Once a photograph of the Earth, taken from outside, is available—once the sheer isolation of the Earth becomes known—a new idea as powerful as any in history will be let loose.
– Sir Fred Hoyle, British astronomer, 1948
In my earliest childhood, when we were taught that the earth is round, it meant the earth was limitless. There is no edge to fall from, as people in centuries past had imagined. You can travel around the world and never stop. The scenery will start repeating but your journey can go on and on. Where people in the past imagined a finite world, modern people like us knew a world that was boundless and ever renewing.
The pictures of earth we saw in our textbooks were necessarily artists' renderings. The planet looked like a flat disk with large areas of brown and green, like a map with borders and labels missing. A few wisps of white appeared here and there to suggest clouds. Space on every side of the disk teemed with comets and stars and other celestial objects.
Then the first photos came back from Apollo 8.
Copies sprouted everywhere. Every classroom had a portrait of the earth posted in the front. Eyes of young and old were drawn to what they saw.
Who could look away? Everything about that world was new and surprising: its brightness, its aquatic blues, its dynamic swirls . . . and all that black, all around.
Image courtesy of NASA