We’ve posted a bit about abrasion holography in the past, but since then, “science hobbyist” extraordinaire Bill Beaty has posted the above vid demonstrating some great examples of his technique. The process is surprisingly simple, requiring some basic materials and a bit of patience –

Scratch-holograms can be made on CD cases using a couple of thumbtacks poked through a stick. Or get fancy and use a professional compass and black painted polycarbonate. Or automate the process with a paperclip stuck into a motorized electric eraser.

Along with instructions on how to draw your own, a comprehensive explanation of the effect works is available on Bill’s site. [Thanks, BJ!]