friends from Johns Hopkins, Harvard, Yale, Princeton, Cornell, Clark,
and other places, met at Columbia and organized the American Physical
Society. The late Professor Rowland, of Johns Hopkins, was elected its
president, and one of its most distinguished members was Professor
Ernest Rutherford, of McGill University, Montreal. He is now Sir Ernest
Rutherford, the Cavendish professor of physics at the University of
Cambridge, occupying the professorial chair once occupied by Maxwell,
then by Rayleigh, and then by Thomson, now Sir John Joseph Thomson,
master of Trinity College, Cambridge. Their names I have mentioned
often in the course of this narrative. It was most unfortunate for
the progress of American physics that because of his failing health
Rowland’s wonderful influence in the society was of short duration. He
died in April, 1901, while still a young man. Rutherford’s wonderful
discoveries in radioactivity were reported regularly by himself at
the meetings of the society, and I often thought that these reports
alone, even without the many other good things which came along, amply
justified the existence of the society. When I compare the American
Physical Society of twenty years ago with the American Physical Society
of to-day I can scarcely believe that so much progress has been
possible in so short a time. I recognize, however, that this remarkable
growth is clue not only to the energy of youth of this country but also
to the energy of youth of New Physics, which I call Electron Physics.
In October, 1899, Rowland delivered his presidential address before
the society at whose head he stood. I can see now how happy he looked
on that memorable occasion. Inspired by the latest revelations in
Electron Physics, he prophesied what new revelations the physicists
should expect in the approaching future. After describing physics as
“a science above all sciences, which deals with the foundation of the
universe, with the constitution of matter from which everything in
the universe is made, and with the ether of space by which alone the
various portions of matter forming the universe affect each other ...”
he stated frankly that the physicists of America “form an aristocracy,
not of wealth, not of pedigree, but of intellect and ideals.... Let us
cultivate the idea of the dignity of our pursuit so that this feeling
may sustain us in the midst of a world which gives its highest praise,
not to the investigator in the pure ethereal physics which our society
is formed to cultivate, but to the one who uses it for satisfying the
physical rather than the intellectual needs of mankind.” He then
pleaded that we “recognize the eras when great thoughts have been
introduced into our subject and honor the great men who introduced
them and proved them correct.” Then, enumerating the great problems of
the physical universe, he asked: “What is matter; what is gravitation;
what is ether and radiation; what is electricity and magnetism; how are
these connected together, and what is their relation to heat?” Now,
these are the very questions which Electron Physics has been trying to
answer since that time; and this is the idealism which the American
physicist has had before him ever since the days of Rowland.
Electromagnetic theory of matter was the first answer to Rowland’s
question: What is matter? But how about the answer to his second
question: What is gravitation? If matter contains nothing but
electrons, if they are really the most fundamental building stones
of matter, then electricity as concentrated and stored up in the
electrons can exert in addition to the well-known electrical force also
a gravitational force. A somewhat novel idea, but ... why not, and why
so? Einstein gives the best answer to this.
To Rowland’s question: What is Ether? Electron Physics gave a puzzling
answer, but the puzzle has led us into a side path of surpassing
beauty. Our famous physicists, Michelson and Morley, are a combination
of two names better known in the world of physical science to-day
than Castor and Pollux were known when Zeus, descending from the
heights of Mount Olympus, sought the companionship of mortal men. The
fame of the twins, Michelson and Morley, not, however, of Michelson
alone, rests upon an experimental demonstration, the importance of
which was not until recently fully appreciated, the demonstration,
namely, that there is no ether drift; that is to say, so far as
man can tell, there is no relative motion between the earth moving
through space and the ether which is supposed to fill all interstellar
space. On the other hand, the hypothesis that the ether moves with
the moving earth leads to insurmountable difficulties. This was,
indeed, a most embarrassing situation! Since Michelson originally,
and, later, Michelson and Morley, employed the radiation of light
in their attempts to detect the ether drift, it became necessary to
re-examine the electromagnetic theory of propagation of light for the
case that light, as in the Michelson and Morley experiment, proceeds
from a source which together with the observer is moving through
space. The famous Professor Lorentz, of Leyden, Holland, whom I have
the honor of knowing personally, made the first successful extension
of this theory, and explained satisfactorily Michelson and Morley’s
result. But the extension was obtained by what was acknowledged to be
a clever notion, and not by an unavoidable physical fact. The same
extension of the theory was obtained by Einstein, but it was founded
upon a broad physical principle which Lorentz’s extension lacked.
