/oss/taxonomy/term/6008/all en /oss/article/technology-you-asked/what-tritium-paint <p>In 1957, Edward Shapiro filed a patent for a novel type of “self-luminous paint.” The concept was not new, luminous paints based on radioactive emissions from radium striking a phosphor such as zinc sulfide were introduced in 1917. Watch dials and compasses that glow in the dark proved to be very useful on the front during World War I. After the war, watches and clocks that featured “Undark” paint became popular among the public until it was phased out by the 1960s.</p> Fri, 28 Jan 2022 20:22:13 +0000 Joe Schwarcz PhD 9011 at /oss