S. Tolver Preston's Explosive Idea
E = mc2 and the Huyghens-Leibnitz
Mass/Energy Identity as a Heuristic Principle in the Nineteenth Century
(Christopher Jon Bjerknes)
Abstract. In 1875, S. Tolver Preston published a prophetic
treatise, which set forth his arguments for the existence of an aethereal
medium in space. The title of this work is Physics of the Ether.
Its purpose is to discredit the spiritualistic concept of "action at a
distance" and to evince the irrationality of the principle of "potential
energy", and replace these mythologies with "physical causes capable of
rational appreciation." Among the many achievements of this heuristic masterpiece
are Preston's arguments for atomic energy, the atomic bomb, a luminal speed
for the propagation of gravity, and the heuristic principle that E =
mc2.
Introduction
Samuel Tolver Preston [b. 1844, was the son of Daniel Bloom Preston
(b. 1807) and Mary Susannah Tolver] set forth arguments in the nineteenth
century, which were to condition life in the twentieth century, and beyond.
In an early attempt to apply Herbert Spencer's "Social Darwinism" in a
constructive way (as opposed to the horrific racism it furthered), Preston
argued for the collegiate education of females, on the grounds that it
would strengthen the genetic stock of males and generally increase the
intelligence of human beings.[1] This opposed the longstanding tradition
that the Church is the bride of Christ, and is obedient; and, therefore,
a woman must obey her husband and shun professional work. In a letter to
Darwin, Preston professed rationalistic words to the effect of, "self-interest
as a motive for conduct is a thing to be commended - and it certainly [is]
I think ... the only conceivable rational motive of conduct: and always
is the tacitly recognized motive in all rational actions."[2] Preston's
equally pragmatic aether theories led him into diverse fields. For example,
Preston speculated on the nature of "Free Will" and brain dynamics - another
of his scientific challenges to the religious ontology and traditions pervasive
in his time.[3]
Preston's profound physical insights were the result of a rational analysis
of phenomena he conducted in the refined language and images of the eighteenth
century homme d'esprit George-Louis Le Sage. Preston's work was
in part a self-described scientific reaction to contemporary "theories
of a vague nature" which proposed "phantom agencies" to account for known
phenomena. His Physics of the Ether [4] is a scientific synthesis
derived from the hypotheses that aether is rarified mass, mass, concentrated
aether; and that aether particles must be in motion and this motion is
conserved. For Preston, as for many of his contemporaries, all things are
modes of motion. These premises evolve subtly into a definition of terms,
identities, and mathematical expressions described in compelling prose,
which assert, among other things, that energy is proportional to mass
times the speed of light squared, yielding incredibly potent kinetic
effects,
"165. To give an idea, first, of the enormous intensity of the store
of energy attainable by means of that extensive state of subdivision of
matter which renders a high normal speed practicable, it may be computed
that a quantity of matter representing a total mass of only one grain,
and possessing the normal velocity of the ether particles (that of a wave
of light), encloses a store of energy represented by upwards of one thousand
millions of foot-tons, or the mass of one single grain contains an energy
not less than that possessed by a mass of forty thousand tons, moving at
the speed of a cannon ball (1200 feet per second); or other wise, a quantity
of matter representing a mass of one grain endued with the velocity of
the ether particles, encloses an amount of energy which, if entirely utilized,
would be competent to project a weight of one hundred thousand tons to
a height of nearly two miles (1.9 miles)."
Towards a Comprehensive Theory of Dynamics
Based on Motion as a Unifying and Vivifying Cause
Preston set a high standard for his work, which many today would consider
naïve, "there can exist but one correct method of viewing any subject
or question whatever." Before we can come to understand Preston and evaluate
the nature of his conclusions and determine his method for arriving at
them, we should first explore the historical context, which led him to
question the mythologies prevalent in his day, and to propose alternative
points of view based on a Le Sagian materialism, which originally arose
as a materialistic exposition on the Epicurean theory of "universal attraction".[5]
Le Sage argued that if space were to contain an extremely fine particulate
aether of "ultramundane particles" moving at light speed in all directions,
these particles would bombard bodies. In the case of a comparatively isolated
body, the bombardment would, statistically, be even on all sides, and a
sort of equilibrium pressure would result. However, bodies would cast "shadows"
on other bodies by blocking out those "ultramundane" aether particles which
strike them. This proposed shadowing effect would cause a net force of
attraction between bodies, in conformity with Newton's inverse square law.
In Preston's day, as today, there was a lingering religious opposition
to any such mechanistic exposition on the cause of gravity, which would
obviate the governance and active intervention of God as the cause of gravity.
