Category Archives: Physics

Dandelin Spheres

John F. Lindner September 6, 2021 9:11 PM

In 1609, Johannes Kepler first described how planets orbit the sun in ellipses. Kepler understood an ellipse as both the locus of points whose distances from two foci sum to a constant and as the intersection of a cone and a plane. But how … Continue reading →

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For Teague

John F. Lindner August 25, 2021 6:39 PM

Sadly and unexpectedly Wooster physics senior Teague Curless ’22 died yesterday. I was fortunate to teach Teague some physics, especially in my Nonlinear Dynamics class last spring. Teague’s semester project beautifully illustrated chaos in a double pendulum — a pendulum swinging … Continue reading →

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Spinors

John F. Lindner August 5, 2021 9:10 PM

Fermions like electrons, protons, and neutrons inhabit a 720° world: 360° rotations negate their quantum states, but 720° rotations restore them. A simple macroscopic model of such spinors is an arrow translating on a Möbius strip: as the center circle rotates, … Continue reading →

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Transition

John F. Lindner June 30, 2021 7:55 AM

As I transition to emeritus status tomorrow, I reflect on 33 years at Wooster. I am thankful for the freedom I’ve had to design my own courses, including eight first-year seminars; for the flexibility to explore a wide range of … Continue reading →

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Free-Fall Spinning Tunnels

John F. Lindner April 28, 2021 9:01 PM

Jump into an evacuated hole drilled straight through a uniform, static Earth-like sphere. Accelerate to 7.9 km/s (or 18 000 m.p.h.) at the center, then decelerate back to zero at the antipodes 42 minutes later! Step out of the hole upside down — … Continue reading →

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Geographic Tongue

John F. Lindner March 3, 2021 3:03 PM

The improbable email was from a pre-dental math major asking about physics research projects combining math and dentistry, but my reaction was, “Yes — only at Wooster!”. Like animated tattoos, the surface patterns of benign migratory glossitis slowly move on the … Continue reading →

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Nightfall

John F. Lindner January 28, 2021 1:17 PM

NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered a sextuply-eclipsing sextuple star system. I think of “Nightfall”. The six stars of TCY 7037-89-I orbit each other in three binary pairs, as in the schematic. The primaries are slightly larger and … Continue reading →

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Chemical Clock

John F. Lindner December 10, 2020 8:22 PM

Wooster’s summer 2019 Sherman-Fairchild group just published, “Disruption and recovery of reaction–diffusion wavefronts interacting with concave, fractal, and soft obstacles”, in Physica A. Working with Fish Yu ’21, Chase Fuller ’19, Margaret McGuire ’20, and Niklas Manz (Physics) was wonderful. … Continue reading →

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Novel Math, Nobel Physics

John F. Lindner October 26, 2020 1:40 PM

When I was a kid I used to read Scientific American at the local library. I loved Martin Gardner‘s Mathematical Games column, and I vividly remember his description of Roger Penrose‘s then recent discovery of two shapes that force a … Continue reading →

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Cookie Cutter

John F. Lindner September 11, 2020 7:23 PM

Cookie dough in a cookie factory moves on a conveyor belt at a constant relativistic speed. A circular cutter stamps out cookies as the dough rushes by beneath it. In the factory frame, the dough is length contracted along the … Continue reading →

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