18, 4 Perkins: The Structure of the Electron 337 
AN EXPLANATION FOR THE STABILITY AND DEFINITENESS 
OF ATOMS 
Whatever be the ultimate nature of electrons, they are bodies 
having apparently constant electric charge and probably con- 
stant mass (if mass is defined properly from a relativity stand- 
point), but no evidence has ever been found that they have 
constant shape under different conditions. So far as I know 
the Lorentz electron, which is a rigid sphere from a relativity 
standpoint, satisfactorily represents electrons which are in uni- 
form motion or in uniform acceleration; but it ig not satisfac- 
tory for any case of an electron in nonuniform acceleration, 
such as, for instance, any electron in an atom. Some, at least, 
of the electrons in atoms are known to have magnetic 
effects, and the facts of radio-activity teach us that even 
nuclei contain electrons in extremely rapid rotation. These 
properties are not accompanied by that steady loss of energy 
by radiation which the classical theory tells us that Lorentz 
electrons in orbits would give. The classical theory tells us 
that to produce such results electricity must be in a form of 
motion which does not cause its distribution in space to vary. 
It is not necessary to point out the reasons why a rotating 
disk, or hollow sphere, or other shapes of circular symmetry 
would not give effects corresponding to experimental data. 
Whether they do or do not, a thin circular ring, rotating about 
its center, would undoubtedly give magnetic effects without 
radiation. 
Now I am far from assuming that an electron is a ring. 
But I object to the assumption of an electron of any shape 
which is perfectly rigid (as the Lorentz electron is from a 
relativity standpoint). We cannot assume that an electron 
has any’ absolutely unchangeable shape without involving a 
contradiction of that principle of common-sense logic which 
says that a physical cause and its effect cannot exist in 
different places at the same time. If we do not assume an 
absolutely unchangeable shape we must assume some force or 
influence which holds the electric charge together. Making 
the least assumption possible, namely, that there is such a 
force, but that we do not know anything about its magnitude, 
we find that any electron in any nonuniformly accelerating field 
will be distorted in a manner similar to the tide producing distor- 
tion of the earth, which is familiar to all of us. Since we have 
made no assumption as to the strength of the forces which 
