A total eclipse of the mind

Pam was irritated. My obsession with the 2017 total solar eclipse, which I had begun to plan for 18 months earlier, had caused us to arise before dawn; I'd budgeted six hours for a three-hour drive from Boise to Arco, Idaho. I fretted about construction delays; a flat tire or deer strike; getting pinned behind a camper on hilly, two-lane roads; a missed turn — not to mention clouds, wildfire smoke and mobs of eclipse chasers.

All were possible, but I probably fussed more than was warranted. My defense: There are only about 70 total solar eclipses per century, scattered around the globe, and I was old enough to worry that after a lifetime as an astronomy buff I might never witness one.

We did encounter a construction delay, and did get stuck behind a camper. I tried to chill, but self-induced stress was apparent, and Pam repeatedly urged, "Relax, relax." I don't think she rolled her eyes, but in her tone I heard them rotate.

I'd scrutinized maps of the shadow's path and calculated that about 20 miles north of Arco we'd reach the center of totality. But as we steered out of town a distant strata of wildfire smoke looked menacing, so I stopped short. We spotted a sign welcoming eclipsers to an open field and happily paid the owner 10 bucks to park, joining 15 others, including three tourists from Germany. We had two hours to spare, and Pam favored me with an "I told you so" glance, only half-amused by my boyish enthusiasm and palpable relief.

Through filtered glasses, we watched the ebony arc of the moon gradually veil the sun, faintly dimming our morning. The instant of totality was a silent eruption. The corona of our star burst into view, a jagged halo of silver light engulfing a black disk fringed with reddish-orange. Everyone gasped or hooted. Stars appeared in the sudden deep dusk, with the planet Venus overhead.

Three nighthawks launched from their dayshift dormancy, swooping over the field.

The witchery lasted for one minute and forty-five seconds. I was so enthralled I forgot to raise my binoculars to magnify the "flames" ringing the solar/lunar circle. When daylight recondensed as abruptly as it had vanished, I received my second reward. Pam, her voice modulated with awe, said, "Now I understand."

Einstein's theory stated that gravity was not a force but rather a result of the curvature of "space-time." (His Special Theory of Relativity in 1905 had merged space and time with matter.) Near a massive body like the sun, space-time would be distorted, Einstein argued. Imagine a billiard table surface that's a rubber sheet. Place a bowling ball — representing the sun — in the middle, and it depresses the sheet. Place a billiard ball — call it a comet — at the edge of the sheet and it rolls right into the "sun," following the "slope" in space-time, the gravitational field generated by the heavier body.

Einstein's test: During totality, when stars become visible near the sun, take precise measurements of their positions — that is, their light grazing the sun's disk — and compare those apparent positions with the true, known positions. General relativity predicted a deflection of 1.75 arcseconds. Starlight would bend as it came around the sun.

British astronomer Arthur Eddington, the first to propose that the sun runs on nuclear fusion, was an ardent advocate for Einstein and keen to perform the test. Eddington's reputation and enthusiasm convinced Astronomer Royal Sir Frank Dyson to officially propose the 1919 eclipse expedition while World War I was still raging in 1917. Dyson also saw the project as means to prevent his good friend Eddington, a conscientious objector, from being sent to a labor camp established for dissenters.

In March 1919, two teams loaded with tons of equipment departed England by steamship for Sobral in Brazil and the island of Principe near the coast of West Africa. Given the vagaries of travel and weather, no one wished to commit all the eggs to one basket. With a generous five to six minutes of totality, and the proximity to the sun of the bright Hyades star cluster, expectations ran high. On the big day, the Brazilian team enjoyed a clear sky, but at Principe, where Eddington himself was stationed, a morning storm obscured the beginning of the event. Eddington was so engaged with instruments that he couldn't even look up.

"We have no time to snatch a glance at it," he said. "We are conscious only of the weird half-light of the landscape and the hush of nature, broken by the calls of the observers, and by the beat of the metronome ticking out the 302 seconds of totality."

The press, however, recognized a great story when it saw one. The day after the announcement of the result, a headline in the Times of London shouted: "Revolution In Science; New Theory Of The Universe; Newtonian Ideas Overthrown."

The romance of the expedition and its decisive outcome, the novelty of the theory, and the power of a feel-good narrative after the horror of the Great War, propelled the message around the world. Einstein became iconic overnight. It didn't matter, as the New York Times noted, that relativity did "not personally concern ordinary human beings." In fact, a majority of people, then as now, didn't understand it and didn't particularly care.

Nevertheless, wrote noted historian Paul Johnson: "The modern world began on 29 May 1919 … . It was grasped that absolute time and absolute length had been dethroned … . All at once, nothing seemed certain in the movement of the spheres."

Johnson argued that in the 1920s the notion percolated into popular consciousness that there were no absolutes, not only in astrophysics, but in all of nature and experience.

"Mistakenly, but perhaps inevitably," wrote Johnson, "relativity became confused with relativism." In the disheartening wake of the Great War, had physics further eroded innocence?

In these two instances confusion might have been an issue of scale. Relativity, like natural selection, deals with phenomena that are not readily perceived in the workaday world. The curvature of space-time and the chemistry of DNA are beyond the range of our natural senses. Yet we have an urge to invest knowledge with meaning — for us, not just for scientists. After all, why bother to know if knowing has no impact?

Einstein wrote: "The only incomprehensible thing about the universe is that it is comprehensible." In other words, why is it that the human mind can figure out what gravity is (or isn't), then devise an experiment to help prove it? There are many possible answers to that question, ranging across a spectrum of religion, philosophy and neuroscience, and it might not be resolvable.

But I believe one thing is clear: our comprehension anoints us with tremendous responsibility. Einstein's famed equation — E=mc2 — helped blaze the path to atomic bombs only four decades after he first worked it out.

Most of us are not going to develop an insight that will provide rhetorical touchstones for historians. But what we know, or what we think we know, and the actions that knowledge inspires have collective impact on the world. Especially so in a global society where we have the capability of instant communication with almost anyone alive. Any message now has potential to "go viral," regardless of validity or worth.

Paul Johnson focused on relativity because "[i]t formed a knife, inadvertently wielded by its author, to help cut society adrift from its traditional moorings in the faith and morals of Judeo-Christian culture."

As I recall the 2017 eclipse, I imagine we moderns are kin to the nighthawks — abruptly awakened and confused. The difference is that their cognizance was innocent and ours is not.