“It’s difficult to make predictions,” the great Danish physicist Niels Bohr liked to say, “especially about the future” – a proverb that captured quite elegantly the gap between what is real and what we can prove. So Bohr hung a horseshoe over his door for luck.

As the evidence of climate change piles up all around us, the remaining cosmic truths can seem infinitely reassuring. The Sommersonnenwende, the midsummer solstice, still falls on June 21st celebrated in the Wachau by a flotilla sailing down the Danube.

The oceanic tide tables are printed years in advance, the turning point to flood tide at the Italian port of Trieste is as immutable as your own looming birthday.

So it was with the eclipse on August 21, visible this time across a broad swathe of North America and suitably ballyhooed to cause monumental gridlock on highways across the country.

“This is the best spot,” Blake Marnell, 52, told The Washington Post. He had driven from San Diego deep into the wheat and bean fields of western Nebraska. “I figured this was the most American place in America to see the American eclipse… We have won the eclipse!” You could hear the voice of alternative facts: “It was huuuge! The biggest crowds ever…”

At a small lake in Upstate New York, two Viennese vacationers joined a far smaller gathering from the village to witness what would indeed be the very real, once-or-twice in a lifetime cosmic truth that science can predict down to the second.

In a festive atmosphere supported by growlers from the brew pub and a genuinely huge tub of ice-cream from the regional dairy, people gazed through black plastic strips or lined up for a peek through one of the two large telescopes, as the moon slid gradually from west to east pushing the crescent sun in an arc over the lens, as shadows swept slowly across the lawn.

It was a gentle eclipse, not like August 11, 1999, when on a hot summer’s day in Vienna, a heavy sky darkened to an eerie grey-green, and all across the Prater the birds and insects quieted to a hush. In the enduring moments of near silence, it was impossible not to feel renewed awe at the power of the universe. In one generation, what were once
hotly debated theories of global warming have matured to nearly immutable truths – as the Dachstein glaciers in Styria keep retreating by a meter a year.

“Any climate change deniers should pay us a visit,” gondola technician Karl Höflehner told Der Standard in 2015.

And for the physicist’s good-luck horseshoe?  Bohr apparently laughed. “I’m told it works whether you believe in it or not.”