THE SUN’S KINGDOM.
By this time you have a pretty fair idea of what is meant by “The Solar
System.”
First you had to think about our Earth’s pathway in the sky, and then
about other pathways, nearer and farther, like vast oval hoops lying
within and without the Earth’s pathways. Lying, all of them, very
nearly on the same level.
But the Planetoids’ paths do not keep at all nearly to that level,
rings of Meteors slope about in different ways, and Comets come and go,
with no known rule, from any part of the heavens.
When we talk of a “level” in the sky--a “plane” is the better word--you
must not think of a solid flat surface any more than you have to
picture real pathways for the planets. No signposts mark the pathways,
and the level or plane cannot be _seen_, except by the way in which the
worlds journey.
How far the Solar System reaches, and where it stops, I cannot tell you.
The Sun’s power goes out beyond his own kingdom: for the distant Stars
feel his pull. Only that gentle pull is very much weaker than the
strong hold which he has over all his own worlds.
Neptune is the most distant world known to us; and Neptune, as you have
heard, is some 2,800 millions of miles away from the Sun.
He is all that way off on one side of the Sun and when he gets round
to the other side he is just as far off in the other direction. So the
breadth of Neptune’s whole pathway, from side to side, is not much less
than _six thousand millions of miles_.
All the other worlds or planets are within that enormous circle, nearer
to the Sun.
But there are comets belonging to the Sun which journey farther off
than Neptune and yet come back from time to time, being held captive by
the Sun.
Whether our Solar System as a whole is six or ten or twenty thousands
of millions of miles across, matters very little. In any case, it is
enormous. And yet, though so enormous, the whole Solar System is but
one little spot in the great Universe of Stars which God has created.
The one Star in our System is the Sun himself. All other Stars are far
away, outside his kingdom and away from it.
Once upon a time, indeed, the worlds may all have been stars; and
the larger planets seem to be still only half-way out of their starry
state. Still they are all either cooled or partly-cooled worlds; not
stars.
A Star is a Sun: and a Sun is a Star. A world, whether cold or hot,
if it does not shine by its own light cannot be called a star. We see
abundance of stars in the sky, but they are so distant that our Sun,
compared with them, is very near us indeed.
A wide, wide gulf of cold and darkness, of emptiness and desolation,
spreads far on every side around our Sun’s kingdom.
That is to say, a wide gulf of what would be cold to our earthly
bodies, of what would be darkness to our human eyes, of what looks like
emptiness and desolation to our little knowledge. But after all, we
cannot see much, we do not really know much!
The distance of our Sun has been found out, and the distances of a few
Stars have been roughly measured. But what may lie between us and them,
who can tell?
We are here on our little Earth, down at the bottom of a deep Ocean
of Air, tied and bound and unable to get away. What man has seen and
learned from the bottom of his air-ocean is indeed very wonderful; but
more wonderful by far are the things which he does not know.
In earlier chapters we have talked about the worlds in smaller sizes,
letting one inch stand always for 2,000 miles.
Now, keeping to exactly that same plan, let us try to picture the
Solar System on a little scale, with not only sizes but distances thus
brought down.
The actual distances you know by this time, perhaps, pretty well. You
know that Mercury is about 35 millions of miles from the Sun, the Earth
about 92 millions, and so on. But it is not easy to see what these
figures really mean, millions and billions sound so much alike.
So now we will fancy the whole big System shrinking and getting smaller
till in every part of it each 2,000 miles has become one tiny inch. Our
small moon, being 2,000 miles through, is thus a minute ball one inch
through.
Bring before your mind the thought of a large shining balloon, for the
Sun, about 35 feet through. This would be in the centre.
Mercury, a crab-apple one inch and a half through, will float round the
Sun at a distance of _one quarter of a mile_.
Venus, a very large apple, nearly four inches through, will float round
it at a distance from the Sun of about _half a mile_.
