Star Talk: Dark Matter and Dark Energy

Discussion in 'Science' started by Max Rockatansky, Oct 21, 2017.

  1. Max Rockatansky

    Max Rockatansky Well-Known Member Past Donor

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    This morning I was watching a rerun of Nat'l Geo's "StarTalk". Dr. Neil deGrasse Tyson had interviewed David Crosby, who turns out to be a science geek as well as a great muscian, and the subject turned to Dark Matter and Dark Energy. (see link below)

    Although most of us are familiar with both terms, Dr. Tyson's answer was interesting to me. He said, among other things, that Dark Matter should really be called Dark Gravity; gravity without a source. Dark Energy was a pressure forcing expansion of the Universe.....and nobody knows what they are. He added that both Dark Energy and Dark Matter compose about 96% of the Universe and everything else, the stuff we know is about, is 4%.

    He also reiterated the chess analogy by Dr. Richard Feynman seen in this link: http://en.chessbase.com/post/feynman-using-chess-to-explain-science

     
  2. tecoyah

    tecoyah Well-Known Member Past Donor

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    Dark matter seems to consist of actual particles with very little interaction beyond gravity, I and many consider the WIMP as the most likely candidate (whatever that turns out to be), and is literally the scaffolding visible matter clings to. Dark energy is interesting and is a term best understood as dark (because we have no idea) and energy (because we have no other word for it). Both may be aspects of neighboring universe bleed and are likely to become more understood in the coming decade once Webb comes online.
     
  3. Max Rockatansky

    Max Rockatansky Well-Known Member Past Donor

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    Possible, but the fact it constitutes 96% of our own Universe was a fascinating revelation to me.
     
  4. tecoyah

    tecoyah Well-Known Member Past Donor

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    Yeah...over the last decade and especially since Kepler came online things have gotten quite exciting in astrophysics and Cosmology. Once we hit the "Dark Age" wall and saw the universe after the big bang but before the first star everyone kiinda went nuts, then we mapped the way Dark matter works and everything got a head butt. Webb will do this on steroids but in a more intense way for QM and theory.
     
  5. Max Rockatansky

    Max Rockatansky Well-Known Member Past Donor

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    Fingers crossed on the launch and fulfillment of expectations.
     
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  6. Jonsa

    Jonsa Well-Known Member Past Donor

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    Very interesting developments lately:

    https://www.newscientist.com/articl...s-missing-matter-has-just-been-finally-found/


    Read more at: https://phys.org/news/2017-10-method-galaxy-clusters-astronomers-mysterious.html#jCp
    Method to weigh galaxy clusters could help astronomers understand mysterious 'dark matter' structures.
     
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  7. Moi621

    Moi621 Well-Known Member Past Donor

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    Dark this and that, just mathematical fudge factors.

    Why not bring back ether theory.

    Dark Matter. Show me!
    No not the math or the reasoning behind the myth. Show me Dark Matter.
     
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  8. primate

    primate Well-Known Member Past Donor

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    We see it. There is the missing mass of galaxies that hold it together. 1/5 of it if black holes etc. The rest is theoretical particles. There are blobs of dark matter some being dark galaxies we use for gravitational lensing. So it is there. Most ARE theoretical particles so that is theory.
     
  9. cerberus

    cerberus Well-Known Member Past Donor

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    I don't know how holes can collide, either. Apparently black holes 'colliding' with each other is what causes gravitational waves. To my simple mind a hole is a void, so how can a mass of nothingness bump into another mass of nothingness? Sounds like something NASA would dream up to me. [​IMG]
     
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  10. HereWeGoAgain

    HereWeGoAgain Banned

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    A density of a billion-billion Kg per meter-cubed isn't nothingness.
     
  11. primate

    primate Well-Known Member Past Donor

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    Neutron stars colliding also produce gravitational waves. They aren't holes and neither is a black hole. You need to understand the definition of a black hole but I'm betting you do as well as understand the process you're appearing to not comprehend.
     
  12. cerberus

    cerberus Well-Known Member Past Donor

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    I can tell you've been reading Science magazine!
     
  13. cerberus

    cerberus Well-Known Member Past Donor

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    I'll tell you what I do understand - I understand when someone's trying to fool me.
     