Many, Roger Cotes, Richard Bentley and Voltaire, among them, considered
the idea of "universal attraction" to be a scientific proof of the existence
and active governance of God. Just as the Church had opposed any refutation
of Aristotle's Physics and Metaphysics, religious extremists
opposed and oppose any mechanistic exposition on a proposed cause of "mutual
attraction". This corrupt attitude toward pure science, which is an offense
against religious freedom, not an expression of it (Descartes, Huyghens
and Leibnitz, who were vocal advocates of aethereal gravitational theories,
were deeply religious men), is exemplified by Bentley's A Confutation
of Atheism from the Origin and Frame of the World, written pursuant
to Newton's letters,[6]
"And first as to that ordinary Cant of illiterate and puny Atheists
[***] That such a mutual Gravitation or spontaneous Attraction can neither
be inherent and essential to Matter; nor even supervene to it, unless impress'd
and infused into it by a Divine Power. (3.) That though we should allow
such attraction to be natural and essential to all Matter; yet the Atoms
of Chaos could never so convene by it, as to form the present System: or
if they could form it, it could neither acquire such motions, nor continue
permanent in this state, without the power and Providence of a Divine Being."[7]
This religious persecution had a chilling effect on research into the physical
causes of gravity and magnetism. The subject became and remained largely
taboo, with a few notable exceptions. Colin Maclaurin's writings evince
how lightly one had (has) to tread when proposing a physical theory of
gravity. He was a diplomatic apologist for such an approach:
"14. As we cannot but conceive the universe, as depending on the first
cause and chief mover, whom it would be absurd, not to say impious, to
exclude from acting in it; so we have some hints of the manner in which
he operates in nature, from the laws which we find established in it. Tho'
he is the source of all efficacy, yet we find that place is left for second
causes to act in subordination to him; and mechanism has its share in carrying
on the great scheme of nature. The establishing the equality of action
and reaction, even in those powers which seem to surpass mechanism, and
to be more immediately derived from him, seems to be an indication that
those powers, while they derive their efficacy from him, are however, in
a certain degree, circumscribed and regulated in their operations by mechanical
principles; and that they are not to be considered as mere immediate volitions
of his (as they are often represented) but rather as instruments made by
him, to perform the purposes for which he intended them. If, for example,
the most noble phaenomena in nature be produced by a rare elastic aetherial
medium, as Sir Isaac Newton conjectured, the whole efficacy
of this medium must be resolved into his power and will, who is the supreme
cause. This, however, does not hinder, but that the same medium may be
subject to the like laws as other elastic fluids, in its actions and vibrations;
and that, if its nature was better known to us, we might make curious and
useful discoveries concerning its effects, from those laws. It is easy
to see that this conjecture no way derogates from the government and influences
of the Deity; while it leaves us at liberty to pursue our enquires concerning
the nature and operations of such a medium. Whereas they who hastily resolve
those powers into immediate volitions of the supreme cause, without admitting
any intermediate instruments, put an end to our enquires at once; and deprive
us of what is probably the most sublime part of philosophy, by representing
it as imaginary and fictitious: by which means, as we observed above, they
hurt those very interests which they appear so sanguine to promote; for
the higher we rise in the scale of nature, towards the supreme cause, the
views we have from philosophy appear more beautiful and extensive. Nor
is there any thing extraordinary in what is here represented concerning
the manner in which the Supreme Cause acts in the universe, by employing
subordinate instruments and agents, which are allowed to have their proper
force and efficacy; for this we know is the case in the common course of
nature; where we find gravity, attraction, repulsion, &c. constantly
combined and compounded with the principles of mechanism: and we see no
reason why it should not likewise take place in the more subtile and abstruse
phaenomena and motions of the system."[8]
Preston courageously and unapologetically confronted the religious bias
and dogma against mechanistic theories of gravitation. He cautions us to
not "attach two ideas to [a] fundamental conception[.]" Motion is
the sole cause, for Preston. He also notes, regarding theories of a vague
nature, "that their very vagueness, in which their real weakness consists,
is employed as a defence against argument: hence the long life of such
theories." This is a reaction against the vague and "spiritualistic" notion
of "action at a distance" as a "cause". The cause of gravity is to this
day considered by some a divine mystery not meant to be understood by humankind.
Consider Cotes' preface to Newton's Principia, where he intimates
that the search for a physical cause for gravity, as opposed to a blind
faith in (mythological and numerological) theological forces, is heresy.
Cotes, seemingly together with Newton, asserts that induction resolves
gravity to the will of God as the ultimate cause of the phenomenon,
"Without all doubt this World, so diversified with that variety of
forms and motions we find in it, could arise from nothing but the perfectly
free will of God directing and presiding over all. [***] All sound and
true philosophy is founded on the appearance of things; which if they draw
us never so much against our wills, to such principles as most clearly
manifest to us the most excellent counsel and supreme dominion of the All-wise
and Almighty Being; those principles are not therefore to be laid aside,
because some men may perhaps dislike them. They may call them, if they
please, miracles or occult qualities; but names maliciously given ought
not to be a disadvantage to the things themselves; unless they will say
at last, that all philosophy ought to be founded in atheism. [***] He must
be blind who from the most wise and excellent contrivances of things cannot
see the infinite Wisdom and Goodness of their Almighty Creator, and he
must be mad and senseless who refuses to acknowledge them.[9] Newton's
distinguished
work will be the safest protection against the attacks of atheists, and
nowhere more surely than from this quiver can one draw forth missiles against
a band of godless men."[10]
Voltaire, also, threatened those who would attempt a Cartesian exposition
on gravity,
"The cause of this cause is among the Arcana of the Almighty. 'Procedes
huc, et non amplius.' (Thus far shalt thou go, and no farther.)"[11]
Preston's fundamental conception is that all things transform as modes
of motion through the impact of particles. These hypothetical particles
bear the measurable properties of inertia, momentum and energy, and "fill"
an otherwise void cosmic "empty space". There is a tacit monadism lurking
in Preston's ideas, which he leaves largely unexplored. He argues through
induction that the gaseous nature of his aether filling "space" is self-evident
and need not be explained in terms of frames of reference, or contained
volumes, other than as ontological absolutes. It is this absolutism, which
ultimately leads him to predict that E = mc2, as an absolute
store of energy contained in material bodies, which can be put to work.
