Space/Science — HabitableZone

Space/Science » in reply to That's the problem making a post like that...

Radium dials
ER — (archived)

It's not likely having a radium dial alarm clock will expose you to dangerous levels of gamma radiation, although the women who worked in the factory painting the numbers on the dials suffered horrific cancers from ingesting the radioactive paint. They were not warned of the dangers of the element and they often moistened their paintbrush bristles with their tongues to keep them flexible.

Those of you who might still own one of these items (what's the half-life of radium?) might like to try a little experiment (be very careful not to actually get any of this stuff on you, I'm not minimizing the hazard of actually getting radium in your body).

Get a high powered magnifier, like a jeweler's loupe or an 8X photographer's magnifier, and focus it carefully on one of the numbers, again, being careful not to actually touch the phosphor, you will have to remove the glass clock face to focus the loupe properly. Turn off the lights until you are completely dark-adapted and look through the loupe at the phosphor. What you will see is a boiling cauldron of miniature green flashes, each one signifying the disintegration of a radium atom and the exciting of the phosphor matrix it is embedded in. You will see a roiling beehive of points of light, or a hard rain falling into a flat lake. It's like staring into the gates of hell.

The first (and only) time I did this I finally realized how tiny atoms are, and how many of them there must be, so that even the occasional decay of a radium nuclei in a tiny sample can produce so many disintegrations in the aggregate. Don't throw the apparatus away when you're finished. You are now its custodian and must dispose of it safely.

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