Dark Matter and Dark Energy

Discussion in 'Science and Technology' started by Dryson, May 28, 2014.

  1. Silvercrest

    Silvercrest Rear Admiral Rear Admiral

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    Where?
     
  2. HIjol

    HIjol Admiral and Consummate Peacemaker Premium Member

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    In a time and place long past...
    ...:techman: nice! :guffaw:
     
  3. iguana_tonante

    iguana_tonante Admiral Admiral

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    Ah, the sweet, sweet sound of desperation.

    So you just happened to post your sarcastic reply here immediately after our disagreement in... the other place? Yeah, sure.
     
  4. Asbo Zaprudder

    Asbo Zaprudder Vice Admiral Admiral

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    Wimp or macho, I'm only axion.
     
  5. GalaxyX

    GalaxyX Rear Admiral Rear Admiral

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    Well you still haven't contributed an actual theory, even though you might be the most qualified person on this thread to do so.

    I know I'd welcome being proved wrong if you have some good factual data that I'm not privy to.
     
  6. iguana_tonante

    iguana_tonante Admiral Admiral

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    I teach astronomy for a living. If you want me to do it for free, you are out of luck.
     
  7. JarodRussell

    JarodRussell Vice Admiral Admiral

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    The universe is stuffed with massive black holes everywhere, apparently most of the galaxies have super giant ones in their centers. Immense bodies of mass, black. Wouldn't that be a more reasonable explanation?

    Another vote against free education.
     
    Last edited: Jun 11, 2014
  8. Robert Comsol

    Robert Comsol Commodore Commodore

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    Well, the way I see it the astrophysical community is unable to explain it.

    Professor Hawking gives the subject a wide berth and apparently prefers to speculate on invading aliens, artificial intelligence etc.

    So it's still the Force that holds our galaxy together (dark matter effect) and another power that tries to disperse celestial bodies (dark energy effect)?

    Bob
     
  9. GalaxyX

    GalaxyX Rear Admiral Rear Admiral

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    I too have wondered about this. When I read about this theory, it seemed a little crackpot to me. But in the end, how can we really know? I don't think we have even remotely close enough information to be able to theorize about black holes and dark matter/energy.

    So as of now, perhaps any theory is as valid as any other.
     
  10. Asbo Zaprudder

    Asbo Zaprudder Vice Admiral Admiral

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    Doesn't explain the anomalous rotation rates of the outer parts of galaxies. You need extra mass outside the disc -- one explanation is indeed massive astrophysical compact halo objects or MACHOs. Other suggested explanations include weakly interacting massive particles (WIMPs), neutrinos, axions and modified Newtonian dynamics (MOND) theory, and I expect someone has a fringe theory that involves cosmic plasmas.

    For a bit more background (albeit from 2002), see for example:

    http://www.astro.caltech.edu/~george/ay20/eaa-wimps-machos.pdf
     
  11. iguana_tonante

    iguana_tonante Admiral Admiral

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    Galaxy rotational curves disagree.

    Free education doesn't mean teachers are not paid. :p If he want to enroll in my courses, he can do it for a very small fee. But if he wants private tutoring, he has to pay good money. ;)

    [​IMG]

    That's the same old argument: I know nothing about it, don't understand how it works, so the truth must be that nobody is actually able explain it.

    I know nothing about virology. When I read about that theory, it seems a little crackpot to me. I mean, tiny fragments of genetic material encased in a protein shell that might or might not actually be alive, which hijacks cells' replication mechanism to reproduce copies of themselves? That's a little out there, don't you think? But in the end, how can we really know? The human body is still a mystery. I don't think we have even remotely close enough information to be able to theorize about stuff that happens inside it. So as of now, perhaps any theory is as valid as any other.

    That's what you are doing. It doesn't work like that. To invoke the wise Carl Sagan "democracy doesn't mean that my ignorance is just as good as your knowledge".
     
  12. Captrek

    Captrek Vice Admiral Admiral

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    That was Isaac Asimov, not Carl Sagan.
     
  13. iguana_tonante

    iguana_tonante Admiral Admiral

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    Whoops! :lol: My bad.
     
  14. Asbo Zaprudder

    Asbo Zaprudder Vice Admiral Admiral

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    Carl Sagan made many similar, apposite quotes:

    We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology.

    We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces.

    For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.

    If we long to believe that the stars rise and set for us, that we are the reason there is a Universe, does science do us a disservice in deflating our conceits?

    But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright Brothers. But they also laughed at Bozo the Clown.
     
  15. iguana_tonante

    iguana_tonante Admiral Admiral

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    It did seem in line with many things Sagan said, so maybe that's why I got it wrong. Still, it was wrong. (See, folks? This is how science operates. ;) )
     
  16. Robert Comsol

    Robert Comsol Commodore Commodore

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    IIRC, Stephen Hawking was still referring to those while these were candidates.

    When it turned out they were not, he stopped talking about the topic. :(

    Bob
     
  17. Asbo Zaprudder

    Asbo Zaprudder Vice Admiral Admiral

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    Stephen Hawking isn't the final arbiter on the validity of the various competing explanations for dark matter. Although some suggestions now seem more likely than others, there is far too little experimental data yet to decide. I quite like axions as an explanation as they might also resolve the strong CP problem in QCD without requiring one of the quark flavours to be massless. However, the Universe gives nary a toss as to what I or anyone else likes.
     
  18. GalaxyX

    GalaxyX Rear Admiral Rear Admiral

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    [​IMG]

    So how do they work? Or do I have to pay you to find out?
     
  19. Asbo Zaprudder

    Asbo Zaprudder Vice Admiral Admiral

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  20. iguana_tonante

    iguana_tonante Admiral Admiral

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