I enjoyed Tim Haymes’ write up in the current LSC mentioning his findings on EG Moore. Seeing the photo of EG Moore’s observatory reminds me how interested I was when I first read Moore’s article back in 1975 that he had used Beta Lights to illuminate key items in the observatory. They do not require a power supply. I couldn’t find a supply at the time.
Moore followed up with a Letter to the Edition in JBAA, 85(3), 283 (1975), https://britastro.org/wp-content/uploads/journals/v085i03j.pdf, about the safety aspects of these Tritium containing lights.
Betalights are still available: https://www.betalight.nl/
I also read “Betalights are generally considered safe due to their lack of electricity and spark risk, and the low-energy beta particles from tritium cannot penetrate the outer casing. In the unlikely event of a breakage, the tritium gas would disperse harmlessly, posing a minimal health risk. The self-luminous technology is reliable, maintenance-free, and certified to meet various safety and building codes”.
So, 50 years on, does anyone use them?