Clebsch-Gordan coefficients are used in quantum mechanics to describe the coupling between angular momenta.
Instead of looking them up in a table, or (gasp!) deriving them, this application lets you dial up the desired coefficient with iPhone interface goodness.
Component angular momenta up to j = 9/2, and composite angular momenta up to j1 + j2 = J = 9 are allowed.
Selection rules, such as m1 + m2 = M, are built-in to the application; coefficients that are trivially zero are inaccessible, so it is easy to see at a glance which possible composite values follow from a given j1, j2.
In addition to the rational root value of each coefficient (e.g. - sqrt(1/2)), a floating point value and its square are also displayed (e.g. -0.7071 and 0.5).
The app name, Poor Gordan, is derived from the frequent misspelling of Mr. Gordans name.
Please forward feature requests to the developer! An atomic physics experimenters toolbox is in the works.