Editor’s Note: Published in 1956, this article proved so popular that it served as the inspiration for Martin Gardner’s legendary Scientific American column Mathematical Games. Read more in our ...

To address the limitations of narrow bandwidth, single-frequency operation, and single-polarization in existing vortex beam generation, a compact single-layer reflective metasurface based on a ...

Hexagons are efficient, safer, and just plain cool—so why don’t cities use them? In this video, I explore the fascinating history of hexagonal urban planning, from its near-adoption in the early 20th ...