Alan, On Mon, 25 Sep 2006 13:33:48 +0100, Alan B. Pearce wrote: > >I think I'm right in saying that DEC 10s had a hardware > >random number generator - based on radioactive decay of > >some reasonably safe element. > > I wonder if it would be classed as "reasonably safe" now. We have an > Fe55 source here for checking out some detectors, and it gets the "full > treatment" in terms of notices on the lab door, restricted access, locked > away in a safe, people wearing radiation badges etc etc etc, despite being > apparently "reasonably safe". LOL! Well smoke detectors even these days may have Americium in them... When I was at school there was a box of radioactive sources in the physics lab. During one meeting of the Electronics Society we got this out (lead-lined box with pieces of Uranium, Strontium, Radium, etc) along with a geiger-counter. It had dire warnings and a set of tweezers for handling the t-shaped holders the tiny pieces were mounted in, but when we found that at least two kids' watches were over ten times as radioactive as any of the samples we dispensed with the tweezers! There was also a clock face which had luminescent markings that were so powerful that you could practically see the green glow in daylight - that was the most powerful emitter of radiation we found. Interestingly, I recently went to a museum that had most of a "Horsa" WWII glider, and you could go into the main part of the fuselage, but the cockpit was roped off. I asked why and was told that (1) they didn't want anyone damaging the instrument panel or controls - it's quite cramped in there and (2) Health and Safety wouldn't let anyone within 3 feet of the instuments because of the luminescent dots on them! Even it they'd known as much as we do now, I suppose in the situation of flying into battle which starts with a controlled crash of the aircraft in enemy trerrritory, the reduction in life-expectancy from the radiation wasn't a major worry... Cheers, Howard Winter St.Albans, England -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist