Momentum conservation and the validity of the center-of-mass law are examined for systems made up of electrostaticcharges and magnets, in terms of the requirements of special relativitytheory. The… Expand

The phenomenon of double $\ensuremath{\beta}$-disintegration is one for which there is a marked difference between the results of Majorana's symmetrical theory of the neutrino and those of the… Expand

We address the following question: In drawing a cycle on n vertices (or a graph all of whose degrees are 2) in the plane with straight line arcs, how many crossings can there be? A complete answer is… Expand