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[page 192, continued:]
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In the first place, we may get a general, relative
conception of the interval referred to, by comparing it with the
inter-planetary
spaces. If, for example, we suppose the Earth, which is, in
reality,
95 millions of miles from the Sun, to be only one foot
from that luminary; then Neptune would be forty feet distant; and
the
star Alpha Lyræ, at the very least, one hundred and fifty-nine.
Now I presume that, in the termination of my
last
sentence, few of my readers have noticed anything especially
objectionable
— particularly wrong. I said that the distance of the Earth from the
Sun
being taken at one foot, the distance of Neptune would be forty
feet, and that of Alpha Lyræ one hundred and fifty[[-]]nine. The
proportion
between one foot and one hundred and fifty-nine has appeared, perhaps,
to convey a sufficiently definite impression of the proportion between
the two intervals — that of the Earth from the Sun, and that of Alpha
Lyræ
from the same luminary. But my account of the matter should, in
reality,
have run thus: — The distance of the Earth from the Sun being taken at
one foot, the distance of Neptune would be forty feet, and that of
Alpha Lyræ one hundred and fifty-nine — miles: — that is
to say, I had
assigned to Alpha Lyræ, in my first statement of the case, only
the
5280th part of that distance which is the least
distance possible at which it can
actually
lie. [page 193:]
To proceed: — However distant a mere planet
is, yet when we look at it through a telescope, we see it under a
certain
form — of a certain appreciable size. Now I have already hinted at the
probable bulk of many of the stars; nevertheless, when we view any one
of them, even through the most powerful telescope, it is found to
present
us with no form, and consequently with no
magnitude
whatever. We see it as a point, and nothing more.
Again: — Let us suppose ourselves walking, at
night,
on a highway. In a field on one side of the road, is a line of tall
objects,
say trees, the figures of which are distinctly defined against the
background
of the sky. This line of objects extends at right angles to the
road,
and from the road to the horizon. Now, as we proceed along the road, we
see these objects changing their positions, respectively, in relation
to
a certain fixed point in that portion of the firmament which forms the
background of the view. Let us suppose this fixed point — sufficiently
fixed for our purpose — to be the rising moon. We become aware, at
once,
that while the tree nearest us so far alters its position in respect
to
the moon, as to seem flying behind us, the tree in the extreme distance
has scarcely changed at all its relative position with the satellite.
We
then go on to perceive that the farther the objects are from us, the
less
they alter their positions; and the converse. Then we begin,
unwittingly,
to estimate the distances of individual trees by the degrees in which
they
evince the relative alteration. Finally, we come to understand how it
might
be possible to ascertain the actual distance of any given tree in the
line,
by using the amount of relative alteration as a basis in a simple
geometrical
problem. Now, this relative alteration is what we call “parallax;” and
by parallax we calculate the distances of the heavenly bodies. Applying
the principle to the trees in question, we should, of course, be very
much
at a loss to comprehend the distance of that tree, which,
however
far we proceeded along the road, should evince no parallax at
all.
This, in the case described, is a thing impossible; but impossible only
because all distances on our Earth are trivial indeed: — in comparison
with
the vast cosmical quantities, we may speak of them as absolutely
nothing.
Now, let us suppose the star Alpha Lyræ
directly
overhead; and let us imagine that, instead of standing on the Earth, we
stand [page 194:] at one end of a straight road
stretching
through Space to a distance equalling the diameter of the Earth’s orbit
— that is to say, to a distance of one hundred and ninety millions
of
miles. Having observed, by means of the most delicate micrometrical
instruments, the exact position of the star, let us now pass along this
inconceivable road, until we reach its other extremity. Now, once
again,
let us look at the star. It is precisely where we left it. Our
instruments,
however delicate, assure us that its relative position is absolutely —
is identically the same, as at the commencement of our unutterable
journey. No parallax — none whatever — has been found.
The fact is, that, in regard to the distance of
the
fixed stars — of any one of the myriads of suns glistening on the
farther
side of that awful chasm which separates our system from its brothers
in
the cluster to which it belongs — astronomical science, until very
lately,
could speak only with a negative certainty. Assuming the brightest as
the
nearest, we could say, even of them, only that there is a
certain
incomprehensible distance on the hither side of which they
cannot
be: — how far they are beyond it we had in no case been able to
ascertain.
We perceived, for example, that Alpha Lyræ cannot be nearer to us
than
19 trillions, 200 billions of miles; but, for all we
knew,
and indeed for all we now know, it may be distant from us the square,
or
the cube, or any other power of the number mentioned. By dint, however,
of wonderfully minute and cautious observations, continued, with novel
instruments, for many laborious years, Bessel, not long ago
deceased,
has
lately succeeded in determining the distance of six or seven stars;
among
others, that of the star numbered 61 in the constellation of the Swan.
