https://justin-eberhardt.com/ Essays from west central Minnesota on skiing, canoeing, teaching, AI and economics. en-us https://justin-eberhardt.com/vines.html https://justin-eberhardt.com/vines.html Fri, 11 Sep 2026 12:00:00 -0500 Greg McColm's metaphor of mathematics as an invisible edifice traced out by visible vines, and what it means as AI reaches parts of the building no one could climb to before. https://justin-eberhardt.com/optional.html https://justin-eberhardt.com/optional.html Mon, 20 Jul 2026 12:00:00 -0500 Training on a 140-foot Minnesota hill for a rim-to-rim-to-rim hike of the Grand Canyon: 40+ miles, 12,000 vertical feet, and a surprise solar eclipse. https://justin-eberhardt.com/nikko.html https://justin-eberhardt.com/nikko.html Thu, 13 Nov 2025 12:00:00 -0600 A predawn solo hike on mountain trails above Nikko, Japan, far from Tokyo's crowds. https://justin-eberhardt.com/AIlimits.html https://justin-eberhardt.com/AIlimits.html Thu, 30 Oct 2025 12:00:00 -0500 AI excels at pattern recognition, but interpolation isn't extrapolation. Why some discoveries remain beyond machine learning. https://justin-eberhardt.com/5trillion_bet.html https://justin-eberhardt.com/5trillion_bet.html Wed, 29 Oct 2025 12:00:00 -0500 A college instructor builds an AI tutoring app on a $2900 Mac and considers what fast-improving consumer hardware means for the $5 trillion AI infrastructure bet. https://justin-eberhardt.com/bitmon.html https://justin-eberhardt.com/bitmon.html Mon, 20 Oct 2025 12:00:00 -0500 What Pokemon card collecting can teach us about Bitcoin, speculation, and bubbles. https://justin-eberhardt.com/fluoro.html https://justin-eberhardt.com/fluoro.html Mon, 01 Feb 2021 12:00:00 -0600 From a 1997 Minnesota high school ski meet to PFAS bans: a skier's history of fluoro wax. https://justin-eberhardt.com/winter.html https://justin-eberhardt.com/winter.html Sun, 01 Dec 2019 12:00:00 -0600 An open letter to critics of winter, in defense of the season 95% of people rank last. https://justin-eberhardt.com/backcountry.html https://justin-eberhardt.com/backcountry.html Sun, 01 Dec 2019 12:00:00 -0600 Skiing Minnesota's less-traveled, ungroomed trails: the state's version of backcountry skiing. https://justin-eberhardt.com/birken.html https://justin-eberhardt.com/birken.html Fri, 01 Mar 2019 12:00:00 -0600 Race report from the 2019 Birkebeinerrennet: 54km on skis across the mountains from Rena to Lillehammer. https://justin-eberhardt.com/trondelag.html https://justin-eberhardt.com/trondelag.html Fri, 01 Mar 2019 12:00:00 -0600 Skiing the Bymarka near Trondheim and discovering the ski hut traditions of Trondelag, Norway.