# IMPORTANT QUESTION: Effects of UV and cosmic rays on bismuth

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This is an unusually important question.

Could one determine the approximate age of a manufactured bismuth/magnesium/zinc composite somehow by the effects of UV, cosmic rays, or some other type of energetic particle acting on the material? For example, by microscopic examination or by some other means, could one estimate the number of cosmic ray impacts on the material and from this estimate the approximate amount of time since the material was manufactured. Also, does any kind of isotopic change happen over time; perhaps again due to cosmic rays or the like? If we could determine the age of this composite to within 10 years or so we could probably proceed. We are assuming that this was made in the 1970s.

We have the material but we cannot identify the manufacturer. It is imperative that we can estimate the age of this stuff. Any suggestion? The potential cost of testing is not a concern.

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Sorry, I don't know, but why? Is it related to something I saw on TV, regarding an alloy that was given to some person by someone unknown, that is supposedly alien? The current owner had taken it to many metallurgists and they couldn't figure anything out. I know this is a vague reference. I think the composition of this alloy did prove to be tremendously unnatural, I think it had bismuth and magnesium though. And it had an unusual distribution of elements in it, it wasn't isotropic, I don't remember what though, maybe micro-strata?

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Originally posted by Jonathan
Sorry, I don't know, but why? Is it related to something I saw on TV, regarding an alloy that was given to some person by someone unknown, that is supposedly alien? The current owner had taken it to many metallurgists and they couldn't figure anything out. I know this is a vague reference. I think the composition of this alloy did prove to be tremendously unnatural, I think it had bismuth and magnesium though. And it had an unusual distribution of elements in it, it wasn't isotropic, I don't remember what though, maybe micro-strata?
Any discussions like that are posted in the Pseudo Science section.

I know that, I didn't mean to imply I wanted to hijack the thread or something, I just wanted to know why, which you still haven't anwsered. [b(]

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Originally posted by Jonathan
I know that, I didn't mean to imply I wanted to hijack the thread or something, I just wanted to know why, which you still haven't anwsered. [b(]
You’re barking up the wrong tree on this one.
I am an industrial consultant by profession.

I've worked with radiation detectors, and have never heard of this type of measurement. In principle, however, I suppose it's possible if the dE/dx is high enough and the surface is "clean" enough.

I would imagine that it would work something like this: The traversing particle creates an energy spike, whose corresponding temperature is high enough to locally melt the material. As the energy spike relaxes, the melted region grows (widens) until the energy density of the spike falls below the melting threshold.

It would be pretty easy to estimate size of the damaged region in this model (I have a formula for it somewhere), but I would anticipate that it might be too small i.e., there might be too much noise from other surface defects. Good luck!

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Originally posted by Ivan Seeking
You’re barking up the wrong tree on this one.
I am an industrial consultant by profession.
--- and, you want free money from PF? Or, are you planning to split the consulting fee for this with Greg?

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