A petri dish is a small container used by scientists, usually biologists, to discover and explore cultured cells, plants, and so on. It’s usually, but not always, 100mm in diameter and 15mm in height. In 1887, it played a key role in discovering penicillin. While petri dishes come in different sizes and other variables scientists do great work with them. They’re only so big; they’re only so small. It’s a 100mm x 15mm constraint where the world is changed. A petri dish is a tangible disc of embracing constraints: there are parameters and boundaries… yet so many wonderful things can happen within those boundaries. A petri dish is a playground for the creativity of a scientist.
A standard “letter” size piece of paper is 8.5″ x 11″ in diameter. A hard drive holds a certain amount of documents. A canvas or piece of fabric can be any size in theory yet at some point it has to be cut.
Stages come in a variety of sizes, yet each is a size. Speeches and sermons can only go so long before they become rants. Soapboxes are only so high, so wide, so placed, so sturdy, and so afforded.
A guitar has only six strings. A ukulele has four. An erhu has two.
What is your petri dish?