Charles Glover Barkla

Charles Glover Barkla was born on June 7, 1877, in Widnes, Lancashire, England. Studying mathematics and physics under Sir Oliver Lodge at University College, Liverpool, Barkla joined Cambridge University's Cavendish Laboratory in 1899 to conduct research under the legendary J.J. Thomson.

Between 1902 and 1911, Barkla conducted experimental studies on the scattering of X-rays by gases, liquids, and solids. He demonstrated that X-rays behave like transverse electromagnetic waves similar to light, proving their polarization. Crucially, Barkla discovered that when substances are exposed to primary X-rays, they emit secondary X-rays that are independent of the substance's chemical combination but strictly characteristic of the chemical element itself.

Barkla categorized these emissions into two distinct spectral series, naming them the 'K' and 'L' radiation series—terminologies that remain universally used in X-ray spectroscopy and atomic physics today. Appointed Professor of Natural Philosophy at the University of Edinburgh in 1913, Barkla was awarded the 1917 Nobel Prize in Physics. He held his Edinburgh chair until his death on October 23, 1944, his work immortalized on the Moon by the lunar crater Barkla.