Instant Egghead - What is Dark Matter?

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1 Comments

1. 1. jtdwyer 12:51 PM 9/21/12

   A 60-second counterpoint...
   Well, the disks of spiral galaxies don't actually spin like a rigidly bound solid disk - but the discrete objects within the disks do rotate at roughly the same velocity regardless of their distance from the axis of rotation.
   
   That contradicted astronomers' expectations that galaxies would rotate in accordance with Keplerian relations, where each planet's velocity is determined by its distance from the gravitational pull of the massive Sun (which contains 99.86% of total Solar system mass).
   
   However, all of the billions of stars and other massive objects in galactic disks each produce their own gravitational field: they are not each independently bound to any central mass; they each gravitationally interact with all other disk masses. Galactic disk objects rotate not as relatively independent planets orbit the Sun, but as loosely bound collections of masses around a common axis.
   
   It is this simplistic misconception of planetary gravitation imposed on very large scale compound objects composed of billions of independently gravitating discrete masses that seemed to require some 'missing mass', or 'dark matter'. All that was ever really missing is the inclusion of disperse gravitational interactions among the billions of aggregated masses.
   
   Please see "Inappropriate Application of Kepler's Empirical Laws of Planetary Motion to Spiral Galaxies Created the Perceived Galaxy Rotation Problem - Thereby Establishing a Galactic Presence for the Elusive, Inferred Dark Matter",
   http://fqxi.org/community/forum/topic/1419

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