to a quite modest place. In fact, how pitifully small, how powerless we human beings must ap- pear to ourselves if we stop to think that the planet Earth on which we live our lives is just a minute, infinitesimal mote of dust; on the other hand how peculiar it must seem that we, tiny creatures on a tiny planet, are nevertheless cap- able of knowing though not the essence at least the existence and the dimensions of the basic building blocks of the entire great Cosmos! But this is still not the end of the wonder of it, Physical research has established as an incon- testable fact that these basic building blocks of the Universe do not exist unrelated in isolated groups, but that all of them are mutually inter- linked according to one uniform plan. In other words, every process in nature is subject to a uni- versal and up toa point knowable I T want to mention at this place just one ex- ample: The law of the conservation of energy. ‘There are various forms of energy in nature— kinetic energy, the energy of gravity, heat, elec tricky, magnetism, All the energies together form the energy supply of the world. The quantity of this energy supply is constant; it cannot be