Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Gravity: Strength in Weakness: CSM

  1. Sep 24, 2003 #1

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Comments? How popular is this notion? I have read about this quite a few times...and Kaku often references this point.
    http://www.csmonitor.com/2003/0924/p25s01-stss.html
     
  2. jcsd
  3. Sep 24, 2003 #2

    Nereid

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    This will likely be the start of a quite lengthy thread.

    Just to take one point:
    The first year's WMAP results (http://map.gsfc.nasa.gov/m_mm.html) suggest (cold) dark matter makes up only ~23%, with neutrinos (hot dark matter) another <1%.
     
  4. Sep 24, 2003 #3

    mathman

    User Avatar
    Science Advisor
    Gold Member

    Just to complete the picture, the remaining stuff (about 70%) is "dark energy" or something like it (Einstein's cosmological constant?), which is responsible for the observation that the expansion of the universe is accelerating.
     
  5. Sep 25, 2003 #4

    Nereid

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Oh, and just BTW, ~4% is made up of 'us stuff' (baryonic matter).

    Not only is the Earth not the centre of the universe

    Not only is the solar system ...

    ... {space to fill in your favourites}

    ... but everything that we can see, feel, touch, ... it's just a 'minor ingredient'.

    Humility anyone?
     
  6. Nov 18, 2003 #5
    In my theory (see "new theory of universe creation" in the theory development category) the excess gravity could be the matter taken into black holes since the dawn of time.
     
  7. Nov 19, 2003 #6
    I do so like the analogy of the water-skeeter!
     
    Last edited: Dec 9, 2003
  8. Nov 20, 2003 #7

    Nereid

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The really cool thing about 'dark matter' is that we should soon start seeing some quite concrete predictions from various theories as to what it is. Even better, as the detritus of the Sag and Car dwarf galaxies becomes better mapped, as various 'dark matter telescopes' come on stream, as AMANDA II (and others) starts working, as LIGO (etc) settles down, GLAST is launched, ... there'll be at least an order of magnitude improvement in observational constraints over the next five years or so.

    Now would be a good time for those with theories to start making firm predictions about what all these wonderful instruments and experiments will actually 'see'!
     
  9. Dec 10, 2003 #8
  10. Dec 10, 2003 #9

    Nereid

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Continue this discussion in Theory Development?

    OMF,

    I had a look at your earlier posts, and feel that you ideas are worth discussing under Theory Development. If you'd care to start a thread there, I'll gladly comment on your idea, its match to observations, and pose some questions which you might like to consider.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?