Every evening, Wilmington daily commercial., 1921-05-14


by experiment.
'As further experimental results are
obtained n may be necessary to change
tho physical Interpretation which the
genius Of Einsten gave to n mafhemat.
ical structure developed by d group Of
brilliant geometera from the time Of
Ricmnnn. But IsinHtein's conception Of
the relation between geometry and phy-
nies is likely To exert Il lasting effect
upon theories concerning the physical
world.
Dir. Brush's Contradictions.
Recently Dr. Brush announced that
he had shown by experiment that grav-
itatiou acts differently upon subjects
of different physical nature. Both the
Newtonian and iginsteln theories OF
Eravita'ion fsre based upon the concep-
tf0n that this Is not the case. Dr.
Brush made no reference "a the exper.
ifnent OF Baron Eotvos Of Hungary In
$3.50, by which he showed that the ac-
ton of prayttation III independent OF
the physical nature OF body.
These experiments rurport to be
much more accurate than those OF Dr.
Brush. They have been accepted as
conclusive by physicists, and ertainly
must be shown 10 be incorrect before
DIR. Brushs results can be accepted"
One fundamental difference between
the Newtonian idea of gravifation ana
that sponsored by Dr. Eanstein is point
cd out as follows In ron-technical lang
uage by Prof. Eisenhart:
According 20 Newtons law Of gravf-
tatson, two bodies attract one another
With force proportional to the product
OF their masses and tnverseIy as the
square OF the distance between the
Dodiea; IL Is based Upon the principles
Of absolute space and time. and deals
with action 81 distance.
feThe Einstein law il based uron the
principle that tho character Of physical
space is determined by the presence
and distf button OF matter, that ID Is
not Euc.idian, and that action takes
place in the neighborhood Of a body.
just as PHYSICIST from tho time Of
F'arada J. we beloved that electrical
action occurs.
BY lie consideration OF certain
mechanical problems. Einstein came 70
the conclusion that in general there ii
no particular system Of time and space
co-ordinates which are Fundamental.
Consequently he has formulated his
theory In times OF any system what
ever. This necessarily ruakes tho
mathematical formulation quite in
VOWED.
However, in the consideration or
special problems. such as planetary
motion. the equations are OF the same
order If difficulty as in tho Newtonian
mechanics. In fact. the equations OF
planetary motion In tho two theories
differ SO little that only in the case Of
the motion OF Mercury is the difference
detachable BY experimental methods now
available. Likewise in the treatment
of the usual mechanical problems met
with on the earth the Newtonian me-
chanics can be employed. For some
time .it has been recognized that this gs
not the case with eiectro-dynanaics as
formulated by Maxwell. However, this
theory has been co-ordinated with the
general theory OF reIatiyity."
Discussing the vagaries Of the planet
Mercury and their Importance IN the
doctrines as developed BY Einsfein,
Prof. Elsenhart said:
His prediction that ray OF light
passing near the sun would be bent
was a by-product Of the theory of gravi-
tation which he had been developing
He had shown that this theory account
ed for the discrepancy IN the motion
of the planet Mercury which had been
known for 200 years.
This was an interesting fact, but
there had been other explanations Of
this phenomenon. Recently we have
been told that ii would be accounted
for by a certain distribution OF finely
divided matter in space, but this re-
auires experimental verification. Also
1t is possible 10 make change in New
tons law which viii account for the
discrepancy. But a verified prediction
gives to theory a claim to be reckoned
with"
The essence Of the findings by Elm
stein is as Prof. Eisenhart points out,
that THE magnitudes of observed space
intervals and time intervals are reIa-
tive to the observer. These conclusions
are based upon the hypothesis that the
velocity Of light is independent of the
velocity OF the source OF light; this
assumption seems TO agree with ex-
pertinent. These ideas form the basis
OF the so-cailed restricted principle Of
RELATIVELY. The general RELATIVELY Of
Einstein represents an extension Of
these ideas so. as to include curvilinear
motion and gravitation"