In 1960 the eleventh General Conference on Weights and Measures redefined the metre in terms of 1,650,763.73 wavelengths of the orange-red emission line of krypton-86 atoms, replacing the physical platinum-iridium bar that had served as the international prototype since 1889. The change anchored measurement to a reproducible natural phenomenon independent of any physical object. It was a landmark in the long project of grounding scientific language in universal constants.

The redefinition of the metre in 1960 exemplified the precision of the atomic age, influencing poetry that engaged with scientific themes. Poets like John Ashbery explored the microscopic universe through innovative forms, reflecting on the intersection of science and art in their works.