Earth, another very big apple, rather bigger than Venus, has her
pathway all round at a distance of _three quarters of a mile_. Ten
feet off from the Earth floats her tiny Moon.
Mars, another very small apple, two inches through, is more than _one
mile_ off from the Sun, with two tiny moons.
Jupiter, a large globe three feet and a half through, travels with his
five moons at a distance of about _three miles and three quarters_--the
Planetoids lying between him and Mars.
Saturn, a globe three feet through, goes round with his moons and rings
at a distance of about _seven miles_.
Uranus, a ball less than one foot and a half through, floats with his
four moons in a pathway over _fourteen miles_ off from the Sun.
Neptune, the outer planet, a rather bigger ball than Uranus, with one
moon, travels at a distance of over _twenty-one miles_.
So, on this little scale, the whole pathway of Neptune would be
somewhere about forty-two miles across.
All the other worlds would have their journeys inside that circle. Only
comets would go farther off than Neptune’s pathway.
Where now must we put the very nearest star known to us in all the sky?
On this scale we must put it about TWO HUNDRED THOUSAND MILES AWAY!
And every single inch in those two hundred thousand miles would stand
for 2,000 miles of _real_ star-distance.
Now do you begin to see what an enormous gap divides us from the stars?
If we could bring down the whole of the great Solar System to so small
a size that it could lie between New York and West Point _then_ the
very nearest star known to us would be nearly as far away as the Moon
is from the Earth. The nearest star would be 200,000 miles off. Our
Moon now is 240,000 miles off.
And this great gap is around the Sun’s kingdom on all sides, stretching
away in every direction. We have not found one single star _nearer_
than that, though countless multitudes of stars are very, very much
farther away.
Can you picture to yourself a little Solar System lying between New
York, and West Point--the whole of it there, unless perhaps a few
comets might stray a short way beyond; all the worlds, all the moons,
all the meteors, nearly all the comets, doing their yearly journeys
round and round in this space of forty-two miles?
And then, around that small kingdom of worlds, a great blank empty
space, north and south, east and west, above and below, in every
direction, nearly as far as the Moon in our sky before a single star
could be reached!
How very, very distant they are you begin now to see; do you not?
At first the Moon seemed a long way off, compared with any country in
our world; till we began to think of the Sun. And then, compared with
the Sun, the Moon seemed near.
And the Sun seemed a very long way off, compared with the Moon; till
we began to think of Neptune. And then, compared with Neptune, the Sun
seemed near.
And Neptune seemed a very, very long way off, compared with the Sun;
till we began to think of the nearest Star. And then, compared with
that Star, Neptune seemed near.
And even the very closest of the Stars, which, compared with Neptune,
seems so desperately far away, would, as compared with yet more distant
Stars, seem almost near!
QUESTIONS.
1. How far does the Solar System reach?
Nobody can say; but at all events beyond Neptune’s pathway.
2. Has the Sun any power beyond his own kingdom?
He has power to attract other stars.
3. Does he pull other stars as strongly as he pulls his worlds?
No: much more gently, because of their great distance.
4. How many stars are in our Solar System?
Only one star, the Sun.
5. What lies round our System, between us and all the stars?
A wide empty space of cold and darkness.
6. Do we really know that it is empty?
We can only say that it seems empty to us. We _know_ very little about
the matter.
7. If we let one inch stand for 2,000 miles, how large will the whole
Solar System be?
Less than 50 miles across. It would lie between New York and West Point.
8. Does this mean the whole of it?
The whole of which we know. Some comets may wander a little farther.
9. On that small scale, how near would Mercury be to the Sun?
About a quarter of a mile off.
10. And Venus?
About half a mile off.
11. And the Earth?
About three quarters of a mile off.
12. And Mars?
Over one mile off.
13. And Jupiter?
About three miles and three quarters off.
14. And Saturn?
About seven miles off.
15. And Uranus?
Over fourteen miles off.
16. And Neptune?
More than twenty-one miles off.
17. And the nearest Star?
About two hundred thousand miles off.