  A novel differential calculus with central inner product is introduced for
kappa-Minkowski space. The `bad' behaviour of this differential calculus is
discussed with reference to symplectic quantisation and A-infinity algebras.
Using this calculus in the Schrodinger equation gives two values which can be
compared with the Planck mass and length. This comparison gives an approximate
numerical value for the deformation parameter in kappa-Minkowski space. We
present numerical evidence that there is a potentially observable variation of
propagation speed in the Klein-Gordon equation. The modified equations of
electrodynamics (without a spinor field) are derived from noncommutative
covariant derivatives. We note that these equations suggest that the speed of
light is independent of frequency, in contrast to the KG results (with the
caveat that zero current is not the same as in vacuum). We end with some
philosophical comments on measurement related to quantum theory and gravity
(not necessarily quantum gravity) and noncommutative geometry.
