Equations for a circle:

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     r = \Ý (x - h)ý + (y - k)ý


     in standard form we have  rý = (x - h)ý + (y - k)ý
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     This is the standard form(s) for the equation of a circle with radius r
     and center at (h,k). Extrapolating into 3-dimensional form I derived
     the following equation to feed my 3-dimensional graphing software:

     z = Sqrt(Sqrt(x * x + y * y))

     or in other words,   z equals the fourth root of (xý + yý).

     this is the equation of spherical gravity as shown in the files
     BLAKHOL1.EXE and BLACKHOL2.EXE. This famous graph shows a 2-dimensional
     plane warped into a third physical dimension by the force of gravity.
     Try to imagine a perfectly elastic sheet of rubber with a ball bearing
     dropped into it. The ball bearing rolls around in ever-smaller circles.
     What physicists are trying to explain is that try to imagine our nice
     little universe, a 3-dimensional object, (the perfectly elastic rubber)
     warped into a fourth physical dimension by the gravity of a black hole
     (ball bearing). The black hole doesn't seem to enter negative graphical
     territory, as you see, it stops. Or does it? It is infuriatingly
     difficult to try to imagine such things, since we are 3-dimensional
     creatures. But it can be done. (Just press a key to exit the pictures).
     It is now accepted that gravity is a relativity concept; all gravity
     warps space.