The distance in this latter instance ascertained, is 670,000 times that
of the Sun; which last it will be remembered, is
95
millions of miles. The star 61 Cygni, then, is nearly 64
trillions
of miles from us — or more than three times the distance assigned, as
the least possible, for Alpha Lyræ.
In attempting to appreciate this interval by the
aid of any considerations of velocity, as we did in endeavoring
to estimate the distance of the moon, we must leave out of sight,
altogether,
such nothings as the speed of a cannon ball, or of sound. Light,
however,
according to the latest calculations of Struve, proceeds at the [page
195:] rate of 167,000 miles in
a second. Thought itself cannot pass through this interval more
speedily
— if, indeed, thought can traverse it at all. Yet, in coming from 61
Cygni
to us, even at this inconceivable rate, light occupies more than ten
years; and, consequently, were the star this moment blotted out
from
the Universe, still, for ten years, would it continue to
sparkle
on, undimmed in its paradoxical glory.
Keeping now in mind whatever feeble conception we
may have attained of the interval between our Sun and 61 Cygni, let us
remember that this interval, however unutterably vast, we are permitted
to consider as but the average interval among the countless
host
of stars composing that cluster, or “nebula,” to which our system, as
well
as that of 61 Cygni, belongs. I have, in fact, stated the case with
great
moderation: — we have excellent reason for believing 61 Cygni to be one
of the nearest stars, and thus for concluding, at least
for
the present, that its distance from us is less than the average
distance between star and star in the magnificent cluster of the Milky
Way.
And here, once again and finally, it seems proper
to suggest that even as yet we have been speaking of trifles. Ceasing
to
wonder at the space between star and star in our own or in any
particular
cluster, let us rather turn our thoughts to the intervals between
cluster
and cluster, in the all-comprehensive cluster of the Universe.
I have already said that light proceeds at the
rate
of 167,000 miles in a second — that is, about 10 millions of miles in a
minute, or about 600 millions of miles in an hour: — yet so far removed
from
us are some of the “nebulæ” that even light, speeding with this
velocity,
could not and does not reach us, from those mysterious regions, in less
than 3 millions of years. This calculation, moreover, is
made
by the elder Herschel, and in reference merely to those comparatively
proximate
clusters within the scope of his own telescope. There are
“nebulæ,”
however, which, through the magical tube of Lord Rosse, are this
instant
whispering in our ears the secrets of a million of ages
by-gone.
In a word, the events which we behold now — at this moment — in those
worlds
— are the identical events which interested their inhabitants ten
hundred
thousand centuries ago. In intervals — in distances such as [page
196:] this suggestion forces upon the soul — rather
than
upon the mind — we find, at length, a fitting climax to all hitherto
frivolous
considerations of quantity.
Our fancies thus occupied with the cosmical
distances,
let us take the opportunity of referring to the difficulty which we
have
so often experienced, while pursuing the beaten path of
astronomical
reflection, in accounting for the immeasurable voids alluded
to —
in comprehending why chasms so totally unoccupied and therefore
apparently
so needless, have been made to intervene between star and star —
between
cluster and cluster — in understanding, to be brief, a sufficient
reason
for the Titanic scale, in respect of mere Space, on which the
Universe is seen to be constructed. A rational cause for the
phænomenon,
I maintain that Astronomy has palpably failed to assign: —but the
considerations
through which, in this Essay, we have proceeded step by step, enable us
clearly and immediately to perceive that Space and Duration are one.
That the Universe might endure throughout an æra
at all
commensurate
with the grandeur of its component material portions and with the high
majesty of its spiritual purposes, it was necessary that the original
atomic
diffusion be made to so inconceivable an extent as to be only not
infinite.
It was required, in a word, that the stars should be gathered into
visibility
from invisible nebulosity — proceed from nebulosity to consolidation —
and so grow grey in giving birth and death to unspeakably numerous and
complex variations of vitalic development: — it was required that the
stars
should do all this — should have time thoroughly to accomplish all
these
Divine purposes — during the period in which all things were
effecting
their return into Unity with a velocity accumulating in the inverse
proportion
of the squares of the distances at which lay the inevitable End.