For Preston, as for Huyghens and Leibnitz, the identity between mass
and energy is the mode of motion. He argues that "action at a distance"
is an impossibility, which requires the "absurd postulate of an infinite
velocity[.]" He further argues that the concept of "potential energy" is
devoid of meaning, because it asserts energy without motion, and confuses
terms by equating, in name only, one state with a completely different
state. A living person can potentially die, and become a dead person, but
such a fact does not render a living person, dead. The state of a mass
in a field of force is not the same as the state of a mass in motion, in
terms of the ability to do work. Should a field of force composed of a
shower of aether particles impart motion to a body, then it is this conserved
motion which is cause, not spiritual "potential" which is cause.
Preston substitutes the action of an intervening medium for the two
myths of "action at a distance" and "potential energy", which he finds
feed off of one another, the fall of one necessarily toppling the other.
He attempts to logically prove that the conservation of energy is only
satisfied by supposing that the aether is a gas of particles in linear
motion, which expand to fill any contained volume. The "forces" of Nature
result from contact with these moving particles of aether. The velocity
of these particles cannot be infinite, for if it were, then the aether
particle which causes the phenomena of gravity and magnetism would have
to concurrently occupy the beginning, middle and end of its journey, an
impossibility.
Preston induces the elasticity and speed of aether particles, which
of logical and experimental necessity (by analogy to an aeriform medium)
must be in motion, from the speed of light. He does not delve into the
metaphysics of why his proposed aether particles move at light speed,
but instead infers this speed as a logical necessity, his necessary singular
exposition of the known phenomena, his ultimate generalization arrived
at through induction from known experimental results.
We see here many of the elements of the theory of relativity, stated
in scientific terms, as opposed to the metaphysics, which later replaced
the scientific hypotheses of this aether theory. "Action at a distance"
must occupy time, due to the fact it is through the action of an intervening
medium that the effects known as "action at a distance" arise. This speed
is the normal speed of aether particles, known through induction to approximate
the speed of light - gravity propagates at the speed of light, a speed
which nothing can exceed, for speed depends upon the size of a particle
and an aether particle is perhaps the smallest fathomable subdivision of
matter, and the fastest motion. Preston induces these Le Sagian ideas from
the properties of light propagation. Le Sage simply wrote, "we assume for
the [gravitational] corpuscles the velocity of light[.]"
From these basic inductions to general principles, Preston begins to
synthesize these generalizations into fantastic and useful conclusions,
"The above deduction, as to the high speed of the ether particles
in their normal state, throws at once a light upon the existence of a vast
store of energy in space of a very intense character, competent to produce
the most forcible observed molecular motions, such as the phenomena of
chemical action, combustion, the explosion of gunpowder, and other remarkable
cases of the development of motion or work, all such effects finding their
explanation in an interchange of motion between the ether and the molecules
of matter under special conditions[.]"
The bombardment of aether particles flying about in space, each with great
energy due to their high velocity, produces an enormous pressure in space.
Taking note of the fact that the tensile strength of steel wire is enormous
and again appealing to reason, Preston holds that matter cannot cohere
with the immense force it does if it is simply composed of isolated masses
suspended in empty space. There must be a "material agent" which causes
this effect, which effect Preston attributes to a pressure differential,
as a logical necessity,
"As to the precise physical process by which a reduction of the pressure
of the intervening medium can take place in the presence of vibrating matter,
we shall reserve the consideration of this point for the present; but it
may be noted that the inference is none the less essential, that a reduction
of the ether pressure does take place in the presence of the opposed vibrating
molecules of the wire, since there remains no other conceivable means of
explaining in a realizable manner why these portions of matter (molecules),
already completely disconnected from each other in the normal state of
the wire, should require this enormous force to shift their positions in
the act of breaking the wire, unless in this act there were something further
to be accomplished than merely to change the positions of molecules in
space. [A change in position of the wire itself, without breaking it, requires
no such powerful force.]"
Preston goes on to attribute the pressure differential to a rarefaction
of the aether between vibrating bodies caused by "stationary waves" between
them, "We have observed that a vibratory movement of matter, under such
conditions that the waves are reflected and thereby stationary vibrations
are formed in the medium, is well qualified to disturb the equilibrium
of pressure of the medium," and makes clear that he does not see cohesion
as the ultimate pressure differential between normal volume elements of
aether and of vacuum; and he gives the example of chemical bonds as a state
of pressure differential far exceeding the force of cohesion. His inferences
again and again produce an increase in force commensurate with a reduction
in scale. The subdivision results in the attenuation of matter into aether
particles, as a limit. He sets a figure of, "500 tons per square inch as
a limiting value for the ether pressure".
Again, there is no metaphysical attempt to delve into the cause of the
normal velocity of aether particles, but Preston does tacitly and ontologically
assume a quite vaguely defined frame of reference for this velocity. This
ontological belief, and Preston's attitudes toward mechanics, truth, and
his epistemological agenda, would today be considered by many to be naïve
and circularly reasoned; but they nevertheless produced predictions which
have been borne out by technological advances in the twentieth century;
and one seriously doubts that these predictions would have arisen in relativity
theory, other than as a thinly veiled repetition (without attribution)
of the conclusions drawn by Preston, Olinto De Pretto [Editor's
note: see for instance Umberto Bartocci, Albert Einstein e Olinto De
Pretto: la vera storia della formula più famosa del mondo, Ed.