Lorentz preferred Einstein’s deduction of his extension, called the
Lorentz transformation. The physical principle just referred to is
now popularly known as the Special Relativity Theory, which Einstein
extended later into the General Relativity Theory. Einstein’s theory
explains very simply the Michelson-Morley experiment, but how does it
answer Rowland’s question: What is Ether? Also very simply by saying
that ether is superfluous in our analysis of physical phenomena.
Faraday expressed a similar view nearly eighty years ago. That,
however, which is essential in this narrative in connection with
Einstein’s relativity theory is the great fact that by it a general
demonstration is furnished that all forms of electrical energy are
a mass which has _inertial as well as gravitational_ activity. In
the electromagnetic theory of matter this demonstration plays a most
important part. One of the schemes of this theory is so simple and
so beautiful, and appeals so strongly even to an imagination not
scientifically trained, that I must tell here very briefly some of its
most striking features.
All atoms are built up from a single atom, the atom of hydrogen,
which consists of a positive electron or proton, the nucleus, and a
single negative electron revolving around it like a satellite around
the central planet. A heavier atom, say an atom of oxygen, consists
of sixteen atoms of hydrogen, the positive nuclei of which form the
positive nucleus or central portion of the oxygen atom. Some of the
negative electrons are distributed among the positive electrons of
the central nucleus, serving to cement them together, and the other
negative electrons are revolving like satellites around the central
nucleus. The number of these satellites is the atomic number of
the atom, and it is this number, and not the atomic weight, which
determines the chemical characteristics of the atoms. This is only
a mere glance into the structure of Electron Physics, made here for
the purpose of pointing out some of the never-dreamt-of possibilities
that Electron Physics holds in view. For instance, four atoms of
hydrogen combining into an atom of helium give off a certain amount
of energy. We say the atoms of hydrogen degrade into the heavier atom
of helium and, thereby, a certain amount of energy is liberated. A
helium atom weighs less than four atoms of hydrogen, because of the
diminished energy per atom of hydrogen, the decrement of the weight
being proportional to the decrement of energy. This is demanded by
Einstein’s theory, which is really an extension of the theory first
proposed by Sir John Joseph Thomson, and it is a remarkable fact that
these weight relations satisfy the prophecy of the theory. The amount
of energy obtained by the degradation of the lighter into heavier atoms
is enormous. But we do not know how to produce the process of this
degradation. The question arises: Do not the young stars, the very hot
stars, which always consist of gases of small atomic weight, obtain a
supply of radiant energy from the degradation of atoms of small into
atoms of high atomic weight, and, if this is so, then why shall we
not some day learn this great secret from the stars? The language of
the stars has many deep secrets to tell; it mystifies me just as much
to-day as it did on the pasturelands of my native village fifty years
ago.
Many other most startling contemplations may be connected with the
new views opened up by Electron Physics, all of them illustrating the
beauty, the wealth, and the power of a new science which represents the
marriage of two great sciences, physics and chemistry.
Industrial science is very much impressed by new discoveries
which, as Rowland expressed it, “deal with the foundation of the
universe,” but which in spite of their revolutionary character are
easily understood by the practical man. Electron Physics abounds in
discoveries of that kind, and it seems that they have rushed upon
us like a cloud-burst. Things have been done that formerly seemed
impossible. Take, for an illustration, a thing which is so familiar
to all, the complete transformation of wireless telegraphy into the
new art which is called Radio. A vacuum-tube with a hot filament
fills up with negative electrons, which are thrown off by the hot
filament. The filament may be said to be radioactive. A current can
be established by applying an electromotive force which drives these
negative electrons from the space surrounding the hot filament to
a positive electrode. Here we have a new type of Crookes’s tube,
operated by a small electrical tension, and not by that of a powerful
induction-coil, which is necessary when the negative electrode is cold.
This current is called the thermionic current, and its value can be
varied in any way we please by a second electrical force which acts
through a third electrode, called the grid, placed in the path of
the thermionic current. This is the so-called audion tube, invented
by a Yale graduate, Doctor Lee De Forest. In the hands of the Western
Electric Company and of the General Electric Company, this tube has
transformed the whole radio art by its amplifying power. My old
inventions of electrical tuning and rectification have been raised to
unexpected powers by the action of these tubes, and the inventions of
my former pupil and research associate, Major E. H. Armstrong, and of
others, have given us the broadcasting art, which surpasses the wildest
expectations of even the rosiest of optimists of a few years ago.