Throughout all this we have no difficulty in
understanding
the absolute accuracy of the Divine adaptation. The density of
the
stars, respectively, proceeds, of course, as their condensation
diminishes;
condensation and heterogeneity keep pace with each other; through the
latter,
which is the index of the former, we estimate the vitallic and
spiritual
development. Thus, in the density of the globes, we have the measure in
which their purposes are fulfilled. As density proceeds — as
the divine intentions are accomplished — [page 197:]
as less and still less remains to be
accomplished — so —
in
the same ratio — should we expect to find an acceleration of the
End: — and thus the philosophical mind will easily comprehend that
the Divine
designs in constituting the stars, advance mathematically to
their
fulfilment: — and more, it will readily give the advance a mathematical
expression; it will decide that this advance is inversely proportional
with the squares of the distances of all created things from the
starting-point
and goal of their creation.
Not only is this Divine adaptation, however,
mathematically
accurate, but there is that about it which stamps it as divine,
in distinction from that which is merely the work of human
constructiveness.
I allude to the complete mutuality of adaptation. For example,
in
human constructions a particular cause has a particular effect; a
particular
intention brings to pass a particular object; but this is all; we see
no
reciprocity. The effect does not re-act upon the cause; the intention
does
not change relations with the object. In Divine constructions the
object
is either design or object as we choose to regard it — and we may take
at any time a cause for an effect, or the converse — so that we can
never
absolutely decide which is which.
To give an instance: — In polar climates the
human
frame, to maintain its animal heat, requires, for combustion in the
capillary
system, an abundant supply of highly azotized food, such as train-oil.
But again: — in polar climates nearly the sole food afforded man is the
oil of abundant seals and whales. Now, whether is oil at hand because
imperatively
demanded, or the only thing demanded because the only thing to be
obtained?
It is impossible to decide. There is an absolute reciprocity of
adaptation.
The pleasure which we derive from any display of
human ingenuity is in the ratio of the approach to this
species
of reciprocity. In the construction of plot, for example, in
fictitious
literature, we should aim at so arranging the incidents that we shall
not
be able to determine, of any one of them, whether it depends from any
one
other or upholds it. In this sense, of course, perfection of plot
is really, or practically, unattainable — but only because it is a
finite
intelligence that constructs. The plots of God are perfect. The
Universe
is a plot of God. [page 198:]
And now we have reached a point at which the
intellect
is forced, again, to struggle against its propensity for analogical
inference
— against its monomaniac grasping at the infinite. Moons have been seen
revolving about planets; planets about stars; and
the poetical
instinct
of humanity — its instinct of the symmetrical, if the symmetry be
but a symmetry of surface: — this instinct, which the Soul, not
only
of Man but of all created beings, took up, in the beginning, from the geometrical
basis of the Universal irradiation — impels us to the fancy of an
endless
extension of this system of cycles. Closing our eyes equally to
deduction and induction, we insist upon
imagining a revolution
of all the orbs of the Galaxy about some gigantic globe which we take
to
be the central pivot of the whole. Each cluster in the great cluster of
clusters is imagined, of course, to be similarly supplied and
constructed;
while, that the “analogy” may be wanting at no point, we go on to
conceive
these clusters themselves, again, as revolving about some
still
more august sphere; — this latter, still again, with its
encircling
clusters, as but one of a yet more magnificent series of
agglomerations, gyrating about yet another orb central to
them —
some
orb still more unspeakably sublime — some orb, let us rather say, of
infinite
sublimity endlessly multiplied by the infinitely sublime. Such are the
conditions, continued in perpetuity, which the voice of what some
people
term “analogy” calls upon the Fancy to depict and the Reason to
contemplate,
if possible, without becoming dissatisfied with the picture. Such, in
general, are the interminable gyrations beyond gyration which we
have
been instructed by Philosophy to comprehend and to account for, at
least
in the best manner we can. Now and then, however, a philosopher proper
— one whose frenzy takes a very determinate turn — whose genius, to
speak
more reverentially, has a strongly-pronounced washer-womanish bias,
doing
every thing up by the dozen — enables us to see precisely that
point
out of sight, at which the revolutionary processes in question do, and
of right ought to, come to an end.
It is hardly worth while, perhaps, even to sneer
at the reveries of Fourrier: — but much has been said, latterly, of
the
hypothesis
of Mädler — that there exists, in the centre of the Galaxy, a
stupendous
globe about which all the systems of the cluster revolve. [page
199:] The period of our own, indeed, has been stated
— 117 millions of years.
That our Sun has a motion in space, independently
of its rotation, and revolution about the system’s centre of gravity,
has
long been suspected. This motion, granting it to exist, would be
manifested
perspectively. The stars in that firmamental region which we were
leaving
behind us, would, in a very long series of years, become crowded; those
in the opposite quarter, scattered. Now, by means of astronomical
History,
we ascertain, cloudily, that some such phænomena have occurred.
