The two pictures shown here accompanied two of the most important “aha!” moments in history. The first is “Photo 51,” taken under the laboratory research of Rosalind Franklin. It shows an X-ray diffraction pattern of DNA, and Franklin, Watson, and Crick used it to figure out the molecular structure of life itself.
The second is a page out of Charles Darwin’s “notebook B,” and shows his drawing of the transmutation of species as branches off of limbs. “I think,” he has scribbled on the top of the page, as he worked out his ideas.
What images in the history of science are your favorites?
