Quantum mind with a cat in a locked steel chamber, wherein the cat's life or death depended on the state of a radioactive atom, whether it had decayed and emitted radiation or not. According to Schrödinger, the Copenhagen interpretation implies that "the cat remains both alive and dead" until the state has been observed. Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics. However, since Schrödinger's time, other interpretations of the mathematics of quantum mechanics have been advanced
Two-body Dirac equations The four-vectors formula_120 and formula_121 have only three independent components since The similarity to the three-dimensional structure of the nonrelativistic Schrödinger equation can be made more explicit by writing the equation in the c.m. frame in which Comparison of the resultant form with the time independent Schr\"{o}dinger equation makes this similarity explicit. A plausible structure for the quasipotential formula_83 can be found by observing that the one-body Klein-Gordon equation formula_127 takes the form formula_128 when one introduces a scalar interaction and timelike vector interaction via formula_129and formula_130. In the two-body case, separate classical and quantum field theory arguments show that