Eclipse Reflects Sun’s Historic Power

(Adapted from an article published by the University of Chicago)

Eclipses have fascinated people since the earliest days of recorded history.

These rare astronomical events have helped explain the world around us—from ancient Mesopotamia, where they were believed to foretell the deaths of kings, all the way to the 20th century, when they helped prove Einstein’s theory of general relativity.

Such interest hasn’t dimmed. People across the United States will have an opportunity on Aug. 21 to witness the first total solar eclipse from coast to coast in 99 years. UChicago faculty, students and alumni are among the hordes of enthusiasts traveling across the country toward the area of “totality,” the 70-mile-wide stripe stretching from Oregon to South Carolina in which the moon will fully block the sun.

Ahead of this historic event, UChicago News asked scholars in fields ranging from theoretical cosmology to Islamic studies to discuss eclipses and their power.

The eclipse that proved Einstein was right

Michael Turner, Bruce V. & Diana M. Rauner Distinguished Service Professor in Physics and Director of the Kavli Institute for Cosmological Physics.

“Astronomers have learned a lot from eclipses, including one in 1919 that proved Einstein was right.

At the time, only a handful of people were aware of general relativity; Sir Arthur Eddington was one of them. He led an eclipse expedition into the Atlantic to find out whether gravity would bend starlight, as predicted by general relativity. What you want to do is look at stars very close to the sun, and see whether the light coming toward us is bent by the sun’s gravity. With the moon blocking the sun, you can get that measurement, and it was exactly what Einstein predicted. The scientific community was agog. It instantly put general relativity on the map, and made Einstein a rockstar.

We’re still learning things from eclipses. One thing people will study during this event is the corona of the sun, which is the glowing aura of gases that surrounds the sun. There are still things we don’t understand about it—such as exactly why it actually burns hundreds of times hotter than the surface of the sun itself.

A few years from now, NASA will launch a probe named after UChicago’s own Eugene Parker that will explore the sun’s corona—closer than any probe has ever come to the sun.”

Continue reading "Eclipse Reflects Sun's Historic Power," by University of Chicago News.

Learn how to view an eclipse safely with this Q&A and video featuring Richard Binzel of MIT's Kavli Institute for Astrophysics and Space Research.