Answer: Henry Moseley

Henry Moseley was one of the most brilliant scientists of the early 20th century and was, unfortunately for the greater pursuit of science and humanity in general, dead by age 27.

In his early twenties, Moseley had already contributed a vast amount to the study of physics and chemistry. He invented the first atomic battery, found a systematic mathematical relationship between the length of the X-ray waves produced and the atomic numbers of the metals used as targets in X-ray tubes (now known as Moseley’s Law), and, perhaps most enduring and most familiar to the layman, he helped to ‘refine and solidify’ the modern atomic number system (previously, atomic numbers were not fixed and their assignment schedule seemed arbitrary and haphazard by modern standards). Henry Moseley also confirmed the predictions of missing elements in the Periodic Table made by other scientists and made predictions of his own concerning other as yet undiscovered elements.

Who knows how much more Moseley would have contributed to the sciences if not for the outbreak of World War I. The timing of the war happened to correspond with a break between academic appointments for Moseley (switching from Manchester to Oxford), and he volunteered to work for the Royal Engineers of the British Army. Moseley was assigned to a force deployed to Turkey and was shot during the Battle of Gallipoli in August of 1915.

After his death, the British government revised their guidelines for the drafting/enlisting of scientists and their eligibility for combat duty; other countries also took note of the loss of Henry Moseley and scientists who had potential for great contributions to both their general fields and their respective country’s war efforts were kept far from the front lines.