William Crookes

Sir William Crookes was an influential English chemist and physicist, renowned for his pioneering work in the fields of spectroscopy and vacuum technology. Educated at the Royal College of Chemistry, he made significant contributions to the understanding of cathode rays through the invention of the Crookes tube in 1875, which led him to propose the existence of 'radiant matter'—a groundbreaking concept that would later be foundational in the study of plasma physics. His discovery of the element thallium in 1861 and the first description of terrestrial helium's spectrum in 1865 further established his reputation as a leading scientist of his time. Beyond his scientific achievements, Crookes was also known for his eclectic interests, which included a fascination with spiritualism. He served as president of the Society for Psychical Research, reflecting his belief in the exploration of the unknown. His invention of the Crookes radiometer and a 100% ultraviolet blocking sunglass lens showcased his innovative spirit. Throughout his life, Crookes was recognized for his originality and industriousness, earning numerous accolades and a substantial income. His diverse contributions to both pure and applied sciences left a lasting legacy, marking him as a significant figure in the scientific community of the late 19th and early 20th centuries.