Mark Galvin

Hi Paul, I just stumbled across this thread and, as the Secretary of Liverpool AS, I thought I should respond. Firstly, I'd like to apologise if our members seemed to ignore you and, separately, your friend. Whilst I don't believe any of them would do this deliberately, it doesn't change the fact that it happened. I suspect it was probably a case of the bystander-effect - everybody thought somebody else would do it. If you can tell me the dates when it happened (even roughly), I can check the signing-in book to see who was there on those evenings and speak with them, but I'll also speak to the larger group to remind them that if they see somebody new who is on their own to go over to them and say hello, have a chat, etc. It greatly worries and upsets me that there is a perception of a clique within our Society and our membership. Yours sincerely, Mark Galvin Secretary, Liverpool Astronomical Society

Hi Vroobel, Just a small note about the lens - you may want to run a Geiger counter over it. Many good-quality older lenses (including Zeiss) contain Thorium in the glass as it improved the optical quality, and emit alpha particles, beta particles and even gamma rays (due to the radioactive decay chain) in varying amounts. As one YouTube video (Radioactive Drew, on a video about radioactive cinema lenses) put it recently, they're generally safe enough to handle but you wouldn't want to sleep with one under your pillow. Most of the radioactive lenses (from cinema projection systems, so quite large) which they tested were pretty safe, but there was at least one which you definitely wouldn't want to be standing next to for too long. A post on https://lenslegend.com/radioactive-lenses/ seems to say that the main danger that can arise is if the lens is cracked, shattered, etc. and microscopic radioactive fragments someone get ingested or inhaled. Anyway, I just thought I'd mention it as it doesn't seem to be common knowledge.