That napkin, now laminated and locked in a safe deposit box in Zurich, was the cornerstone of her entire ASME submission for the Journal of Turbomachinery .
On it, Tanaka had sketched a stress-strain curve and written six lines of data.
But her document had no title. The napkin just had scribbles. And the "source"? A bar that closed in 2008.
Then she added, in square brackets per ASME rules for notes: [Editor’s note: Original medium is a paper napkin; photographic facsimile available from corresponding author upon reasonable request.]