Maciej Cegłowski has made a persuasive case against human boots on Mars in the foreseeable future. Not only am I convinced that he's right in specific case, but ever since reading Kim Stanley Robinson's Aurora a few years ago, I've largely divorced myself from the romantic falsehood of galactic manifest destiny. Let's just build more telescopes and robots while we work on fixing up where we are always, always, always going to live.
While acknowledging that not everybody finds deeply technical discussions of things they only faintly understand to be compelling viewing, I found Brian Karis's 90-minute keynote address totally engrossing. He discusses his year-long intellectual journey towards what became Unreal Engine 5's virtualized geometry technology not in terms of the technical triumph that it ultimately was but rather the messy process of dead-ends, hunches, and lonely groping in the dark that it took to get there.
In his relating of the experience of working on a problem where a solution was far from guaranteed, Karis's humility and curiosity are genuinely inspirational.
Shot in 1902, “The Flying Train” takes viewers on an uncommonly crisp journey aboard a suspended railcar. Throughout the two-minute video, riders see Wuppertal residents walking across pedestrian bridges and down dirt roadways more than a century ago. The city is known still today for its schwebebahn, which is a style of hanging railway that’s unique to Germany.
This led me to look up the Wikipedia article for Wuppertal Schwebebahn, which in addition to being a still-functioning hanging rail system over a century old, is—if I don't miss my guess—a double dactyl.