4 ms·
It should be noted that cesium dating works for counterits produced in last ~60 years (or less) as Cesium-137 half-life of about 30 years.
by vzaliva 1y ago
It should be noted that cesium dating works for counterits produced in last ~60 years (or less) as Cesium-137 half-life of about 30 years.
- avidiax 1y agoWouldn't that just mean that the detector needs to be increasingly sensitive to detect a late-1940's forgery?
- rtkwe 1y agoYou should also be able to use the presence of the decay daughters as another way to detect forgeries.
- philipkglass 1y agoCesium 137 decays to barium 137 which is stable and naturally occurring, so the cesium daughter wouldn't be useful for this case (non-destructive testing of sealed wine bottles).
- rtkwe 1y agoAh, inconvenient that it doesn't have a longer chain of gamma emitting daughters.
- numpad0 1y agoHalf life is just time until only half of the original amount remains. Double that and it represents the time it takes to halve again. The actual detection threshold would be separate from half life.
- perihelions 1y agoThe idea with cesium-137 is that it didn't exist naturally in significant quantities prior to 1945. An airtight container, sealed from the atmosphere prior to 1945, should not contain any. It's not like some other radioisotopes using in dating, such as carbon-14, which are continuously produced naturally (i.e. by cosmic rays initiating nuclear reactions in the high atmosphere). In that case, an airtight container had a known concentration at the time of its sequestration, and radioisotope dating (to oversimplify) counts the number of half-lives that elapsed since that point. (Or with the example of organic matter—the number of half-lives since a tree was felled into lumber—since it ceased metabolizing atmospheric gases).
- extraduder_ire 1y agoNuclear explosions in the atmosphere also changed the isotopic concentration of the atmosphere so much that it's a clear delineation of the "modern era" in almost all radioisotope dating.