Scientific American – September 2023: The issue features ‘Dinosaur Giants – How the biggest animals ever to walk Earth got so huge; The Science of Narcissism; Deep-Sea Mining; How AI learns What No One Taught It, and more…

Rare ‘Pinwheel’ Stars Are a Beautiful Astronomical Puzzle

The doomed class of stars named Wolf-Rayets produce mysterious pinwheel shapes

By Peter Tuthill

Deep-Sea Mining Could Begin Soon, Regulated or Not

Mining the seafloor could boost global production of clean energy technology—and destroy the ocean in the process

By Olive Heffernan

How Sauropod Dinosaurs Became the Biggest Land Animals Again and Again

New research hints at how sauropod dinosaurs got to be so gargantuan

By Michael D. D’Emic