Image of the Week: The Spot of Arago Arago's spot is visible at the center of the shadow behind a spherical ball bearing illuminated with a laser. Although the obstruction is opaque, coherent superposition of the diffracted light from around the circumference constructively interferes to produce a bright spot on-axis. —Jason Zweiback, Triangulum Technology, Diablo, CA, USA *Link in Bio #laser #light #arago