On 11/4/2016 5:24 PM, Poul-Henning Kamp wrote:
Yes, that sounds about right for an isotope with a 40 billion years half-life.
The problem with the half life number is that the cylinder still was marked "radioactive" complex with the radiation symbol. Radioactivity (for legal purposes) is a binary property. We used to mark CBT's "cesium device, non radioactive" because the work "cesium" means "cesium 137 nuclear fallout" to many people. Reminds me of an interesting Jack Kusters story. There was some customer who was having problems with his atomic clocks being noisy (I don't remember exactly the story) but the bottom line was that they determined it was because of helium contamination. Kusters was called in to answer to the customer about this contamination and how they were going to fix it. Kusters measured the air in the customer's plant and found that in contained helium. But the customer did not use helium at all in the plant. Kusters pointed out that that could mean only one thing: the plant had a radon problem, and radon breaks down into helium. Kusters told the customer that if they dropped the complaint, he wouldn't have to say anything about radon to anyone. That was the last heard about the helium problem. Rick _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.