4 ms·
That article mentions them dangling a wrist watch over the space ball to see if it was radioactive. How would this work?
by adzm 4y ago
That article mentions them dangling a wrist watch over the space ball to see if it was radioactive. How would this work?
- nynx 4y agoPerhaps tritium in the watch hands.
- pvg 4y agoTritium is itself radioactive and used in watches to make a luminescent material glow. I think zinc sulphide was common and it would probably glow if lit up enough. Not sure you want to be near something that makes your watch dial markings glow visibly more than the radium or tritium that's in the paint, though.
- Hextinium 4y agoThe tritium interacts with a phosphor through beta decay, so presumably if you hung a watch near it the phosphor would glow brighter with higher concentration of beta decay. Basically a sort of visual Geiger counter.
- pvg 4y agoZinc sulphide, from brief googling, seems like it would glow in anything so if this was a thing, it probably makes most sense for gamma radiation since the 'detector' isn't being massively lit up by that internally already.
- perihelions 4y agoSure, but run the inverse-square law on the difference between a ~100 micron paint layer and a source that's ~1 meter away.
- greggsy 4y agoThat’s what I was thinking when I read it. I have no idea if tritium emits more radioluminescence near a source though.
- perihelions 4y agoIt wouldn't. edit: It's obvious the quoted person had no idea what they were doing -- even a few seconds at arms' length from a fresh nuclear reactor core would be fatal. And quite a few satellites in that era were nuclear-powered. It's not as if accurate knowledge of radiation was readily available, in the 1970's.
- pvg 4y agoThey didn't shoot nuclear reactor cores into space. RTGs are still dangerous but people do stand next to them. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#/media/File:RTG_radiation_measurement.jpg https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
- perihelions 4y agoBelieve it or not, lots of nuclear fission satellites in the 1960's-70's. https://en.wikipedia.org/wiki/Nuclear_power_in_space#Fission_systems https://en.wikipedia.org/wiki/Nuclear_power_in_space#Fission...
- pvg 4y agoYou're right, I didn't realize they fired quite that many (31?!) BES-5s into space and those are really the only non-experimental ones. Still, the chances of one of those falling out of orbit as a functioning reactor are about nil.
- perihelions 4y agoThe posterior probability, given that you've already found a very rare piece of space debris, would have been high. https://xkcd.com/795/ https://xkcd.com/795/ (By the way, there's an documented instance [0] mentioned in the sibling comments. The hazard is much worse than you'd think: the space reactor didn't simply fall in one piece, but left a trail of fragments 600 km long, some of which were lethally radioactive. It's pretty lucky this one happened in an uninhabited wasteland). [0] https://en.wikipedia.org/wiki/Kosmos_954 https://en.wikipedia.org/wiki/Kosmos_954
- neurostimulant 4y agoIf it's a digital / quartz watch, it might stop working if the electronics got too much radiation.
- crispyambulance 4y agoThey probably thought the dial paint would fluoresce brightly when exposed to radiation, like some florescent substances glow when exposed to UV. Would it work for alpha or gamma radiation? ¯\_(ツ)_/¯ Whatever the case, sure, it's certainly not a reliable safety test. But it was wise to keep this thing away from people. RTG's do have highly dangerous materials like polonium or strontium and there have been accidents.