On this
ground it has been declared that our system is moving to a point in the
heavens diametrically opposite the star Zeta Herculis: — but this
inference
is, perhaps, the maximum to which we have any logical right.
Mädler,
however,
has gone so far as to designate a particular star, Alcyone in the
Pleiades,
as being at or about the very spot around which a general revolution
is performed.
Now, since by “analogy” we are led, in the first
instance, to these dreams, it is no more than proper that we should
abide
by analogy, at least in some measure, during their development; and
that analogy which suggests the revolution, suggests at the same
time
a central orb about which it should be performed: — so far the
astronomer
was consistent. This central orb, however, should, dynamically, be
greater
than all the orbs, taken together, which surround it. Of these there
are
about 100 millions. “Why, then,” it was of course demanded, “do
we not see this vast central sun — at least equal in
mass
to 100 millions of such suns as ours — why do we not see
it — we, especially, who occupy the mid region of the cluster —
the
very locality near which, at all events, must be situated this
incomparable
star?” The reply was ready — “It must be non-luminous, as are our
planets.”
Here, then, to suit a purpose, analogy is suddenly let fall. “Not so,”
it may be said — “we know that non-luminous suns actually exist.” It
is
true that we have reason at least for supposing so; but we have
certainly
no reason whatever for supposing that the non-luminous suns in question
are encircled by luminous suns, while these again are
surrounded
by non-luminous planets: — and it is precisely all this with which
Mädler
is called upon to find any thing analogous in the heavens — for it is
precisely
all this which he imagines in the case of the Galaxy. [page
200:]
Admitting the thing to be so, we cannot help here picturing to
ourselves
how sad a puzzle the why is it so must prove to all à
priori philosophers.
But granting, in the very teeth of analogy and of
every thing else, the non-luminosity of the vast central orb, we may
still
inquire how this orb, so enormous, could fail of being rendered visible
by the flood of light thrown upon it from the 100 millions of
glorious
suns glaring in all directions about it. Upon the urging of this
question,
the idea of an actually solid central sun appears, in some measure, to
have been abandoned; and speculation proceeded to assert that the
systems
of the cluster perform their revolutions merely about an immaterial
centre
of gravity common to all. Here again, then, to suit a purpose, analogy
is let fall. The planets of our system revolve, it is true, about a
common
centre of gravity; but they do this in connexion with, and in
consequence
of, a material sun whose mass more than counterbalances the rest of the
system.
The mathematical circle is a curve composed of an
infinity of straight lines. But this idea of the circle — an idea
which,
in view of all ordinary geometry, is merely the mathematical, as
contradistinguished from the practical, idea — is, in sober fact, the practical
conception which alone we have any right to entertain in regard to the
majestic circle with which we have to deal, at least in fancy, when we
suppose our system revolving about a point in the centre of the Galaxy.
Let the most vigorous of human imaginations attempt but to take a
single
step towards the comprehension of a sweep so ineffable! It would
scarcely
be paradoxical to say that a flash of lightning itself, travelling forever
upon the circumference of this unutterable circle, would still, forever,
be travelling in a straight line. That the path of our Sun in such an
orbit
would, to any human perception, deviate in the slightest degree from a
straight line, even in a million of years, is a proposition not to be
entertained: —
yet we are required to believe that a curvature has become apparent
during
the brief period of our astronomical history — during a mere point —
during
the utter nothingness of two or three thousand years.
It may be said that Mädler has really
ascertained
a curvature in the direction of our system’s now well-established
progress [page 201:] through Space. Admitting,
if necessary,
this fact to be in reality such, I maintain that nothing is thereby
shown
except the reality of this fact — the fact of a curvature. For its thorough
determination, ages will be required; and, when determined, it will be
found indicative of some binary or other multiple relation between our
Sun and some one or more of the proximate stars. I hazard nothing [[,]]
however,
in predicting that, after the lapse of many centuries, all efforts at
determining
the path of our Sun through Space, will be abandoned as fruitless. This
is easily conceivable when we look at the infinity of perturbation it
must
experience, from its perpetually-shifting relations with other orbs, in
the common approach of all to the nucleus of the Galaxy.
But in examining other “nebulæ” than that of
the
Milky Way — in surveying, generally, the clusters which overspread the
heavens — do we or do we not find confirmation of Mädler’s
hypothesis?
