When nucleons fuse with neighbors, there is mass loss and great energy emitted. We discuss the great jump in fusion mass lost when four nucleons are fused together compared to three. About 4 times as much mass is lost, but we show how this is largely expected since 4 times as many triangular planes with ‘donut holes’ are formed vs. for 3 nucleons. Specifically, we show how after 3 Hydrogen-1 atoms fuse to form 1 Helium-3 atom, the mass lost equals twice the mass of a sphere sized to barely fit through the array’s donut hole, with an error of about 1 part in 5000. Finally, we discuss implications of all the above and related topics, including supplementing the present neutron-proton based ‘binding energy’ method with a more revealing electron-proton based one.