Andromeda, Bologna, 1999; information on line: http://www.dipmat.unipg.it/~bartocci/listast.htm,
points 9 and C] and others, through relativity theory's more complicated
ontological fictions, which have no inductive justification, and which
reify purely abstract conceptualizations of dimension. In contrast to relativity
theory, Preston's ideas are based on quantifiable measurements, on measurable
relations, ultimately resolved into the most scientific expressions of
our empirical sensual experience, the sense of resistance to touch, which
is "pressure" and "matter", as a measurable thing; and the separation of
distance through time, which velocity constitutes a measurable relation.
Preston proposes a dynamic "material agency", the aether.
Preston derives the density of the aether. This is quite significant
to his later derivations of the store of energy contained in the density
of matter, and the powerful effects which he predicts will occur should
matter be subdivided into aether particles,
"In connection with this subject, it may be of great interest to contemplate
the possibility of the following as a physical problem. If we suppose a
given mass of matter and a given volume of space, the volume of the space
being supposed vastly greater than that of the mass of matter. Then it
becomes possible, by the subdivision of the this mass of matter (which
may be readily conceived to carried out to any extent), to pervade the
entire volume of the space with matter, or there is no limit to the degree
of close proximity into which the particles of matter pervading this space
may be brought by continuous subdivision, the approach of the particles
going on continuously without limit as the subdivision progresses. Thus,
with a given mass of matter there is no limit to the extent of space that
may be pervaded by matter by continued subdivision, or there may be no
appreciable portion of the vast volume of space but what contains myriads
of particles of matter. The normal state of this finely subdivided matter
may be conceived to be a state of motion or a state of rest; if a state
of motion, then we may observe the physical possibility of the existence
of a store of energy of an extreme intensity, and which, from the minuteness
and small length of path of the moving particles, must be concealed; this
motion being also necessarily attended by the production of an intense
and at the same time evenly balanced pressure, the smoothness and uniformity
of the pressure, and the consequent concealment of its existence from the
senses, being more and more complete as the subdivision progresses."
Preston concludes that the aether is made up of subdivided particles of
matter, which conclusion is happily in agreement with the velocity and
properties of light propagation. He infers a posteriori a relation
between the subdivision of matter and an increase in the speed of particles,
which ultimately results through the subdivision of mass in aether particles
moving at or slightly above light speed. In a statement of the working
principle of the atomic bomb, Preston avows,
"If now we imagine, merely for illustration, each of these air molecules
to be subdivided into a million parts, and that the speed of each component
part has been increased a thousand times. The presence of the ether within
the receiver may be left out of account for the present. Then by this imaginary
process of subdivision, the mean distance of these parts of matter (which
we shall term 'particles') would be so reduced as to bring these particles
into closer proximity than the molecules of air outside the receiver (the
mean distance of the particles of the subdivided matter being inversely
as the cube root of the their number). The pressure against the interior
of the receiver, which is as the square of the speed of the particles,
would now be increased a million-fold; and yet this result is attained
without any increase in the absolute value of the energy of each particle,
for the energy has, by the reduction of mass, remained precisely the same
for each particle as before, although the total energy has become vastly
greater, this energy being now subdivided among a large number of particles,
and the pressure maintained by a greatly increased number of moving particles.
We might imagine this process of subdivision, or this reduction of mass
combined with increase of speed, to go on progressively, and thus the total
energy would be continually increasing, and the mean distance and mean
length of path of these small moving masses or particles would be continually
diminishing, and therefore the concealment of this motion from the senses
would be more and more complete. The pressure would continually rise in
intensity, and at the same time become more even and perfectly balanced
as the number of particles increased.
We might thus imagine this process to go on progressively, until at
length the dimensions, mean distance, and speed of the ether particles
themselves had been reached; or its possible thus step by step to arrive
at a just conception of the wonderful intensity of the store of energy
that is rendered physically practicable, and the high static value of the
pressure that may be reached, under the simple mechanical conditions of
an extensive subdivision of matter combined with a high speed."
The "speed of the ether particles" is that of a wave of light, and the
"absolute value of the energy of each particle" when reduced to aether
is mc2, which is described in Preston's prose in section
165 of his book, as quoted here above in the introduction. S. Tolver Preston
provided a qualitative and quantitative theory, which set in motion the
search for atomic energy and weaponry, a search which was ultimately successful.
His contributions to science deserve far greater mention. Preston was indeed
a man of science, who did not flinch when opposing the religious zealotry
he confronted. We would do well to follow his example and oppose "theories
of a vague nature" which propose "phantom agencies" like "space-time" and
replace them with "physical causes capable of rational appreciation."
Notes
[1] S. T. Preston, "Evolution and Female Education", Nature,
(23 September 1880), pp. 485-486; Revised, Original essays. I. On the
social relations of the sexes. II. Science and sectarian religion. III.
On the scientific basis of personal responsibility, with a reprint from
an essay on "Evolution and female education," revised from Nature, September
23, 1880, Williams and Norgate, London, Edinburgh, (1884).
[2] S. T. Preston paraphrased in F. Darwin & A.C.
Seward, Editors, More letters of Charles Darwin, Volume 2, Chapter
8, John Murray, London, (1903), p. 52, Letter 421.
[3] S. T. Preston, "On a Point Relating to Brain Dynamics",
Nature,
(13 May 1880), pp. 29-30; Responses by G. Romanes, Nature, Volume
22, p. 75, and W. C. Ley, Nature, Volume 22, (10 June 1880), p.
121; Reply by Preston, Nature, (10 June 1880), p. 121.
