LATER SCIENCE
The position, as we have described it, was that which may be said to
have existed up to about twenty years ago. Since then much new light
has come. Indeed, Lord Kelvin, speaking at Clerkenwell on February
26th, 1904, is reported in _The Times_ to have said, referring to the
extraordinary progress of scientific research, that it "had, perhaps,
been even more remarkable and striking at the beginning of the
twentieth century than during the whole of the nineteenth."
Let us take first that which he had more particularly in mind, the
advance in the knowledge of the constitution of Matter.
In an address delivered before the British Association at Bradford in
1873, Clerk Maxwell had stated the conclusions to which science had, up
to that time, been led in its investigations of matter. Throughout the
natural universe it had been shewn, by Spectrum Analysis, that matter
is built up of {69} molecules. These molecules, according to the most
competent judgment, were incapable of sub-division without change of
substance, and were absolutely fixed for each substance. "A molecule
of hydrogen, for example, whether in Sirius, or in Arcturus, executes
its vibrations in precisely the same time." The relations of the parts
and movements of the planetary systems may and do change, but "the
molecules--the foundation-stones of the natural universe--remain
unbroken and unworn."
As a result of this, it was maintained that "the exact equality of each
molecule to all others of the same kind gives it, as Sir John Herschel
has well said, the essential character of being a manufactured article,
and precludes the idea of its being eternal and self-existent." "Not
that science is debarred from studying the internal mechanism of a
molecule which she cannot take to pieces ... but, in tracing back the
history of matter, science is arrested when she assures herself, on the
one hand, that the molecule has been made, and on the other that it has
not been made by any of the processes we call natural."
So the case had stood for some while until science, through its
indefatigable inquirers, shewed that it was in very deed "not debarred
from studying the internal mechanism of a molecule," nor, perhaps, from
taking it to pieces. In 1895 came the {70} discovery of the X-rays by
Roentgen in Germany, to be followed in a year by Becquerel's discovery
of spontaneous radio-activity, and in a couple of years by the
remarkable further discovery, made by Madame Curie, of what was termed
"radium," a substance that went on producing heat _de novo_, keeping
itself permanently at a higher temperature than its surroundings, and
spontaneously producing electricity.
This in itself was a new fact of extraordinary interest. For long,
discussion had been waged between two departments of scientific
inquirers. The geologists and biologists had demanded hundreds, and
perhaps thousands, of millions of years to allow for the developments
with which they were concerned. The physicists, led by Lord Kelvin,
refused to admit the demand, claiming that it could be proved
mathematically that it was impossible that the sun could have been
giving out heat at its present rate for more than a hundred million
years, at the very outside. The appearance of radium robbed this
argument of its cogency. It is true that an examination of the sun's
spectrum has not, as yet, revealed any radium lines, but it is well
known that helium, a transformation product of radium, is present in it.
And this modification of our views as to the {71} probable age of our
solar system was far from being the only result of this latest
discovery. Investigations which followed into radio-activity led the
Cambridge professors, Larmor and Thomson, to conclude that electricity
existed in small particles, which were called "electrons."[1] These
seem to be the ingredients of which atoms are made. A molecule is
composed of two or more atoms. That of hydrogen, for example, has two;
that of water three; and so on up to a thousand or more.
Molecules are very small. If a drop of water were magnified to the
size of the globe, the molecules would be seen to be less than the size
of a cricket ball!
Atoms are much smaller. "The atoms in a drop of water outnumber the
drops in an Atlantic Ocean." Electrons are much smaller still--about
"a thousand-million-million times smaller than atoms."[2]
Within the atom thousands or tens of thousands of these electrons are
moving in orderly arrangement, at terrific speed, round and about one
another. The amount of energy required to build up a molecule of any
degree of complexity is very great, and it is {72} by the breaking down
of complex molecules into simple ones that all our mechanical work is
done. And this is not all, for not only can the molecule be thus
broken in pieces, but the atom itself is capable of disintegration.
"Although we do not know how to break atoms up, they are liable every
now and then themselves to explode, and so resolve themselves into
simpler forms." "Atoms of matter are not the indestructible and
immutable things they were once thought."[3] The idea of the amount of
energy thus revealed as available for all kinds of active work is so
vast as to baffle calculation and even imagination. It has been said
that there is energy enough in fifteen grains of radium, if it could
all be set free at once, to blow the whole British Navy a mile high
into the air. The thought that we are thus encompassed on every side
by pent up potentialities of force, which if uncontrolled might at any
moment work our destruction, may well deepen in us the sense of the
need, not only for an originating, but for a continually directing mind
to superintend the conduct of the universe.
We have referred to more than one change of view to which the new
discoveries have led. We shall doubtless find that there are other
scientific theories {73} which will have ere long to be modified.
Already it is recognised that the arguments of Lord Kelvin (he was then
Sir William Thomson) and of Clerk Maxwell, which were based upon
calculations as to the "dissipation of energy," can scarcely remain
unaffected by what we now know, and suspect, of the crumbling and
re-forming of atoms.
And there are hints abroad of even more revolutionary suggestions. If
there has been one principle more imperatively and unanimously insisted
upon than another, it has been the uniformity of Nature's laws. What
then are we to make of a remark like the following, made by Professor
J. J. Thomson, perhaps only half-seriously, to the British Association
at Cambridge, in 1904? "There was one law," he said, "which he felt
convinced nobody who had worked on this question"--the radio-activity
of matter--"would ever suggest, and that was the constancy of Nature."
Not less startling is it to be told that a question may yet be raised
which will challenge "the conception of a luminiferous aether, which
for half a century has dominated physical science. It is possible," so
we are informed, "that the field of electro-magnetic energy surrounding
an electric charge in motion moves with it, and that the vibrations of
light travel through this moving {74} field, instead of through an
ocean of stagnant aether."[4]
One further quotation of singular interest may be added. It is taken
from an address to students by the President of the Institution of
Mining and Metallurgy.[5]
"Twenty years ago," he said, "the idea held that inorganic chemistry
was almost a dead science--dead in the sense of being apparently
completed in many of its aspects, and that its records could be safely
confided to the encyclopaedia.... A modified conception of life is now
becoming co-extensive with the whole range of our experience. Even a
simple inorganic crystal does not spring ready formed from its solvent,
but first passes through phases of granulation and striation comparable
with those which characterise the beginnings of vital growth. Metals
exhibit in some respects phenomena similar to those possessed by
organised beings. Thus, they show fatigue under long continued stress,
and they recover their strength with rest. They are also susceptible
to certain of the poisons which destroy organic life. Matter, broadly,
is no longer merely dead masonry from which the edifice to shelter life
{75} is constructed, but also appears to be the reservoir of that
energy which is developed, altered and drawn into vitality itself....
The indestructibility of matter bids fair to become relegated to the
museum of outworn theories; and with it will probably go our present
conceptions as to the conservation of energy."
It is clear, then, that the tasks awaiting the students of physical
science are likely to be as arduous, and we may hope as full of reward,
as they have been at any time in the past. Meanwhile, it does look as
if there were truth in Mr. Balfour's remark that "Matter is not merely
explained, but is explained away."[6]
[1] The weighing and measuring of the electron were first announced by
Professor Thomson to the British Association meeting at Dover, in 1899.
[2] Sir Oliver Lodge.
[3] Sir Oliver Lodge. _Life and Matter_, p. 28.
[4] Whetham. _The Foundations of Science_, p. 50.
[5] H. L. Sulman, at the Sir John Cass Institute, November 29th, 1911.
[6] Presidential Address to British Association, 1904.
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