Five brilliant military gadgets designed by students.

The surprising history of powdered alcohol.

Pictorial history of the pocket knife.

Collection of bat-eating spiders. Related, kind of: Acid-spewing beetles inspire new defense tactic for ATMs.

A backstage tour of the Channel Tunnel.

Elegant henna tattoo crowns help cancer patients cope with their hair loss.

ICYMI, Friday’s links are here, and include a marsupial that has marathon sex until it goes blind and drops dead, a smile-inducing animation of a dog searching for his boy during a zombie apocalypse, and photos of lava meeting surf.