[4] S. T. Preston, Physics of the Ether, E. &
F. N. Spon, London, (1875).
[5] G. L. Le Sage, read by P. Prevost to the Berlin Academy
in 1782, "Lucrèce Neutonien", Nouveaux Mémoires de l'Académie
royale des Sciences et Belles-Lettres de Berlin,Year 1782, (Berlin,
1784), pp. 404-427; reprinted in Notice de la Vie et des Écrits
de George-Louis Le Sage, Chez J. J. Paschoud, Genève, (1805),
pp. 561-604; English translation by C. G. Abbot with an introduction by
S. P. Langley appears in: "The Le Sage Theory of Gravitation", Annual
Report of the Board of Regents of the Smithsonian Institution Showing the
Operations, Expenditures, and Condition of the Institution for the Year
Ending June 30, 1898,(U.S.) Government Printing Office, Washington,
(1899), pp. 139-160. W. Thomson, S. Tolver Preston, H. A. Lorentz, and
J. J. Thomson, among many others, pursued Le Sage's shadow theory of ultramundane
particles. Maxwell and Poincaré opposed it, on the basis that it
would result in excessive heat accumulation.
[6] I. Newton, Four Letters from Sir Isaac Newton to
Doctor Bentley containing Some Arguments in Proof of a Deity, London,
(1756) [Editor's note: see also Episteme N.
5, March 2002]. Edward B. Davis has presented significant
scholarship on Newton's religious views: "Newton's Rejection of the 'Newtonian
World View': The Role of Divine Will in Newton's Natural Philosophy", Fides
et Historia, Volume 22, Number 2, (Summer 1990), pp. 6-20; reprinted
Science
and Christian Belief, Volume 3, Number 1, (1991), pp. 103-117; reprinted
with additions Facets of Faith and Science, Volume 3, University
Press of America, Lanham, Maryland, (1996), pp. 75-96.
[7] R. Bentley, A Confutation of Atheism from the Origin
and Frame of the World, Part 3, Phoenix, London, (1693), pp. 4, 20-21.
[8] C. Maclaurin, "Of the Supreme Author and Governor
of the universe, the True and Living God", An Account of Sir Isaac Newton's
Philosophical Discoveries, Book 4, Chapter 9, Patrick Murdoch, London,
(1748), pp. 388-390.
[9] R. Cotes, in I. Newton, The Mathematical Principles
of Natural Philosophy, London, (1729), from "THE PREFACE OF Mr. Roger
Cotes", not paginated.
[10] R. Cotes, Cote's preface to the second edition of
Newton's Principia. Sir Isaac Newton's Mathematical Principles
of Natural Philosophy and his System of the World, University of California
Press, Berkeley, Los Angeles, London, (1962), p. XXXIII.
[11] F. M. A. Voltaire, "On Attraction", Letters on
England, Letter 15.
* * * * *
[We believe it worthwhile to add an ending section about
the important question: vis viva versus kinetic energy]
Clash of Leibnitz and Newton Space as Meta-Aether
There was in Preston's day an emerging rejection of the Newtonian ideas
of mystical "force" as a cause of phenomena among "empty space". Fechner
stated,
"All that is given is what can be seen and felt, movement and the
laws of movement. How then can we speak of force here? For physics, force
is nothing but an auxiliary expression for presenting the laws of equilibrium
and of motion; and every clear interpretation of physical force brings
us back to this. We speak of laws of force; but when we look at the matter
more closely, we find that they are merely laws of equilibrium and movement
which hold for matter in the presence of matter. To say that the sun and
the earth exercise an attraction upon one another, simply means that the
sun and earth behave in relation to one another in accordance with definite
laws. To the physicist, force is but a law, and in no other way does he
know how to describe it. . . All that the physicist deduces from his forces
is merely an inference from laws, through the instrumentality of the auxiliary
word 'force'." [12]
T. H. Pasley, in 1835, averred,
"Of the nature of matter the knowledge is limited to the principle
of inertia. Matter being inert it can do nothing and bodies formed of inert
matter are incapable of acting in any manner: the want of power cannot
originate power: hence cause must consist in means independent of action
by matter. Matter consisting in unorganized molecules, it appeared nothing
out of reason to conclude that the whole and all things they go to form
are inert. For if a body be broken its parts are inactive, and the body
itself to be in an acting state requires to be impelled by means such as
itself does not possess. The inertia of matter therefore is evident. Matter
being inert it cannot either attract or repel. But then, how is universal
gravitation, acknowledged by all the most learned of the world and demonstrated
mathematically, to be set aside, and wherein is cause of it and attraction
be rejected. The difficulty is as great as the Authorities who make no
difficulty of supporting these principles and causes are exalted in fame.
The greatest difficulty however lies in reconciling them with the Inert
nature of Matter. Matter has no acting properties as it is essentially
inert. Acting implies being in motion; motion requires physical impulse
foreign to that which is made to act, and from the atoms of matter being
unalterable, by nothing but physical impulse can they be affected, nor
can the effect be other than motion. Wherefore, gravitating, and repelling
are not properties of either matter or bodies. [***] In moral philosophy
inertia means inferior ability and ability sluggishly exerted; in Physics
it signifies no ability or power whatever. Making inertia a 'passive power'
amounts to no power; power implies acting, passive power not acting or
that can act, but power is never passive. Inertia being an 'inert force'
is the same as force without force: 'vis inertiae' is the force
of inactivity, the power of inability. All bodies are convertible into
powers, but are such only while being made to act. To say a body 'resists'
by means of its inertia, is making nothing a physical force. Who can conceive
force at rest. Inertia causing 'an endeavour and perserverance in a body
to continue in motion or at rest' is a contradiction in terms [***] Inertia
is no cause, it is nothing active or passive. The resistance of a ponderable
body at rest is caused by that which makes it ponderable. Inertia being
nothing is productive of nothing; it may be said to be the zero of cause."
