100 PHYSICS OF MATTER 



The relations which have been found to exist between atoms and 

 molecules are no more disturbed by the behavior of radioactive sub- 

 stances than by the explosion of nitroglycerine. We have learned that 

 what we have provisionally called atoms are, at least in some cases, as 

 has long been believed, very complex in their structure. We should 

 hardly expect an architect to lose confidence in houses, if he finally 

 learns that the bricks with which he is familiar are not the final ele- 

 ments in their structure. That the bricks are made up of molecules, 

 and the molecules of atoms, and the atoms of electrons, and that 

 some houses have been observed to fall into pieces and give off energy, 

 would hardly affect the usefulness of houses which do not fall to 

 pieces, even if inertia is shown to be an electromagnetic phenomenon. 

 And I think we should all remember that the proposition that matter 

 has mass is fundamentally different from the proposition that a mass 

 of matter has inertia. If inertia can be explained to be an electro- 

 magnetic quantity, and if it can be measured in new units, we have 

 not changed the properties of matter. It is still matter, and it still 

 has both mass and inertia. If inertia is an electromagnetic phe- 

 nomenon, it may be measured in terms of the fundamental units in 

 which all electromagnetic quantities are measured, the units of 

 length, time, and mass. 



Formerly a force was measured in terms of the unit of mass only. 

 People talked about a force of one pound. Later it was discovered 

 that a force could also be measured in terms of the pound, the foot, 

 and the second. At this time we did not hear any intimation that 

 matter had had its day and was about to be abolished. 



In physics we now think we have reached the domain of small 

 things. But the electron may also be a very complex structure. If 

 we accept Poynting's view of the nature of electromagnetic in- 

 duction, the electron in a conductor is acted upon by a distant and 

 moving electron, through a medium external to the conductor. The 

 experimental verification of this is very convincing. In addition to 

 this complex machinery we have to deal with machinery of gravita- 

 tion. 



We may always assume that nature is everywhere complex and 

 ingenious. A visitor to our solar system, who should begin to study 

 it from our earth, might begin with physical astronomy. He finally 

 comes to chemistry, to zoology, and the phenomena of life, to gov- 

 ernmental organization, to the moral and religious influences which 

 dominate the lives and actions of men, to the simultaneous juris- 

 diction of state and federal courts within the same territory. By the 

 time he had come to know this world as we know it, he would con- 

 clude that this universe of ours, which he first perceived as a faint 

 and distant speck of light in the blazing firmament of stars, is, after 

 all, very wonderful, and very much more complex than was at first 



