William D. Coolidge was an American physical chemist and inventor who made important contributions to three areas of twentieth-century technical development. He developed a pliable filament that improved the electric light, making it possible to mass produce the electric light bulb for commercial, industrial, and personal use. He developed X-ray technology so that it was possible to adapt X-ray techniques to many areas of medicine and technology. He also played a role in the development of the atomic bomb used by the United States at the end of World War II.

William David Coolidge was born on a farm in Hudson, Massachusetts, on October 23, 1873, to Albert Edward Coolidge, a shoe factory worker, and Martha Alice Shattuck. As a young boy, Coolidge showed an ability for electrical and mechanical projects. This ability was evident from the fact that he spent much of his spare time in a local machine...