[13]
Pasley identified many of the fatal flaws in the Epicurean mythologies,
for example,
"[W]itness the Newtonian Theory of Gravitation, Attraction and Repulsion,
which, it is said 'Newton has proved to the whole world direct and regulate
the System.' But as gravitating, attracting and repelling cannot belong
to inert bodies, formed as all are of inert matter, the adopted theory,
in these respects, is utterly fallacious and untrue. Gravitating by the
Planets of their own accord is as movement in the lifeless; attraction
as the will of the dead; and repulsion as antipathy possessed by a stone.
The whole of these and all such monstrocities have origin solely in the
theory of Perception being rejected where most applicable, and in coupling
Activity with Inertia." [14]
Preston wanted to replace these myths with a physical agent, which obeyed
the principle of the conservation of energy. Perhaps the most famous name
associated with the principle of the conservation of energy, the foundation
of Preston's natural philosophy, is Julius Robert Mayer. He sought a meaningful
definition of the concept of "force" and this is likely why Preston, in
working out the energy store in bodies through Joule's and Clausius' methods,
deduced Leibnitz' vis viva, as opposed to kinetic energy,[16] as
the absolute store of energy contained in mass. In 1807, Thomas Young defined
"energy" in English as,
"The term energy may be applied, with great propriety, to the product
of the mass or weight of a body, into the square of the number expressing
its velocity."[17]
Mayer stated, in 1852, in an effort to provide a "generic conception
of
'force,'"
"On the other hand, the product of the pressure into the space through
which it acts, or, again, the product - or half-product - of the mass into
the square of the velocity, is named 'force.' In order that motion may
actually occur, it is in fact necessary that the mass, whatever it may
be, should under the influence of a pressure, and, in the direction of
that pressure, traverse a certain space, 'the effective space' (Wirkungsraum):
and in this case a magnitude which is proportional to the 'pushing force'
and
to the effective space, likewise receives the name 'force;' but to distinguish
it from the mere pushing force, by which alone motion is never actually
brought about, it is also called the 'vis viva of motion,' or 'moving
force.' With the generic conception of 'force,' the higher mechanics,
as an essentially analytic science, is not concerned. In order to arrive
at it, we must, according to the general rule, collect together the characters
possessed in common by the several species. As is well known, the definition
so obtained runs thus - 'Force is every thing which brings about or tends
to bring about, alters or tends to alter motion'. This definition, however,
it is easy to see, is tautological; for the last fourteen words of it might
be omitted, and the sense would be still the same. [***] If a mass M, originally
at rest, while traversing the effective space s, under the influence
and in the direction of the pressure
p, acquires the velocity c,
we have ps = Mc2. Since, however, every production
of motion implies the existence of a pressure (or of a pull) and an effective
space, and also the exhaustion of one at least of these factors, the effective
space, it follows that motion can never come into existence except at the
cost of this product, ps = Mc2. And this it is
which for shortness I call 'force.'"[18]
Preston focused on the notion of aethereal pressure (as opposed
to mystical "forces" of gravitation and magnetism exerted upon a mass by
a mass via "action at a distance") again and again in opting for the formulation
of the absolute store of energy as E = mc2 , as
opposed to E = ½ mv2. This is perhaps due
to the fact that most of the writings on the principle of the conservation
of force from the 1840's focused on Galilean-Leibnitzian style experiments
with falling masses. Leibnitz' arguments for a conserved vis viva
against Descartes' momentum were initially a posteriori and depended
upon experiments of gravitation on the Earth. However, by 1875 it was an
anomaly for Preston to not see the "transference of work" done by a body
thrown upwards against the "resistance" of "gravity" as ½ mv2.
Preston wrote,
"26. In considering the high normal velocity of the ether particles,
it is to be expected beforehand that this agent must exert an extremely
forcible pressure upon the molecules of matter, even if every allowance
be made for the extreme low density of the agent; for it is important to
note that the pressure exerted is as the square of the speed of the particles
of the agent, and therefore the pressure rises in a very rapid ratio as
the speed increases; so that taking into account this fact, in conjunction
with the high velocity of the particles, we must be prepared to find this
pressure will have a very high value. In looking to physical phenomena
for an indication of this pressure, and also with the object, if possible,
of arriving at a limiting value for its intensity, or the value which this
pressure must at least attain on the lowest computation, we will consider
one observed fact. [***] 53. Secondly, it may be shown that an excess of
energy is imparted to the surrounding medium by a vibrating mass or molecule,
due to a second separate physical cause, which we shall now consider. We
have observed that the speciality of a vibrating movement is to affect
the normal velocity of the component particles of the medium in such a
way that equal increments and decrements of velocity are experienced. But
it is an important principle to observe, that when masses of matter experience
equal increments and decrements of velocity so that the mean velocity remains
unaltered, that, nevertheless, the energy being as the square of the velocity,
the value for the energy does not remain unaltered. Thus, if we take the
case of two equal masses having equal velocities, which we may express
by V, the energy in each case being expressed by V2, and the
total energy therefore by 2V2. If now we suppose one of the
masses to receive an increment of velocity v, its velocity therefore
becoming V + v, the other mass experiencing an equal decrement of
velocity, its velocity becoming V - v; then although the mean value
for velocity has remained unchanged, yet the value for energy has by no
means remained unchanged, for the energy of each mass being as the square
of its velocity, the total energy now becomes (V + v)2
+ (V - v)2 = 2V2 + 2 v2.
