SF Chron: Thanksgiving week draws 40 million Americans into theaters — the same number of weekly moviegoers as in 1920, when the U.S. population was 1/3 what it is today. Possible because in 1920, we had no media choices. Radio probably, but no TV. In addition to being almost the sole source of audio-visual entertainment, the movie theater was also where people went for newsreels – the only moving images people got of the world outside.
That aside, it’s a trip just to think of the U.S. — or of the world — with 1/3 of its current population. Imagine any crowded scene, and visually remove 2/3 of the people from it. All those non-existent persons. All that elbow room. You don’t have to go that far back to be weirded out by population trends, either. There were 4 billion people on earth when I was born in the mid-60s. Today, 6 billion+ — the world’s population has expanded by 50% since I’ve been alive. Visualize 8.5 billion, which will be the world population by the time Miles is my age. Try 100 years ahead, or 200.
More about world populations here:
http://www.worldchanging.com/archives/000151.html