Today, in applications where it is warranted (like spacecraft instrument dials and certain types of sensors, for example), the radiation source is tritium (radioactive hydrogen) or an isotope of promethium, either of which has a vastly shorter half life than radium. read more
Not all radiation glows green, but some does (when it interacts with matter). It is also not just any green, but a luminous green; that is a green that generates its own light. I would call it a parable or a morality tale, not a myth; a truth related by means of a fictional story. read more
The ionizing radiation of radium made the phosphor glow green. The advantage was a bright green light that lasts for hundreds of years and was even visible at day. The danger of ionizing radiation was not known to this time and many of the workers suffered from serious diseases like cancer. read more