Rosalind Franklin, born #OTD in 1920, used X-ray crystallography to make this image—the second image in this gallery—of a DNA molecule, known as Photo 51. The dark patches showed DNA bases, while the cross shape revealed for the first time DNA's famous helical structure. #WCW . . . . . . . . . . #womancrushwednesday #hbd #onthisday #happybirthday #rosalindfranklin #dna #helix #photo51 #science #biology #genetics #history #sciencehistory #women #womancrush #womeninscience