THE COMET THAT CAME BUT ONCE.

By E. W. MAUNDER, F.R.A.S.

Not quite a year ago the “Threatening Comet,” which some

too-imaginative writers foretold would return in fifteen years, and

occasion the entire destruction of our earth, by rushing into the sun,

and exciting it to a terrible degree of heat was foretold. How little

reason there was to fear such a catastrophe! We never expected that,

so far from having fifteen years to wait before the truth or error of

the prediction was demonstrated, in less than six months a glorious

stranger would present himself to our gaze, and reveal that, in one way

or another, the dismal prophecy had been wrong. The message which the

wonderful comet, that was so impressive an object in the morning sky

of last October, had to convey has been interpreted in various senses.

Perhaps the most probable is, that he and his bright predecessors of

1880 and 1843, which had been supposed to be one and the same object,

were not really so, but only members of the same family. If so,

then the very groundwork of the theory, on which the return in 1897

was foretold, would be cut away, and in its place a whole vista of

marvellous possibilities would be opened out to us.

But our present purpose is not to dwell on these, nor to enlarge on

the history, past or future, of any comet which from time to time has

returned, or may return, to our skies, but to read the lesson conveyed

in the marvellous fact that there are comets which visit us _but once_.

The devout Kepler, after his last great discovery, sat down content

“to wait a century for a reader.” He had not long passed away ere

the reader was sent, one who read his book to good purpose indeed.

Kepler had been able to discover three laws to which the planets were

obedient, but as to whether there was any connection between those

laws, why the planets followed them rather than any others which might

have been framed, and what laws the satellites and comets of the system

were subject to, Kepler could not tell. Newton, on the contrary,

discovered the great underlying principle, of which the laws of Kepler

were only some of the necessary consequences, and showed not merely how

the planets moved, but also to a great extent why they did so.

Newton had not long established his law of gravitation before he

arrived at a strange discovery. Assuming his theory to be correct, he

worked out by rigid mathematical processes the shape of the orbits

which the planets must follow. Since we know that they travel in

ellipses, we should naturally have expected that an ellipse would be

the resulting orbit, but instead Newton found he had arrived at an

expression which embraced not one curve but four.

Of these four, one was the oval or ellipse, another the circle, but the

other two were curves of a very different shape indeed, curves which

did not enclose a space, but which had each two ends, which, however

far they were prolonged, could never meet. And directly this fact was

recognized, an unlooked-for truth was made plain. Comets, which had

hitherto been regarded as perfectly lawless bodies, as irregular and

uncontrolled as the thoughts of an opium-dreamer seem to be, were now

seen to be integral parts of our solar system. For though so many of

them enter our system but once, never having visited it before, never

to visit it again, yet since these all travel, in obedience to the

sun’s attraction, in one or other of these strange unending curves,

curves which are a necessary consequence of the law of gravitation,

they are manifestly members of the solar family; without them it would

be imperfect, without them the law of gravitation were but partially

illustrated.

Let us follow in imagination the travels of one such comet through the

untold ages of its life. It may have started on its tremendous voyage

whilst the earth was yet a star, or rather a miniature sun, instinct

with fire and light, and all through the long ages during which the

earth was cooling down and becoming fitted to be the habitation of

living things, the comet slowly but steadily pursued its way. On the

earth one form of life succeeded another, the sea overcame the land

time after time, and time after time the continents flung off the

yoke, and emerged with ampler borders and fairer scenes. At length the

predestined prince came to his heritage, and Man was made ruler over

the perfected earth—too soon, alas! to forfeit his vice-regal crown

by an act of flagrant rebellion. And still through all these ages,

compared with which the whole lifetime of our race is but a moment,

that distant comet held on its course, never swerving by a hair’s

breadth from the appointed path, obedient to the law, the self-same

law that decrees the fall of the ripened fruit. But it was still far

away, and still it pressed slowly but steadily forward, whilst kingdoms

rose and fell, and nations multiplied and decayed. But gradually

a quicker energy began to throb within it, and a stronger impulse

drew it forward. The old slow pace could not suffice for its growing

impatience, and it pressed forward with ever-increasing speed. At

length it dashes across the orbit of Neptune; it has entered the solar

system at last. No lingering now, no slow and halting pace; quicker and

quicker it presses on, and Uranus is past. A shorter interval still,

and glorious Saturn, with his noble rings and numerous satellites, is

left behind, and a few years more and it shoots across the path of the

giant planet Jupiter. The asteroids and Mars are passed by next, and

now, filled with a passionate desire, it whirls along, brightening as

it speeds, and flaming streamers flying behind it. Moving more quickly

still, it crosses the orbit of the Earth. Venus is reached next;

