The New York herald., 1922-06-11


RELATIVELY AND THE UNIVERSE.
BY DR.. Harry Schmidt. Translated
by Il. Wichmann. Robert NJ Me
Bride & Co.
"HE peculiar difficulty presented
by the theory Of relatively is
that, while it embodies a dis
tincttvely new and perhaps epoch
making conception of the universe,
the mathematical formula on which
it is based are wholly beyond the
reach OF the layman. Fortunately,
however. the general results and i'm
plications of the theory can be COM
pretended far more readily than
the mathematics that supports it:
and already there have appeared
numerous books that undertake to
explain the essence OF relatively to
the average man. Among such works
are the two volumes under review,
both of which accomplish excellently
their task of making clear the ele-
ments of Einstein's theory. The
style of DIR. Schmidt's book is the
more animated of the two. the more
lucid. and the better adapted to the
requirements of the man not well
grounded in science; but Prof. Thir-
rings monograph has the advantage
of probing more deeply into the SUBJ
ject. of dealing with it more COM
prehensiveIy and of coordinating the
entae system of ideas that forms
the background and the substance of
relatively.
From these two volumes we learn
that relativity is not single but
double: that it consists of both
special and a general theory. each of
which is TO be regarded as a work
of genius. The special theory i'm
plies. to begin with. that motion is
merely relative: that the speed Of
any moving object can be calculated
only with reference to its observers,
and that. given more than one OBJ
server. the same object may be said
to be moving at more than one speed
at the same time. There is no abso-
lutte meaning in length, neither is
there an absolute meaning in a time
interval: in other words, time as well
as space is relative. and an event
which from the point of view of one
observer occurs simultaneously with
another may from the standpoint of
a second observer happen before it,
and as seen by a third observer may
take place after IL. This leads to the
conclusion that there is a closer
connection than has generally been
supposed between time and space;
that space is really r-dimensional
and that the fourth dimension OF
space is time.
Closely related to these results is
the theory OF the electromagnetic
construction of matter-the theory
that mass and energy are identical:
that energy travelling through a
vacuum may have weight and exert
a gravitational pull: that, accord
ingiy energy and matter are at
root one and the same thing, and that
the apparent changes which energy
undergoes are really changes in the
observer. since energy maintains
constantly its fundamental electrical
Character. One Of the important con-
sequences of this theory is the re-
pudiation OF the old conception OF
the ether of space: for. since energy
as conceived by Einstein can act
through a vacuum. there is no rea-
son to postulate the existence OF any
all embracing medium.
Even more revolutionary Is the
general theory Of relatively. This
sewers connection with the geometry
OF Euclid. advances a theory Of
gravitation differing from that of
Newton and concludes that all
straight lines are the arcs OF enor-
nous circles. that light Is DETECTED