn't create a new generalised source of "antigravity".

    And there is no reason to think it would create an anisotropy. Why would these supermassive blackholes be distributed in a non-random fashion? What extra factor are you claiming would be in play?

    Again, I don't see the dots being connected. You would have to provide the motivating argument.

    Now it is also quite possible that a belief in dark energy is wrong. It is merely an optical effect - http://www.canterbury.ac.nz/news/2017/uc-cosmologists-reframe-dark-energy-debate-with-new-supernova-study.html

    But of course we do have a missing mass problem. And more than that, dark energy ensures the Universe - being apparently so evenly balanced - could defeat the prospect of a gravitational collapse. So - like inflation - it is a useful idea to be true.

    You seem to be headed towards a hypothesis that creates more problems than it would solve. So there would have to be good evidence of an actual anisotropy to want to go there.

    Just saying. Physics would accept weaker evidence for an effect that reduces complexity - like dark energy or inflation - than for an effect that would increase it.

    Hence you have to provide a good motivation for why the way you are heading would simplify anything for cosmology.
  • BC
    13.2k
    Well, we haven't actually found any dark matter yet, so how does anyone know how it would behave in a "universal black hole" whatever that is? Something... dark matter, dark energy, may exist and may have to exist to explain the accelerating expanding universe and the gravity that holds galaxies together -- isn't that the theory?

    It seems to me that you have run out on thin ice covering cold deep water. It won't turn out well. I suggest (a la cartoon) that you circle back to solidly frozen land without stopping to look down--at which point you would plunge into the icy deep
  • mpc755
    10
    I'm suggesting dark energy is the outflow of a Universal black hole. There is a singular super-super-supermassive black hole that we are in the outflow of.

    All of our visible universe exists in the outflow of the Universal black hole.
  • mpc755
    10
    I'm suggesting you read the article linked to in my original post and attempt to conceptualize our visible universe being in the outflow of a Universal black hole.
  • apokrisis
    6.8k
    What, the entire visible universe and this putative unproven anisotropy is so vanishingly faint?

    And you still haven’t said why the dark matter outflow would be seen as a generalised acceleration rather than a generalised deceleration. Are you suggesting dark matter has antigravity?
  • mpc755
    10
    In the article the gas accelerates outward and away from the host galaxy, and winds up far beyond the host galaxy. At the scale of a Universal black hole the gas is now galaxy clusters. The galaxy clusters accelerate outward and away from the Universal black hole.

    Our visible universe is in a larger version of the following outflow:

    main-qimg-71bf50388902449e4b7e4158df120a7a-c

    2a52baf87715fa5cfd26287f7546dbb8.jpg

    Our Universe looks like the following:

    blackhole.jpg?itok=PV2i94T3&fc=50,50

    drawn-universe-torus-20.jpg
  • Changeling
    1.4k
    Iff you look into a black hole, do you really see the end of time?
  • skyblack
    545
    If you rip the minute and the hour hands of the clock, what time is it right at the center?
  • skyblack
    545
    Your sand castles are all along the circumference, hence they are repeatedly being washed away by the tides of time.

    When the circumference is reduced to the center, where everything is tethered to, well....you won't be running around like a dog on a leash along predictable circles.
  • Astro Cat
    29
    Hi, I'm new to the forum. I'm a physics grad student, and some of my first research was to assist in constraining the dark energy using Type 1a supernovae at high redshift ranges.

    The title asks, "Is dark energy the outflow of dark matter from a universal black hole?"

    No, that wouldn't be right. Despite the term "dark" appearing in both terms, dark energy and dark matter don't have anything to do with one another. Dark matter is just a form of matter that is non-baryonic and that doesn't interact with electromagnetic radiation (because of this, it behaves very differently: it doesn't clump, for instance, because most clumping mechanisms depend on radiating energy away).

    Dark energy is a negative pressure (meaning it is repulsive): it has a negative equation of state (probably exactly -1, if it is a cosmological constant -- but we have only constrained it to <-0.6). If the universe is imagined to be like a fluid (an assumption that is apt), then there has to exist some kind of negative pressure in order to get a universe that looks like the one that we see. We just call that negative pressure "dark energy."

    (I'm trying to keep this within layman's terms, but for the more adventurous: we observe a universe that is isometric and homogeneous at scales above a few hundred Mpc but which is also apparently asymptotically flat. If we add up all of the energy densities of radiation, baryonic matter, and dark matter, we should see a universe that is not flat: in order to get a universe that's flat like the one that we see, there must exist an energy density with a negative equation of state. That's dark energy.)
  • 180 Proof
    14.1k
    :cool: :up:

    Welcome to TPF.
  • jgill
    3.6k


    Welcome aboard. There are several physicists on TPF but they like to cloak themselves in dark matter. :cool:
  • T Clark
    13k
    Dark energy is a negative pressure (meaning it is repulsive): it has a negative equation of state (probably exactly -1, if it is a cosmological constant -- but we have only constrained it to <-0.6). If the universe is imagined to be like a fluid (an assumption that is apt), then there has to exist some kind of negative pressure in order to get a universe that looks like the one that we see. We just call that negative pressure "dark energy."Astro Cat

    Welcome to the Philosophy Forum, where science goes to die. Or, alternatively, where bad science goes after it gets kicked off actual science forums. It's nice to read a clear, knowledgeable explanation of a genuine scientific topic.
  • Astro Cat
    29


    Thanks for your welcomes!

    Well, I will try to keep the science a little more sane around here then (I know how it goes, I've been posting on a couple of other philosophy forums as well). At least whenever it falls within my purview anyway!
  • jgill
    3.6k
    Welcome to the Philosophy Forum, where science goes to dieT Clark

    Accompanied by its handmaiden mathematics. :roll:
  • T Clark
    13k
    Accompanied by its handmaiden mathematics.jgill

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