Why has the radioluminescence industry given up after a few poor attempts? Ok, radium was too radioactive and a 1600 year half-life was ott. Then they immediately swap to insufficient radioisotopes with useless short half-life. Out of the hundreds of isotopes available (probably available for free in nuclear waste) is there seriously not a usable and relatively safe alpha or beta emitter with a reasonable half-life of say 100- 200 years that could be used with the wide array of modern phospors. Are scientists just being lazy or is it another problem of nanny states scared that if we are not wrapped up in cotton wool we will stab ourselves in the eye with a fork