Mystery of dark matter may have been solved

Discussion in 'Science, Tech, & Space Exploration' started by ChrisIB, Dec 5, 2018.

  1. ChrisIB

    ChrisIB Honorable

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    Mystery of dark matter may have been solved by Oxford scientists
    I get that tensors are just scalars and vectors but negative gravity? how does that relate to the curvature of space time?
     
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  2. Dejan Corovic

    Dejan Corovic Honorable

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    Now we just need metamaterial that can create that negative mass & energy.
     
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  3. Thomas R. Morrison

    Thomas R. Morrison Honorable

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    Hahaha...this is hilarious. So, for 70 years the mainstream physics community has been heaping ridicule and scorn upon the ufology community because witnesses have been describing the levitation of these devices as "antigravity." And nearly all of the academics cried out that antigravity was physically impossible because 1.) it would violate the positive energy theorem - this turned out to be untrue, and 2.) it would appear to require the existence of matter with negative mass, which they said was absurd and impossible.

    Then in 1998 we discovered that the galaxy clusters are accelerating away from each other; in other words, there's an antigravitational field acting between the galaxy clusters. That was such an embarrassing finding that they've been calling it "dark energy" instead of "antigravity" ever since.

    And now it appears that there may be a fluid of exotic matter (i.e. that possesses negative mass) surrounding the galaxy clusters, which is producing both "the dark matter effect" (in this model the negative mass fluid is producing an antigravitational acceleration upon the galaxies from the outside, thereby producing the illusion of "missing matter" within the galaxies) and also "the dark energy effect" which is accelerating the galaxy clusters apart from one another. And in this model, this negative mass fluid is being created right now as part of the natural dynamics of the universe. So if this model is correct, then we should eventually be able to make this stuff in the lab. If that's true, then we'll eventually be able to build our own UFOs, and conduct rapid manned missions to other star systems.

    Here's the link to the full 20-page paper. This should be a fun read:

    http://inspirehep.net/record/1644598/files/1712.07962.pdf

    Usually when people talk about tensors, they mean a rank-2 tensor, which is defined by a matrix. Rank-0 tensors are scalars, rank-1 tensors are vectors, and rank-2 tensors are matrices (in general relativity gravity is described by a rank-2 tensor, the Einstein tensor). That's how GR describes the manifold of spacetime; it's a higher order than a vector equation.

    We've known that the dark energy effect manifests as a negative gravitational field since 1998. Negative gravity, or if you prefer, "antigravity," curves spacetime in the opposite direction from ordinary gravitation. So if you think of the gravitational field around a planet or a star as a "well," then negative gravity can be thought of as a "hill." A negative gravitational field also produces a gravitational blueshift, instead of the ordinary gravitational redshift. This stuff isn't theoretical anymore, it's now a key feature of modern astrophysical studies that are examining an effect known as the late-time integrated Sachs-Wolfe effect. Counterintuitively, this effect "warms" photons from the cosmic microwave background radiation when they pass through regions of higher density like galaxy clusters, and "cools" photons that pass through supervoids where the dark energy effect (aka antigravity) dominates.

    Generally relativity always permitted negative gravity. In fact the cosmological constant that Einstein invented to produce a static universe - before we learned about the Big Bang which rendered that notion obsolete, is a negative gravity term in the Einstein field equation - they brought it back when we discovered the dark energy effect. But if this theory is correct, then "the cosmological constant" isn't a constant after all - it's produced by a fluid with negative mass which gathers around galaxy clusters in the form of gigantic halos.
     
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  4. Dejan Corovic

    Dejan Corovic Honorable

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    Yeah, hopes are high, but lets not get overheated.

    I've seen papers where autors claimed that galaxies spin faster just because of lots of matter that hadn't been accounted for inside galaxies (don't have link). It still could go both ways.

    This new theory seems to be testable in a simple way with radio astronomy. So we might know soon.

    There is a really easy to understand description of Sach-Wolfie's effect here:

    Integrated Sachs-Wolfe Effect
     
    Last edited: Dec 5, 2018
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  5. Dejan Corovic

    Dejan Corovic Honorable

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    Is it possible that "warm" and "cool" should swap the places here because it makes it difficult to understand? When photons pass through galaxy clusters they are redshifted to longer wavelengths as they lose energy. Loss of energy means that photons are "cooled", since cooling means lowereing enrgy. Opposite, when photons pass through supervoids they gain energy and photons are blueshifted or "warmed". Gaining energy makes somthing warmer.

    I know that in human terms red is warm, and blue is cool, but in reality that's illusion caused by presence of water molecules in our body. And water molecules are of the similar wavelength as IR and red wavelengths so water heats up and we feel warmer.
     
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  6. Thomas R. Morrison

    Thomas R. Morrison Honorable

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    Look at it this way: in an otherwise unchanging universe, a photon approaching a galaxy cluster gets blueshifted as it approaches the center of the gravity well (with respect to an observer at that center of the well), and then gets redshifted by the exact same amount as it exits the gravity well. There would be no net change in the energy.

    But the universe is evolving. Galaxy clusters are constantly coalescing into more tightly bound conditions (each star is undergoing fusion, for example) which releases radiant energy (light) into the cosmos at large - so galaxy clusters are slowly losing mass. And therefore the gravity well of a galaxy cluster grows slightly more shallow over time. So the photon approaching the galaxy cluster gets blueshifted (gains energy) as it approaches the center by a greater degree than it gets redshifted on the way out, because the gravity well isn't quite as deep as it exits the other side, hundreds of thousands or millions of years later. So it ends up slightly blueshifted, aka "warmer," by the time it reaches our telescopes. The inverse effect happens with respect to supervoids, which causes the photon to end up with a lower energy and frequency, i.e., it becomes "cooler."

    That's why I said that the late-time integrated Sachs-Wolfe effect is counterintuitive, at first blush anyway.
     
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  7. Dejan Corovic

    Dejan Corovic Honorable

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    I understand your explanation, but don't they teach in textbooks that superclusters red-shift passing photons? Wasn't that a reason why superclusters look a bit yellowish/golden? We don't see blue shifting from photons that pass through clusters?
     
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  8. Thomas R. Morrison

    Thomas R. Morrison Honorable

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    Well, there are two additional things to consider here. One, a photon originating within a gravity well will be redshifted, and two, the Hubble expansion and the cosmological acceleration produce a cosmological redshift. And of course there are Doppler redshifts and blueshifts to consider as well, due to incidental velocity differentials. They have to account for all of that stuff to tease out the ISW effect signals.

    Sure we do - that's the strongest part of the ISW effect signal. Photons passing through, or by, galaxy clusters are definitely left with a detectable warming, i.e., a residual blueshift, because the net galaxy cluster mass drops somewhat during the long transit period. The cooling from the supervoids is a much weaker signal, but they say they've detected it and the current surveys are honing those signals, so it's not purely theoretical anymore.
     
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  9. Shadowprophet

    Shadowprophet N=R^.fp.ne.f1.fi.fc.L

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    I would be more impressed but it's honestly about damn time. 70 plus years three generations. It's too long to wait.
     
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  10. Dejan Corovic

    Dejan Corovic Honorable

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    These are all animations from that paper that equates dark mater and negative mass
     
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  11. Shadowprophet

    Shadowprophet N=R^.fp.ne.f1.fi.fc.L

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    Wonderful, I love these kinds of videos,
     

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