Burlington Northern Railroad Bridge 5.1 across the Willamette River, Portland, OR. (Google Earth imagery).

Colorado River near Pangas Viejas, northern Mexico. Google Earth / Maxar Technologies / CNES/Airbus imagery. Western megadrought is the worst in 1,200 years. npr.org/2022/02/14/108…

A billiards trajectory with a change of hue/luminance on each reflection, animated by cycling through hues.

A 390 million-year-old hyper-compound eye in Devonian phacopid trilobites #optics #TrilobiteTuesday nature.com/articles/s4159…

A Minkowski island is dissected into smaller copies of itself, showing that is is a 16-rep rep-tile. en.wikipedia.org/wiki/Rep-tile

OTD in 1990, Hubble launched its epoch-making oracle eye into the cosmos. The teenage Tracy K. Smith, not knowing she would become Poet Laureate of her country, had watched her father—one of NASA's first black engineers—work on it. Her stunning ode: themarginalian.org/2022/02/11/uni…

Columbia River Gorge

1/ i am writing a book on applied dynamical systems. you can find a working draft here: www2.math.upenn.edu/~ghrist/prepri…

Requirements: IBM PC, CGA, 4.77 MHz 8088, hard drive Holy. Shit. youtube.com/watch?v=-xJZ9I…

Northern flicker feather

The Kochawave curve, a variant of the Koch curve. Beautiful paper by Rémy Sigrist. arxiv.org/abs/2210.17320

SE Hawthorne and 37th, looking west from near the Bahgdad Theater sign toward the current Moberi business. Left: 2/2/1941, by Al Monner (Alfred Anthony, 1909-1998). Right: 2/11/2023 digitalcollections.ohs.org/southeast-hawt… #portland #pdx #oregon #portlandoregon

Pale blue dot, 2/14/1990. "... but the globe he inhabits,—nay, the whole system of which it forms so small a part,—might be annihilated, and its extinction be unperceived in the immensity of creation." - On the connexion of the physical sciences”, Mary Somerville, 1834

Landforms near Durkee, Oregon. Imagery from Google Earth.

Amazing! Four guys discovered an aperiodic monotile. It's a shape that looks sort of like a hat, not all that complicated, a 13 sided polygon, and you can use it to tile the entire plane, but at no point will the pattern become periodic and repeat. Long paper about it here. (1/2)

Escher on loneliness and creativity themarginalian.org/2022/10/04/esc…

My new NYT Magazine cover story is a portrait of a family with a genetic mutation that causes early-onset dementia. Frontotemporal Dementia (FTD) strikes in the prime of life. In this family, everyone had a 50% chance of having the mutation. There’s no cure.1/2 nytimes.com/2023/07/20/mag…

Apollo 16 launch footage taken from the atop Vehicle Assembly Building (VAB).