Author: John F. Lindner

  • Measuring the Solar System

    John F. Lindner

    Thousands of years ago, ancient astronomers like Aristarchus and Eratosthenes combined careful observations with simple mathematics to measure the solar system, especially the diameters D of Earth, Luna (Earth’s moon), Sol (Earth’s star, the sun), and the radii r of their orbits. You too can do this, but it helps to observe an eclipse or two.…

  • Wooster’s Time Crystals

    John F. Lindner

    Saturday, March 8, 2008. A heavy snow, one of the heaviest I remember, shuts down the city of Wooster. Streets are undriveable, so I walk to Taylor Hall, getting snow in my boots. Taylor is deserted, as the College has begun Spring Break, but like yesterday, Kelly and I work all afternoon and evening in…

  • Venus’s Supercritical Ocean

    John F. Lindner

    The pressure and temperature near the surface of Venus are so high that its carbon dioxide atmosphere is a global ocean of a remarkable state of matter, a supercritical fluid, which fills any container like a gas but is as dense as a liquid. I created a carbon dioxide pressure versus temperature phase diagram using…

  • Percy & Ginny

    John F. Lindner

    A chill went through the spaceflight community last week as NASA reported that it had lost contact with the Ingenuity Mars helicopter. Delivered to Mars underneath the Perseverance rover and intended as a 5-flight 30-sol tech demo, it had vastly exceeded expectations, including the first successful powered flight off Earth, a true Wright brothers moment,…

  • Summer of ’19

    John F. Lindner

    Due to the pandemic, the summer of 2019 was regrettably and unexpectedly my last Wooster summer research program, but the team was amazing. Niklas Manz and I obtained Sherman-Fairchild funding to work with Margaret McGuire ’20, Yang (Fish) Yu ’21, and Chase Fuller ’19 to computationally study reaction-diffusion phenomena.  All three of their projects have…

  • Chemistry Does General Relativity

    John F. Lindner

    I hired Kiyomi from Hawai’i for our NSF REU summer program in spring 2020 amidst fears of the pandemic that eventually postponed the program two years. When she finally arrived in summer 2022, I had already retired from Wooster, where my last year was completely remote, classes via Teams, but several of those included Daniel.…

  • Magic Scroll

    John F. Lindner

    When I bought my house, I knew I would soon need to replace its heat pump, which was almost 20 years old. Earlier this month, with my old pump laboring under a cold snap, I upgraded to a new version, which boasts a history of elegant inventions. Powered by electricity, heat pumps circulate a low-boiling-point…

  • All Engine(s) Running

    John F. Lindner

    I asked Siri to wake me at 7:15 this morning so I could watch SpaceX’s second Integrated Flight Test of Super Heavy Starship, the biggest and most powerful rocket ever built. Unfortunately, my house suffered a rare power outage an hour or two earlier, so I found myself lying in bed watching the coverage on…

  • Diversity Improves Machine Learning

    John F. Lindner

    For the last two years, the Nonlinear Artificial Intelligence Lab and I have labored to incorporate diversity in machine learning. Diversity conveys advantages in nature, yet homogeneous neurons typically comprise the layers of artificial neural networks. In software, we constructed neural networks from neurons that learn their own activation functions (relating inputs to outputs), quickly…

  • Neural network does quantum mechanics

    John F. Lindner

    A particle confined to an impassable box is a paradigmatic and exactly solvable one-dimensional quantum system modeled by an infinite square well potential. Working with Bill Ditto, Elliott Holliday and I recently explored some of its infinitely many generalizations to two dimensions, including particles confined to regions that exhibit integrable, ergodic, or chaotic classical billiard…

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