In the sense that it changes gradually over time, sure, Earth’s evolving.
And revolving at 900 miles an hour.
Assuming they meant rotation, as in the Earth spinning on its axis (and not around the sun, as revolving typically indicates), then yes, this is true at certain latitudes.
It’s orbiting at 19 miles a second, so it’s reckoned,
Yes, pretty much: Our orbital velocity is 29.78 km/hour, or 18.5 miles/second.
The sun that is the source of all our power.
For the most part, yes. The sun powers photosynthesis, allowing plants and plant-eating animals to thrive. Our energy needs also mostly derive from the sun: Old plants and animals can turn into fossil fuels, and renewable sources like solar and hydroelectric power ultimately originate with our local star. But! Nuclear energy and geothermal energy both have independent power sources, so it’s not quite all our power.
The sun, and you and me, and all the stars that we can see,
Are moving at a million miles a day,
Alas, our first major error. All the stars visible to the naked eye are indeed within the Milky Way (not counting the combined light from other galaxies), but our orbital speed around the galactic center is about 200 km/s, or roughly 11 million miles a day. The song is off by an order of magnitude.
In an outer spiral arm, at 40,000 miles an hour,
The solar system is in an outer spiral arm of our galaxy, but again we’re going at 200 km/s, or 450,000 mph. But 40,000 mph is about the same as “a million miles a day,” so at least the song’s consistent.
Of the galaxy we call the Milky Way.