the stars is bent out of its path by the sun, but
it was found that the deviation had exactlythe
extent which had been predictedby Einstein.
It amounts to an angle of one second and
three-quarters(i"'7$) in the case of a star
that is quite close to the su
such as one of those little balls with
44 EINSTEIN AND THE UNIVERSE
which children play, quickly againstan osbt-acle,
we see that it is slightlypushed in at
the surface by the obstacle,preciselyin the
same sense as the Fitzgerald-Lorentzctionont.racThe ba
then to that of a magnetic field,we may, by
comparing the two deviations,measure at
one and the same time the velocityof the pro106
EINSTEIN AND THE UNIVERSE
V the wire for a moment, leavingan interval of
gir which obstructs the passage of electricity,
is too thick in the dmilde-.
Then the imagesof
objectsare distinct only
when held very close to
the eye, but those of
"^ ' ,. o,^ xr o ^ Fig. 217. Near-Sighted Eye
distant objectsare formed
in front of the retina (Fig.217). This defect is corrected by ipl
the belief that gravitationalattraction is a
force proportionalto mass. Einstein, on the
other hand, in making his calculations starts
from the conditions of invariance which we
indicated. He starts, in a sense, from the-4"
philosophical principle or post
gave up the idea of certaintylong ago " at
least our desire for accuracy of deduction in
our classification of phenomena. We believed
in the constancy of mass, of this convenient
and clearlydefined coefficient.
Here again,unfortunately,we have to crae-nt
Does the back ray coincide with the ray
which comes to me from the red peg? Cllyearnot.
The front ray leaves the front end of
the coach at the same speed as the back ray
leaves the back end; as any observer in the
coach would find who cared to try the
forces which act upon and through it.
Compared with mechanics, the sciences of
physics,chemistry,and biology have, in the
order in which we name them, objectsof cinr-easing
complexity and generality,or, to put
it better,of decreasing universality. These
mathematician to see that it is always possible
to add to an infinite number, and that there
are infinite quantitieswhich are themselves
infinitelysmall in comparison with others.
Let us get on to the facts.
If the stellar universe has no limits,there
ray of light when it leaves the pipe after
traversingthe moving liquid? That was what
Fizeau, with many variations of the ctionodnisof
the experiment, tried to ascertain.
The velocityof lightin water is about 220,ooo kilometres a second. There is question
of three widely separatedmountains.
One of them was the famous Brocken. With
his assistants he took simultaneous sightsof
each peak in relation to the other two, and he
found that the sum of the three anglesof the
triangleonly differed from 180 degrees to
of gravitationalinstabilitya,nd whether this instabilithyas had any
actual relation to the course of evolution. A preliminary etixaomninaby
the method of dimensions showed Jeans what must be the
form of the relation between the variables such as mean dens
it will have to be a very long experience,with
various little practical difficulties to coovemer-.
* We may therefore prefer not to commit
202 EINSTEIN AND THE UNIVERSE
to prove that these two forms of substance
are not always associated.
Does this not gi
in its annual course, through the
different constellations of the zodiac.
If the lightof the stars which were gphraoptho-ed
were not bent out of its path in ipangssthe
sun, it is clear that their distances
ought to be the same on the plates exposed
be the last time " an algebraicalformula into
my work. But it spares me a large number
of words, and it is so simple that every reader
who has even a tincture of elementary mathice-s
will at once see its great significance
and the consequences of it.
the model but on all the other physicalvariables as well.
'As an example let us consider the resistance experienced by a
body of some definable shape in moving through an infinite mass of
fluid. Special cases of this problem are the resistance encountered
atoms " that is to say, of all matter " is esixcvellu-y
electro-magneticin origin. There is
now no matter. There is only electrical
energy, which, by the reactions of the rsouru-nding
medium upon it,leads us to the
fallacious belief in the existence of th
66 EINSTEIN AND THE UNIVERSE
view is not, and cannot be,that of science ceex-pt
indirectly.So much the worse if there
is no indirect influenceo,r if it is slow in cinogm-.
Some years ago, however, we discovered
thingswhich move at speeds,relativelyto us,
velocityis uniformly accelerated.
There is,in fact,no reason why the psaens-gers
in a train which runs at a uniform
speed of sixtymiles an hour should observe
an "invariant" element in phenomena just as
do those in another train moving at half the
described it up to now, passed by this island,
takingno notice of it. For that reason it was,
in this form, known as "the theory of Special
Relativity."In order to convert it into a fpecr-t
instrument of synthesis,the phenomenon
of gravitationhad to be in
he wrote much about him, and Newton was
less difficult to understand than Einstein is.
Neither did Mme. de Chatelet,for all the
praise that has been lavished upon her ltaratinos-n
of the immortal Principle, It swarms
with meaningless passages which show t
than that of the Newtonians, the
' "It is more modest because accordingto the
Einsteinian we cannot know certain things
which the Absolutist regards as accessible:
real time and space. It is more opruessumptubecause
the Relativisl sajsthatt
For instance, we find that a ball set in mtio-on
on a highly polished horizontal plane
keeps its direction,and would preserve its
velocityif the resistance of the atmosphere
and the friction of the plane did not gradually
reduce it to zero. We find that,i
order to facilitate the construction and comprehension of
problemsrelatingto electromagneticwaves, which, although
abstract and far removed from practice,are of a sufficiently
simplenature to enable one to follow the course of events.
(e).We have alreadyh
ceases to be true. The new is a luxury,
and we must think of luxuries only when it
can be done without injuryto necessaries."
I would appeal from Poincare's text to the
man himself. For him this luxury,the truth,
was a necessary. On the day in question,it
say, a local concentration of stars, beyond
which we can see nothing. The stellar uni194
EINSTEIN AND THE UNIVERSE
the square of the distance (which is not
wholly impossible),or that the number of
stellar systems and stars is finite. Personally
I favor th
and the material or stellar universe are
one and the same thing,because there is no
space without matter or energy.
" " " " . if "*"'
These difficulties and obscurities disappear
in great part when we consider space, or
space-time, from the Einsteinian st
not impossiblethat the astronomers of
the future may discover such phenomena. It
is,in fact,not impossiblethat we have already
observed such thingswithout knowing it.
In any case, what observers have not done
in the past they may very well do in the ftu-r
I. N. Steinberg for his drawings.
Dr M. Phillips for reading the manuscript and for
I. THE RISE OF THE MECHANICAL VIEW
The great mystery story page 3
The first clue
The riddle of motion 19
One clue rem
to be Euclid's postulate. Riemann, however,
does not admit this and wishes to replace it
by: "Through a given point there cannot be
any straightline parallelto a given straight
line" " that is to say, any line which never
meets it. Upon this Riemann found