Now the value for the total energy before this change of velocity took
place was only 2V2. The total energy has therefore, by merely
changing the velocities by equal amounts (so as not to affect the mean
velocity), received a notable increase represented by the amount 2v2.
This is an important point, on account of the direct and practical bearing
which it has on the phenomena of vibratory motion; the above indicating
that the change of the velocities of the component particles of the medium
by equal amounts, which it is the special function of a vibratory motion
of matter to effect, is itself a direct cause whereby a certain excess
or surplus of energy is communicated to the medium. [***] 98. Important
Influence of Subdivision. - One of the most important practical consequences
following from the extensive state of subdivision, which is the characteristic
of the molecular condition of matter, is the vast extent of surface which
is thereby brought under the action of the ether pressure. This is a fact
of importance, by a due appreciation of which the great energy of the action
of the ether upon molecules will appear no longer discordant or inconsistent,
but the fact may be brought into harmony with ordinary mechanical principles,
this vast extent of surface being the fitting mechanical condition for
the production of static and dynamic effects of extreme intensity. [***]
[114] III. High Normal Speed of Component Particles. - This physical
quality is absolutely essential to constitute a powerful dynamic agent,
for without this high speed dynamic effects of a high intensity cannot
be produced. Second, this high normal speed of the particles is the sole
condition on which the loss of motion sustained by the ether can be replenished
with that degree of speed which is essential to render a continuous dynamic
effect of a high intensity possible to the ether. Third, this high speed
of the component particles is the sole quality by which the loss of motion
sustained by the ether in producing a given dynamic effect can be subdivided
or distributed over a large volume of the ether, whereby a notable local
disturbance of the equilibrium of the ether is prevented. Fourth, this
quality is essential for the rapid interchange of motion between masses
and molecules of matter at a distance from each other, the rapidity of
intercommunication or exchange of motion being strictly limited by the
normal speed of the particles of the intervening agent. Fifth, this high
speed of the component particles is necessary to render possible the existence
of a store of energy of a high value, without the encumbrance of a large
quantity of matter in space. Sixth, the high normal velocity of the ether
particles is the necessary mechanical condition to enable an intense pressure
to be exerted by the ether upon the molecules of matter, without the movements
of these molecules and masses being obstructed by the agent exerting the
pressure. For, in the first place, by this high speed of the component
particles an intense pressure is attainable (more especially as the pressure
rises as the square of the speed) without the necessity for the
agent being dense, by which the free passage of masses of matter through
the agent would be obstructed. In the second place, the high speed of the
component particles enables masses of matter to pass through the agent
with the least disturbance of its equilibrium, or with a minimum of resistance
from this cause, the agent becoming almost impalpable; the exertion of
an intense pressure by the agent being itself the necessary condition to
render the agent adapted to control forcibly the molecules of matter in
stable equilibrium, as exhibited in the general phenomena of 'cohesion,'
or the aggregation of the molecules of matter generally. The above may
serve as a general summary of the special physical qualities of the ether;
and it may be noted that if the attempt were made beforehand, as a mechanical
problem or speculation, to devise or scheme out what special physical qualities
an agent should possess in order to be mechanically fitted to produce the
varied physical effects of the character observed, then the scheme of the
ether would be found to constitute the only possible solution of which
the mechanical problem admits; or the ether may be contemplated as a piece
of mechanism specially adapted to its work. [***] 128. We shall now proceed
to consider more closely the mode or general principle upon which physical
processes effect themselves, and it will be our endeavour to show that
these processes resemble one another in a second fundamental aspect, viz.
that all these processes are cyclical, i. e. consist in a transference
of motion from the ether through matter to the ether, or consist in a transference
of motion from and to the same source; and therefore that all physical
processes, however diverse and varied, are identical in this fundamental
respect; or that every observed motion whatever came from the ether at
one time, and will return to the ether at some subsequent time. This theorem
may be shown to be a necessary consequence resulting from the fundamental
principle of conservation. The normal state of the ether is a state of
motion, or the component particles of the ether transfer their motions
among themselves, and this motion is of necessity permanently maintained.
The ether, therefore, constitutes a source of motion. A mass or
molecule of matter, on the other hand, cannot possibly be in motion without
continually giving up some of its motion to the surrounding ether, which
motion is rapidly carried off to a distance in the form of waves; so that
matter cannot possibly remain in motion, unless the motion be renewed by
the ether as rapidly as it is being dissipated in the ether, which would
constitute a cyclical process. Since, therefore, the motion of matter
is being continually dissipated in the ether, the ether constitutes the
receptacle
of all the motions of matter. The ether therefore must, in accordance with
the principle of conservation, be the source of all the motions
of matter, for matter cannot evolve motion out of itself. Also, since matter
cannot retain its motion, but must be always dependent on the ether for
any supply of motion, matter therefore cannot in any case constitute a
source
of motion. The ether therefore constitutes both the source and the receptacle
of all the motions of matter, or this would constitute the theorem
that all physical processes are cyclical, or consist in a transference
of motion from and to the same source, and accordingly that all physical
processes are correlated in this fundamental respect. [***] 135. Amount
of energy being dependent on the quantity of matter in motion and on the
square of the velocity of motion, and since motion cannot come into
existence spontaneously, or go out of existence spontaneously, but in accordance
with the principle of conservation, the sum of energy must remain constant;
it follows, therefore, that whenever there is a loss of motion by matter,
there must be a simultaneous gain of motion by matter, or the loss and
gain of motion must be simultaneous, for a loss of motion without
a simultaneous gain of motion would involve for an interval of time an
annihilation of energy. It follows, therefore, as a necessary consequence
from this, that the energy expended in any physical process whatever can
be solely dependent on and due to motion simultaneously imparted, i. e.
