How far is the moon from the earth?
The moon is nearly 240,000 miles from the earth.
How far is the sun from the earth?
The sun is nearly 92,000,000 miles from the earth.
How long does it take the light of the sun to reach the earth?
It takes about eight minutes; therefore, the light of the sun must travel about twelve millions of miles in a minute, or two hundred thousand miles in a second of time. At this rate, the light would come from the moon to the earth in a little more than one second of time. It would take no longer for it to come than it does for the pulse to beat once, or the clock to make one tick.
Eclipses.
How do we know that the earth is round, like a ball?
We know that the earth is round like a ball, because its shadow is similar to the shadow of a ball.
How else do we know that the earth is round?