By the 20th century eclipse tourism became popular. In 1927 three million people travelled to northeast England to see a total solar eclipse. One who made the trip was famed writer Virginia Woolf who rode for six hours on an overnight train from London to North Yorkshire. Throngs of people were already there. The eclipse lasted 24 seconds.
Two years earlier, in 1925, the Moon's shadow ran along a path from Minnesota to New York and Connecticut. Newspaper editors estimated that as many as 20 million people might have witnessed that total solar eclipse.
Which brings us to the question: How many people will be standing in the Moon's shadow when it crosses the United States on August 21, 2017?
It does not sweep across the country. It explodes! And the explosion continues to build for weeks until the main event.
Eclipse mania is a real phenomena. The roots go back to ancient times when the Babylonians staged week-long festivals to celebrate the occurrence of an eclipse. The precise meeting of the Sun and the Moon in the sky was always a cause for concern. It was clearly a bad omen.
To prepare for the possibility of dire consequences, in Babylon, the king was often removed the throne, temporarily, and a substitute put in his place. The substitute was given all the physical trappings of being king. He slept in the royal bedchamber. He wore the royal robes. Then after the eclipse was over and the time of foreboding had passed, the substitute was executed and the real king reascended the throne.
New York, 1932
'Eclipse mania' mania
Here are the basic numbers. Fifteen million people live along the eclipse path. All they have to do is stand outside their homes to see the eclipse. And, because of the excellent roadway system, 300 million people live less than an 18-hour drive from the eclipse path.
If 1-in-20 people decide to travel to see the eclipse, that is 15 million people. Add that to the people already living along the eclipse path, and at least 30 million people should see totality. But that estimate is probably too low.
There are more than 260 million vehicles in the United States, and so there is ample transportation to the eclipse path. And the eclipse will occur in August when the skies should be clear across the entire country. And few children will be in school. And this is the first total solar eclipse to be seen from an industrialized country since the beginning of social media.
Many of those who will be making the trek to see the August 21 eclipse are not yet aware that they will be going. They will be prompted to go, on short notice, because of the endless reminders about the eclipse that will fill social media. And that will create history's largest flash mob.
Furthermore, unlike other astronomical events—meteors showers or comets—an eclipse is certain. And that—with the phenomenon of social media—will add millions who will go to see the eclipse.
Reunion Island, 2016