KERRLANDERS and CARTLANDERS… Here I am indebted to the author who created FLATLANDERS, a very good exercise in thinking… PERHAPS I may liken my situation to FLATLANDERS, one of whom lives in a flat spacetime, and the other whose sheet is hilly, ahah. The first one says, all my triangles have 3 angles totalling 180 degrees. The second says, well here this is only true if you keep them small, pocket-sized. Otherwise the total is larger…

In Kerr geometry, SPIN rules. In flatspace, the g_ii are each -1 in an <x,y,z> system. In Kerr, we have:

g_11 ((radial)) = (r^2 + cos^2) / (r^2 + 1) and g_22 ((theta)) = (r^2 + cos^2) . To form g^11 and g^22, just invert each. In flatspace spherical coords, we use

<1, r, rsin(theta)> as the ‘metric’ . [[ Or, the square of these terms.]]

# FLATLANDERS

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