I could not sleep for thinking of the sky,
The unending sky, with all its million suns
Which turn their planets everlastingly
In nothing, where the fire-haired comet runs.
If I could sail that nothing, I should cross
Silence and emptiness with dark stars passing,
Then, in the darkness, see a point of gloss
Burn to a glow, and glare, and keep amassing,
And rage into a sun with wandering planets
And drop behind, and then, as I proceed,
See his last light upon his last moon's granites
Die to dark that would be night indeed.
Night where my soul might sail a million years
In nothing, not even
Death, not even tears.

• How do we know that the planet Earth really revolves and rotates?
• What is the structure of the interior of the Earth?
• What causes mountain ranges, volcanos, and earthquakes?
• Where did the Earth’s oceans and atmosphere come from and how have they changed with time?
• Why does air temperature vary with altitude?
• What is the greenhouse effect and how does it influence the temperature of the Earth?