Oh, okay. I see what is happening now. For any 1/r^n where n>0, the density at the center climbs toward infinity and overwhelms the mass of the rest of the disk, so it basically just acts like a point mass at the center. I will have to top it off.

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Let's put together the pieces of The Grand Puzzle . (website)

"Let's define another operator, Sz, which we won't pay any attention to."
"This transformation will automatically make zero equal zero."
"It may be true that zero equals zero -- and that is certainly an equality -- but I don't want to go into the details at this time."