The New York herald., 1922-12-31

has given way 10 the simplicity and
beautiful order revealing motions obey
ing the inverse square law OF Newton
During the progress Of these investiGa-
tions our conceptions of distance and
dimensions have been gradually modified
till now we are made aware that the
universe has a radius which may even
exceed hundred or a hundred and
fifty thousand light years.
While the astronomer has thus been
reaching out to greater and yet still
greater distances i'm the direction toward
the infinite. the physicist. the chemist,
on the other hand, have Ioun6 solar and
planetary systems Of nearly infinitesi-
NAL dimensions within the realm of the
chemical atom. The radius of the cleo
tron Is just ee-trilioniths of an inch
and it's distance from the nucleus is in
the same ratio to its size as the distance
of the earth from the sun"
Dr. Mitchell showed the radical change
in the different sciences since the dis
covery of radioactivity in 1896. when 1t
was found that the atoms were actually
disintegrating with the liberation of
great quantities of energy. The study
OF astronomy has been facilitated bJ the
invention of the great spectroscopes
which analyze the light emitted by the
stars.
EIcctrons Vfbrate In Orbits.
The electrons of the atom are not
in stationary state. but may be con-
sidered as vibrating back and forth in
different orbits. sometimes closer to the
nucleus and again more distant. II
will make these changes with the lib
GRAFTON or absorption of energy setting
up light vibration 10 the ether at the
same time. 1t so happens that the cleo
irons are confined to definite orbits and
therefore only certain kinds of light
can be radiated
Therefore, when we spread the light
OF the star out into rainbow band by
the use of a prism we find 1t streaked
with lines all caused by the emission
of radiations from a definite kind of
atom. The higher the temperature, the
more abused the atom will be and the
more lines appear. so the spectrum of a
star does more than reveal the chemical
substances there. for we can now get
the temperature. The temperature
scale was calibrated by the use of the
sun. which was found to be about 5000
degrees, while many stars go as high
as $4,000.
When the atom gets hotter than a
certain fixed amount the vibration of the
eleCtrOn becomes so violent tIlat IRE
quently il is thrown entirely away from
the nucleus. This is called the process
of ionization and is very important In
interpreting the conditions on the star.
If helium atom which originally pos
sesses two electrons had one of them
torn out evidently 1t would vibrate very
much in the same way that hydrogen
does for the two are exactly the same
except that the helium nucleus possesses
twice the electric charge of the other.
number of years ago, before
helium had been discovered in the
laboratory, Prof Pickering of Harvard
found a number of lines In the spectrum
that resembled those Of hydrogen with
the exception that they were just twice
as closely packed. Later. with helium
established as their source. it was very
plain that the theory exactly explained
the structure of this intricate spectrum.
IOnization of Gases.
Within the last year or so much has
been done on the theory of ionization
of gases In the atmospheres of the stars.
BY bombarding the atoms in the labora-
tory with electricity driven by various
forces we have been able to reproduce
and study many of the conditions
present In the stars and apply these
quantities to astrophysical problems.