imparted at the time of the expenditure of the energy; for unless
motion be imparted at the time, energy cannot be expended at all, for to
expend motion without imparting motion would be to annihilate energy; indeed,
the motion imparted is itself the measure of that expended, and is the
sole cause of its expenditure, i. e. motion can only be expended in the
communication of motion, and in that fact lies apparent the principle of
the Indestructibility of Motion. [***] 163. Absolute Quantity
of Energy in the Unit Volume of Space. - We shall now consider more
particularly the energy enclosed by the ether, with the endeavour to give
some idea of the absolute value of the energy represented by the motion
of the ether particles contained within a given portion of space, with
the object, if possible, to fix upon a limiting value for this energy,
or the lowest value consistent with what physical facts would require.
The conditions required in order to determine the amount of energy enclosed
in the unit volume of space are clearly, first, a knowledge of the quantity
of matter in the form of ether contained in the unit volume of space (i.
e. the density of the ether); and secondly, the normal velocity of the
ether particles. Now, although we do not know the density of the ether
independently, nevertheless since density is determined by pressure and
velocity of component particles, if, therefore, by a known limiting value
for the velocity of the ether particles, a limiting value for the ether
pressure can also be fixed upon, then a limiting value for the ether density
is thereby given. The limiting value for the velocity of the ether particles
is given by the measured velocity of a wave of light. As regards the value
for pressure, we take the estimate already fixed upon: that this amounts
to 500 tons per square inch as the lowest limiting value. There are valid
grounds for inferring that this value for pressure has been under-estimated;
for we assumed the total ether pressure as a small multiple of the observed
difference of pressure in the case of 'cohesion,' whereas, as before remarked,
it is a known fact that the force required to separate chemically combined
molecules must be many times greater, this indicating the high intensity
of the controlling ether pressure, and showing that an estimate of this
pressure from the case of 'cohesion' must be but an inadequate representation
of the reality. The tremendous energy developed in explosives, which is
the very energy of the ether itself, is a direct indication of the intensity
of the ether pressure, which is the necessary accompaniment of this energy.
That this value for pressure has been under-estimated, a bare consideration
of the dependent value for density would almost show, for the ether density
corresponding to this pressure (1/5264800 of the atmospheric density) represents
a density so insignificant as to be less than that of the best gaseous
vacua."
Additional Notes
[12] Fechner quoted in H. Vaihinger's, Philosophy of
the 'As if', Barnes & Noble, Inc., New York, (1966), p. 215; translated
by C. K. Ogden.
[13] T.H. Pasley, A Theory of Natural Philosophy, on
Mechanical Principles, Divested of All Immaterial Chymical Properties,
Showing for the First Time the Physical Cause of Continuous Motion,
Whittaker & Co., London, (1836), Preface and pp. 145-146.
[14] Pasley, ibid. xcii.
[15] See for example the many works of Marc Seguin and
M. F. de Boucheporn, Cf. The Correlation and Conservation of Forces,
D. Appleton, New York, (1867), pp. 4, 76-82; W. B. Taylor, "Kinetic Theories
of Gravitation", Annual Report of the Board of Regents of the Smithsonian
Institution, U. S. Government Printing Office, Washington, (1877),
pp. 205-282. Another good example is A. Anderssohn, Die Mechanik der
Gravitation, Breslau, (1874); and Zur Loesung des Problems ueber
Sitz und Wesen der Anziehung, Breslau, (1874); and Physikalische
Prinzipien der Naturlehre, G. Schwetschke, Halle, (1894). See also:
G. Hoffmann, Die Anderssohn'sche Drucktheorie und ihre Bedeutung für
die einheitliche Erklärung der physischen Erscheinung, G. Schwetschke,
Halle, (1892). For some, the aether become their embodiment of the Tertullian-Newtonian
pantheistic God and Holy Wind. See, for instance, Philipp Spiller, Die
Urkraft des Weltalls nach ihrem Wesen und Wirken auf allen Naturgebieten,
Verlag der Stuhr'schen Buchhandlung (S. Gerstmann), Berlin, (1876).
[16] G. G. Coriolis, Du calcul de l'effet des machines,
ou Considérations sur l'emploi des moteurs, Paris, (1829). Coriolis
used the term "force vive". First use of the term "kinetic energy"
in English is perhaps by Thomson and Tait, Good Words, (October,
1862).
[17] T. Young, A Course of Lectures on Natural Philosophy
and the Mechanical Arts, Volume 1,Taylor and Walton, London, (1845),
p. 59.
[18] J. R. Mayer, translated by J. C. Foster, "Remarks
on the Mechanical Equivalent of Heat", The Correlation and Conservation
of Forces, D. Appleton, New York, (1867), pp. 331, 336.
- - - - -
Christopher Jon Bjerknes is an American historian
of science, who has authored six books and numerous articles on the theory
of relativity and on Albert Einstein. His most recent book, Albert
Einstein - The Incorrigible Plagiarist, is reviewed in this same volume
of Episteme.
cbjerknes@attbi.com