  14. Max Rockatansky

    Max Rockatansky Well-Known Member Past Donor

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    Agreed. Why is it that people who don't understand math and physics deny it exists since they can't understand it?
     
  15. Max Rockatansky

    Max Rockatansky Well-Known Member Past Donor

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    Some science links on Dark Matter and/or Dark Energy:
    https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy
    More is unknown than is known. We know how much dark energy there is because we know how it affects the universe's expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 68% of the universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, everything ever observed with all of our instruments, all normal matter - adds up to less than 5% of the universe. Come to think of it, maybe it shouldn't be called "normal" matter at all, since it is such a small fraction of the universe.

    [​IMG]
    Universe Dark Energy-1 Expanding Universe
    This diagram reveals changes in the rate of expansion since the universe's birth 15 billion years ago. The more shallow the curve, the faster the rate of expansion. The curve changes noticeably about 7.5 billion years ago, when objects in the universe began flying apart as a faster rate. Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart.


    https://www.space.com/g00/20930-dark-matter.html?i10c.referrer=https://www.google.com/
    Proving the unseen
    If scientists can't see dark matter, how do they know it exists?

    Scientists calculate the mass of large objects in space by studying their motion. Astronomers examining spiral galaxies in the 1950s expected to see material in the center moving faster than on the outer edges. Instead, they found the stars in both locations traveled at the same velocity, indicating the galaxies contained more mass than could be seen. Studies of the gas within elliptical galaxies also indicated a need for more mass than found in visible objects. Clusters of galaxies would fly apart if the only mass they contained were visible to conventional astronomical measurements.

    Albert Einstein showed that massive objects in the universe bend and distort light, allowing them to be used as lenses. By studying how light is distorted by galaxy clusters, astronomers have been able to create a map of dark matter in the universe.

    All of these methods provide a strong indication that most of the matter in the universe is something yet unseen.

    [​IMG]
    This Hubble Space Telescope composite image shows a ghostly "ring" of dark matter in the galaxy cluster Cl 0024+17.
    Credit: NASA, ESA, M.J. Jee and H. Ford (Johns Hopkins University)
     
  16. cerberus

    cerberus Well-Known Member Past Donor

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    Why is it that people believe everything they're told without any evidence?
     
  17. cerberus

    cerberus Well-Known Member Past Donor

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    Ooh look, another pretty (meaningless) CGI courtesy of NASA.
     
  18. Max Rockatansky

    Max Rockatansky Well-Known Member Past Donor

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    LOL
     
  19. HereWeGoAgain

    HereWeGoAgain Banned

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    Magazine? LOL! And how is your horse and buggy this morning?

    No, I looked up the density of a black hole. There is something called "technical literature". Look up the definition some time.
     
  20. HereWeGoAgain

    HereWeGoAgain Banned

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    He trolls science threads making stupid comments.
     
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  21. tecoyah

    tecoyah Well-Known Member Past Donor

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    Why is it that people with no alternate explanation for things, dismiss the explanation presented by thousands of people that spend lifetimes figuring it out?

    Purposeful Ignorance seems the most likely.
     
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  22. tecoyah

    tecoyah Well-Known Member Past Donor

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    They are not stupid to him...they are the peak of his intellectual ability.
     
  23. Moi621

    Moi621 Well-Known Member Past Donor

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    Nice try, no cigar.
    Looks to Moi like y'gotta believe. More like a religion with numbers and theory to back it up.
    The Church of Dark Matter & Dark Energy does sound Satanic, don't it.
     
  24. AltLightPride

    AltLightPride Well-Known Member

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    It's impossible by definition. By definition dark matter is matter that doesn't emit light. Since it doesn't emit light, you can't see it :)

    Most things in science work by inference. If the Sun didn't emit light, you could still know where it is because the planets revolve around it. Dark matter works the same.

    Dark energy is more of a mathematical fluke tho.
     
  25. Moi621

    Moi621 Well-Known Member Past Donor

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    Ether could fit the bill.
    Just apply some Ether Theory and say it is the fudge factor that makes the universe fit our expectations.
    Arithmetic is no excuse to say something is.
    We can make anti matter.
    Make some dark matter too.

    And what about anti Dark Matter and anti Dark Energy? Got math?



    Moi :oldman:
    Dark Matter Atheist.
     

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