The Explorabook remains a highlight of my childhood. John Cassidy wrote it in collaboration with the Exploratorium and included a magnet bar, agar gel, diffract

The Explorabook remains a highlight of my childhood. John Cassidy wrote it in collaboration with the Exploratorium and included a magnet bar, agar gel, diffraction grating, mirror, Fresnel lens, Moire spinner, and other fun stuff. More importantly it was written in a humorous, accessible way that didn't talk down to you and stoked wonder. For example, the section on light talked about how lenses worked but also hinted that light had both particle and wave behaviors (e.g. interference from the diffraction grating), which blew my mind as a kid.