Evening star., 1937-01-15
SCIENTIST LOOKS
INTO MOLECULES.
Ultra Microscope Made by
Firing Bullets of Light
Described.
BY THOMAS r. HENRY.


Firing bullets of light at vibrating
targets a million times too small TO
be seen. thus obtaining in effect an
ultra microscope which enables one
to look at the insides of molecules, was
described before the annual meeting
of the Washington section of the
American Chemical Society last night
by DR.. James H. Hibben Of the
Geophysical Laboratory of the Car
negie Istitution.
The method, first described eight
years ago by a Hindu phyicist, has
been developed by DR.. Hibben to a
point where it is throwing much new
light on the fundamental structure of
matter. and has far-reaching implica
tions in chemistry and medicine.
Light, as DR.. Hibben explained, con-
sists of streams of tiny particles known
as photons which travel at the terrific
speed of approximately 10000 miles
a second. They move in waves, the
length of wave depending on the
energy with which the particle IS
fired" The wave-length, in turn. de-
termines the color of the light from
the invisible infra-red through the
visible spectrum of colors to the in
visible ultra violet and X-rays.
Molecules Are Little Worlds.
All matter is made up of molecules.
A molecule is a combination of atoms
of different elements which are vi
brating at various rates and in va
rious directions. 1t is, as DR.. Hibben
explained, a dynamic system of atoms
each molecule little world by it.
self.
Now when a bullet hits a target
which it cannot penetrate it is de-
f1ected at an angle-or it may be
broken into pieces and the fragments
fly away at various angles In any
event the bullet loses some of the
energy with which it was fired when
it hits something. 1t only had so much
energy in the beginning, and part of
this has been used up.
The same thing happens when a
bullet of light, or photon, hits the Vi
brating atom in molecule. Only in
this case less energy means a longer
wave-length-and longer wave
length means different color. What
was blue light will turn into green
light and what was green light into
yellow light,
Roman Spectrum System.
This is the basis Of the Roman spec
trum system, being used by Dr. Hibber
at the geophysical laboratory. Ligh,
Of single wave-length is fired from
a mercury lamp into translucent
substance-say a single wave-length
of blue light into water. Most of il
will pass through without hitting any.
thing, but some of the blue photon.
will hit the hydrogen and oxyger
atoms in the water molecule Wher
they do this they will come out or
the other side not as blue photons bu
as green, yellow or red photons, de.
pending on how much energy the col
lision has cost them.
1t is possible to calculate mathe-
matically how much energy such a
bullet should lose when it hits an
atom of a specified size. vibrating al
a specified rate in a specified way
The actual results can be checked
against such calculations, or one
can calculate back from them to
determine just what sort of an object
they have hit
Up to few years ago, DR.. Hibben
pointed out, the idea of looking into
molecule" would have been con-
sidered highly fantastic since this
was vastly beyond the possibilities of
any microscope ever dreamed of.
Then it was found that X-ray bullets
could be fired" and from the Splash
es" on Photographic plates which re-
suited from the reflections mathe-
maticians could figure about where
the different atoms were in the struc-
ture of the molecule.
But it was as if they were standing
Still. The x-ray splashes gave no IN
dication how they were moving, but
only their special conflguration In
relation to each other. The social
activities in the dark world of the
molecule seemed forever hidden. Now,
DR.. Hibben explained, it is as if they
were going on in glass house, so
long as the substance is one which
light will go through.
Minute Differences Important.
The properties of the molecule-
especially its interactions with other
things-depend about as much on how
the molecules are moving with respect
to each other, DR.. Hibben pointed out,
as on their special configuration.
Minute differences often are of extreme
Importance.
The changed wave-lengths of light,
DR.. Hibben explained, are recorded
on a Photographic plate after pass
ing through a spectroscope which
splits the light into its distinct wave
lengths. The method permits very
exact analysis but a special technique
is required to read the significance
of the faint black lines which are
photographed
Not only do the resulting spectra,
DR.. Hibben explained, make it pos
sible to get dynamic picture of the
molecule, but sometimes provide an
extremely delicate method of chemi-
cal analysis, since minute amounts
of irnnIlrjties Stronp1v offacf tho ,,at