Wherever Electron Physics has entered there have sprung up new crops
of the rarest fruit, and it is no wonder that there are to-day so many
workers in the newly discovered fertile fields of the electromagnetic
theory. Attend any meeting of the American Physical Society and you
will be convinced that the research in the university laboratories as
well as in the research laboratories of our industries would satisfy
even the highest expectations of the men who fifty years ago, under the
leadership of Joseph Henry, started the movement in favor of higher
scientific research. The university and the industrial laboratories
are mindful of Rowland’s admonition: “In choosing subjects for our
investigation, let us, if possible, work upon those subjects which
will finally give us advanced knowledge of some great subject.” What
subject can be greater than eternal truth, and that aim, according to
my definition, is idealism in science.
It is very true that our American scientific research activities in
physics and chemistry are so alive to-day because they have been
greatly stimulated by the wonderful advances, through electron physics,
in the electromagnetic theory, and in its very successful applications
to technical and industrial problems. But it is also true that the
scientific research activities in other branches, like biology, which
are not closely connected with the electromagnetic theory and its
applications, have also blossomed up with wonderful rapidity during the
last twenty-five years. It will be conceded, I think, that all these
activities in abstract science are to a very substantial extent due to
the rapid rise of the American university and to its splendid influence
upon the mentality of our industries. But in this democratic country,
covering a vast area, each State has the privilege of regulating in its
own way its own educational programme and policy, and each privately
endowed university can pursue its own ideals in its own way without
worrying very much about any other university. Lack of unity and
uniformity was, therefore, always felt, and there was always a strong
although often an unconscious desire in the hearts of scientific men
to bring about a uniformity in the aims and aspirations of higher
scientific research in our universities. The American Association for
the Advancement of Science made quite a number of efforts in this
direction, but the progress was slow. The great World War forced us to
make another big effort in this direction, and this time the effort
succeeded beyond all expectations. The following story of this big
effort is, I am sure, of national importance, and should be known by
every intelligent person in the United States.
Just as the cultivation of science in the United States was first taken
up in the technical schools, like the School of Mines of Columbia
College, the Massachusetts Institute of Technology, and many others,
and not in colleges or universities, so the organization of scientific
associations took place first among the engineers, the graduates
of the technical schools. The American Society of Civil Engineers,
the American Institute of Mining and Metallurgical Engineers, the
American Society of Mechanical Engineers, and the American Institute of
Electrical Engineers, for instance, were organized some time before
most of the present associations in abstract science, that is in
mathematics, physics, chemistry, and biology were organized. Even the
youngest among the leading engineering societies, that is, the American
Institute of Electrical Engineers, was organized in the early eighties,
whereas the American Physical Society was organized nearly twenty years
later, in 1899.
The organization of these technical societies did not wait for the
arrival of the American university. But, nevertheless, when the
American university arrived, and with it the research laboratories
in the fundamental sciences, it improved the quality of the American
engineer, and of the American engineering societies, just as it
improved the scientific standards of the American industrial
organizations. The National Academy of Sciences deserves here a special
consideration. It is an association of workers in _abstract science_,
principally, but, contrary to what I have just said, it is, like the
American Philosophical Society, founded by Franklin, older than any
of our national engineering societies. Its early birth was due to the
conditions created by the Civil War. Joseph Henry, I imagine, suggested
to President Lincoln that a mobilization of the scientific resources
of the North would improve greatly its military strength, and thus the
National Academy of Sciences was chartered by Congress during the Civil
War, in 1863, and was approved by President Lincoln. It was a creation
of the Civil War, and is in many respects an institution which forms a
part of the Federal Government. I shall describe now how the National
Academy of Sciences, itself a creation of the Federal Government during
the Civil War, gave birth during the World War to another national
scientific institution which is the climax of the great scientific
movement started fifty years ago. I have watched this movement almost
from its very beginning up to the present time; yes, I have been a part
of it during its most active period, and I believe that I understand
its full meaning.
The four leading engineering societies, mentioned above, were in quite
a flourishing condition at the beginning of this century; flourishing
not only with regard to the number, but also with regard to the
quality of their membership, and their progress was speeding on with
remarkable rapidity. For instance, the papers read before the American
Institute of Electrical Engineers in 1900, and the discussions which
followed them, were immeasurably superior to those read in 1890,
when I first became a member of this Institute, because the quality
of its membership was also immeasurably superior. The great American
industries paid much more respectful attention to these engineering
societies than when I first came to Columbia College in 1889. The
greatest among the American captains of industry of those days, the
late Andrew Carnegie, held them in so high an esteem that he presented
a magnificent gift to them which led to the formation of the United
Engineering Society. This happened in 1904, and marks one of the great
events in the history of American technical science.