traversing now in a moment of time space it once took a year to travel

over, it rushes past Mercury. And now the bright goal is at hand, and

quivering through all its mighty length with the fierce excitement, it

speeds forward at a swifter pace still. And now, glorious with jets

streaming ten thousand miles before it, and tail ten million leagues

behind, it hurls itself into the corona, the region of that strange

pearly glow which in total eclipses is seen to surround the Sun. And

still it hurries forward, but not into the Sun, its headlong speed is

now far too great for even that mighty attraction to be able to check

it in its course, and draw it in to itself. It ploughs its way perhaps

even at the rate of a million miles an hour, round nearly half of the

circumference of the sun, through the regions where the prominences

play—those rosy flames that rise and rush with such terrific heat and

force from the Sun’s glowing bulk; and its brief period of splendor is

over. Away from the Sun, it falls back through the corona, across the

orbits of Mercury, Venus, and the Earth, with ever-slackening speed,

and fading as it goes, it recedes toward outer unknown space. Never

again in all eternity will it approach our Sun, never again will it

know the fierce throbbings of that four hours’ sojourn in the home of

the prominences; never, too, will it revisit those places where it

was wandering in the outer darkness when it first heard the imperious

summons which it had thus obeyed. Slower, ever slower will it travel,

out in the fathomless night, the solar system left far behind. Once and

once only has it entered it, once and once only could it enter. The

Earth, with its attendant Moon, has revolved for millions of years,

enjoying without cease spring, summer, autumn, and winter. But this

strange body, whose winter was from creation, whose summer lasted but

a few short hours, and whose second winter, so far at all events as it

derives heat and light from our Sun, shall last till heaven and earth

depart like a vesture that is rolled together, whose movements are so

unlike our evenly moving earth, is no mere lawless wanderer—is no

intruder on the happy family of the solar system; it is ruled in its

every movement by the self-same law that guides our earth. Without it,

or bodies like it, gravitation would be but imperfectly illustrated,

and but part of the homage due would be paid to our Sun.

How great a change has taken place in our views since the time when

men looked upon comets as miracles and portents, as special acts of

creation, obedient to none of the ordinary laws of nature! And since

Newton’s day, changes as great as that which he effected in astronomy

have been effected in other sciences; and the unity of law, and the

universality of its reign, are acknowledged on every side. The idea

of special acts of creation, or that God interferes with the regular

working of his laws, is discredited, and creation itself is pushed far

back into the unfathomed past.

But this view opens out a most serious question. If God’s only work was

to make the world at the beginning, and give it wholesome laws, leaving

it then to itself, what room is there for religion and prayer—for faith

and hope? And indeed, arguing in this very manner, there are men of

science who tell us expressly that the only good which prayer can do

is to make the petitioner feel more at ease in his mind; that Elijah

praying for rain was no whit wiser than a Kaffir or Ashanti conjuror.

But God has _not_ left his world to itself, and every law of nature is

nothing but the expression of his all-pervading, ever-acting will. How

else can the sun, which can not, according to Newton’s first law, of

itself move a single inch, make the earth spin round it, at the rate of

many miles a second? It explains nothing, it is only to put the fact

into other words, if, when an apple falls, we say “the earth attracted

it.” But “it is the will of God” _is_ an explanation and a sufficient

one, and we may be well assured that unless he expressly ordered it,

not even a toy, released from a baby’s feeble grasp, could ever move

downwards toward the ground. Were he to cease to will, the universe

would cease to be, for in the beginning it came into existence by his

simple word, and from that time “he upholdeth all things by the word of

his power.” And in these words revelation teaches us what science never

could—behind dead nature to see an ever-living, ever-acting God.

The mistake men made was this: Some things seemed to them to be orderly

and regular, others disorderly and irregular; and they foolishly

fancied the latter to be therefore more immediately God’s work than

the former, thinking him “altogether such an one as themselves.” And

so, when further knowledge showed that those things which had seemed

irregular were as fully ordered by law as any of the others, it

appeared as if God’s authority and power were diminished, since, in

their ignorance, men had thought disorder a proof of his more immediate

acting. But “God is not the author of confusion,” nor is he touched

with caprice or change, for he hath declared “I am the Lord, I change

not.” Perfect law and perfect harmony, are what the Scriptures teach us

to expect in all God’s works, and that every advance of science shows

such perfection far to transcend all our previous conceptions, should

surely not shake our faith in him and in his word, but strengthen and

confirm it.

But yet another difficulty remains. If everything in the universe is

ordered according to law, how is it possible for miracles, and in a

more general sense, answers to prayer, to take place? Perhaps the

comet may help us here. Could anything seem more miraculous, more to

contradict the general experience of the solar system, with its planets

ever revolving in closed orbits round the sun, than the appearance of a

body which rushed straight toward the sun, took one half-turn round it,

and then receded from it by a different path, never, never to return?

Could anything seem more like an interference by the Maker with the

laws which he had made? It _did_ seem so until the underlying law was

discovered, and then the seeming discord was perceived to be really

the note needed to complete the perfect harmony. We at best only stand

where Kepler stood, we know only little fragmentary laws, and we can

not affirm that occurrences which seem as much outside their scope as

comets are outside Kepler’s laws, are not really necessary members of

the greater system of which we have no knowledge as yet. That miracles

are ruled by law may be gathered from many a passage in the Holy Word.

Miracles are “set” in the Church, as much as apostles and teachers.

“This kind goeth not out but by prayer and fasting;” “he could do no

mighty works there because of their unbelief,” are not obscure hints of

such a law—a spiritual law, it is true, but none the less a law.

We can watch the progress of science, then, without anxiety or

fear; “rooted and grounded in faith,” believing that the Lord is

King.—_London Sunday Magazine._

[_End of Required Reading for March._]

The Chautauquan, Vol. 03, March 1883 A Monthly Magazine Devoted to the Promotion of True Culture. Organ of the Chautauqua Literary and Scientific Circle. · 第 26 / 105 题