CHAPTER VIII.. The Sun by Day.

THE SUN BY DAY.

If you look at the Sun in our sky before he sets, and then, a little later, at the Moon when she has risen, it might seem that the two are very much of the same size and very much at the same distance.

To be sure, the Sun is the brightest; a great deal the brightest. He has such a dazzling face that you cannot look at him steadily. But certainly he does not look larger than the Moon.

What do you think the size of the Sun really and truly is?

Once upon a time people supposed him to be about as big as he looked. And afterwards they fancied that perhaps he might be even as large as a little country called Greece, a much smaller country than England.

But the Sun is bigger than England, bigger than America, bigger than all the oceans of the Earth heaped together; bigger than the Moon, bigger than the whole Earth, bigger than Earth and Moon rolled into one--oh, we are a long way off yet from the truth!

The Sun is a round globe in shape, like the Earth and the Moon. But he is ever so much larger.

Our Moon, as you know, is about two thousand miles through from side to side. Our Earth is nearly eight thousand miles through. But that enormous globe, the Sun, is--how much do you guess?--is about eight hundred and fifty thousand miles through!

Can you picture to yourself what this means? Rather hard, is it not!

The Earth seems so big to us who live upon its surface, and yet she is so small beside the great Sun!

Suppose you had a huge hollow ball the size of the Sun. And suppose you wished to run through that hollow ball a very, very long knitting-needle--eight hundred and fifty thousand miles long--so as just to go from side to side of the huge ball. And suppose upon that big knitting-needle you wished to string a great many Earths or Moons, exactly like our Earth or our Moon, as large beads might be strung close together upon a wire.

How many worlds, the size of our Earth, do you think you would need to reach all through the Sun from side to side? And how many worlds the size of our Moon?

You would want more than one hundred Earths. And if, instead of Earths, you chose to string Moons on the big needle, you would need more than four hundred Moons.

These would not fill up the enormous hollow ball. They would only reach through in one straight line from side to side, showing the diameter of the Sun.

Now try again to think of the Moon as a tiny ball, softly bright on one side, only one inch through; and of the Earth as another ball, shining on one side, four inches through. Think of them, if you like, as a large grape and a small cocoa-nut made of silver.

Then take the same measure for the Sun, letting one little inch do duty always for two thousand miles. The Sun must dwindle and dwindle in size till every two thousand miles in him has become a single inch.

We shall then have a huge ball, or balloon, four hundred and twenty-six inches, or some thirty-five feet, through, from side to side.

Thirty-five feet is a great deal more than four inches. One foot is twelve inches long.

You have seen many a tall man close upon six feet in height. This balloon, to picture the Sun, must be so large that six tall men might be put inside it, one upon the head of another. The whole string of six tall men would about make the through measure of the globe.

So we have a Moon the size of a large grape, an Earth the size of a small cocoa-nut, and a Sun the size of a balloon big enough to contain six men in a long row, one upon another. The two little balls would shine softly, on one side only; but the large balloon should be exceedingly brilliant and dazzling all round.

If the Moon is so tiny and the Sun is so huge, how is it that they seem to be the same size in our sky?

Because of the very great difference in their distance from us. The Moon is near; the Sun is far away.

Suppose you are looking at a man near at hand and at a house miles away; which seems to you the bigger? Of course the man, because he is so close. Yet really the house is much the larger of the two.

The Moon is only about two hundred and forty thousand miles off; but the Sun is about ninety-two millions of miles away.

Think what a difference! Two hundred and forty thousands are only a small part of a single million; for a million is a thousand thousands. If you have one thousand beads in a heap, you would need one thousand of those heaps to make a million beads. And when you get to the idea of what is meant by a million, you have to remember that the Sun’s distance is ninety-two times that number of miles.

After all, we cannot comprehend these figures; they are too bewildering. We may talk of thousands and millions of miles, but we do not see them in our minds.

The chief thing to do is to gain some notion of one distance side by side with another: and here the three balls all help us again.

Picture to yourself the tiny Moon-ball, as big as a large grape, and the Earth-ball, as big as a small cocoa-nut; and in your mind put the two ten feet apart. There you have the sizes and the distance of the Earth and the Moon brought down from thousands of miles to inches.

Then picture to yourself the Sun, as big as a balloon--the length of six tall men through its middle--and in your mind put that balloon three quarters of a mile away from the small Earth and Moon. Somebody will tell you of a house or a place about three-quarters of a mile away from your house, if you ask.

Now do you see how great the difference is between the distance of the Sun from us and the distance of the Moon?

Close upon four thousand feet off, instead of only ten feet off! Almost thirteen hundred yards, instead of a little over three yards! Ninety-two millions of miles, instead of two hundred and forty thousand miles!

The kind or quantity of difference between the two is the same, whether we reckon it in inches or feet, in yards or miles, in hundreds, or thousands, or millions of miles.

The Moon and Sun are quite unlike in their way of shining.

Our little Moon has no brightness of her own. She only shines when and where the Sun shines upon her.

But the radiance of the Sun is his own; it is a part of himself. He shines because it is in him to shine; it is his nature to shine. He is brilliant all round, not on one side only. If the Sun were destroyed the Moon would shine no longer. But if the Moon and the Earth and all the Planets came to an end it would make no difference in the brightness of the Sun.

The Sun’s shining is like the shining of the Stars, not like that of the Earth and the Moon: for the Sun himself is a Star; one Star among millions of Stars. He only looks so much larger and brighter than other Stars because he is so much nearer than they are.

Our Earth and Moon are not stars; they are planets, or worlds, travelling round the Sun, and belonging to him. They are not hot bodies, glowing with their own light; but cool and dark bodies, bright only when the Sun shines on them. Moonlight, and also Earthlight--which we, living on the Earth, cannot see--are both really reflected Sunlight.

There are other planets also, besides the Earth and the Moon, belonging to the Sun: such as Venus, and Mars, and Jupiter. None of these planets are Stars. They are all Worlds.

QUESTIONS.

1. What shape is the Sun?

Like the Earth and the Moon, a globe or sphere in shape.

2. What is the Sun’s diameter?

The Sun is about 850,000 miles through.

3. Why do the Sun and Moon seem about the same size in our sky?

Because the Moon is very near, and the Sun very distant.

4. How far off is the Sun?

About 92 millions of miles.

5. What would be the sizes of these three globes, if we let one inch stand for 2,000 miles?

The Moon would be a ball one inch in diameter; the Earth a ball four inches in diameter; the Sun a ball thirty-five feet in diameter.

6. What would be their distances, brought down thus?

The Moon would be about ten feet off from the Earth, and the Sun would be about three-quarters of a mile from them both.

7. How many thousands of miles make a million miles?

A thousand thousands.

8. How does the Moon shine?

By reflecting Sunlight.

9. How does the Sun shine?

By his own brightness.

10. Which part of Moon and Sun are bright?

The Moon, like the Earth, is bright only on that side which faces the Sun; but the Sun is brilliant all round.

11. Is the Sun a World?

No, the Sun is a Star.

12. Are the Planets Stars?

No; the Planets, like Earth and Moon, are Worlds.