JACKI LYDEN, host:
The waning autumnal light this time of year has set our commentator, Ruth Levy Guyer, to meditating on the sun.
RUTH LEVY GUYER: Five billion years ago, a mammoth cloud of dust and gas collapsed to form a simple, average star. Five billion years from now, that star will swell and then engulf and fry the Earth. We humans seem complacent toward that star, expecting it to rise each morning, presuming it will set at night. But let us not forget, without that star in just that place, no plant or animal would be alive and all our oceans would be ice or would have boiled away.
The grandeur of the sun is surely astronomical, not just for its showiness when there are clouds at dawn and dusk, and not just when it flashes green before it plunges in the sea, but also for its awesome power to heal our skin or hurt it, to set our body clocks each day, to give off energy so vast, a term was coined, the yatawatt(ph) the billion-billion megawatt.
Sometimes the sun can startle us, as when the moon pulls up in front to block its glow. And many shudder when the sun forsakes the Earth this way. Birds no longer sing, and cows stand up or turn and head for home. But there are those who chase the shocking daytime dark. They travel far afield to catch eclipses where they peek or stalk totality in supersonic jets. Five thousand seven hundred and ninety years ago, an Indian first recorded night at day. And since that time the eclipsed sun has taught us much.
Astronomers discovered through their spectroscopes a gaseous element they had never known. They named it helium in homage to the Grecian god, and only later also found it here on Earth.
And then, in 1991, the eclipse came to the astronomers, an observer wrote. They amassed on Mauna Kea with its majestic telescopes and marveled as the Hawaiian morning sky grew black. From 14,000 feet above the sea they watched a gaseous loop 10 times the height of Earth flow from the surface to the sun's corona. They saw coronal particles stream forth as solar wind.
Last winter I too stood on Mauna Kea, but I was there to see the sun go down and then stayed on to watch as the Milky Way's 100 billion other average stars came out. A few days later, I arose just hours after I had gone to sleep to catch the sunrise at the summit of a different place. The wind was howling at the pitch black rim of Haleakala. The air was frigid. We watchers huddled close. It took some time, but then the sky began to get a bit of light. Marshmallowy clouds filled the vast volcanic crater like foamy milk inside a cappuccino cup. On the horizon there appeared a slender shimmering bracelet of gold. The sky grew orange, chrome, then lemon bright; the bracelet glistened. Suddenly its center glowed the way a diamond shines atop a ring. A sphere rose up resplendent in the sky. The sun was back. A brand new day had dawned. And only fools would fail to find that ordinary star extraordinary.
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LYDEN: Ruth Levy Guyer teaches courses in bioethics and infectious disease at Haverford College.