Interesting concept from Thingiverse user 12meyer. All kinds of potential problems here, so this is more of a “way to think outside the box” kind of shout-out than the “where can I invest in your start-up” kind. One can, of course, dim fluorescent bulbs electrically, but it turns out to be kind of a PITA. The idea here is to exploit the spiral shape of the bulb itself to make an opaque cover that screws on or off to block more or less light, respectively.

Mechanically dimmed fluorescent lamp