Terrazzo hints for Saturday, September 12, 2026

Today's subject comes from science.

The caption reads: “The most useful accident in medicine.”

You place 9 stones into a frame of 50 cells. Every cell is filled exactly once.

• Solitude. No two sun cells may touch, not even corner to corner.
• The Vein. The vein cells must form one unbroken path between the frame's two notches, with no branches and no loops.

Start with the largest region the Laws name: it has the fewest ways to fit.

A Contaminated Dish

Alexander Fleming left for holiday in 1928 without tidying his bench. He returned to a petri dish of staphylococcus with a blot of mould on it, and a clear halo around the blot where the bacteria had died. He noted it, published it, and largely moved on — he could not purify enough of the substance to matter. A decade later Howard Florey and Ernst Chain did the unglamorous chemistry, growing mould in hospital bedpans and biscuit tins. By 1944 penicillin was being made in factories in time for the Normandy landings. Fleming's luck was real; the twelve years of work after it were not.