Every evening, Wilmington daily commercial., 1921-04-19

studying the same phenomenon. ana
one of the observers IN moving with
respect to the other. they will not arrive
al the same numerical results from their
observations. Consequently time and
mass and distance exist only In relation
to the observer.
The older physics, ne went on.
clashed with these relativistic concep-
tonB of moving bodies and motion.
Physics had 10 bc modified. and the
most notable change was now law
for tho motion Of very rapidly moving
mass points, which was soon verified In
the case Of electrically laden particles.
The doctrine OF the conservation of
mass lost It's Importance and became
merged In the doctrine of the conser-
vation of energy.
But this special rolat~ity' theory.
which dealt only with observed phe~
uomena In arbitrarily selected sya-
TENS of co-0rdinates. had consequences
which reached beyond itself. The laws
could not be limited in their application
10 systems Of co-ordnatcs in uniform
motion Of mere translation with regard
10 each other without twisting or
acceleration. They applied universally.
And the theory of their application was
the general theory Of relativity.
Such n general theory had 20 in
clude the theory Of gravitation, and
came into conflict with tho Eowtoniau
theory which has been 50 long ac-
cepted. Nevertheless. the attempt was
made 10 apply tho relatively theory to
gravitation. and actual experiment and
observation justified the hope that the
relativistic conception If gravitation
may be possible.
But the woy Prof Einstcin said,
proved harder than was al FIRST ex~
pectcd. because It contradicted the ge-
ometry of Euclid In other words. the
laws in accord with which material
bodies are arranged in space do not
agree with tho laws Of space prescribed
by the Eucidial eebrnetry Of solids. Tho
old concepts Of straight and plane"
and parallel" lose their old meaning.
Tho universe becomes finite instead of
Infinite. glohular conception instead
~ nm indefinitely extended space. and
bodies exist not in three dimensions but
in four. mathomatically
Time the Fourth Dimension.
whore body was formerly placed
~ 60 ordinate fixing Its relation above
or below. 10 right or left. in front ~ or
/ behind n second point Of reference.
under the conception Of roativity and
| motion II must also be placed IN time.
| Conceived as moving in relation 70
other moving points II must not only
be somewhere. but somewhere A. each
definite moment Of time. Time. there
| fore. said Prof Ginstefn. became the
| fourth dimension.
The new theory of gravitation. he
stated. diverges widely from the old
+, Newtonian theory In its basic prin-
| cipie But IN actual application. the
/ two agree so closely that it has been
! difficult 10 ind cases in which the
i actual differences could be subjected 70
| observation
Prof E.iustein IL ~ middle age and
medium height and build. he has the
/ lenine head Of musician. pailid face,
| very brilliant dark eyes. a pleasant, low
/ voice, and a manner so unassuming
/ that at times he seemed hashful, par
+ tieulariy Ii the face Of the warm ap-
I pIause which greeted both has entrance
/ 10 the room and the close OF his address.
III attempting 70 make his meaning
/ clear he used gesture frequently. large
i s. as a visual indication Of the direction
i and nature Of movements and forces
which he vas discussing and anaIyzing.
/ He spoke for an exact hour.
The College of the City of New York
announced yesterday a series Of lee
/ lures by Prof Albert Einstetn. 70 be
given in the Doremus Lecture Theatre
Of the Chemistry building. Convent
avenue and l4Oth street. AT 4 O'Clock on
the afternoons OF April IS, 10. 20 and
y. The subjects are as follows,
April l8-The Special Relativity
/ Theory.
April I9-General Relatively and
/ Gravitation.
April 2o-The Physical Significance
/ of Enthropy and Quanta.
April Light Ether and Radia-
! ton.
The course IS not 10 be open 10 the
public. only persons Of considerable
science in this and Heighboring States.
follow Prof Einsteins $ reasoning. In
vitat3ons accordingly have been extend
ed only 20 the more prominent men Of
scence in this and neighborins States