Evening star. [volume] (Washington, D.C.) 1854-1972, 1928-11-02
OPTICIANS TO PAY
NICHOLSON HONOR
Scientist to Describe Latest
Experiment in Measuring
Velocity of Light.

The American Optical Society this
afternoon will pay honor to one of
Americas most distinguished scientists,
Prof. Albert A. Nicholson of the Uni
versity of Chicago, whose work is the
basis of one of the great revolutions in
modern thought.
The list of Prof Michelson's achieve
ments in the field of optics starts with
his determination, so years ago, OF a
method for measuring exactly the veloc-
ity Of light. This was followed by the
invention of the interferometer, the
marvellous mechanism which has been
one of the outstanding factors in ex-
tending mans knowledge Of outer space,
measurements of the rigidity of the
earth-revealing earth tides, and the fa-
nous Nicholson Morley experiment on
ether drift, which was the basis of the
Eingtein theory.
This afternoon Prof. Nicholson will
tell the society of the results of his repe-
tition of this experiment in 1928. 1t was
first performed in 1887. It was designed
to prove the existence of universal
medium, the hypothetical ether, through
which the world and the entire universe
moves.
Two Light Beams Sent.
It consisted in sending out two beams
of light, rejecting both back to a COM
mon source, and determining accurately
the difference in time of the return.
One beam was shot out in the direc-
ton of the motion of the earth. On its
return Journey, it wes supposed, the
earth would catch up slth it so that its
return Journey would take less time
than its outward journey. The other
beam was shot simultaneously at right
angles to the first. This beam, it was
assumed, would have to cover two sides
of triangle in returning to its starting
point, the base of a triangle being the
distance covered by the earth since the
departure of the beam. Thus the beam
shot straight ahead should have re-
turned a fraction of a second sooner
vhan the beam shot at right angles to it
because it would not have so much
space to cover.
The result of the experiment was
negative. Both light impulses returned
at exactly the same time. This was
one of the fundamental experiments in
the history of physics, comparable in
results with the falling apple of Sir
Isaac Newton The result was ap-
parently unexplainable until Albert
Einstein, a German professor, pro-
pounded his famous theory. which did
away with the need of a hypothetical
ether altogether in explaining physical
phenomena
Prof. Nicholson was at first one OF
the foremost opponents of the Einstein
theory. He has since come partly to
accept it, although he believes that the
ether conception still is necessary. Re-
Gently the results of the original experi-
ment have been questioned by Prof.
Dayton c. Miller of the Case School
of Applied Science at Cleveland, who
repeated it under improved conditions.
Result Is Awaited.
Spurred by the work of Miller, DR..
Nicholson last Winter repeated his ex-
pertinent The first announcement OF
the result will be made this afternoon
and is awaited with intense interest by
physicists. If the results are different
from those of 40 years ago it will mean
another serious disturbance of the
physicists ideas of the structure OF the
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