If I understand correctly we can’t do it to anything new because the ratios in the atmosphere got messed up after nuclear weapon testing in the 1950s. Anything breathing after that time can’t be properly compared with this technique. Maybe that will change though.
Only on geologic timescales, though, which requires special preservation, otherwise there won’t be any remains.
Nah. The half-life is 5700 ±30 years. A 5% difference from normal can absolutely be measured and will occur in 422 ±3 years.
So not human timescales but not geological ones, either.
If my bones survive for 500 years will it be enough?
If I understand correctly we can’t do it to anything new because the ratios in the atmosphere got messed up after nuclear weapon testing in the 1950s. Anything breathing after that time can’t be properly compared with this technique. Maybe that will change though.