The Washington herald. [volume] (Washington, D.C.) 1906-1939, 1921-12-30
ATOMIC LIGHT
THEORY RIVALS J
RELATIVITYLAW
Quantum Theory Declares
Atoms Give Oh Light
In Jumps.
FRIDAY. DECEMBER -. ,s.L
POPULAR EXPLANATION
OF BASIC THEORY.

OF BASIC THEORY.
TORONTO. Dec. 2s.-rhe GUAM.
tum theory of radiation. declared 70
be one OF the two really great the
ories developed In this century, was
discussed at a Joint meeting of
msthematicians. physicists. and
chemists Of the American Assoc,a-
ton for the Advancement OF Sci
ence here today.
DR.. W. ID. Harkins. Of the Unlver-
sity of Chicago. leader OF the dis
cussion. has furnished what is be-
lieyed to be the first popular e1-
PLANTATION Of this new theory:
The qusntum theory is Of much
more practical Importance at pres
ent than the Einstein theory of rel
stivity. IL is concerned with the
emission giving on and ABSORB
ton talking up) OF light by atoms.
and the fundamental ideas involved
are easily understood, though no
short popular exposition Of the the
DRY seems to have been hitherto
undertaken"
"All material substance. whether
solids. liquids or gases, are now
known to be made up Of atoms.
which are so small that in a solid.
loo. 900. 900 OF them would lie on a
straight line only an inch long. In
spite Of their smallness. each Atom
10 believed to constitute a mInia-
ture solar system, in which the
place OF the sun is taken BY a
minute nucleus charged with posi-
tive electricity. Around the nucleus
is a system Of planets which are
also much more minute than the
atom, and these are called negative
electrons. since each Of them con-
sists Of a charge of negative cleo
tricity. We may szy that the atom
IL an atomic system. just as the
sun and the planets taken together
are designated as the solar sys-
tenn"
The qusntum theory is OF great
Importance because IL changes the
ideas OF the older mechanics. Ac-
cording 90 the older theory an
atomic system could move in
large number Of different WAYS. or
more scientifically stated. the sys-
tenn was supposed to be canabie
VI a OF states oil
motion. The quantum theory con-
siders that the older theory. Is cor
rect IN many Of its features. but
mobiles 10 by stating that "of. all
the states % motion Cor ways o.
moving prescribed by the older
theory. only q. certain number ac-
tually do occur and what these
states are is specified by the the
ory.-
Thus the change brought about
by the new theory is the introduce
ton OF the idea that events which
were previously supposed 20 occur
as continuous processes actually a.
occur in steps. The change IL Some
what analogous TO that brought
about when the smooth gentle slope
OF a watercourse down q mountain
is interrupted by dams. The streuI-.
then cannot flow down continuously
but must descend by jumps.
atomic systems also send rout a
wave motion known as ordinary
light. invisible or ultraviolet light
and as N-rays- These are all &c
scribed by the one word radiation
The quantum theory says that Just
as the height Of a fall may be
Judged by the noise IL makes when
the amount OF water flowing over
the dam is known so the eneiE
change or the height Of fair In IN
atomic system may be judged by the
color Of the light which is emitted.
The quantum theory. sometime
known as the atomic theory ot
radiation. was first suggested By
the great physicist Planck IN ta-
year 1900. or just ninety-seven yea
after the development OF the atomic
theory OF matter by Dalton. Since
IL concerns itself with the relations
between matter and radiation IL Is
Of fundamental significance In con
noction with almost all processes
which we know. IL is obvious thar
IL is Of direct importance in conue"-
ton with our own vision: IL should
interest the artist and ali who are
fond OF light and color II f. one -
the most basal principles concerned
with chemical action. with ioniza-
ton. and with electricity, and is S-p-
posed by some OF the adherents o.
the theory to relate TO the amount
OF heat involved in all changes 90
state. such as in the evaporation o.
liquids. etc. and 20 the SPECIFIC heat
which Is the amount Of heat used in
heating a unit mass OF a substance
until its temperature rises by one
degree"
Wn