Evening star., 1935-02-19

! save the atom. It also was essential
to explain the precision Of the wave
lengths emitted by atoms Of different
elements which made up their charac-
teristic spectra.
But If the quantum theory was true
how could the Newtonian trajectory
be real. Light exerts pressure against
the moving object it hits. The trajec-
tory of the cannon ball or the orbit
Of the planet must be slightly different
very slightly, indeed-with light hit
ting upon it than 1t would be in total
darkness, or rather in a condition
completely removed from radiation of
any kind.
Now II this pressure were cont1nu-
GUS from all directions due allowance
could be made for it or, since it is in
calculably small, 1t could be dis
counted altogether. But the pressure
is not continuous. 1t comes in precise
amounts. It is not like the steady
pressure OF water from hose. 1t Is
like the pressure from a stream OF
machine gun bullets coming from
all directions. Hence any object In
a trajectory or orbit will be knocked
helter-skelter in this way and that
as the light bullets from different
directions hit 1t. Hence there Is no
way Of telling where it will be at any
given time. Its path now has breadth
as well as length and curvature. All
that can be said is that it will be
somewhere on its road through space.
It may be in the middle Of the road,
on one side or on the opposite side.
OF course, this makes no difference
for any actually observable object.
For a cannon ball, for example, the
variation would be in terms of bill
lionths Of centimeters. For celes-
tial body the Zig-zag in the path
would amount to only few feet, which
would be of no consequence whatever
in determinations made In terms OF
light years. These objects are
bounced back and forth by light along
paths, the widths Of which are un-
observably small, so that they can be
considered merely as lines.
But when it comes to the strange
universes Of the infinitely little-the
atoms-it makes a great deal OF diff
ference. In this unimaginably tiny
space the force of the impact OF
uuantum and the size Of the object
hit-the electron-are comparable.
The moving electron is knocked side
wise for very great distances, con-
sidering the space inside the atom.
The phenomenon cannot be discount
ed in calculations, and since 1t Is
discontinuous, no precise account can
be taken of it. Hence, one never can
predict Just where given electron
will be at any given instant.
The best that can be done, taxing
all elements of the phenomenon into
consideration, is to make Statistical
determination of its probable position
or where the average electron Will
be. It may or may not apply to any
particular electron. Position can De
designated not by precise point, out
by a normal probability curve. 1t Is
much the same procedure as would De
used by an actuary in determining the
average span Of life Of population.
In one sense 1t is very precise indeed.
Life insurance companies can bet on
it and be sure of making money, If
they write enough policies. But when
applied to any individual It has very
little meaning. No actuary can tell
when John Jones will die more pre-
cisely than somewhere between one
day and a century.
Such is Prof. Gamow's explanation
of the principle of indeterminism," "
which has caused one Of the greatest
storms in scientific thinking known in
a half century. What difference does
it make? In ordinary affairs of life,
Of course, none at all. But the atom
Is the foundation of all things. Every
kthing is an assembly Of atoms. The