Analyze the poem

He Worried About It
The sun’s heat will give out in ten million years more—
And he worried about it.
It will sure give out then, if it doesn’t before—
And he worried about it.
It will surely give out, so the scientists said
In all scientifical books he had read,
And the whole boundless universe then will be dead—
And he worried about it.
And some day the earth will fall into the sun—
And he worried about it—
Just as sure and as straight as if shot from a gun—
And he worried about it.
When strong gravitation unbuckles her straps,
“Just picture,” he said, “what a fearful collapse!
It will come in a few million ages, perhaps”—
And he worried about it.
And the earth will become much too small for the race—
And he worried about it—
When we’ll pay thirty dollars an inch for pure space—
And he worried about it.
The earth will be crowded so much, without doubt,
That there won’t be room for one’s tongue to stick out,
Nor room for one’s thought to wander about—
And he worried about it.And the Gulf Stream will curve, and New England grow torrider—
And he worried about it—
Than was ever the climate of southernmost Florida—
And he worried about it.
Our ice crop will be knocked into small smithereens,
And crocodiles block up our mowing-machines,
And we’ll lose our fine crops of potatoes and beans—
And he worried about it.
And in less than ten thousand years, there’s no doubt—
And he worried about it—
Our supply of lumber and coal will give out—
And he worried about it.
Just then the ice-age will return cold and raw,
Frozen men will stand stiff with arms outstretched in awe,
As if vainly beseeching a general thaw—
And he worried about it.
His wife took in washing—half a dollar a day—
He didn’t worry about it—
His daughter sewed shirts the rude grocer to pay—
He didn’t worry about it.
While his wife beat her tireless rub-a-dub-dub
On the washboard drum of her old wooden tub,
He sat by the stoves and he just let her rub—
He didn’t worry about it