Author Archives: John F. Lindner

About John F. Lindner

John F. Lindner was born in Sleepy Hollow New York and educated at the University of Vermont and Caltech. He is a professor of physics and astronomy at The College of Wooster. He has enjoyed multiple yearlong sabbaticals at Georgia Tech, University of Portland, and University of Hawai'i. His research interests include nonlinear dynamics, celestial mechanics, and variable stars.

Kelly Twin Paradox

Yesterday astronaut Scott Kelly returned from nearly a year in free fall aboard the International Space Station to join his identical twin brother Mark back on Earth. Due to their different spacetime paths, I estimate that Scott aged about 9 ms … Continue reading

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A New Kind of Astronomy

One of the first things I did as a grad student in 1982 was tour the Laser Interferometer Gravitational Wave Observatory (LIGO) prototype on the Caltech campus about a block from my dorm. It was housed in a utilitarian L-shaped … Continue reading

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Hillary & Armstrong

You’re probably familiar with the iconic photograph of Edmund Hillary standing atop Earth’s highest mountain wearing an oxygen mask in air so thin the sky is almost black as space — but actually, Hillary’s companion Tenzing Norgay didn’t know how … Continue reading

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Ticktock Deadbeat Escapement

The escapement is one of history’s greatest inventions; it enables a collection of wood or metal to tell time. The animation below illustrates a pendulum clock’s deadbeat escapement, apparently introduced by Richard Townseley, Thomas Tompion, and George Graham in the … Continue reading

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The Falcon Has Landed

Monday evening, the first of SpaceX’s 70 m (or 230 ft) Falcon 9 full thrust launch vehicles successfully deployed 11 satellites to low Earth orbit — and performed reversal, supersonic retrograde, and landing burns to return the first stage to … Continue reading

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This month is the 100th anniversary of Albert Einstein’s November 1915 discovery of the gravitational field equations of General Relativity, in which test masses move along the straightest possible paths (called geodesics) in spacetime curved by the density and flux … Continue reading

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The Martian

Ridley Scott’s The Martian (2015) is the best Mars movie I have yet seen. Genuinely faithful to Andy Weir’s popular novel, The Martian chronicles astronaut Mark Whatney’s struggle to survive on Mars, after being accidentally stranded there, and the efforts … Continue reading

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19th Century Foreground, 20th Century Background

Although some early aviation aficionados allege other flights (or hops) preceding the Wright brothers’ experiments at Kitty Hawk on 1903 December 17, the Wright Flyer did fly four times that day, including a final flight nearly one minute long, with … Continue reading

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On the Shore of the Arctic Ocean

It was a privilege to spend the 2014-2015 academic year and summer on sabbatical at the University of Hawai’i in Honolulu. During the last week of July, I stood on the spectacular beach at Kailua near sunset and said to … Continue reading

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Rubik’s Cube Puzzles

As a kid, I enjoyed solving the “15 puzzle”, a sliding puzzle consisting of a 4×4 grid of 15 squares. However, I was amazed at a kind of 3D analogue of the 15 puzzle: Ernö Rubik’s 1974 masterpiece, which is … Continue reading

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