I Made a Birthday Cake but It Was Too Small to See
Get your party hats on, because April 25th is the birthday of nanotechnology pioneer Eric Drexler! Among other things, Drexler coined the term "grey goo" in his 1986 book Engines of Creation: The Coming Era of Nanotechnology to describe what might happen if hypothetical nanoscale assemblers self-replicated out of control and ate up everything else on the planet.
Drexler is also the author of Nanosystems: Molecular Machinery, Manufacturing, and Computation and a blog, Metamodern: The Trajectory of Technology. Recent posts include Nanotechnology in Science Fiction (and vice versa and Why I Hate "Nanobots".