We do not. The forms of the clusters are exceedingly diverse
when
casually viewed; but on close inspection, through powerful telescopes,
we recognise the sphere, very distinctly, as at least the proximate
form
of all: — their constitution, in general, being at variance with the
idea
of revolution about a common centre.
“It is difficult,” says Sir John Herschel, “to
form
any conception of the dynamical state of such systems. On one
hand,
without a rotary motion and a centrifugal force, it is hardly possible
not to regard them as in a state of progressive collapse. On
the
other, granting such a motion and such a force, we find it no less
difficult
to reconcile their forms with the rotation of the whole system [meaning
cluster] around any single axis, without which internal collision would
appear to be inevitable.”
Some remarks lately made about the “nebulæ” by
Dr.
Nichol, in taking quite a different view of the cosmical conditions
from
any taken in this Discourse — have a very peculiar applicability to
the
point now at issue. He says:
“When our greatest telescopes are brought to bear
upon them, we find that those which were thought to be irregular, are
not
so; they approach nearer to a globe. Here is one that looked oval; but
Lord Rosse’s telescope brought it into a circle. . . . Now there occurs
a
very remarkable circumstance in reference to these comparatively
sweeping
circular masses of nebulæ. We find they [page 202:]
are not entirely circular, but the reverse; and that all around them,
on
every side, there are volumes of stars, stretching out apparently
as
if they were rushing towards a great central mass in consequence of the
action of some great power.”*
Were I to describe, in my own words, what must
necessarily
be the existing condition of each nebula on the hypothesis that all
matter
is, as I suggest, now returning to its original Unity, I should simply
be going over, nearly verbatim, the language here employed by Dr.
Nichol,
without the faintest suspicion of that stupendous truth which is the
key
to these nebular phænomena.
And here let me fortify my position still
farther,
by the voice of a greater than Mädler — of one, moreover, to whom
all
the
data of Mädler have long been familiar things, carefully and
thoroughly
considered. Referring to the elaborate calculations of Argelander — the
very researches which form Mädler’s basis — Humboldt,
whose
generalizing
powers have never, perhaps, been equalled, has the following
observation:
“When we regard the real, proper, or
non-perspective
motions of the stars, we find many groups of them moving in
opposite
directions; and the data as yet in hand render it not necessary, at
least, to conceive that the systems composing the Milky Way, or the
clusters,
generally, composing the Universe, are revolving about any particular
centre
unknown, whether luminous or non-luminous. It is but Man’s longing for
a fundamental First Cause, that impels both his intellect and fancy to
the adoption of such an hypothesis.Ӡ [page
203:]
The phænomenon here alluded to — that of “many
groups
moving in opposite directions” — is quite inexplicable by Mädler’s
idea;
but arises, as a necessary consequence, from that which forms the basis
of this Discourse. While the merely general direction of each
atom
— of each moon, planet, star, or cluster — would, on my hypothesis, be,
of course, absolutely rectilinear; while the general path
of all bodies would be a right line leading to the centre of all; it is
clear, nevertheless, that this general rectilinearity would be
compounded
of what, with scarcely any exaggeration, we may term an infinity of
particular
curves — an infinity of local deviations from rectilinearity — the
result
of continuous differences of relative position among the multitudinous
masses, as each proceeded on its own proper journey to the End.
I quoted, just now, from Sir John Herschel, the
following
words, used in reference to the clusters: — “On one hand, without a
rotary
motion and a centrifugal force, it is hardly possible not to regard
them
as in a state of progressive collapse.” The fact is, that, in
surveying
the “nebulæ” with a telescope of high power, we shall find it
quite
impossible,
having once conceived this idea of “collapse,” not to gather, at all
points,
corroboration of the idea. A nucleus is always apparent, in the
direction
of which the stars seem to be precipitating themselves; nor can these
nuclei
be mistaken for merely perspective phænomena: — the clusters are really
denser near the centre — sparser in the regions more remote from it. In
a word, we see every thing as we should see it were a collapse
taking
place; but, in general, it may be said of these clusters, that we can
fairly
entertain, while looking at them, the idea of orbitual movement
about
a centre, only by admitting the possible existence, in the
distant
domains of space, of dynamical laws with which we are
unacquainted.
On the part of Herschel, however, there is
evidently a reluctance to regard the nebulæ as in “a
state of
progressive
collapse.” But if facts — if even appearances justify the supposition
of
their being in this state, why, it may well be demanded, is he
disinclined
to admit it? Simply on account of a prejudice; — merely because the
supposition
is at war with a pre-conceived and utterly baseless notion — that of
the
endlessness — that of the eternal stability of the Universe. |
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