It is of considerable historical interest to observe here that
Carnegie’s magnificent gift to these national engineering societies
is closely connected with a very modest move made by the American
Institute of Electrical Engineers, nearly thirty years ago. The late
Doctor Schuyler Skaats Wheeler, at one time president of the American
Institute of Electrical Engineers, had purchased the famous electrical
library of the late Latimer Clark, of London, and had presented it
to the Institute. But the Institute had no building of its own, and,
therefore, no place for housing permanently this unique library.
Several of the members of the Institute, including myself, were looking
around anxiously for some practical scheme which would provide the
Institute with a home of its own, where the Latimer Clark library
could be permanently located. It was obvious that Andrew Carnegie,
who was always interested in libraries, should be selected as our
first point of application. We never had to appeal to anybody else;
Mr. Carnegie was most generous. The engineering societies appealed
to his lively imagination. It was the engineer who assisted him in
the development of the great steel industry, and it was the engineer
upon whom he relied to maintain the American steel industry in the
leading position which it had won, in a great measure, by Carnegie’s
initiative and efforts. He had already paid a splendid tribute to
science for the service it had rendered to him when he created and
richly endowed the Carnegie Institution of Washington, which was to
provide and does provide ample facilities to American genius in its
efforts to solve some of the great problems in science. I mention here
as an illustration the endowment of the Mount Wilson Astrophysical
Observatory at Pasadena, California, an act which has borne magnificent
fruit under Professor George Ellery Hale’s direction. Instead of
giving to the American Institute of Electrical Engineers a building
for a library, Mr. Carnegie presented to the four national engineering
societies a building for their permanent home, with suitable
accommodations for a great library, for administrative offices, for
conference and meeting rooms, for lecture-rooms, and for a great
assembly hall. One of the objects of the United Engineering Society
was, according to its charter, to hold and administer this princely
gift “for the purpose of advancing the engineering arts and sciences
in all their branches and for maintaining a free public engineering
library.” The famous Latimer Clark electrical library is now a part of
this great engineering library. The four national societies represented
by the United Engineering Society have a carefully picked membership
of over fifty thousand, and the magnificence of their home on
Thirty-ninth Street, near Fifth Avenue, New York, is fully justified
by their great prestige. I never look upon this beautiful structure
without being thrilled by the thought that the treasures it contains in
the form of organized scientific achievement and brains are among the
greatest of the many rich assets of this nation.
Sixteen years ago, Mr. Carnegie and myself represented the American
Philosophical Society at the memorial service for the late Lord Kelvin,
the famous scientist. It was held in the great hall of the Engineering
Building. As we sat on the platform, waiting for the commencement of
the ceremony, I scanned the beautiful proportions of the great hall,
and they appeared to me more beautiful than ever. “You must feel
very happy when you look at this splendid gift which you made to the
Engineering Society,” said I to Mr. Carnegie, who sat on my right. “I
do, yes indeed I do, and I hope that some day you may experience the
same feeling of happiness which comes from giving,” responded the great
ironmaster. “Perhaps I will,” said I, “but remember that I am a Serb,
and not a Scot: it takes a Scot to understand and to practise the art
of giving.” “But it also takes a Scot to understand and to practise the
art of taking,” said Mr. Carnegie, and his vigorous eyes sparkled with
the light of good-natured humor.
Another event occurred in the history of the four founder societies
which will always mark the beginning of a new epoch in American
science. Another captain of American industry extended a generous hand
to the United Engineering Society, offering to aid it in its work of
“advancing the engineering arts and sciences in all their branches.”
It is very significant that this second generous captain of industry
was in many respects a striking contrast to the first, the late Andrew
Carnegie. I am speaking now of Ambrose Swasey of Cleveland, Ohio. He,
like Carnegie, started his industrial career with very small training
in technical sciences. What he knew about engineering and manufacturing
he had obtained by practical experience. Ambrose Swasey is a splendid
illustration of a disciplined intellect trained by the training of his
hand. I have always believed that the most striking difference between
the American and the European is due to the fact that the American
in his early youth receives a much better manual training than the
European does, and that this accounts for the American directness
of thought, judgment, and action. I never saw a better illustration
of this theory than Mr. Ambrose Swasey. He began his career as a
machinist, and when a little over thirty years of age he and a friend
of his, Mr. Warner, another young machinist, started a manufacturing
plant of their own, making fine machine-tools and astronomical
instruments of precision. The shops of Warner and Swasey became famous
all over the world for their wonderful workmanship.